CN112956106B - A vehicle power supply system and a method for overvoltage protection - Google Patents

Abstract

The embodiments of the present application provide a vehicle power supply system and an overvoltage protection method, which ensures that when an overvoltage fault occurs in the main power supply, each electrical load device will no longer receive continuous and overvoltage power supply from the main power supply, and is well protected Each electrical load device ensures driving safety and reduces driving risks. The vehicle power supply system includes: a main power supply, a first control device, a first battery, a second battery, a first power supply device, a second power supply device, and at least one electrical load device, the first power supply device includes a first power supply switch, and a second power supply device The power supply device includes a second power supply switch; the main power supply is used to generate an output voltage; the first control device is used to: monitor the output voltage generated by the main power supply; when the output voltage meets the first voltage level, disconnect the first power supply switch and the second power supply switch A power supply switch is used to stop the main power supply from supplying power to at least one electrical load device, and the voltage value corresponding to the first voltage level reflects that a secondary overvoltage fault occurs in the main power supply.

Description

A vehicle power supply system and a method for overvoltage protection

technical field

The embodiments of the present application relate to the technical field of circuits, and in particular, to a vehicle power supply system and an overvoltage protection method.

Background technique

In vehicles not equipped with an advanced driving assistance system (ADAS), a direct current/direct current (DC/DC) and a battery provide low-voltage power for new energy vehicles, or through a generator and A battery provides low-voltage power for a car or diesel vehicle. In recent years, with the development and popularization of ADAS, and in order to meet the electrical safety requirements and functional safety requirements of the vehicle power supply system, the solution of equipping dual batteries in the vehicle power supply system has become a necessary measure to meet the functional requirements of ADAS. The aforementioned dual battery solution is understood to mean that the vehicle is equipped with two 12V batteries, and then the two 12V batteries and DC/DC are used to provide low-voltage power for new energy vehicles, or the two 12V batteries and power generation. The machine provides low-voltage power for automobiles or diesel vehicles.

However, in the related art, when an overvoltage fault occurs in the DC/DC of the vehicle power supply system, although the power supply to the dual batteries can be cut off, when a serious overvoltage fault occurs in the DC/DC, the power supply to the steering EPS cannot be cut off. The power supply of the electrical load device will continue to damage the electrical load device due to the overvoltage of the power supply, thereby bringing the risk of driving safety.

Therefore, how to ensure that the electrical load device is not damaged when a serious overvoltage fault occurs in the DC/DC has become an urgent problem to be solved.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a vehicle power supply system and an overvoltage protection method, which ensure that when an overvoltage fault occurs in the main power supply, each electrical load device will no longer receive continuous overvoltage power supply from the main power supply, and the protection is intact. Each electrical load device is installed; then the driving safety is guaranteed and the driving risk is reduced.

In order to solve the above problems, the embodiments of the present application provide the following technical solutions:

In a first aspect, an embodiment of the present application provides a vehicle power supply system. The vehicle power supply system may include: a main power supply, a first control device, a first battery, a second battery, a first power supply device, a second power supply device, and at least one An electrical load device, the first power supply device includes a first power supply switch, and the second power supply device includes a second power supply switch; wherein, the first end of the first power supply switch is connected to the main power supply, and the second end of the first power supply switch is connected to the first control The device is connected; the first end of the second power supply switch is connected to the main power supply, and the second end of the second power supply switch is connected to the first control device; the main power supply is used to generate an output voltage; the first control device is used to: monitor the main power supply The generated output voltage; when the output voltage meets the first voltage level, the first power supply switch and the second power supply switch are turned off, so that the main power supply stops supplying power to at least one electrical load device, wherein the voltage value corresponding to the first voltage level Indicates that a secondary overvoltage fault occurs in the main power supply.

It should be understood that the described secondary overvoltage fault can be understood as that the voltage value corresponding to the corresponding first voltage level will damage all components in the vehicle power supply system, such as: each electrical component in at least one electrical load device. load device, etc. In addition, the described electrical load devices may include, but are not limited to, steering EPS (electric power steering system), brake ESP, vehicle controller, ADAS controller, lights and other electrical components, which are not limited here. In addition, the described first battery and second battery may also be lithium batteries, lead-acid batteries, etc., and the described first power supply switch and second power supply switch may be PMOS transistors, NMOS transistors, etc., which are not limited here. The above-mentioned main power source may be a DC/DC converter or the like.

Therefore, in order to ensure that at least one electrical load device in the vehicle power supply system is not damaged when a secondary overvoltage fault occurs in the main power supply, so as to avoid damage to the electrical load device during driving. dangerous phenomenon. In the above manner, the first control device needs to monitor the output voltage generated by the main power supply in real time, and determine whether the output voltage is greater than the first preset voltage threshold, and the described first preset voltage threshold corresponds to the first voltage level; and When the output voltage is greater than the first preset voltage threshold, it is necessary to disconnect the first power supply switch and the second power supply switch connected to the main power supply, so that the main power supply can stop supplying each of the at least one electrical load device to each of the electrical load devices. Power supply, which cuts off the power supply path of the main power supply for each electrical load device, and ensures that each electrical load device will no longer receive continuous overvoltage power supply from the main power supply when a secondary overvoltage fault occurs in the main power supply. , which perfectly protects each electrical load device.

Optionally, in some examples, the first power supply device further includes a first discharge switch, and the second power supply device further includes a second discharge switch; the first end of the first discharge switch is connected to the third end of the first power supply switch, and the first end of the first discharge switch is connected to the third end of the first power supply switch. The second end of a discharge switch is connected to the first battery, the third end of the first discharge switch is connected to the first control device; the first end of the second discharge switch is connected to the third end of the second power supply switch, and the second end of the discharge switch is connected to the third end of the second power supply switch. The second end is connected to the second battery, and the third end of the second discharge switch is connected to the first control device; the first control device is further configured to: close the first discharge switch before disconnecting the first power supply switch and the second power supply switch A switch and a second discharge switch to enable the first battery and the second battery to supply power to at least one electrical load device.

It should be noted that, since the main power supply does not have a secondary overvoltage fault, the voltage at which each electrical load device can work mainly comes from the main power supply. Therefore, in the above manner, the first control device first closes the first discharge switch and the second discharge switch, and then opens the first power supply switch and the second power supply switch, so that the path for the main power supply to supply power to each electrical load device can be cut off. not only protects each electrical load device perfectly, but also can provide power for the electrical load device during the cut-off process, from the main power supply to the seamless switching between the first lithium battery and the second lithium battery, so that the The barrier-free work of the electrical load device is guaranteed.

Optionally, in some other examples, the first power supply device further includes a first charging switch, and the second power supply device further includes a second charging switch; the first end of the first charging switch is connected to the third end of the first power supply switch , the second end of the first charging switch is connected to the first battery, the third end of the first charging switch is connected to the first control device; the first end of the second charging switch is connected to the third end of the second power supply switch, and the third end of the first charging switch is connected to the first control device; The second end of the second charging switch is connected to the second battery, and the third end of the second charging switch is connected to the first control device; the first control device is also used for: when the output voltage meets the second voltage level and does not meet the first control device At a voltage level, the first power supply switch and the second power supply switch are closed to enable the main power supply to supply power to at least one electrical load device, and the first charging switch is turned off to make the main power supply stop supplying power to the first battery, and disconnection The second charging switch is used to stop the main power supply from supplying power to the second battery. The voltage value corresponding to the second voltage level reflects the occurrence of a primary overvoltage fault in the main power supply, and the voltage value corresponding to the second voltage level is lower than the voltage corresponding to the first voltage level. value.

It should be noted that the described primary overvoltage fault can be understood as that the voltage value corresponding to the corresponding second voltage level will only cause damage to the first battery and the second battery, such as failure to work normally, short circuit, etc. Through the above method, since the output voltage gradually increases from low voltage to high voltage, after continuously monitoring the output voltage of the main power supply, the first control device can also judge whether the output voltage satisfies the above-mentioned second voltage level; When the output voltage meets the above-mentioned second voltage level and does not meet the first voltage level, first close the first power supply switch and the second power supply switch, so that the output voltage of the main power supply 10 can supply power for at least one electrical load device, ensuring that each The electrical load device does not stop working due to lack of electricity; finally, the first charging switch is turned off, so that the main power supply stops supplying power to the first battery, thereby cutting off the path for the main power supply to supply power to the first battery, avoiding the need for the first battery to supply power. The battery is damaged by overvoltage; similarly, the second charging switch needs to be disconnected to realize that the main power supply stops supplying power to the second battery, thereby cutting off the path for the main power supply to supply power to the second battery, ensuring that the second battery is not damaged. Overvoltage damage.

Optionally, in other examples, the first control device is further configured to: obtain a first charging voltage sent by the first battery and a second charging voltage sent by the second battery, where the first charging voltage indicates that the first battery is The effective voltage value required by the current battery state of the first battery, the second charging voltage indicates the effective voltage value required by the second battery in the current battery state of the second battery; the first charging voltage and the second charging voltage are compared to obtain the voltage difference; based on the voltage difference, close the first charging switch or the second charging switch; send a first signal to the main power supply, the first signal is used to instruct the main power supply to charge the first battery or the first battery according to the first charging voltage or the second charging voltage The second battery performs voltage compensation. In the above manner, after the first battery determines the effective voltage value required by itself (that is, the first charging voltage mentioned above), and the second battery determines the effective voltage value that it needs (that is, the second charging voltage mentioned above), the The first control device closes the first charging switch or the second charging switch based on the voltage difference between the two, and then the main power supply conducts voltage for the first battery or the second battery according to the requested first charging voltage or second charging voltage The compensation can gradually realize that the first battery and the second battery can be evenly charged under different voltage states, thereby reducing the voltage difference between the first battery and the second battery, and prolonging the service life of the first battery and the second battery.

Optionally, in some other examples, the first control device is configured to: when the voltage difference is greater than a preset threshold, close the first target switch, where the first target switch is connected to the battery corresponding to the first target voltage. The charging switch, the first target voltage is the minimum voltage between the first charging voltage and the second charging voltage; sending a second signal to the main power supply, the second signal is used to instruct the main power supply according to the first target voltage, to and the first target switch The connected battery supplies power. In the above manner, if the voltage difference is greater than the preset threshold, it reflects that the first charging voltage required by the first battery and the second charging voltage required by the second battery have a large difference and are in a relatively unbalanced state. Therefore, in order to reduce the voltage difference between the first battery and the second battery, the first control device should determine the minimum voltage among the first charging voltage and the second charging voltage, and then close the battery connected to the battery corresponding to the minimum voltage. charging switch. Then, by sending a second signal to the main power supply, it is informed that the main power supply needs to charge the corresponding battery according to the minimum voltage, so as to reduce the voltage difference between the two batteries and achieve voltage balance.

Optionally, the first control device is configured to: when the voltage difference is less than or equal to a preset threshold, close the first charging switch and the second charging switch; send a third signal to the main power supply, where the third signal is used to indicate the main power The power supply supplies power to the first battery connected to the first charging switch and to the second battery connected to the second charging switch according to a second target voltage, where the second target voltage is the first charging voltage and the second charging voltage the maximum voltage in . Through the above method, when the voltage difference is less than or equal to the preset threshold, if the main power supply only supplies power to the high-voltage battery, the low-voltage battery cannot be charged all the time, resulting in an increasing voltage difference between the batteries. Therefore, the first The control device should close the first charging switch and the second charging switch, so that the main power supply can supply power to the first battery and the second battery according to the maximum voltage, reduce the voltage difference between the batteries, and prolong the service life of the battery.

Optionally, in some other examples, the first control device is further configured to: monitor the voltage of the first battery and the voltage of the second battery; the voltage of the first battery reflects the occurrence of an undervoltage fault in the first battery, Or the voltage condition of the second battery reflects that when the second battery has an undervoltage fault, the first charging switch, the second charging switch, the first discharging switch and the second discharging switch are turned off. In the above manner, the first control device continuously monitors the voltage of the first battery and the voltage of the second battery, and if the voltage of the first battery is lower than the rated voltage, it means that the first battery has an undervoltage fault; or, If the voltage of the second battery is lower than the rated voltage, it reflects that the second battery has an undervoltage fault. In this way, when the first battery has an undervoltage fault or the second battery has an undervoltage fault, the first control device should isolate the first battery and the second battery to prevent the battery from discharging externally and accepting power. Specifically, the first control device needs to turn off the first charging switch and the first discharging switch, and turn off the second charging switch and the second discharging switch. Not only can the first battery and the second battery be isolated, but also it can be ensured that there will not be a large difference in the voltage difference between the first battery and the second battery.

Optionally, in other examples, any one of the first power supply device and the second power supply device includes the first control device, or neither the first power supply device nor the second power supply device includes the first control device. In the above manner, only one first control device may be included in the vehicle power supply system, and specifically, it may be deployed in any one of the first power supply device and the second power supply device; it may not be deployed in any one of the power supply devices. , for example: it can be deployed in equipment such as the main power supply, which can save costs. In addition, the deployment mode of the first control device is not limited, and rich usage modes are provided for different usage scenarios.

Optionally, the first control device described above includes an electronic control unit ECU.

