CN108973758A - A kind of charging recognition methods of charging system for electric automobile and electric car charging circuit - Google Patents

Abstract

The invention discloses a kind of charging recognition methods of charging system for electric automobile, for electric vehicle charge interface access charging equipment when to interface voltage it is effective identify and secure connection, including detecting the first charging voltage of the power transformer at the charging interface when the charging interface of the electric car is electrically connected to charging equipment；Connection electric signal is detected to charging equipment by the vehicle mobile equipment of electric car；The second charging voltage of the power transformer is detected at the charging interface of the electric car；Measuring the alternating voltage that the charging equipment provides according to first charging voltage and the second charging voltage includes extra voltage；And according to the output impedance at the measurement movement change power transformer, wherein measurement movement includes: when ratio between first charging voltage and the second charging voltage is in a pre-set interval, determine provided by alternating voltage include extra voltage.

Description

A charging identification method for an electric vehicle charging system and an electric vehicle charging circuit

technical field

Embodiments of the present invention mainly relate to electric vehicle charging technology, more specifically, embodiments of the present invention mainly relate to an identification method for judging whether the charging interface of an electric vehicle charging pile is safe to charge, and such an identification circuit.

Background technique

The electric vehicle industry is one of the strategic emerging industries that the country focuses on. Various regions have started the construction of electric vehicle charging distribution networks and electric vehicle charging stations. Electric vehicles mainly use the power provided by the on-board battery pack to drive AC and DC electric motors to supply vehicle driving power. Electric vehicles are roughly divided into proprietary electric vehicles and hybrid vehicles according to their battery drive types. Proprietary electric vehicles pass Driven by pure batteries, the battery needs to be charged after the battery is exhausted, while a hybrid vehicle can provide vehicle power through other power engines (such as gasoline, natural gas, etc.), and can charge the battery pack at the same time during driving. After the power is exhausted, the battery pack is used for energy supply. Hybrid electric vehicles can be divided into series mode and parallel mode. In the series mode, the mechanical energy output from the engine is converted into electrical energy through the generator, and the electrical energy is supplied to the battery or motor, so that the vehicle is always driven by the motor. Such a car is for The concept of adding an engine and a generator to the conventional electric vehicle to increase the driving range; the vehicle can also be driven by using battery power in parallel, and the vehicle can be driven by only the engine (gasoline or diesel), and the two powers can be used in parallel source, and depending on the driving conditions, the parallel mode enables the engine and motor to simultaneously drive the vehicle.

Usually, with the continuous development and innovation of the current automobile manufacturing industry, the intelligence of the car itself has risen to a stage. Vehicle users can communicate and interact with the vehicle CAN bus through the vehicle terminal, especially if the vehicle terminal is equipped with GPS. The navigation device can send position information to the remote vehicle server terminal by means of positioning.

When the electric vehicle vehicle is connected to the charging station by cable, the power of the on-board battery is obtained from the charging point. At the same time, users can also charge through other cables or connecting wires, and these cables are usually not standard charging cables, so there may be risks during the charging process, such as overvoltage, user electric shock or leakage. The purpose of these non-standard charging methods is mainly to increase the charging speed and increase the input of current or voltage. However, due to the poor quality of some cables, there is a greater risk of the aforementioned, so it is necessary to design a method that can identify this type of charging. Circuits and ways of identifying risks.

Contents of the invention

The purpose of the technical solution of the present invention is to design a charging identification method for the electric vehicle charging system, which is used for effective identification and safe connection of the interface voltage when the electric vehicle charging interface is connected to the charging device, and the charging interface can judge whether the cable is a standard specification , can be compared and judged by identifying the first and second charging voltages from the charging interface. On the other hand, the vehicle-mounted mobile device (such as a vehicle-mounted intelligent terminal, a user's handheld device, etc.) determines whether to charge according to the judgment result. In another embodiment mainly related to this identification circuit, the impedance on the current path can be increased to reduce the input voltage, so as to maintain a stable state of charging.

Technical solution: a charging identification method for an electric vehicle charging system, comprising: when the charging interface of the electric vehicle is electrically connected to the charging device, detecting the first charging voltage of the power transformer at the charging interface; The device detects the connection electrical signal to the charging device; detects the second charging voltage of the power transformer at the charging interface of the electric vehicle; measures the AC voltage provided by the charging device according to the first charging voltage and the second charging voltage including an additional voltage; and changing the output impedance at the power transformer according to the determining action, wherein the determining action includes: the ratio between the first charging voltage and the second charging voltage is within a predetermined interval , make sure that the supplied AC voltage contains additional voltage.