In a second aspect, the embodiments of the present application provide another vehicle power supply system. The vehicle power supply system may include: a main power supply, a first control device, a first battery, a second battery, a first power supply device, a second power supply device, and At least one electrical load device, the first power supply device includes a first control device and a first power supply switch, and the second power supply device includes a second control device and a second power supply switch; the first end of the first power supply switch is connected to the main power supply, the first The second end of the power supply switch is connected to the first control device; the first end of the second power supply switch is connected to the main power supply, and the second end of the second power supply switch is connected to the second control device; the main power supply is used to generate an output voltage; a control device for: monitoring the output voltage generated by the main power supply, and when the output voltage meets the first voltage level, disconnecting the first power supply switch, so that the main power supply stops supplying power to at least one electrical load device, wherein the first power supply The voltage value corresponding to the voltage level reflects the secondary overvoltage fault of the main power supply; the second control device is used for: monitoring the output voltage generated by the main power supply, and disconnecting the second power supply switch when the output voltage meets the first voltage level, to stop the mains supplying power to at least one electrical load device.

It should be noted that in this example, two control devices are used to control the power supply switches in their respective power supply devices, so that when a secondary overvoltage fault occurs in the main power supply, not only can each electrical load device no longer receive the main power supply The continuous overvoltage power supply protects each electrical load device perfectly; and the power supply switches in the respective power supply devices are controlled separately, which can also improve the control efficiency.

Optionally, in other examples, the first power supply device further includes a first discharge switch, and the second power supply device further includes a second discharge switch; the first end of the first discharge switch is connected to the third end of the first power supply switch, The second end of the first discharge switch is connected to the first battery, the third end of the first discharge switch is connected to the first control device; the first end of the second discharge switch is connected to the third end of the second power supply switch, and the second discharge switch The second end of the second battery is connected to the second battery, and the third end of the second discharge switch is connected to the second control device; the first control device is also used for: before disconnecting the first power supply switch, close the first discharge switch to The first storage battery supplies power to at least one electrical load device; the second control device is further configured to: close the second discharge switch before turning off the second power supply switch, so as to enable the second storage battery to supply power to the at least one electrical load device.

Through the above method, when a secondary overvoltage fault occurs in the main power supply, the first control device first closes the first discharge switch and then opens the first power supply switch; the second control device also closes the second discharge switch first, and then opens the second discharge switch. Power switch. It not only realizes the seamless switching from the main power source to the first lithium battery and the second lithium battery in the process of cutting off the main power supply to provide power for each electrical load device, but also makes the electrical load device work without obstacles. It can also cut off the power supply path of the main power supply for each electrical load device, and completely protect each electrical load device.

Optionally, in some other examples, the first power supply device further includes a first charging switch, and the second power supply device further includes a second charging switch; the first end of the first charging switch is connected to the third end of the first power supply switch , the second end of the first charging switch is connected to the first battery, the third end of the first charging switch is connected to the first control device; the first end of the second charging switch is connected to the third end of the second power supply switch, and the third end of the first charging switch is connected to the first control device; The second end of the second charging switch is connected to the second battery, and the third end of the second charging switch is connected to the second control device; the first control device is also used for: when the output voltage meets the second voltage level and does not meet the first voltage level At a voltage level, the first power supply switch is closed to enable the main power supply to supply power to at least one electrical load device, and the first charging switch is turned off to stop the main power supply from supplying power to the first battery. The voltage value corresponding to the second voltage level It reflects that a primary overvoltage fault occurs in the main power supply, and the voltage value corresponding to the second voltage level is smaller than the voltage value corresponding to the first voltage level; the second control device is also used for: when the output voltage meets the second voltage level and does not meet the first voltage level At a voltage level, the second power supply switch is closed to enable the main power supply to supply power to at least one electrical load device, and the second charging switch is disconnected to stop the main power supply supplying power to the second battery.

It should be noted that the above-mentioned voltage value corresponding to the second voltage level reflects the occurrence of a primary overvoltage fault in the main power supply, and the value is smaller than the voltage value corresponding to the first voltage level (that is, the voltage value reflecting the foregoing secondary overvoltage fault). ). Moreover, the battery can also be destroyed when a primary overvoltage fault occurs in the main power supply, and a secondary overvoltage fault does not occur.

Therefore, in the scenario where the power supply device is controlled by two control devices, in order to protect the battery, the first control device should first close the first power supply switch when the output voltage meets the second voltage level but does not meet the first voltage level. Then turn off the first charging switch. The main purpose is to ensure that each electrical load device can obtain the power provided by the main power supply through the first power supply switch, so that the driving safety is guaranteed, and the first battery is cut off to receive the power provided by the main power supply through the first charging switch. And, the second control device should also close the second power supply switch first, and then open the second charging switch when the output voltage meets the second voltage level but not the first voltage level, so as to ensure the driving safety at the same time. , the second battery 3 is cut off to receive the power provided by the main power source through the second charging switch, thereby protecting the second battery.

Optionally, in other examples, the first control device or the second control device is further configured to: obtain the first charging voltage sent by the first battery and the second charging voltage sent by the second battery, the first charging voltage Indicates the effective voltage value required by the first battery in the current battery state of the first battery, and the second charging voltage indicates the effective voltage value required by the second battery in the current battery state of the second battery; compare the first charging voltage with the second battery The charging voltage is used to obtain the voltage difference; the first control device is used to close the first charging switch according to the voltage difference; or the second control device is used to close the second charging switch according to the voltage difference.

It can be seen from this that, after the first control device or the second control device compares the obtained first charging voltage and the second charging voltage to obtain the corresponding voltage difference, the first control device can determine the voltage difference according to the voltage difference. The first charging switch is closed; alternatively, the second charging switch is closed by the second control device based on the voltage difference. The purpose is to enable the corresponding control device to send a signal to the main power supply after closing the first charging switch or the second charging switch, notifying that the main power supply needs to be the first charging voltage or the second charging voltage as requested. The battery or the second battery compensates for the voltage, and gradually realizes that the first battery and the second battery can be charged evenly under different voltage states, thereby reducing the voltage difference between the first battery and the second battery, and prolonging the voltage difference between the first battery and the second battery. Service life of the second battery.

Optionally, in other examples, when the voltage difference is greater than a preset threshold, the first control device is configured to: when the first charging voltage is less than the second charging voltage, close the first charging switch to realize the main power supply Compensate the voltage of the first battery according to the first charging voltage; or, the second control device is configured to: when the first charging voltage is greater than the first charging voltage, close the second charging switch, so as to realize that the main power source is charged according to the second charging voltage The voltage compensates the voltage of the second battery.

Optionally, in other examples, when the voltage difference is less than or equal to a preset threshold, the first control device is used to close the first charging switch, and the second control device is used to close the second charging switch, so as to realize the main The power supply performs voltage compensation to the first battery and the second battery according to a second target voltage, where the second target voltage is the maximum voltage among the first charging voltage and the second charging voltage. It should be noted that if the voltage difference is less than or equal to the preset threshold, it reflects that the difference between the first charging voltage required by the first battery and the second charging voltage required by the second battery is small.

In the above manner, the voltage of the first battery and the second battery is compensated by the maximum voltage, so that the voltage difference between the batteries can be reduced, and it is avoided that when only one battery is charged, the other battery is not charged, which may cause damage to the other battery. The larger the pressure difference occurs.

Optionally, in some other examples, the first control device is further configured to: monitor the voltage condition of the first battery; when the voltage condition of the first battery reflects that an undervoltage fault occurs in the first battery, disconnect the first charging switch and the first discharge switch, and send a fourth signal to the second control device to instruct the second control device to disconnect the second charging switch and the second discharging switch.

It should be noted that the described undervoltage fault can be understood as the voltage of the battery itself is lower than the rated voltage. Therefore, in the above manner, in the scenario where the first control device and the second control device respectively control two power supply devices, the first control device can also monitor the voltage of the first battery in real time; The voltage situation reflects that when the first battery has an undervoltage fault, not only the first charging switch and the first discharging switch should be disconnected, so as to achieve neither receiving the power provided by the main power source nor discharging externally, and isolating the first battery; and It is also necessary to notify the second control device to disconnect the second charging switch and the second discharging switch, the purpose of which is to prevent the second battery from continuing to receive the power provided by the main power supply and discharging to the outside, thereby preventing the isolated first battery and second battery from being isolated. The pressure difference between them increases.

Optionally, in some other examples, the second control device is further configured to: monitor the voltage condition of the second battery; when the voltage condition of the second battery reflects that an undervoltage fault occurs in the second battery, disconnect the second charging switch and the second discharge switch, and send a fifth signal to the first control device to instruct the first control device to disconnect the first charging switch and the first discharging switch.

Optionally, in some other examples, the second end of the second power supply switch is further connected to the first control device, the third end of the second discharge switch is further connected to the first control device, and the third end of the second charging switch is also connected to the first control device. It is also connected with the first control device; the second control device is also used for: monitoring the operating state of the second control device; the first control device is also used for: reflecting the operation of the second control device in the operating state of the second control In case of failure, the second power supply switch, the second charging switch or the second discharging switch are controlled.

In the above manner, in addition to being connected to the first power supply switch, the first charging switch and the first discharging switch, the first control device can also be connected to the second power supplying switch, the second charging switch and the second discharging switch. In this way, if the second control device determines that it has a running failure after monitoring its own operating state, it can send a signal to the first control device through a communication line, etc., to inform the first control device that it needs to act as a backup control device. Role, control the second power switch, the second charge switch or the second discharge switch. It can be seen from this that in the case where the second control device cannot work normally due to a fault, the second power supply switch, the second charging switch or the second discharging switch can still be controlled by the backup first control device, so as to realize the occurrence of In the event of an overvoltage fault, the driving safety of the vehicle can still be guaranteed, and the second battery will not be damaged by the overvoltage.

In addition, it should be noted that when the second control device fails and the first control device takes over the work of the second control device, it can also be considered that only the first control device controls the first power supply switch and the first charging device. switch, a first discharge switch, a second power supply switch, a second charge switch or a second discharge switch. The specific case that is controlled by only one first control device can be understood with reference to the content described in the vehicle power supply system provided by the first aspect, and detailed descriptions are not repeated here.

Optionally, in other examples, the second end of the first power supply switch is further connected to the second control device, the third end of the first discharge switch is further connected to the second control device, and the third end of the first charging switch is also connected to the second control device. It is also connected to the second control device; the first control device is further used for: monitoring the operating state of the first control device; the second control device is also used for: reflecting the first control device operating in the operating state of the first control When a fault occurs, the first power supply switch, the first charging switch or the first discharging switch are controlled.

It should be noted that after the first control device monitors its own operating state and determines that an operating failure has occurred, it can send a signal to the first control device through a communication line, etc., to inform the first control device that it needs to act as a backup control device. It controls the second power supply switch, the second charging switch or the second discharging switch. In the case that the first control device cannot work normally due to a fault, the first power supply switch, the first charging switch or the first discharge switch can still be controlled by the second backup control device, so as to realize that when the main power supply has an overvoltage fault, the The driving safety of the vehicle can still be guaranteed, and the first battery is not damaged by overvoltage.

Optionally, the first control device includes a first electronic control unit ECU, and the second control device includes a second ECU.

In a third aspect, the embodiments of the present application provide an overvoltage protection method, which can be applied to a vehicle power supply system. The method may include: monitoring an output voltage generated by a main power supply in the vehicle power supply system; judging whether the output voltage satisfies The first voltage level, wherein the voltage value corresponding to the first voltage level reflects the occurrence of a secondary overvoltage fault in the vehicle power supply system; when the output voltage meets the first voltage level, the first power supply switch and the second power supply switch in the vehicle power supply system are disconnected. A power switch to stop the mains power supplying power to the at least one electrical load device.

In another possible implementation manner, the method may further include: before opening the first power supply switch and the second power supply switch, closing the first discharge switch and the second discharge switch, so that the first battery and the second battery Power is supplied to at least one electrical load device.

In another possible implementation manner, the method may further include: when the output voltage meets the second voltage level and does not meet the first voltage level, closing the first power supply switch and the second power supply switch, so as to realize the main power supply to the At least one electrical load device supplies power, and turns off the first charging switch so that the main power supply stops supplying power to the first battery, and turns off the second charging switch, so that the main power supply stops supplying power to the second battery, and the second voltage level corresponds to The voltage value of , reflects that a primary overvoltage fault occurs in the main power supply, and the voltage value corresponding to the second voltage level is smaller than the voltage value corresponding to the first voltage level.

In another possible implementation manner, the method may further include: acquiring a first charging voltage sent by the first battery and a second charging voltage sent by the second battery, where the first charging voltage indicates that the first battery is in the first battery The effective voltage value required by the current battery state, the second charging voltage indicates the effective voltage value required by the second battery in the current battery state of the second battery; the first charging voltage and the second charging voltage are compared to obtain the voltage difference; Based on the voltage difference, the first charging switch or the second charging switch is closed; the first signal is sent to the main power source, and the first signal is used to instruct the main power source to charge the first battery or the second battery according to the first charging voltage or the second charging voltage. Perform voltage compensation.

In another possible implementation manner, closing the first charging switch or the second charging switch based on the voltage difference includes: when the voltage difference is greater than a preset threshold, closing the first target switch, where the first target switch is the first target switch. A charging switch connected to a battery corresponding to a target voltage, where the first target voltage is the minimum voltage between the first charging voltage and the second charging voltage; a second signal is sent to the main power supply, and the second signal is used to instruct the main power supply to follow the first charging voltage and the second charging voltage. A target voltage to supply power to the battery connected to the first target switch.

In another possible implementation manner, closing the first charging switch or the second charging switch based on the voltage difference includes: when the voltage difference is less than or equal to a preset threshold, closing the first charging switch and the second charging switch ; Send a third signal to the main power supply, the third signal is used to instruct the main power supply to carry out the process to the first battery connected to the first charging switch and to the second battery connected to the second charging switch according to the second target voltage Power is supplied, and the second target voltage is the maximum voltage among the first charging voltage and the second charging voltage.

In another possible implementation manner, the method may further include: monitoring the voltage of the first battery and the voltage of the second battery; the voltage of the first battery reflects the occurrence of an undervoltage fault in the first battery or the second battery The voltage condition of the battery reflects that when an undervoltage fault occurs in the second battery, the first charging switch, the second charging switch, the first discharging switch and the second discharging switch are disconnected.

In a fourth aspect, embodiments of the present application provide a driving device, including the vehicle power supply system described in any possible design of the first aspect or the second aspect.

In a fifth aspect, an embodiment of the present application provides a chip, including the vehicle power supply system described in any possible design of the first aspect or the second aspect.

In a sixth aspect, an embodiment of the present application provides a first control device, including: a processor and a memory; the memory is used to store program instructions, and when the first control device runs, the processor executes the program stored in the memory instruction, so that the first control device executes the method for overvoltage protection according to the third aspect.

In the technical solutions provided by the embodiments of the present application, since the voltage value corresponding to the first voltage level reflects that a secondary overvoltage fault has occurred in the main power supply, the described secondary overvoltage fault can be understood as the corresponding first voltage level The corresponding voltage value will damage all components in the vehicle power supply system, including each of the at least one electrical load device. Therefore, the first control device monitors the output voltage of the main power supply, and when the output voltage meets the above-mentioned first voltage level, disconnects the first power supply switch and the second power supply switch connected to the main power supply, so that the main power supply The power supply can stop supplying power to each of the at least one electrical load device. Compared with the existing solution, the power supply to the electrical load device cannot be cut off. In the embodiment of the present application, a corresponding power supply switch is added to the power supply device, and when an overvoltage fault occurs in the main power supply, the power supply switch is turned off to cut off the power supply. The path for the main power supply to supply power to each electrical load device ensures that in the event of a secondary overvoltage fault in the main power supply, each electrical load device will no longer receive continuous overvoltage power supply from the main power supply, and perfectly protects each electrical load device. An electrical load device; then the driving safety is guaranteed and the driving risk is reduced.

Description of drawings

1 is a schematic structural diagram of a vehicle power supply system provided by the prior art;

FIG. 2 is a schematic frame diagram of a vehicle power supply system provided in an embodiment of the present application;

FIG. 3 is a schematic frame diagram of another vehicle power supply system provided in an embodiment of the present application;

FIG. 4 is a schematic frame diagram of another vehicle power supply system provided in an embodiment of the present application;

FIG. 5 is a schematic frame diagram of another vehicle power supply system provided in an embodiment of the present application;

FIG. 6 is a schematic frame diagram of another vehicle power supply system provided in an embodiment of the present application;

FIG. 7 is a schematic frame diagram of another vehicle power supply system provided in an embodiment of the present application;

FIG. 8 is a schematic frame diagram of another vehicle power supply system provided in an embodiment of the present application;

FIG. 9 is a schematic frame diagram of another vehicle power supply system provided in an embodiment of the present application;

FIG. 10 is a schematic frame diagram of another vehicle power supply system provided in an embodiment of the present application;

11 is a schematic diagram of an overvoltage protection method provided in an embodiment of the present application;

12 is a schematic diagram of another method for overvoltage protection provided in an embodiment of the present application;

13 is a schematic diagram of another method for overvoltage protection provided in an embodiment of the present application;

14 is a schematic diagram of a hardware structure of a first control device provided by an embodiment of the present application;

FIG. 15 is a schematic structural diagram of a first control device provided by an embodiment of the present application.

Detailed ways

The embodiments of the present application provide a vehicle power supply system and an overvoltage protection method, which ensure that when an overvoltage fault occurs in the main power supply, each electrical load device will no longer receive continuous overvoltage power supply from the main power supply, so that the power supply is in good condition. Each electrical load device is protected; then the driving safety is guaranteed and the driving risk is reduced.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances such that the embodiments of the application described herein can, for example, be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

With the development and popularization of ADAS, and in order to meet the electrical safety requirements and functional safety requirements of the vehicle power system, the solution of equipping dual batteries in the vehicle power system has become a necessary measure to meet the functional requirements of ADAS. In short, two 12V batteries are equipped on the vehicle, and then the two 12V batteries and DC/DC are used to provide low-voltage power for new energy vehicles, or the two 12V batteries and generators are used for automobiles or Diesel vehicles provide low voltage power.

However, in the related art, when an overvoltage fault occurs in the DC/DC in the vehicle power supply system, although the power supply to the dual batteries can be cut off, when a serious overvoltage fault occurs in the DC/DC, the power supply to the electronic power assist cannot be cut off. The power supply of electrical load devices such as a steering system (electric power steering, EPS) will cause the electrical load device to continue to be damaged due to the overvoltage of the power supply, thereby bringing about a risk of driving safety. For example, FIG. 1 shows a schematic structural diagram of a vehicle power supply system provided in the prior art. It can be seen from FIG. 1 that the vehicle power supply system consists of a first DC/DC11, a second DC/DC12, a first battery 21, a second battery 22, a connection control device 30, an electrical load device 40, and switches 51-54. . Wherein, when the first series of power supply fails, the connection control device 30 can realize the overvoltage protection of the first battery 21 and the second battery 22 by opening the switch 51 and the switch 53 and closing the switch 52 and the switch 54; or , in the second series of power failure, the connection control device 30 controls the opening of the switch 52 and the switch 54, and closes the switch 51 and the switch 53, so as to realize the overvoltage protection of the first battery 21 and the second battery 22. However, in the case of the above two kinds of power failures, once the power supply voltage output by the first DC/DC 11 or the second DC/DC 12 is over-voltage, since the connection control device 30 controls the opening or closing of the switches 51 to 54, only the It is used to realize the overvoltage protection of the first battery 21 and the second battery 22, and the power supply to the electrical load device 40 cannot be cut off, thereby causing the electrical load device 40 to continue to be damaged due to the overvoltage of the power supply voltage. driving safety risks.

Therefore, in order to solve the above problems, the embodiments of the present application provide a vehicle power supply system, which is applied to driving equipment to avoid damage to the electrical load device and ensure driving safety when the power supply voltage is overvoltage. The above-mentioned driving devices may be smart cars, bridge cars, trucks, motorcycles, buses, recreational vehicles, amusement vehicles, construction vehicles, diesel vehicles, etc., which are not particularly limited in the embodiments of the present application.

It can be understood that, since the aforementioned vehicle power supply system may include at least two batteries, a corresponding power supply device may also be correspondingly connected to each battery. While controlling the main power supply to supply power to the battery through the power supply device, there are two situations as follows:

1. Two power supply devices are controlled by one control device at the same time.

2. The power supply devices connected to each battery are controlled by two control devices respectively.

For the above-mentioned first situation, it can also be divided into the following two situations for understanding: the control device can be deployed in any one of the two power supply devices; or, any one of the two power supply devices is not Including the control device. It should be noted that, whether any one power supply device includes the control device, or both power supply devices do not include the control device, the control device has similar functions in controlling the two power supply devices.

In addition, it should be understood that in the following FIGS. 2 to 4 , only the first control device is deployed on the first power supply device as an example for description. In practical applications, the first control device can also be deployed in the second power supply device; the first control device can also be deployed outside the first power supply device and the second power supply device, for example: deployed in the main power supply, etc. , to save costs.

Taking the first control device deployed in the first power supply device as an example, referring to FIG. 2 , it is a schematic frame diagram of a vehicle power supply system provided in an embodiment of the present application.

As shown in FIG. 2 , the vehicle power supply system provided in this embodiment of the present application may include a main power supply 10 , a first control device 20 , a first battery 31 , a second battery 32 , a first power supply device 41 and a second power supply device 42 , at least An electrical load device 50 . Wherein, the aforementioned first power supply device 41 may include a first power supply switch 411, and the second power supply device 42 may include a second power supply switch 421; wherein, the aforementioned main power supply 10 is used to generate an output voltage;

The first control device 20 is used for:

monitoring the output voltage generated by the main power supply 10;

When the output voltage meets the first voltage level, the first power supply switch 411 and the second power supply switch 421 are turned off, so that the main power supply 10 stops supplying power to the at least one electrical load device 50 , wherein the voltage value corresponding to the first voltage level reflects A secondary overvoltage fault has occurred in the main power supply 10 .

It should be noted that the first end of the first power supply switch 411 is connected to the main power supply 10, the second end of the first power supply switch 411 is connected to the first control device 20, and the first end of the second power supply switch 421 is connected to the main power supply 10. The second end of the second power supply switch 421 is connected to the first control device 20 .

In this embodiment, the voltage value corresponding to the above-mentioned first voltage level reflects that a secondary overvoltage fault occurs in the main power supply 10 . The described secondary overvoltage fault can be understood as that the voltage value corresponding to the corresponding first voltage level will damage all components in the vehicle power supply system, for example: each electrical load device in the at least one electrical load device 50 etc.; and damage other components in the driving equipment where the vehicle power system is located, such as: the engine, transmission, global positioning system, wireless communication system, on-board computer, accelerator, etc. in the driving equipment. In addition, the above-mentioned electrical load devices may include, but are not limited to, steering EPS, body electronic stability program (ESP), vehicle controller, ADAS controller, lights and other electrical components.

In order to ensure that at least one electrical load device 50 in the vehicle power supply system is not damaged when a secondary overvoltage fault occurs in the main power supply 10, so as to avoid damage to the electrical load device during driving dangerous phenomenon. Therefore, the first control device 20 needs to monitor the output voltage generated by the main power supply 10 in real time, and determine whether the output voltage is greater than the first preset voltage threshold, and the described first preset voltage threshold corresponds to the first voltage level; and When the output voltage is greater than the first preset voltage threshold, the first power supply switch 411 and the second power supply switch 421 connected to the main power supply 10 need to be disconnected, so that the main power supply 10 can stop supplying power to at least one electrical load device 50 Each electrical load device supplies power, which cuts off the path for the main power supply 10 to supply power to each electrical load device, and ensures that each electrical load device will no longer receive the main power when a secondary overvoltage fault occurs in the main power supply 10. 10 of the continuous overvoltage power supply, perfectly protects each electrical load device.

It should be noted that the above-described first control device 20 may be an ECU, which is not specifically limited here. In addition, the described first storage battery 31 and second storage battery 32 may also be lithium batteries, lead-acid batteries, etc., which are not limitedly described here. In addition, the described main power source 10 may be a DC/DC converter, etc., which is not limited here. In addition, the aforementioned first power supply switch 411, second power supply switch 421, and subsequent first discharge switch 412, second discharge switch 422, first charging switch 413, and second charging switch 423 can all be PMOS transistors, NMOS transistors etc., not limited here.

Optionally, in some examples, when the main power source 10 cuts off the path for supplying power to each electrical load device, to avoid the situation that each electrical load device cannot continue to work because it does not store corresponding power. FIG. 3 shows a schematic structural diagram of another vehicle power supply system provided in an embodiment of the present application. In combination with the vehicle power supply system shown in FIG. 2, the first power supply device 41 in the vehicle power supply system shown in FIG. 3 further includes a first discharge switch 412, and the second power supply device 42 further includes a second discharge switch switch422;

The first control device 20 is further used for:

Before opening the first power supply switch 411 and the second power supply switch 421 , the first discharge switch 412 and the second discharge switch 422 are closed to enable the first battery 31 and the second battery 32 to supply power to the at least one electrical load device 50 .

It should be noted that the first end of the first discharge switch 412 is connected to the third end of the first power supply switch 411 , the second end of the first discharge switch 412 is connected to the first battery 31 , and the third end of the first discharge switch 412 is connected to the first battery 31 . The first end of the second discharge switch 422 is connected to the third end of the second power supply switch 421, the second end of the second discharge switch 422 is connected to the second battery 32, and the second end of the second discharge switch 422 is connected to the second battery 32. The third end is connected to the first control device 20 .

In this example, since the main power supply 10 does not have a secondary overvoltage fault, the voltage at which each electrical load device can work mainly comes from the main power supply 10 . Therefore, once the secondary overvoltage fault occurs in the main power supply 10, the first power supply switch 411 and the second power supply switch 421 are disconnected to cut off the power supply path of the main power supply 10 for each electrical load device, in order to avoid each electrical load device. The load device cannot continue to work because the corresponding power is not stored. Before disconnecting the first power supply switch 411 and the second power supply switch 421, the first control device 20 also needs to control the closing of the first discharge switch 412 connected to the first battery 31 and the second battery connected to the second battery 32. The closing of the two discharge switches 422 enables the currents of the first battery 31 and the second battery 32 to pass through the first discharge switch 412 and the second discharge switch 422 to reach the at least one electrical load device 50 , and then to the at least one electrical load device 50 . power supply to each electrical load device.

In the above manner, the first control device 20 first closes the first discharge switch 412 and the second discharge switch 422, and then opens the first power supply switch 411 and the second power supply switch 421, so that the main power supply 10 can be cut off for each electrical When the power supply path of the load device is used, it not only protects each electrical load device well; but also can provide power for the electrical load device during the cut-off process, from the main power source 10 to the first lithium battery and the second lithium battery. The seamless switching of the electric load device ensures the barrier-free work of the electrical load device.