In one embodiment, it further includes when it is determined that the provided AC voltage contains extra voltage, by electrically connecting the power transformer to a voltage limiting circuit provided on the electric vehicle to eliminate the extra voltage.

In one embodiment, the removed excess voltage is factored into an on-board energy storage device. The energy storage device may include a supercapacitor bank or other battery packs. The current shunted to this part is relatively small compared to the charging current for the electric vehicle battery, and this part of the current is mainly for the power supply of a small current in the vehicle.

In one embodiment, it further includes cutting off the path of the power transformer when it is determined that the provided AC voltage contains an extra voltage, for example, a relay is set at the charging interface, and the connection with the charging pile is directly cut off when it is determined that there is an extra voltage path.

In another embodiment, the electric vehicle charging circuit includes an electric vehicle charging interface and a charging station charging device matched therewith, wherein the charging interface of the electric vehicle includes: a circuit for converting the AC current of the charging device into a DC current A power transformer; a vehicle-mounted mobile device connected to the power transformer, used to detect the first charging voltage and the second charging voltage of the power transformer at the charging interface, and measure the first charging voltage and the second charging voltage according to the first charging voltage and the second charging voltage. The AC voltage provided by the charging device includes an additional voltage; and a control circuit connected to the power transformer for changing the output impedance of the power transformer according to the measurement action. The charging device includes: a power supply identification circuit configured to respond to a connection electrical signal from the charging interface; a controller connected to the power supply identification circuit configured to receive a data signal from the charging interface; connected to the controller A suppression circuit configured to: reduce the voltage provided to the charging interface in response to a portion of the data signal representing an output impedance at the power transformer; or cut off a path to the power transformer.

In one embodiment, it further includes a voltage limiting circuit connected to the power transformer, configured to eliminate this part of the extra voltage when it is determined that the AC voltage provided by the charging device contains the extra voltage.

In one embodiment, it further includes an overvoltage protection circuit connected to the power transformer, configured to disconnect the vehicle-mounted mobile device or the vehicle-mounted battery from the charging device when the voltage measured at the power transformer is greater than a preset voltage. electricity.

In one embodiment, an impedance control circuit is provided between the power transformer and the voltage limiting circuit, which is configured to work in a bypass state when it is not determined that the AC voltage provided by the charging device contains an extra voltage, as A current path; and when it is determined that the AC voltage provided by the charging device includes an extra voltage, it works in a higher resistance state, and at this time suppresses a part of the current path.

In one embodiment, the charging interface sends the identification code of the charging equipment to the charging pile through the vehicle-mounted mobile equipment, such as the vehicle-mounted computing system. After the identification code of the charging equipment is received by the controller, the vehicle information is confirmed, and then the charging and electricity bills are carried out. measure.

The power transformer can be used to provide working voltage to the vehicle, and the charging interface can be used to receive data commands from the charging pile. The voltage limiting circuit can be used to change the impedance of the power path between the power transformer and the charging pile device in response to receiving data instructions from the charging pile, and reduce the current from the charging pile when a preset threshold amount of current is drawn through the voltage limiting circuit. The voltage of the pile charging equipment to the power transformer.

For a fuller understanding of the nature and advantages of embodiments of the invention, reference should be made to the ensuing detailed description and accompanying drawings. Other aspects, objects and advantages of the invention will be apparent from the following drawings and detailed description. However, the scope of the present invention will be fully apparent from the description of the claims.

Description of drawings

Figure 1 is a block diagram of the structure and principle of the electric vehicle charging circuit.

Detailed ways

Referring to Fig. 1, the electric vehicle charging circuit includes an electric vehicle charging interface 1 and a charging station charging device 2 (for example, a charging pile) connected to it by a cable, and the charging interface 1 of the electric vehicle includes an AC for connecting the charging pile 2 to the electric vehicle. A power transformer 11 that converts alternating current into DC direct current; the vehicle-mounted mobile device 12 connected to the power transformer 11 is used to detect the first charging voltage and the second charging voltage of the power transformer 11 at the charging interface, according to the The first charging voltage and the second charging voltage determine whether the AC voltage provided by the charging pile 2 includes additional voltage; and the impedance control circuit 13 connected to the power transformer 11 is used to change the power transformer according to the measurement action The output impedance at 11.