Optionally, in general, the output voltage of the main power supply 10 will gradually increase from a low voltage to a high voltage. If the output voltage of the main power supply 10 satisfies the second voltage level but does not satisfy the first voltage level, the output voltage of the main power supply 10 will not cause damage to at least one electrical load device 50, but will also damage the first electrical load device 50. A battery 31 and a second battery 32 were damaged. Therefore, the above-mentioned first control device 20 can also control the main power source 10 to stop supplying power to the first battery 31 and the second battery 32 to avoid damage to the batteries. Specifically, reference may be made to FIG. 4 , which shows a schematic structural diagram of another vehicle power supply system provided in an embodiment of the present application.

As can be seen from FIG. 4 , on the basis of the vehicle power supply system described in conjunction with FIG. 2 or FIG. 3 , the aforementioned first power supply device 41 further includes a first charging switch 413 , and the second power supply device 42 further includes a second charging device switch 423.

The first control device 20 is further used for:

When the output voltage meets the second voltage level and does not meet the first voltage level, the first power supply switch 411 and the second power supply switch 421 are closed, so that the main power supply 10 supplies power to at least one electrical load device 50 and the first power supply switch 50 is disconnected The charging switch 413 is used to stop the main power supply 10 from supplying power to the first battery 31, and the second charging switch 423 is turned off to stop the main power supply 10 supplying power to the second battery 32. The voltage value corresponding to the second voltage level reflects the main power supply. 10 A primary overvoltage fault occurs, and the voltage value corresponding to the second voltage level is smaller than the voltage value corresponding to the first voltage level.

The first end of the first charging switch 413 is connected to the third end of the first power supply switch 411 , the second end of the first charging switch 413 is connected to the first battery 31 , and the third end of the first charging switch 413 Connected to the first control device 20; the first end of the second charging switch 423 is connected to the third end of the second power supply switch 421, the second end of the second charging switch 423 is connected to the second battery 32, and the second charging switch 423 The third end is connected to the first control device 20 .

It should be noted that the second terminal of the first charging switch 413 can also be connected to the first terminal of the first discharging switch 412 to realize the connection with the first battery 31 ; similarly, the second terminal of the second charging switch 423 The terminal can also be connected with the first terminal of the second discharge switch 422 to realize the connection with the second battery 32 . There is no specific description here.

In addition, the voltage value corresponding to the second voltage level described above can reflect that a primary overvoltage fault occurs in the main power supply 10 . The described first-level overvoltage fault can be understood as the voltage value corresponding to the corresponding second voltage level will only cause damage to the first battery 31 and the second battery 32, such as failure to work normally, short circuit, etc.

It should be understood that the voltage value corresponding to the aforementioned second voltage level is smaller than the voltage value corresponding to the aforementioned first voltage level. That is to say, the degree of device damage caused by the primary overvoltage fault in the main power supply 10 reflected by the voltage value corresponding to the second voltage level is lower than the main power supply reflected by the voltage value corresponding to the first voltage level 10 The degree of device damage caused by secondary overvoltage faults.

In addition, since the output voltage gradually increases from low, after continuously monitoring the output voltage of the main power supply 10, the first control device 20 can also determine whether the output voltage satisfies the above-mentioned second voltage level; then, When the output voltage meets the above-mentioned second voltage level and does not meet the first voltage level, the first power supply switch 411 and the second power supply switch 421 are closed first, so that the output voltage of the main power supply 10 can supply power to at least one electrical load device 50 , It is ensured that each electrical load device does not stop working due to lack of electricity; finally, the first charging switch 413 is turned off to realize that the main power supply 10 stops supplying power to the first battery 31, thereby cutting off the main power supply 10 for the first battery 31. The path for power supply avoids the damage of the first battery 31 by overvoltage; similarly, the second charging switch 423 needs to be turned off to realize that the main power supply 10 stops supplying power to the second battery 32, thereby cutting off the main power supply 10 for the second battery 32. The path for the second battery 32 to supply power ensures that the second battery 32 is not damaged by overvoltage.

It should be noted that, the first control device 20 can determine whether the output voltage meets the above-mentioned second voltage level, and does not meet the first voltage level, by judging whether the output voltage is greater than the second preset voltage threshold, but less than the above-mentioned first voltage threshold. Preset voltage threshold. If the output voltage is greater than the second preset voltage threshold and less than the first preset voltage threshold, it means that the output voltage satisfies the second voltage level. The described first preset voltage threshold is the above-mentioned minimum limit value of the first voltage level, and the second preset voltage threshold value is the minimum limit value of the second voltage level.

Optionally, generally speaking, in a driving device with ASAD, if the voltage difference between the first battery 31 and the second battery 32 in the vehicle power system becomes larger and larger, the first battery 31 will be affected. and the overall performance of the second battery 32, for example, the driving equipment is powered off during driving, the main power source 10 cannot fully charge the battery, etc., which will greatly reduce the service life of the battery. Therefore, if the voltages between the first battery 31 and the second battery 32 can present a relatively balanced state, the service life of the first battery 31 and the second battery 32 can be prolonged.

Therefore, in other examples, the above-mentioned first control device 20 can also be used for:

Obtain the first charging voltage sent by the first storage battery 31 and the second charging voltage sent by the second storage battery 32. The first charging voltage indicates the effective voltage value required by the first storage battery 31 in the current battery state of the first storage battery 31. The second charging voltage indicates the effective voltage value required by the second battery 32 in the current battery state of the second battery 32;

comparing the first charging voltage and the second charging voltage to obtain a voltage difference;

Based on the voltage difference, close the first charging switch 413 or the second charging switch 423;

A first signal is sent to the main power supply 10, and the first signal is used to instruct the main power supply 10 to perform voltage compensation to the first battery 31 or the second battery 32 according to the first charging voltage or the second charging voltage.

In this example, the first battery 31 may determine the corresponding first charging voltage according to its own battery state. The described first charging voltage can reflect the effective voltage value required by the first battery 31 in the current battery state, that is, how many volts the main power supply 10 needs to provide the first battery 31 in order to effectively charge the first battery 31, And the first-level overvoltage fault described in the aforementioned Figure 4 has not occurred. It should be noted that the described battery state of the first battery 31 itself may include, but is not limited to, the temperature, power SOC, state of health (SOH), voltage value, and voltage loss of the first battery 31 .

Similarly, the second battery 32 can also determine the corresponding second charging voltage according to its own battery state. The described second charging voltage can reflect the effective voltage value required by the second battery 32 in the current battery state, that is, how many volts the main power source 10 needs to provide the second battery 32 in order to effectively charge the second battery 32, And the first-level overvoltage fault described in the aforementioned Figure 4 has not occurred. It should be noted that the described battery state of the second battery 32 itself may also include, but is not limited to, the temperature, power SOC, state of health, voltage value, voltage loss, and the like of the second battery 32 .

In this way, after the first battery 31 determines the first charging voltage and the second battery 32 determines the second charging voltage, the first control device 20 can be notified of the first charging voltage and the second charging voltage through a communication line or the like. Then, after receiving the first charging voltage and the second charging voltage, the first control device 20 determines the voltage difference between the first charging voltage and the second charging voltage, and then controls the first charging according to the voltage difference The switch 413 or the second charging switch 423 is closed. Then, after the first charging switch 413 or the second charging switch 423 is closed, the first control device 20 informs the main power supply 10 by means of a first signal, etc., so that the main power supply 10 follows the aforementioned first charging voltage or second charging voltage. The charging voltage compensates the voltage of the first battery 31 or the second battery 32 .

In the above manner, after the first battery 31 determines the effective voltage value required by itself (ie, the first charging voltage described above), and the second battery 32 determines the effective voltage value required by itself (ie, the second charging voltage described above) , the first control device closes the first charging switch 413 or the second charging switch 423 based on the voltage difference between the two, and then the main power supply 10 charges the first battery 31 according to the requested first charging voltage or second charging voltage Or the second battery 32 performs voltage compensation, and gradually realizes that the first battery 31 and the second battery 32 can be charged evenly under different voltage states, thereby reducing the voltage difference between the first battery 31 and the second battery 32 and extending the Service life of the first battery 31 and the second battery 32 .

It should be noted that, in other embodiments, the process of closing the first charging switch 413 or the second charging switch 423 by the first control device 20 based on the voltage difference can be achieved by comparing the magnitude relationship between the voltage difference and the preset threshold. Then, different control strategies are implemented according to the comparison results. Specifically, it can be understood from the following two aspects:

①. The voltage difference is greater than the preset threshold.

②, the voltage difference is less than or equal to the preset threshold.

The following will give a detailed introduction to the above situations ① and ②, as follows:

1) For the case where the voltage difference shown in ① above is greater than the preset threshold. The first control device 20 is specifically used for:

When the voltage difference is greater than the preset threshold, the first target switch is closed, the first target switch is the charging switch connected to the battery corresponding to the first target voltage, and the first target voltage is between the first charging voltage and the second charging voltage the minimum voltage;

A second signal is sent to the main power supply 10, where the second signal is used to instruct the main power supply 10 to supply power to the battery connected to the first target switch according to the first target voltage.

In this example, the above-mentioned preset threshold reflects that the voltage of the first battery 31 and the voltage of the second battery 32 are in a relatively balanced state. Therefore, after determining the voltage difference between the first charging voltage and the second charging voltage, the first control device 20 compares the magnitude relationship between the voltage difference and the preset threshold. If the voltage difference is greater than the preset threshold, it reflects that the first charging voltage required by the first battery 31 and the second charging voltage required by the second battery 32 are quite different, and are in a relatively unbalanced state.

Therefore, in order to reduce the voltage difference between the first battery 31 and the second battery 32, the first control device 20 should close the first target switch; and then send the second signal to the main power supply 10 to inform the main power supply 10 that the The first target voltage is used to charge the battery connected to the first target switch, so as to reduce the voltage difference between the two batteries and achieve voltage balance. It can be understood that the aforementioned first target voltage is the minimum voltage among the first charging voltage and the second charging voltage. In addition, the described first target switch is a charging switch connected to the battery corresponding to the first target voltage.

For example, when the voltage difference is greater than the preset threshold, if the first charging voltage is smaller than the second charging voltage, the first control device 20 can close the first charging switch 413 connected to the first battery 31, and then inform the main power supply 10, The first battery 31 is powered by the main power source 10 according to the first charging voltage. Likewise, if the first charging voltage is greater than the second charging voltage, the first control device 20 can close the second charging switch 423 connected to the second battery 32, and then inform the main power supply 10 that the main power supply 10 will charge the second charging voltage according to the second charging voltage. The second battery 32 is powered.

2) For the case where the voltage difference shown in the above ② is less than or equal to the preset threshold. The first control device 20 is specifically used for:

When the voltage difference is less than or equal to the preset threshold, closing the first charging switch 413 and the second charging switch 423;

Send a third signal to the main power supply 10, the third signal is used to instruct the main power supply 10 to charge the first battery 31 connected to the first charging switch 413 and the battery connected to the second charging switch 423 according to the second target voltage. The second battery 32 supplies power, and the second target voltage is the maximum voltage among the first charging voltage and the second charging voltage.

In this example, similar to the situation of ① above, if the voltage difference is less than or equal to the preset threshold, it means that the difference between the first charging voltage required by the first battery 31 and the second charging voltage required by the second battery 32 is relatively high. small, in a basically unbalanced state.

Therefore, in order to reduce the pressure difference between the first battery 31 and the second battery 32, and to ensure that the low-voltage battery can be charged. The first control device 20 should close the first charging switch 413 and the second charging switch 423 when the voltage difference is less than or equal to the preset threshold; and then notify the main power supply 10 that it needs to The first storage battery 31 connected to the first power supply switch 411 is charged according to the second target voltage, and the second storage battery 32 connected to the second charging switch 423 is supplied with power. It should be noted that the above-mentioned second target voltage is the maximum voltage among the first charging voltage and the second charging voltage.

For example, when the voltage difference is less than or equal to the preset threshold, if the first charging voltage is less than the second charging voltage, the first control device 20 can close the first charging switch 413 and the second charging switch 423, and then notify the main The power supply 10 supplies power to the first storage battery 31 and the second storage battery 32 according to the second charging voltage from the main power supply 10 . Similarly, if the first charging voltage is greater than the second charging voltage, the first control device 20 can also close the first charging switch 413 and the second charging switch 423, and then inform the main power supply 10 that the main power supply 10 will charge the first charging voltage according to the first charging voltage. The first battery 31 and the second battery 32 are powered. Through the above method, when the voltage difference is less than or equal to the preset threshold, if the main power supply 10 only supplies power to the high-voltage battery, the low-voltage battery cannot be charged all the time, resulting in an increasing voltage difference between the batteries. A control device 20 should close the first charging switch 413 and the second charging switch 423, so that the main power supply 10 can supply power to the first battery 31 and the second battery 32 according to the maximum voltage, reduce the voltage difference between the batteries, and prolong the use of the battery life.

Optionally, in other examples, if the voltage of the battery is lower than the rated voltage due to its own short-circuit, over-discharge, etc., and the battery continues to be used, it is easy to cause danger and affect the service life of the battery. battery, and manually overhaul the battery to avoid the battery being scrapped. Therefore, the above-mentioned first control device 20 can also be used for:

monitoring the voltage of the first battery 31 and the voltage of the second battery 32;

When the voltage of the first battery 31 reflects that the first battery 31 has an undervoltage fault, or the voltage of the second battery 32 reflects that the second battery 32 has an undervoltage fault, the first charging switch 413 and the second charging switch 423 are turned off. , a first discharge switch 412 and a second discharge switch 422 .

In this example, the first control device 20 continuously monitors the voltage of the first battery 31 and the voltage of the second battery 32. If the voltage of the first battery 31 is lower than the rated voltage, it means that the first battery 31 has Undervoltage fault; or, if the voltage of the second battery 32 is lower than the rated voltage, it reflects that the second battery 32 has an undervoltage fault. In this way, when the first battery 31 has an undervoltage fault or the second battery 32 has an undervoltage fault, the first control device 20 should isolate the first battery 31 and the second battery 32 to prevent the battery from discharging externally and accepting power supply . Specifically, the first control device 20 needs to turn off the first charging switch 413 and the first discharging switch 412 , and turn off the second charging switch 423 and the second discharging switch 422 . Not only can the first battery 31 and the second battery 32 be isolated, but also it can be ensured that the voltage difference between the first battery 31 and the second battery 32 will not be significantly different.

It should be noted that the above-mentioned FIGS. 2-4 only take the first control device 20 deployed on the first power supply device 41 as an example for description. In practical applications, the first control device 20 may also be deployed in the second power supply device 42 , which is not described herein as a limitation.

In addition, the first control device 20 can also be deployed outside the first power supply device 41 and the second power supply device 42. For details, please refer to FIG. 5, which is a schematic structural diagram of another vehicle power supply system provided in this embodiment of the application. . In addition, it should be noted that the difference between the vehicle power supply system shown in FIG. 5 and the vehicle power supply system shown in the aforementioned FIG. 2 to FIG. The illustrated first power supply device 41 and the second power supply device 42 do not include the first control device 20 , while any one of the power supply devices in FIGS. 2 to 4 includes the first control device 20 . However, the function of the first control device 20 in the vehicle power supply system shown in FIG. 5 can be specifically understood with reference to the content described in the foregoing FIGS. 2 to 4 , and will not be repeated here.

The above description mainly focuses on the first case (that is, two power supply devices are controlled by one control device at the same time), and the second case (that is, two control devices respectively control the power supply connected to each battery) will be described below with reference to the accompanying drawings. power supply).

Taking the first power supply device 41 including the first control device 20 and the second power supply device 42 including the second control device 21 as an example, FIG. 6 shows a schematic structural diagram of another vehicle power supply system provided in the embodiment of the present application . As shown in Figure 6, the vehicle power system may include:

The main power source 10 , the first control device 20 , the first battery 31 , the second battery 32 , the first power supply device 41 , the second power supply device 42 and at least one electrical load device 50 , the first power supply device 41 includes the first control device 20 and the first power supply switch 411, the second power supply device 42 includes the second control device 21 and the second power supply switch 421;

a main power supply 10 for generating an output voltage;

The first control device 20 is configured to: monitor the output voltage generated by the main power supply 10, and when the output voltage meets the first voltage level, disconnect the first power supply switch 411, so that the main power supply 10 stops supplying the at least one electrical load device 50 Power supply, wherein the voltage value corresponding to the first voltage level reflects the occurrence of a secondary overvoltage fault in the main power supply 10;

The second control device 21 is configured to: monitor the output voltage generated by the main power supply 10, and when the output voltage meets the first voltage level, turn off the second power supply switch 421, so that the main power supply 10 stops supplying the at least one electrical load device 50 powered by.

It should be noted that the first end of the first power supply switch 411 is connected to the main power supply 10 , the second end of the first power supply switch 411 is connected to the first control device 20 and the second control device 21 ; The terminal is connected to the main power supply 10 , and the third terminal of the second power switch 421 is connected to the first control device 20 and the second control device 21 .

In this embodiment, the voltage value corresponding to the first voltage level reflects that a secondary overvoltage fault occurs in the main power supply 10 (for details, please refer to the content of FIG. 2 for understanding, which will not be repeated here).

As can be seen from FIG. 6 , the first control device 20 may be deployed in the first power supply device 41 , and the second control device 21 may be deployed in the second power supply device 42 . In this way, the first control device 20 turns off the first power supply switch 411 when monitoring that the output voltage of the main power supply 10 meets the first voltage level, so that the main power supply 10 cannot continue to provide power for at least one electrical load device 50; similarly , the second control device 21 also turns off the second power supply switch 421 when the output voltage of the main power supply 10 meets the first voltage level, so that the main power supply 10 cannot continue to provide power for at least one electrical load device 50 . In the above manner, by deploying a control device in each power supply device, each control device can control the corresponding power supply switch in each power supply device to cut off the main power supply when the secondary overvoltage fault occurs in the main power supply 10 The path 10 for supplying power to at least one electrical load device 50 ensures that when a secondary overvoltage fault occurs in the main power supply 10, each electrical load device will no longer receive the continuous overvoltage power supply of the main power supply 10, and is perfectly protected. each electrical load device; and by separately controlling the power supply switches in the respective power supply devices, the control efficiency is also improved.

It should be noted that, in practical applications, the above-mentioned first control device 20 may also be deployed in the second power supply device 42, and the second control device 21 may also be implemented in the first power supply device 41, which is not limited in the specific embodiment of the present application. illustrate.

Optionally, based on the vehicle power supply system shown in FIG. 6 , FIG. 7 shows another schematic structural diagram of the vehicle power supply system provided in the embodiment of the present application. As can be seen from FIG. 7 , the first power supply device 41 further includes a first discharge switch 412 , and the second power supply device 42 further includes a second discharge switch 422 .

The first control device 20 is further configured to: close the first discharge switch 412 before turning off the first power supply switch 411, so as to realize that the first battery 31 supplies power to the at least one electrical load device 50;

The second control device 21 is further configured to: close the second discharge switch 422 before the second power supply switch 421 is turned off, so that the second battery 32 supplies power to the at least one electrical load device 50 .

In this example, in the case of a secondary overvoltage fault in the main power supply 10, the first control device 20 can also turn off the first power supply switch 411 so that the main power supply 10 stops supplying power to at least one electrical load device 50. The first discharge switch 412 is closed first, so that the first battery 31 connected to the first discharge switch 412 can supply power to each electrical load device. Similarly, before turning off the second power supply switch 421 so that the main power supply 10 stops supplying power to at least one electrical load device 50 , the second control device 21 may also close the second discharge switch 422 first, so that the second discharge switch 422 is connected with the second discharge switch 50 . The second battery 32 connected at 422 is capable of powering each electrical load device.

In the above manner, when a secondary overvoltage fault occurs in the main power supply 10, the first control device 20 first closes the first discharge switch 412, and then opens the first power supply switch 411; the second control device 21 also closes the second discharge switch first. 422, and then turn off the second power switch 421. It not only realizes the process of cutting off the main power supply 10 to provide power for each electrical load device, but also realizes the transition from the main power supply 10 to the seamless switching between the first lithium battery and the second lithium battery, so that the electrical load device can work without obstacles. It is guaranteed; and it can also cut off the power supply path of the main power supply 10 for each electrical load device, and perfectly protect each electrical load device.

Optionally, on the basis of the vehicle power supply system shown in FIG. 6 or FIG. 7 , FIG. 8 shows another schematic structural diagram of the vehicle power supply system provided in the embodiment of the present application. As can be seen from FIG. 8 , the first power supply device 41 further includes a first charging switch 413 , and the second power supply device 42 further includes a second charging switch 423 .

The first control device 20 is further configured to: close the first power supply switch 411 when the output voltage meets the second voltage level and does not meet the first voltage level, so as to realize that the main power supply 10 supplies power to at least one electrical load device 50, and Turn off the first charging switch 413, so that the main power supply 10 stops supplying power to the first battery 31, the voltage value corresponding to the second voltage level reflects the occurrence of a primary overvoltage fault in the main power supply 10, and the voltage value corresponding to the second voltage level is smaller than the first battery 31. A voltage value corresponding to a voltage level;

The second control device 21 is further configured to: when the output voltage meets the second voltage level and does not meet the first voltage level, close the second power supply switch 421, so as to realize that the main power supply 10 supplies power to at least one electrical load device 50, and The second charging switch 423 is turned off, so that the main power source 10 stops supplying power to the second storage battery 32 .

It should be noted that the first end of the first charging switch 413 is connected to the third end of the first power supply switch 411 , the second end of the first charging switch 413 is connected to the first battery 31 , and the third end of the first charging switch 413 is connected to The first control device 20 and the second control device 21 are connected; the first end of the second charging switch 423 is connected to the third end of the second power supply switch 421 , the second end of the second charging switch 423 is connected to the second battery 32 , The third end of the second charging switch 423 is connected to the first control device 20 and the second control device 21 .

In addition, the above-mentioned voltage value corresponding to the second voltage level reflects that a primary overvoltage fault occurs in the main power supply 10 , and the value is smaller than the voltage value corresponding to the first voltage level (for understanding with reference to the description of FIG. 4 ). Furthermore, the battery is also destroyed when a primary overvoltage fault occurs in the main power supply 10 and a secondary overvoltage fault does not occur.

Therefore, in the scenario where the power supply device is controlled by two control devices, in order to protect the battery, the first control device 20 should first close the first power supply switch when the output voltage meets the second voltage level but does not meet the first voltage level 411, and then turn off the first charging switch 413. Its purpose is mainly to ensure that each electrical load device can obtain the power provided by the main power supply 10 through the first power supply switch 411, so that the driving safety is guaranteed, and the first battery 31 is cut off to accept the main power supply 10 through the first charging switch. 413 provides power. And, the second control device 21 should also close the second power supply switch 421 first, and then open the second charging switch 423 when the output voltage meets the second voltage level and does not meet the first voltage level, so as to achieve safe driving conditions. At the same time, the second battery 32 is cut off to receive the power provided by the main power source 10 through the second charging switch 423 , thereby protecting the second battery 32 .

Optionally, in other examples, the first control device 20 or the second control device 21 is further configured to:

Obtain the first charging voltage sent by the first storage battery 31 and the second charging voltage sent by the second storage battery 32. The first charging voltage indicates the effective voltage value required by the first storage battery 31 in the current battery state of the first storage battery 31. The second charging voltage indicates the effective voltage value required by the second battery 32 in the current battery state of the second battery 32;

comparing the first charging voltage and the second charging voltage to obtain a voltage difference;

the first control device 20 for closing the first charging switch 413 according to the voltage difference; or,

The second control device 21 is configured to close the second charging switch 423 according to the voltage difference.

In this example, after the first control device 20 or the second control device 21 compares the obtained first charging voltage and the second charging voltage, and obtains the corresponding voltage difference, the first control device 20 can The first charging switch 413 is closed by the voltage difference; or, the second charging switch 423 is closed by the second control device 21 based on the voltage difference. The purpose is to enable the corresponding control device to send a signal to the main power supply 10 after closing the first charging switch 413 or the second charging switch 423 to notify the main power supply 10 that the first charging voltage or the second charging voltage is required. , to compensate the voltage of the first battery 31 or the second battery 32, and gradually realize that the first battery 31 and the second battery 32 can be charged evenly under different voltage states, thereby reducing the difference between the first battery 31 and the second battery 32. The voltage difference between them can prolong the service life of the first battery 31 and the second battery 32 . For details, it can be understood with reference to the content described in the embodiment in the foregoing first case (that is, two power supply devices are controlled by one control device at the same time), which will not be repeated here.

It should be noted that, the first control device 20 and the second control device 21 can close the charging switch controlled by the first control device 20 and the second control device 21 by comparing the voltage difference with the preset threshold value, and then the first control device 20 and the The second control device 21 controls according to the comparison result.

Specifically, when the voltage difference is greater than the preset threshold, it is reflected that the first charging voltage required by the first battery 31 and the second charging voltage required by the second battery 32 have a large difference, and are in a relatively unbalanced state, At this time, it is only necessary to perform voltage compensation for the battery with the minimum voltage. Therefore, if the voltage difference is greater than the preset threshold, the first control device 20 can close the first charging switch 413 when judging that the first charging voltage is less than the second charging voltage; and notify the main power supply 10 by means of a signal or the like , the voltage of the first battery 31 is compensated by the main power supply 10 according to the first charging voltage. Similarly, if the voltage difference is greater than the preset threshold, the second control device 21 may close the second charging switch 423 when judging that the first charging voltage is greater than the second charging voltage; and notify the main power supply by means of a signal or the like 10. The main power supply 10 performs voltage compensation on the second battery 32 according to the second charging voltage.

In addition, if the voltage difference is less than or equal to the preset threshold, it reflects that the difference between the first charging voltage required by the first battery 31 and the second charging voltage required by the second battery 32 is relatively small. At this time, the voltage of the first battery 31 and the second battery 32 can be compensated by the maximum voltage, so as to reduce the voltage difference between the batteries and avoid that when only one of the batteries is charged, the other battery is not charged, and the other battery is not charged. This results in a larger pressure difference. Therefore, if the voltage difference is less than or equal to the preset threshold, the first control device 20 needs to close the first charging switch 413, and the second control device 21 also needs to close the second charging switch 423, and notify the main power supply by means of signals or the like 10. The main power supply 10 performs voltage compensation to the first storage battery 31 and the second storage battery 32 according to the maximum voltage of the first charging voltage and the second charging voltage.

Optionally, in other examples, the above-mentioned first control device 20 can also be used to: monitor the voltage of the first battery 31 ; when the voltage of the first battery 31 reflects that the first battery 31 has an undervoltage fault , disconnect the first charging switch 413 and the first discharging switch 412 , and send a fourth signal to the second control device 21 to instruct the second control device 21 to disconnect the second charging switch 423 and the second discharging switch 422 .

In this example, the described undervoltage fault can be understood as the voltage of the battery itself is lower than the rated voltage. For details, it can be understood with reference to the content described in the embodiment in the foregoing first case (that is, two power supply devices are controlled by one control device at the same time), which will not be repeated here.