In one embodiment, it further includes a voltage limiting circuit 15 connected to the power transformer 11, configured to eliminate the extra voltage when it is determined that the AC voltage provided by the charging pile or the cable contains extra voltage.

In one embodiment, it further includes an overvoltage protection circuit 17 connected to the power transformer 11, configured to disconnect the vehicle-mounted mobile device 12 or the vehicle-mounted battery 18 when the voltage measured at the power transformer 11 is greater than a preset voltage Obtain electricity from charging pile 2.

In one embodiment, an impedance control circuit 13 is provided between the power transformer 11 and the voltage limiting circuit 15, which is configured to work in a bypass when it is not determined that the AC voltage provided by the charging pile 2 contains additional voltage. state, as a current path; and when it is determined that the AC voltage provided by the charging pile 2 includes additional voltage, it works in a relatively high resistance state, and at this time suppresses a part of the current path.

The bypass state may correspond to the interface built-in relay 16 working in a conduction state. Since the relay 16 has a lower resistance than the resistor 14, the current supplied from the power transformer 11 can be transmitted substantially unchanged through the power of the current path. The voltage limiting circuit 15 can also work in a power limiting state. According to the first embodiment of the present invention, when the voltage limiting circuit 15 is in the power limiting working state, the change of the impedance 14 can be set to limit the amount of power transferred from the charging post 2 to the power transformer 11 through the resistor 14 . For example, a change in impedance 14 may limit the amount of voltage provided to the charging interface, and in some cases, impose a greater limit on the amount of voltage provided to the vehicle in response to sinking a greater amount of current through voltage limiting circuit 15 .

In one embodiment, the impedance change in the power limited state can be achieved by placing the relay 16 in the open state. As a result of the higher resistance of the relay 16 compared to the resistive element 14 , the current supplied from the power transformer 11 can pass through the resistive element 14 . Since the resistance of the resistive element 14 is larger than the small one, the supplied voltage is relatively lower, so that a larger current flows through the impedance 14.

In one embodiment, the charging device 2 includes a power source identification circuit 21 configured to respond to a connection electrical signal from the charging interface 1; a controller 22 connected to the power source identification circuit 21 is configured to receive a signal from the charging The data signal of the interface 1; the suppression circuit 23 connected to the controller 22 is configured to respond to the data signal part of the data signal representing the output impedance of the power transformer 11, and reduce the power supplied to the charging interface 1 voltage; or cut off the path with the power transformer 11.

In another embodiment, the charging identification method of the electric vehicle charging system includes: when the charging interface 1 of the electric vehicle is electrically connected to the charging device 2, detecting the first charging voltage of the power transformer 11 at the charging interface 1 ; detect the connection electrical signal to the charging device 2 through the vehicle-mounted mobile device 12 of the electric vehicle; detect the second charging voltage of the power transformer 11 at the charging interface of the electric vehicle; according to the first charging voltage and the second charging voltage Voltage measurement The AC voltage provided by the charging device 2 includes an additional voltage; and changing the output impedance of the power transformer 11 according to the measurement action, wherein the measurement action includes: between the first charging voltage and the second charging voltage When the ratio between the charging voltages is within a preset range, it is determined that the provided AC voltage includes the extra voltage.

In one embodiment, if it is determined that the charging pile 2 or the cable has a possible additional voltage, the charging interface 1 can perform additional operations. For example, the power consumed by the charging interface 1 from the power transformer 11 can be controlled based on the foregoing determination. For example, if it is determined that the charging post 2 contains additional voltage, the charging post 2 can transmit power to the power transformer 11 via the charging interface, which can be used to operate the internal circuit of the vehicle or charge other internal batteries of the vehicle. On the other hand, if it is determined that no additional voltage is included, the charging interface 1 may prevent power from being delivered to the power transformer 11 via the charging interface. In this way, the charging pile 2 can only use the charging interface that is determined to include the voltage limiting circuit 15 for charging or data operation, so that users can use it.

In one embodiment, the communication between the charging pile 2 and the charging interface 1 or the establishment of a power path between the power transformer 11 and the charging pile 2 through the charging interface, the charging pile 2 can send an identification of the charging interface on its controller 22 Code, if it does not receive a valid charging interface identification code in response, the charging post may try to send such a request again with a different identification code than before. On the other hand, if a valid charging interface identification code is received, the charging pile can transmit power to the power transformer 11 via the charging interface. In some cases, although the charging post 2 can start receiving power after receiving a valid charging interface identification code, the charging post 2 can continue or stop transmitting power after determining whether the charging interface 1 includes the voltage limiting circuit 15 .