Therefore, in the scenario where the first control device 20 and the second control device 21 respectively control two power supply devices, the first control device 20 can also monitor the voltage of the first battery 31 in real time; and in the first battery 31 The voltage situation reflects that when the first battery 31 has an undervoltage fault, not only the first charging switch 413 and the first discharging switch 412 should be disconnected, so as to neither accept the power provided by the main power supply 10 nor discharge externally, and isolate the The first battery 31; and also need to notify the second control device 21 to disconnect the second charging switch 423 and the second discharging switch 422, the purpose of which is to prevent the second battery 32 from continuing to receive the power provided by the main power source 10 and discharging externally, thereby The occurrence of an increase in the pressure difference between the isolated first battery 31 and the second battery 32 is prevented.

Optionally, in other examples, the above-mentioned second control device 21 can also be used to: monitor the voltage of the second battery 32 ; when the voltage of the second battery 32 reflects that an undervoltage fault occurs in the second battery 32 , the second charging switch 423 and the second discharging switch 422 are disconnected, and a fifth signal is sent to the first control device 20 to instruct the first control device 20 to disconnect the first charging switch 413 and the first discharging switch 412 .

It can be understood that, if the voltage of the second battery 32 reflects that the second battery 32 has an undervoltage fault, the second control device 21 also needs to isolate the second battery 32 . The specific isolation method can be understood with reference to the above-mentioned method for the first control device 20 to isolate the first battery 31 , which will not be repeated here.

Optionally, in other examples, if the first control device 20 fails and cannot work normally, the second control device 21 can also take over the first control device 20 and execute the first control device 20 function performed. Similarly, if the second control device 21 fails to work normally due to failure, the first control device 20 can also perform the functions performed by the second control device 21 instead. Therefore, the first control device 20 and the second control device 21 are mutually backup, so that even if one of the control devices fails to work, the corresponding functions can also be performed, so as to ensure the safety during driving and improve the overall safety. . To this end, referring to FIG. 9 , which is a schematic structural diagram of another vehicle power supply system provided in the embodiment of the present application. On the basis of the above 8 and the optional embodiment, it can be seen from FIG. 9 that the second end of the second power supply switch 421 is also connected to the first control device 20, and the third end of the second discharge switch 422 is also connected to the first control device 20. The control device 20 is connected, and the third end of the second charging switch 423 is also connected to the first control device 20 .

In addition, the second control device 21 is also used for: monitoring the operating state of the second control device 21;

The first control device 20 is further configured to: control the second power supply switch 421 , the second charging switch 423 or the second discharging switch 422 when the operating state of the second control reflects that the second control device 21 has a running failure.

In this example, in addition to connecting the first power supply switch 411 , the first charging switch 413 and the first discharging switch 412 , the first control device 20 is also connected to the second power supplying switch 421 , the second charging switch 423 and the second discharging switch 422 connections. In this way, if the second control device 21 determines that an operating failure has occurred after monitoring its own operating state, it can send a signal to the first control device 20 through a communication line, etc., to inform the first control device 20 that it needs to act as a backup The role of the control device is to control the second power supply switch 421 , the second charging switch 423 or the second discharging switch 422 . It can be seen from this that in the case where the second control device cannot work normally due to a fault, the second power supply switch 421, the second charging switch 423 or the second discharging switch 422 can still be controlled by the backup first control device, thereby realizing the When the main power supply has an overvoltage fault, the driving safety of the vehicle can still be guaranteed, and the second battery will not be damaged by the overvoltage.

It should be noted that, when the second control device 21 fails and the first control device 20 takes over the work of the second control device 21, it can also be considered that only the first control device 20 controls the first power supply switch 411, The first charging switch 413 , the first discharging switch 412 , the second power supply switch 421 , the second charging switch 423 or the second discharging switch 422 . The specific case of only being controlled by the first control device 20 can be understood with reference to the content described in the above-mentioned first case (ie, two power supply devices are controlled by one control device at the same time), which will not be repeated here.

Optionally, in other examples, if the first control device 20 fails, the second control device 21 can also take over the work of the first control device 20 . For details, please refer to FIG. 10 , which is a schematic structural diagram of another vehicle power supply system provided in an embodiment of the present application. It can be seen from FIG. 10 that the second end of the first power supply switch 411 is also connected to the second control device 21 , the third end of the first discharge switch 412 is also connected to the second control device 21 , and the third end of the first charging switch 413 is also connected to the second control device 21 . Connected to the second control device 21 .

In addition, the first control device 20 is further used for: monitoring the running state of the first control device 20;

The second control device 21 is further configured to: control the first power supply switch 411 , the first charging switch 413 or the first discharging switch 412 when the operating state of the first control reflects that the first control device 20 has an operating failure.

It can be understood that, when the first control device 20 fails, the second control device 21 will take over the work of the first control device 20. For details, please refer to the content described in FIG. 9 above for understanding, which will not be repeated here. illustrate.

The vehicle power supply system provided by the embodiments of the present application has been described in detail above mainly from the perspective of functional modules, based on the vehicle power supply system provided in the foregoing FIG. 2 to FIG. 5 . Please refer to FIG. 11 , which is a schematic diagram of an overvoltage protection method provided in an embodiment of the application. The overcurrent protection method can be applied to the vehicle power supply system described in FIGS. 2 to 5 , as shown in FIG. 11 . , the method can include:

1101. Monitor the output voltage generated by the main power supply in the vehicle power supply system.

1102. Determine whether the output voltage meets the second voltage level, where the voltage value corresponding to the second voltage level reflects that a primary overvoltage fault occurs in the main power supply.

In this example, the voltage value corresponding to the second voltage level described above can reflect that a primary overvoltage fault occurs in the main power supply. The described first-level overvoltage fault can be understood as that the voltage value corresponding to the corresponding second voltage level will only cause damage to the first battery and the second battery, such as failure to work normally, short circuit, etc. Specifically, it can be understood with reference to the content described in the foregoing FIG. 4 , which is not repeated here.

Therefore, after continuously monitoring the output voltage, it is necessary to judge whether the output voltage satisfies the second voltage level, so as to judge whether the output voltage will damage the first battery and the second battery. Specifically, it can be determined whether the output voltage is greater than the second preset voltage threshold and less than the above-mentioned first preset voltage threshold (ie, it is understood as a voltage value corresponding to the first voltage level). If the output voltage is greater than the second preset voltage threshold and less than the first preset voltage threshold, the subsequent step 1103 may be performed. The described first preset voltage threshold is the above-mentioned minimum limit value of the first voltage level, and the second preset voltage threshold value is the minimum limit value of the second voltage level. Specifically, it can be understood with reference to the content described in the foregoing FIG. 4 , which is not repeated here.

It should be noted that, if it is determined that the output voltage is less than or equal to the second preset voltage threshold, the aforementioned step 1101 may be continued, which is not described here.

1103. When the output voltage meets the second voltage level and does not meet the first voltage level, control the closing of the first power supply switch and the second power supply switch, so that the main power supply supplies power to at least one electrical load device, and controls the first charging The switch and the second charging switch are disconnected, so that the main power supply stops supplying power to the first battery and the second battery, the voltage value corresponding to the second voltage level is smaller than the voltage value corresponding to the first voltage level, and the voltage corresponding to the first voltage level is The value reflects a secondary overvoltage fault in the vehicle power system.

In this example, when the output voltage meets the second voltage level and does not meet the first voltage level, controlling the closing of the first power supply switch and the second power supply switch enables the main power supply to supply power to at least one electrical load device, ensuring driving Safety. And by controlling the disconnection of the first charging switch and the second charging switch, the main power supply stops supplying power to the first battery and the second battery, so as to ensure driving safety, avoid continuing to supply power to the battery, and protect the battery from The voltage is getting bigger and bigger and is damaged, which affects the service life.

Specifically, it can be determined whether the output voltage is greater than the second preset voltage threshold and less than the above-mentioned first preset voltage threshold (ie, it is understood as a voltage value corresponding to the first voltage level). If the output voltage is greater than the second preset voltage threshold and less than the first preset voltage threshold, it means that the output voltage satisfies the second voltage level and has not yet reached the first voltage level. The described first preset voltage threshold is the above-mentioned minimum limit value of the first voltage level, and the second preset voltage threshold value is the minimum limit value of the second voltage level. Specifically, it can be understood with reference to the content described in the foregoing FIG. 4 , which is not repeated here.

1104. Control the closing of the first discharge switch and the second discharge switch, so that the first battery and the second battery supply power to at least one electrical load device.

In this example, only a primary overvoltage fault occurs in the main power supply at this time, and no secondary overvoltage fault occurs. However, when a secondary overvoltage fault occurs in the subsequent main power supply, in order to ensure driving safety, it is necessary to disconnect the first power supply switch and the second power supply switch to stop the main power supply from supplying power to at least one electrical load device. It can be seen from this that if the first power supply switch and the second power supply switch are disconnected, at least one electrical load device cannot continue to receive the power provided by the main power supply, and thus cannot work normally. Then, in this case, it is necessary to control the closing of the first discharge switch and the second discharge switch, so that the first battery and the second battery can supply power to each electrical load device, and ensure that each electrical load device can supply power to the two batteries. Under the voltage, it will continue to work normally. The seamless switching of the power supply from the main power supply to the battery is realized to ensure driving safety.

1105. After closing the first discharge switch and the second discharge switch, determine whether the output voltage meets the first voltage level.

In this example, as the output voltage continues to rise from low voltage to high voltage. Therefore, after closing the first discharge switch and the second discharge switch to achieve seamless switching of the power supply to provide voltage for each electrical load device, it can be further determined whether the output voltage meets the first voltage level. The voltage value corresponding to the described first voltage level reflects that a secondary overvoltage fault occurs in the main power supply, and the secondary overvoltage fault can damage all components in the vehicle power supply system, including damage to each electrical load device, affecting driving safety. Specifically, it can be understood with reference to the content described in the foregoing FIG. 2 , which is not repeated here.

It should be noted that the output voltage can be compared with a first preset voltage threshold (ie, a voltage value corresponding to the first voltage level). If the output voltage is greater than the first preset voltage threshold, the subsequent step 1106 may be performed.

In addition, if the output voltage is less than or equal to the first preset voltage threshold, the previous step 1101 may be continued, which will not be described here.

1106. When the output voltage meets the first voltage level, disconnect the first power supply switch and the second power supply switch in the vehicle power supply system, so that the main power supply stops supplying power to at least one electrical load device.

Specifically, after comparing the output voltage with the first preset voltage threshold, if the output voltage is greater than the first preset voltage threshold, it means that the output voltage satisfies the first voltage level. At this time, by controlling the disconnection of the first power supply switch and the second power supply switch, the main power supply can be stopped to continue supplying power to at least one electrical load device. In the above manner, it can be ensured that at least one electrical load device in the vehicle power supply system is not damaged, thereby avoiding a dangerous situation due to damage to the electrical load device during driving.

Based on the example described in FIG. 11 above, referring to FIG. 12 , it is a schematic diagram of an overvoltage protection method provided in an embodiment of the present application. Specific steps are as follows:

1201. Determine the first charging voltage required by the first battery and the second charging voltage required by the second battery.

In this example, the described first charging voltage can reflect the effective voltage value required by the first battery in the current battery state, that is, how many volts the main power supply needs to provide the first battery in order to effectively charge the first battery, And there is no one-level overvoltage fault described above. It should be noted that the described battery state of the first battery itself may include, but is not limited to, the temperature, power SOC, state of health (SOH), voltage value, voltage loss and the like of the first battery. In addition, the second battery can also determine the corresponding second charging voltage according to its own battery state. The described second charging voltage can reflect the effective voltage value required by the second battery in the current battery state, that is, how many volts the main power supply needs to provide the second battery in order to effectively charge the second battery, and it has not yet occurred. The primary overvoltage fault described above. It should be noted that the described battery state of the second battery itself may also include, but is not limited to, the temperature, power SOC, state of health, voltage value, voltage loss, and the like of the second battery 32 .

1202. Compare the first charging voltage and the second charging voltage to obtain a voltage difference.

1203. Determine whether the voltage difference is greater than a preset threshold.

In this example, the corresponding voltage difference is obtained by making a difference between the first charging voltage and the second charging voltage. Then, the magnitude between the voltage difference and the preset threshold is determined. If it is determined that the voltage difference is greater than the preset threshold, the subsequent steps 1204-1206 are performed; otherwise, if it is determined that the voltage difference is less than or equal to the preset threshold, the subsequent steps 1207-1209 are performed.

1204. When the voltage difference is greater than the preset threshold, control the closing of the first target switch, the first target switch is the charging switch connected to the battery corresponding to the first target voltage, and the first target voltage is the first charging voltage and the first target voltage. The minimum of two charging voltages.

1205. Output a second signal, where the second signal is used to instruct the main power supply to supply power to the battery connected to the first target switch according to the first target voltage.

1206. Control the main power supply to supply power to the battery connected to the first target switch according to the first target voltage.

In this example, if the voltage difference is greater than the preset threshold, it reflects that the difference between the first charging voltage required by the first battery and the second charging voltage required by the second battery is relatively large and is in a relatively unbalanced state. Therefore, in order to reduce the voltage difference between the first battery and the second battery, the first control device should determine the minimum voltage among the first charging voltage and the second charging voltage, and then connect the battery connected to the battery corresponding to the minimum voltage. The charging switch is closed, and then the power supply line between the main power supply and the battery corresponding to the minimum voltage is connected. In this way, the main power supply can be controlled to supply power according to the battery corresponding to the minimum voltage among the first charging voltage and the second charging voltage, and gradually increase the voltage of the battery corresponding to the minimum voltage, so as to reduce the voltage difference between the two batteries and realize The voltage is balanced, so that the service life of the battery can be extended.