In one embodiment, when it is determined that the provided AC voltage contains extra voltage, electrically connecting the power transformer 11 to the voltage limiting circuit 15 provided on the electric vehicle to eliminate the extra voltage.

In one embodiment, the removed excess voltage is split into an on-board energy storage device 19 . The energy storage device 19 may include a supercapacitor bank or other battery packs. The current shunted to this part is relatively small compared to the charging current for the electric vehicle battery, and this part of the current is mainly for the power supply of a small current in the vehicle.

In one embodiment, the charging interface 1 sends the charging device identification code to the charging pile 2 through the vehicle-mounted mobile device 12, such as the vehicle-mounted computing system. After the charging device identification code is received by the controller 22, the vehicle information is confirmed and then charged. and electricity metering.

The power transformer 11 can be used to provide working voltage to the vehicle, and the charging interface 1 can be used to receive data commands sent from the charging pile 2 . The voltage limiting circuit 15 can be used to change the impedance of the power path between the power transformer 11 and the charging pile device 2 in response to receiving a data command from the charging pile 2, and when a preset threshold amount of current is drawn through the voltage limiting circuit 15, The voltage from the charging post 2 to the power transformer 11 is reduced.

Claims (9)

1. A charging identification method for an electric vehicle charging system, characterized in that it comprises: when the charging interface of the electric vehicle is electrically connected to a charging device, detecting the first charging voltage of the power transformer at the charging interface; The on-board mobile device of the car detects the connection electrical signal to the charging device; detects the second charging voltage of the power transformer at the charging interface of the electric car; measures the charging device according to the first charging voltage and the second charging voltage providing an alternating voltage comprising an additional voltage; and varying an output impedance at said power transformer according to said determining action, wherein said determining action comprises: a ratio between said first charging voltage and a second charging voltage at a When within the preset range, it is determined that the supplied AC voltage includes the extra voltage. 2. The charging identification method of the electric vehicle charging system according to claim 1, further comprising: when it is determined that the provided AC voltage contains additional voltage, by electrically connecting the power transformer to the electric vehicle The voltage limiting circuit to eliminate this part of the extra voltage. 3. The charging identification method of the electric vehicle charging system according to claim 2, characterized in that: the part of the eliminated extra voltage is decomposed into an on-board energy storage device. 4 . The charging identification method of the electric vehicle charging system according to claim 1 , further comprising: cutting off the path of the power transformer when it is determined that the provided AC voltage contains extra voltage. 5. An electric vehicle charging circuit, comprising an electric vehicle charging interface and a charging station charging device matched therewith, characterized in that the charging interface of the electric vehicle includes: a circuit for converting the AC current of the charging device into a DC current A power transformer; a vehicle-mounted mobile device connected to the power transformer, used to detect the first charging voltage and the second charging voltage of the power transformer at the charging interface, and measure the first charging voltage and the second charging voltage according to the first charging voltage and the second charging voltage. The AC voltage provided by the charging device includes an additional voltage; and an impedance control circuit connected to the power transformer for changing the output impedance of the power transformer according to the measurement action. 6. The electric vehicle charging circuit according to claim 5, characterized in that it further comprises a voltage limiting circuit connected to the power transformer, configured to eliminate the AC voltage provided by the charging device when it is determined that the AC voltage contains extra voltage. some extra voltage. 7. The electric vehicle charging circuit according to claim 6, characterized in that it further comprises an overvoltage protection circuit connected to the power transformer, configured to shut off when the voltage measured at the power transformer is greater than a preset voltage. Drive on-board mobile devices or on-board batteries to obtain power from charging equipment. 8. The electric vehicle charging circuit according to claim 6, wherein the impedance control circuit is configured to work in a bypass state when it is not determined that the AC voltage provided by the charging device contains additional voltage, as the current path; and when it is determined that the AC voltage provided by the charging device includes an extra voltage, gradually increasing the resistance resistance value to suppress a part of the current path. 9. The electric vehicle charging circuit according to claim 5, wherein the charging device comprises: a power source identification circuit configured to respond to a connection electrical signal from the charging interface; a controller connected to the power source identification circuit , configured to receive a data signal from a charging interface; a suppression circuit connected to the controller, configured to: respond to a data signal portion of the data signal representing an output impedance at the power transformer, reduce charging the voltage provided by the interface; or cut off the access to the power transformer.