1207. When the voltage difference is less than or equal to the preset threshold, control the closing of the first charging switch and the second charging switch.

1208. Output a third signal, where the third signal is used to instruct the main power supply to supply power to the first storage battery connected to the first charging switch and to the second storage battery connected to the second charging switch according to the second target voltage, The second target voltage is the maximum voltage among the first charging voltage and the second charging voltage.

1209. Supply power to the first battery and the second battery according to the second target voltage.

Likewise, if the voltage difference is less than or equal to the preset threshold, it means that the difference between the first charging voltage required by the first battery and the second charging voltage required by the second battery is relatively small and is in a basically unbalanced state. Therefore, in order to reduce the voltage difference between the first battery and the second battery and ensure that the low-voltage battery can be charged, the first charging switch and the second charging switch should be closed, and then the main power supply to the first battery and the second battery should be turned on. between the power supply lines. Then, the main power supply is controlled to supply power to the first battery and the second battery according to the maximum voltage of the first battery and the second battery. Through the above method, when the voltage difference is less than or equal to the preset threshold, if the main power supply only supplies power to the high-voltage battery, the low-voltage battery cannot be charged all the time, resulting in an increasing voltage difference between the batteries. Therefore, the first The control device should close the first charging switch and the second charging switch, so that the main power supply can supply power to the first battery and the second battery according to the maximum voltage, reduce the voltage difference between the batteries, and prolong the service life of the battery.

It can be understood that, the method for realizing overvoltage protection based on the voltage difference in this embodiment can be specifically understood with reference to the partial contents of the vehicle power supply system described in the optional examples in FIG. 2 to FIG. 5 , which will not be described here. Repeat the description.

In addition, in the case of an overvoltage failure of the main power supply, if an undervoltage failure of the battery occurs, it can be understood with reference to the schematic diagram of the overvoltage protection method shown in FIG. 13 . details as follows:

1301. Monitor the voltage of the first battery and the voltage of the second battery.

1302. Control the first charging switch, the second charging switch, and the first discharging switch when the voltage condition of the first battery reflects the occurrence of an undervoltage fault in the first battery, or the voltage condition of the second battery reflects the occurrence of an undervoltage fault in the second battery and the opening of the second discharge switch.

In this example, if the voltage of the battery is lower than the rated voltage due to its own short-circuit, over-discharge, etc., then continuing to use the battery will easily cause danger and affect the service life of the battery. Only by isolating the battery and repairing the battery manually , to avoid the battery being scrapped. Therefore, the voltage of the first battery and the voltage of the second battery should be continuously monitored. If the voltage of the first battery is lower than the rated voltage, it means that the first battery has an undervoltage fault; or, if the second battery The voltage is lower than the rated voltage, reflecting the undervoltage fault of the second battery. In this way, when the first battery has an undervoltage fault or the second battery has an undervoltage fault, the first battery and the second battery should be isolated to prevent the battery from discharging externally and receiving power. Specifically, the isolation can be achieved by disconnecting the first charging switch and the first discharging switch, and disconnecting the second charging switch and the second discharging switch. Not only can the first battery and the second battery be isolated, but also it can be ensured that there will not be a large difference in the voltage difference between the first battery and the second battery.

To sum up, the overvoltage protection method described in FIGS. 11-13 is mainly applied to the vehicle power supply system provided in the aforementioned FIGS. 2-5 (that is, the vehicle power supply system includes only one control device). For the method of overvoltage protection applicable to the vehicle power supply system described in the aforementioned FIG. 6-FIG. 10, you can also refer to the method described in the aforementioned FIG. 11-FIG. 13 and the aforementioned method in FIG. 6-FIG. The content of the described vehicle power supply system is to be understood, and no further description is given here.

The foregoing mainly introduces the solutions provided by the embodiments of the present application from the perspectives of hardware and methods. It can be understood that the functions of the first control device in the above-mentioned FIG. 2-FIG. 5, and the first control device and the second control device in FIG. 6-FIG. 10 can also be realized based on the form of computer software. Different approaches may be used to implement the described functionality for each particular application, but such implementations should not be considered beyond the scope of this application. In addition, since the function of the first control device is similar to the function of the second control device, only the first control device is used as an example for description in the following.

Described from the perspective of an entity device, the above-mentioned first control device may be implemented by one entity device, or may be jointly implemented by multiple entity devices, or may be a logical function unit in one entity device, which is not specifically described in this embodiment of the present application. limited.

For example, the above-mentioned first control device may be implemented by the first control device in FIG. 14 . FIG. 14 is a schematic diagram of a hardware structure of a first control device provided by an embodiment of the present application. The first control device includes at least one processor 1401 and a memory 1402 .

The processor 1401 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (server IC), or one or more programs used to control the program execution of the present application. of integrated circuits.

Memory 1402 may be read-only memory (ROM) or other type of static storage device that can store static information and instructions, random access memory (RAM), or other type of static storage device that can store information and instructions It can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disk storage, optical disk storage ( including compact discs, laser discs, compact discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or capable of carrying or storing desired program code in the form of instructions or data structures and capable of being stored by a computer any other medium taken, but not limited to this. The memory 1402 may exist independently, or the memory 1402 may be integrated with the processor 1401 .

The memory 1402 is used for storing computer-executed instructions for executing the solution of the present application, and the execution is controlled by the processor 1401 . The processor 1401 is configured to execute the computer-executed instructions stored in the memory 1402, thereby implementing the overvoltage protection method provided by the above method embodiments of the present application.

As a possible implementation manner, the computer-executed instructions in the embodiment of the present application may also be referred to as application code, which is not specifically limited in the embodiment of the present application.

In a specific implementation, as an embodiment, the processor 1401 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 14 .

In a specific implementation, as an embodiment, the first control device may include multiple processors, for example, the processor 1401 and the processor 1403 in FIG. 14 . Each of these processors can be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (eg, computer-executed instructions).

From the perspective of functional units, the present application may divide the first control device into functional units according to the above method embodiments. For example, each functional unit may be divided corresponding to each function, or two or more functions may be integrated into one in the functional unit. The above-mentioned integrated functional units may be implemented in the form of hardware, and may also be implemented in the form of software functional units.

For example, in the case of dividing each functional unit in an integrated manner, FIG. 15 shows a schematic structural diagram of a first control device. As shown in FIG. 15 , an embodiment of the first control device of the present application may include a monitoring unit 1501 and a processing unit 1502;

a monitoring unit 1501, configured to monitor the output voltage generated by the main power supply;

A processing unit 1502, configured to disconnect the first power supply switch and the second power supply switch when the output voltage meets a first voltage level, so that the main power supply stops supplying power to the at least one electrical load device , wherein the voltage value corresponding to the first voltage level reflects that a secondary overvoltage fault occurs in the main power supply.

It should be noted that in order to ensure that at least one electrical load device in the vehicle power supply system will not be damaged when a secondary overvoltage fault occurs in the main power supply, so as to avoid damage to the electrical load device during driving Dangerous phenomenon occurs. In the above manner, the monitoring unit 1501 needs to monitor the output voltage generated by the main power supply in real time; and the processing unit 1502 judges whether the output voltage is greater than the first preset voltage threshold, and the described first preset voltage threshold is consistent with the first voltage level. and the processing unit 1502 needs to disconnect the first power supply switch and the second power supply switch connected to the main power supply when the output voltage is greater than the first preset voltage threshold, so that the main power supply can stop supplying at least one electrical load device In this way, the power supply path of the main power supply for each electrical load device is cut off, and it is guaranteed that each electrical load device will no longer receive the main power supply when a secondary overvoltage fault occurs in the main power supply. The continuous overvoltage power supply perfectly protects each electrical load device.

In some examples, the processing unit 1502 may be further configured to: before opening the first power supply switch and the second power supply switch, close the first discharge switch and the second discharge switch, so that all the The first battery and the second battery supply power to the at least one electrical load device.

In the above manner, the processing unit 1502 first closes the first discharge switch and the second discharge switch, and then opens the first power supply switch and the second power supply switch, so that when the path for the main power supply to supply power to each electrical load device is cut off, It not only protects each electrical load device perfectly; but also can provide power for the electrical load device during the cut-off process, and the seamless switch from the main power supply to the first lithium battery and the second lithium battery makes the electrical load The barrier-free work of the device is guaranteed.

In another possible implementation manner, the processing unit 1502 may also be used for:

When the output voltage meets the second voltage level and does not meet the first voltage level, the first power supply switch and the second power supply switch are closed, so as to realize the supply of the main power supply to the at least one electrical load power supply to the device, and turn off the first charging switch to stop the main power supply from supplying power to the first battery, and turn off the second charging switch to stop the main power supply from supplying power to the second battery The battery supplies power, the voltage value corresponding to the second voltage level reflects that a primary overvoltage fault occurs in the main power supply, and the voltage value corresponding to the second voltage level is smaller than the voltage value corresponding to the first voltage level.

In the above manner, after continuously monitoring the output voltage of the main power supply, the processing unit 1502 can also determine whether the output voltage satisfies the above-mentioned second voltage level; then, when the output voltage satisfies the above-mentioned second voltage level and does not satisfy the first At the voltage level, first close the first power supply switch and the second power supply switch, so that the output voltage of the main power supply can supply power to at least one electrical load device, ensuring that each electrical load device does not stop working due to no power; Turn on the first charging switch to realize that the main power supply stops supplying power to the first battery, thereby cutting off the path for the main power supply to supply power to the first battery and preventing the first battery from being damaged by overvoltage; similarly, it is also necessary to disconnect the second battery. The charging switch is used to realize that the main power supply stops supplying power to the second battery, thereby cutting off the path for the main power supply to supply power to the second battery, and ensuring that the second battery is not damaged by overvoltage.

In another possible implementation manner, the processing unit 1502 may also be used for:

Obtain a first charging voltage sent by the first battery and a second charging voltage sent by the second battery, the first charging voltage indicating that the first battery needs to be in the current battery state of the first battery The effective voltage value of the second charging voltage indicates the effective voltage value required by the second battery in the current battery state of the second battery;

comparing the first charging voltage and the second charging voltage to obtain a voltage difference; closing the first charging switch or the second charging switch based on the voltage difference;

Sending a first signal to the main power supply, where the first signal is used to instruct the main power supply to charge the first battery or the second battery according to the first charging voltage or the second charging voltage compensation.

In the above manner, after the first battery determines the effective voltage value required by itself (that is, the first charging voltage mentioned above), and the second battery determines the effective voltage value that it needs (that is, the second charging voltage mentioned above), the Based on the voltage difference between the two, the processing unit 1502 closes the first charging switch or the second charging switch, and then the main power supply performs voltage charging for the first battery or the second battery according to the requested first charging voltage or second charging voltage. The compensation can gradually realize that the first battery and the second battery can be charged evenly under different voltage states, thereby reducing the voltage difference between the first battery and the second battery, and prolonging the service life of the first battery and the second battery.

In another possible implementation manner, the processing unit 1502 may also be used for:

When the voltage difference is greater than a preset threshold, the first target switch is closed, the first target switch is a charging switch connected to the battery corresponding to the first target voltage, and the first target voltage is the first target switch the minimum voltage of the charging voltage and the second charging voltage;

A second signal is sent to the main power source, where the second signal is used to instruct the main power source to supply power to the storage battery connected to the first target switch according to the first target voltage.

In the above manner, in order to reduce the voltage difference between the first battery and the second battery, the processing unit 1502 should determine the minimum voltage among the first charging voltage and the second charging voltage, and then close the battery connected to the battery corresponding to the minimum voltage. charging switch. Then, by sending a second signal to the main power supply, it is informed that the main power supply needs to charge the corresponding battery according to the minimum voltage, so as to reduce the voltage difference between the two batteries and achieve voltage balance.

In another possible implementation manner, the processing unit 1502 may also be used for:

When the voltage difference is less than or equal to a preset threshold, closing the first charging switch and the second charging switch;

Send a third signal to the main power source, the third signal is used to instruct the main power source to charge the first battery connected to the first charging switch and the second battery according to the second target voltage. The second battery connected to the charging switch supplies power, and the second target voltage is a maximum voltage among the first charging voltage and the second charging voltage.

Through the above method, when the voltage difference is less than or equal to the preset threshold, if the main power supply only supplies power to the high-voltage battery, the low-voltage battery cannot be charged all the time, resulting in an increasing voltage difference between the batteries. Therefore, the processing unit 1502 should close the first charging switch and the second charging switch, so that the main power supply can supply power to the first battery and the second battery according to the maximum voltage, reduce the voltage difference between the batteries, and prolong the service life of the battery.

In another possible implementation manner, the processing unit 1502 may also be used for:

monitoring the voltage condition of the first battery and the voltage condition of the second battery;

When the voltage condition of the first battery reflects that the first battery has an undervoltage fault, or the voltage condition of the second battery reflects that the second battery has an undervoltage fault, disconnect the first charging switch, the second charging switch, the first discharging switch and the second discharging switch.

In the above manner, the processing unit 1502 continuously monitors the voltage of the first battery and the voltage of the second battery. If the voltage of the first battery is lower than the rated voltage, it means that the first battery has an undervoltage fault; or, if the voltage of the first battery is lower than the rated voltage When the voltage of the second battery is lower than the rated voltage, it reflects that the second battery has an undervoltage fault. In this way, when the first battery has an undervoltage fault or the second battery has an undervoltage fault, the first control device should isolate the first battery and the second battery to prevent the battery from discharging externally and accepting power. Specifically, the first control device needs to turn off the first charging switch and the first discharging switch, and turn off the second charging switch and the second discharging switch. Not only can the first battery and the second battery be isolated, but also it can be ensured that there will not be a large difference in the voltage difference between the first battery and the second battery.

In the embodiment of the present application, the first control device is presented in the form of dividing each functional unit in an integrated manner. A "functional unit" herein may refer to an application-specific integrated circuit (ASIC), a processor and memory executing one or more software or firmware programs, an integrated logic circuit, and/or other devices that can provide the above-mentioned functions . In a simple embodiment, those skilled in the art can imagine that the first control device may take the form shown in FIG. 14 .

For example, the processor 1401 in FIG. 14 may execute the instructions by calling the computer stored in the memory 1402, so that the first control device executes the method in any one of the method embodiments in FIGS. 11-13 .

Specifically, the functions/implementation process of the monitoring unit 1501 and the processing unit 1502 in FIG. 15 can be realized by the processor 1401 in FIG. 14 mobilizing the computer execution instructions stored in the memory 1402 .

The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the present application.

Claims (19)

1. A vehicular power supply system characterized by comprising:

the power supply system comprises a main power supply, a first control device, a first storage battery, a second storage battery, a first power supply device, a second power supply device and at least one electrical load device, wherein the first power supply device comprises a first power supply switch, and the second power supply device comprises a second power supply switch;

the first end of the first power supply switch is connected with the main power supply, and the second end of the first power supply switch is connected with the first control device; the first end of the second power supply switch is connected with the main power supply, and the second end of the second power supply switch is connected with the first control device;

the main power supply is used for generating an output voltage;

the first control device is configured to:

monitoring the output voltage generated by the primary power source;

when the output voltage meets a first voltage level, disconnecting the first power supply switch and the second power supply switch to enable the main power supply to stop supplying power to the at least one electrical load device, wherein a voltage value corresponding to the first voltage level reflects that a secondary overvoltage fault occurs in the main power supply;

the first power supply device further comprises a first charging switch, and the second power supply device further comprises a second charging switch;

the first end of the first charging switch is connected with the third end of the first power supply switch, the second end of the first charging switch is connected with the first storage battery, and the third end of the first charging switch is connected with the first control device;

the first end of the second charging switch is connected with the third end of the second power supply switch, the second end of the second charging switch is connected with the second storage battery, and the third end of the second charging switch is connected with the first control device;

the first control device is further configured to:

when the output voltage meets a second voltage level and does not meet the first voltage level, closing the first power supply switch and the second power supply switch to enable the main power supply to supply power to the at least one electrical load device, and opening the first charging switch to enable the main power supply to stop supplying power to the first storage battery, and opening the second charging switch to enable the main power supply to stop supplying power to the second storage battery, wherein a voltage value corresponding to the second voltage level reflects that a primary overvoltage fault occurs to the main power supply, and a voltage value corresponding to the second voltage level is smaller than a voltage value corresponding to the first voltage level.

2. The vehicle power supply system according to claim 1, wherein the first power supply device further includes a first discharge switch, and the second power supply device further includes a second discharge switch;

the first end of the first discharge switch is connected with the third end of the first power supply switch, the second end of the first discharge switch is connected with the first storage battery, and the third end of the first discharge switch is connected with the first control device; the first end of the second discharging switch is connected with the third end of the second power supply switch, the second end of the second discharging switch is connected with the second storage battery, and the third end of the second discharging switch is connected with the first control device;

the first control device is further configured to:

closing the first and second discharge switches to cause the first and second batteries to supply power to the at least one electrical load device prior to opening the first and second power switches.

3. The vehicle power supply system according to claim 1, wherein the first control device is further configured to:

acquiring a first charging voltage sent by the first storage battery and a second charging voltage sent by the second storage battery, wherein the first charging voltage indicates an effective voltage value required by the first storage battery in the current battery state of the first storage battery, and the second charging voltage indicates an effective voltage value required by the second storage battery in the current battery state of the second storage battery;

comparing the first charging voltage with the second charging voltage to obtain a voltage difference value;

closing the first charge switch or a second charge switch based on the voltage difference;

and sending a first signal to the main power supply, wherein the first signal is used for indicating the main power supply to perform voltage compensation on the first storage battery or the second storage battery according to the first charging voltage or the second charging voltage.

4. The vehicle power supply system according to claim 3, characterized in that the first control means is configured to:

when the voltage difference value is greater than a preset threshold value, closing a first target switch, wherein the first target switch is a charging switch connected with a storage battery corresponding to a first target voltage, and the first target voltage is the minimum voltage of the first charging voltage and the second charging voltage;

and sending a second signal to the main power supply, wherein the second signal is used for indicating the main power supply to supply power to a storage battery connected with the first target switch according to the first target voltage.

5. A vehicular power supply system according to claim 3, characterized in that the first control means is configured to:

when the voltage difference value is smaller than or equal to a preset threshold value, closing the first charging switch and the second charging switch;

and sending a third signal to the main power supply, wherein the third signal is used for indicating the main power supply to supply power to a first storage battery connected with the first charging switch and a second storage battery connected with the second charging switch according to a second target voltage, and the second target voltage is the maximum voltage of the first charging voltage and the second charging voltage.

6. The vehicle power supply system according to any one of claims 2 to 5, wherein the first control device is further configured to:

monitoring a voltage condition of the first battery and a voltage condition of the second battery;

and when the voltage condition of the first storage battery reflects that the first storage battery has undervoltage faults or the voltage condition of the second storage battery reflects that the second storage battery has undervoltage faults, the first charging switch, the second charging switch, the first discharging switch and the second discharging switch are switched off.

7. The vehicular power supply system according to any one of claims 1 to 5, characterized in that any one of the first power supply device and the second power supply device includes the first control device, or neither of the first power supply device and the second power supply device includes the first control device.

8. The vehicular power supply system according to any one of claims 1 to 5, characterized in that the first control means includes an Electronic Control Unit (ECU).

9. A vehicular power supply system characterized by comprising:

the power supply system comprises a main power supply, a first control device, a first storage battery, a second storage battery, a first power supply device, a second power supply device and at least one electrical load device, wherein the first power supply device comprises the first control device and a first power supply switch, and the second power supply device comprises a second control device and a second power supply switch;

the first end of the first power supply switch is connected with the main power supply, and the second end of the first power supply switch is connected with the first control device;

the first end of the second power supply switch is connected with the main power supply, and the second end of the second power supply switch is connected with the second control device;

the main power supply is used for generating an output voltage;

the first control device is configured to: monitoring the output voltage generated by the main power supply, and when the output voltage meets a first voltage level, turning off the first power supply switch to stop the main power supply from supplying power to the at least one electrical load device, wherein a voltage value corresponding to the first voltage level reflects that a secondary overvoltage fault occurs in the main power supply;

the second control device is configured to: monitoring the output voltage generated by the primary power supply and disconnecting the second power supply switch when the output voltage meets the first voltage level to cause the primary power supply to stop supplying power to the at least one electrical load device;

the first power supply device further comprises a first charging switch, and the second power supply device further comprises a second charging switch;

the first end of the first charging switch is connected with the third end of the first power supply switch, the second end of the first charging switch is connected with the first storage battery, and the third end of the first charging switch is connected with the first control device;

the first end of the second charging switch is connected with the third end of the second power supply switch, the second end of the second charging switch is connected with the second storage battery, and the third end of the second charging switch is connected with the second control device;

the first control device is further configured to: when the output voltage meets a second voltage level and does not meet the first voltage level, closing the first power supply switch to supply power to the at least one electrical load device by the main power supply, and opening the first charging switch to stop the main power supply from supplying power to the first storage battery, wherein a voltage value corresponding to the second voltage level reflects that a primary overvoltage fault occurs to the main power supply, and is smaller than a voltage value corresponding to the first voltage level;

the second control device is further configured to: when the output voltage meets the second voltage level and does not meet the first voltage level, the second power supply switch is closed to supply power to the at least one electrical load device by the main power supply, and the second charging switch is opened to stop the main power supply from supplying power to the second storage battery.

10. The vehicle power supply system according to claim 9, wherein the first power supply device further includes a first discharge switch, and the second power supply device further includes a second discharge switch;

the first end of the first discharging switch is connected with the third end of the first power supply switch, the second end of the first discharging switch is connected with the first storage battery, and the third end of the first discharging switch is connected with the first control device; the first end of the second discharging switch is connected with the third end of the second power supply switch, the second end of the second discharging switch is connected with the second storage battery, and the third end of the second discharging switch is connected with the second control device;

the first control device is further configured to: closing the first discharge switch to enable the first battery to supply power to the at least one electrical load device prior to opening the first power supply switch;

the second control device is further configured to: closing the second discharge switch to enable the second battery to supply power to the at least one electrical load device prior to opening the second power supply switch.

11. The vehicle power supply system according to claim 9,

the first control device or the second control device is further configured to:

acquiring a first charging voltage sent by the first storage battery and a second charging voltage sent by the second storage battery, wherein the first charging voltage indicates an effective voltage value required by the first storage battery in the current battery state of the first storage battery, and the second charging voltage indicates an effective voltage value required by the second storage battery in the current battery state of the second storage battery;

comparing the first charging voltage with the second charging voltage to obtain a voltage difference value;

the first control device is used for closing the first charging switch according to the voltage difference value; or the like, or a combination thereof,

the second control device is used for closing the second charging switch according to the voltage difference value.

12. The vehicle power supply system according to claim 11, wherein when the voltage difference value is greater than a preset threshold value,

the first control device is configured to: when the first charging voltage is smaller than the second charging voltage, closing the first charging switch to realize voltage compensation of the main power supply to the first storage battery according to the first charging voltage; or the like, or a combination thereof,

the second control device is configured to: and when the first charging voltage is greater than the first charging voltage, closing the second charging switch to realize the voltage compensation of the main power supply to the second storage battery according to the second charging voltage.

13. The vehicle power supply system according to claim 11, wherein when the voltage difference is smaller than or equal to a preset threshold, the first control device is configured to close the first charge switch, and the second control device is configured to close the second charge switch, so that the main power supply compensates the voltage of the first storage battery and the second storage battery according to a second target voltage, wherein the second target voltage is a maximum voltage of the first charge voltage and the second charge voltage.

14. The vehicle power supply system according to any one of claims 10 to 13, wherein the first control device is further configured to:

monitoring a voltage condition of the first battery;

and when the voltage condition of the first storage battery reflects that the first storage battery has an undervoltage fault, disconnecting the first charging switch and the first discharging switch, and sending a fourth signal to the second control device to instruct the second control device to disconnect the second charging switch and the second discharging switch.

15. The vehicular electric power source system according to any one of claims 10 to 13, characterized in that the second control device is further configured to:

monitoring a voltage condition of the second battery;

and when the voltage condition of the second storage battery reflects that the second storage battery has an undervoltage fault, disconnecting the second charging switch and the second discharging switch, and sending a fifth signal to the first control device to instruct the first control device to disconnect the first charging switch and the first discharging switch.

16. The vehicle power supply system according to any one of claims 10 to 13, wherein the second terminal of the second power supply switch is further connected to the first control device, the third terminal of the second discharge switch is further connected to the first control device, and the third terminal of the second charge switch is further connected to the first control device;

the second control device is further configured to: monitoring the operating state of the second control device;

the first control device is further configured to: and when the running state of the second control device reflects that the second control device has running fault, controlling the second power supply switch, the second charging switch or the second discharging switch.

17. The vehicle power supply system according to any one of claims 10 to 13, wherein the second terminal of the first power supply switch is further connected to the second control device, the third terminal of the first discharge switch is further connected to the second control device, and the third terminal of the first charge switch is further connected to the second control device;

the first control device is further configured to: monitoring the operating state of the first control device;

the second control device is further configured to: and when the running state of the first control device reflects that the first control device has running fault, controlling the first power supply switch, the first charging switch or the first discharging switch.

18. A vehicular power supply system according to any one of claims 9-13, characterized in that the first control means includes a first electronic control unit ECU, and the second control means includes a second electronic control unit ECU.

19. A method of overvoltage protection, applied to a vehicle power supply system according to any one of claims 1 to 8, or to a vehicle power supply system according to any one of claims 9 to 18, the method comprising:

monitoring an output voltage generated by a main power supply in the vehicle power supply system;

judging whether the output voltage meets a first voltage level, wherein a voltage value corresponding to the first voltage level reflects that a secondary overvoltage fault occurs in the vehicle power supply system;

when the output voltage meets the first voltage level, disconnecting a first power supply switch and a second power supply switch in the vehicle power system to cause the main power supply to stop supplying power to at least one electrical load device;

when the output voltage meets a second voltage level and does not meet the first voltage level, closing the first power supply switch and the second power supply switch to enable the main power supply to supply power to the at least one electrical load device, disconnecting a first charging switch in the vehicle power supply system to enable the main power supply to stop supplying power to the first storage battery, and disconnecting a second charging switch in the vehicle power supply system to enable the main power supply to stop supplying power to the second storage battery, wherein a voltage value corresponding to the second voltage level reflects that a primary overvoltage fault occurs in the main power supply, and a voltage value corresponding to the second voltage level is smaller than a voltage value corresponding to the first voltage level.

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