CN118983899A

CN118983899A - A circuit and method for flexibly configuring the number of lithium battery strings to be detected

Info

Publication number: CN118983899A
Application number: CN202411048050.7A
Authority: CN
Inventors: 张广栋
Original assignee: Suzhou Aisikong Technology Co ltd
Current assignee: Suzhou Aisikong Technology Co ltd
Priority date: 2024-08-01
Filing date: 2024-08-01
Publication date: 2024-11-19

Abstract

The invention relates to the technical field of battery protection, in particular to a circuit and a method capable of flexibly configuring the number of strings of detected lithium batteries. The circuit comprises: the integrated chip is used for protecting lithium batteries with different serial numbers; the dial switch comprises at least four positions, and each position is provided with two gears of ON and OFF; the four positions of the dial switch are respectively connected with the other ends of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, and are used for flexibly configuring 2 strings, 3 strings, 4 strings and 5 strings of batteries through different switch combinations. The circuit and the method for flexibly configuring the number of the detected lithium battery strings, provided by the invention, realize the aim that a single circuit board is suitable for configuring a plurality of batteries such as 2 strings, 3 strings, 4 strings and 5 strings by adopting a circuit structure and a configurable dial switch design.

Description

Circuit and method capable of flexibly configuring number of detected lithium battery strings

Technical Field

The invention relates to the technical field of battery protection, in particular to a circuit and a method capable of flexibly configuring the number of strings of detected lithium batteries.

Background

In the field of lithium battery protection, conventional battery protection circuit designs typically require a specific peripheral circuit configuration for different numbers of battery strings. The method designs different circuits according to the detected battery string number, adopts different material spare parts for processing and production in the production process, and increases the production cost and the stock pressure. Even if the method of commonly designing the circuit is adopted, different materials are still needed to be selected for mounting according to the serial number of the lithium batteries in the production process, and the problems of production and inventory management are not completely solved although the variety of the circuit board is reduced.

Disclosure of Invention

The invention provides a circuit and a method capable of flexibly configuring the number of detected lithium battery strings so as to solve the technical problem that a lithium battery protection circuit is not flexible enough.

The technical scheme for solving the technical problems is as follows:

in one aspect, a circuit for flexibly configuring the number of strings of lithium batteries to be detected is provided, the circuit comprising:

The integrated chip is used for protecting lithium batteries with different serial numbers;

the dial switch comprises at least four positions, and each position is provided with two gears of ON and OFF;

a first resistor R1, one end of which is connected to the SEL1 end of the integrated chip;

a second resistor R2, one end of which is connected to the SEL2 end of the integrated chip;

a third resistor R3, one end of which is connected to the SEL2 end of the integrated chip; and

One end of the fourth resistor R4 is connected to the SEL1 end and the SEL2 end of the integrated chip;

The four positions of the dial switch are respectively connected with the other ends of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, and are used for flexibly configuring 2 strings, 3 strings, 4 strings and 5 strings of batteries through different switch combinations.

Still further, the integrated chip further includes a VDD terminal and a VSS terminal;

When configured as a 2-string battery, the first and fourth positions of the dial switch are set OFF, and the second and third positions are set ON, so that the SEL2 signal is connected to VSS through R4, and the SEL1 signal is connected to VSS through R4.

Further, when configured as 3 strings of batteries, the dial switch has a first position ON, a second position OFF, a third position OFF, and a fourth position ON, so that the SEL2 signal is connected to VDD through R2 and the SEL1 signal is connected to VSS through R4.

Further, when the configuration is 4 strings of batteries, the dial switch is turned ON at the first position, turned OFF at the second position, turned ON at the third position, and turned OFF at the fourth position, so that the SEL2 signal is connected to VSS through R4 and the SEL1 signal is connected to VDD through R1.

Further, when configured as a 5-string battery, the dial switch has a first position ON, a second position OFF, a third position ON, and a fourth position OFF, such that the SEL2 signal is connected to VDD via R2 and the SEL1 signal is connected to VDD via R1.

Still further, the circuit further comprises:

The power management unit is used for supplying power to the integrated chip;

The temperature sensor is used for detecting the temperature of the lithium battery and transmitting a signal to the integrated chip;

the current detection circuit is used for detecting the charge and discharge current of the lithium battery and transmitting a signal to the integrated chip; and

And the voltage detection circuit is used for detecting the voltage of the lithium battery and transmitting a signal to the integrated chip.

Furthermore, the integrated chip comprises an overvoltage protection module, an undervoltage protection module, an over-temperature protection module, a low-temperature protection module, an overcurrent protection module and a short-circuit protection module.

In another aspect, there is provided a method of flexibly configuring the number of strings of detected lithium batteries, using the circuit for flexibly configuring the number of strings of detected lithium batteries as described above, the method comprising the steps of:

providing an integrated chip for protecting lithium batteries with different serial numbers;

Providing a dial switch, comprising at least four positions, wherein each position has two gears of ON and OFF;

the four positions of the dial switch are respectively connected with four resistors R1, R2, R3 and R4;

and by adjusting different position combinations of the dial switch, different connection modes are formed between R1, R2, R3 and R4 and the SEL1 end and the SEL2 end of the integrated chip, so that flexible configuration of batteries of 2 strings, 3 strings, 4 strings and 5 strings is realized.

Further, the process of providing an integrated chip for protecting lithium batteries with different serial numbers includes the following steps:

overvoltage protection is carried out on the lithium battery through the integrated chip;

the lithium battery is subjected to undervoltage protection through the integrated chip;

over-temperature protection is carried out on the lithium battery through the integrated chip;

the lithium battery is subjected to low-temperature protection through the integrated chip;

Overcurrent protection is carried out on the lithium battery through the integrated chip;

And carrying out short-circuit protection on the lithium battery through the integrated chip.

Still further, the method further comprises the steps of:

detecting the temperature of the lithium battery and transmitting a temperature signal to the integrated chip;

detecting charge and discharge current of the lithium battery and transmitting a current signal to the integrated chip;

and detecting the voltage of the lithium battery and transmitting a voltage signal to the integrated chip.

The beneficial effects of the invention are as follows:

The circuit and the method for flexibly configuring the number of the detected lithium battery strings, provided by the invention, realize the aim that a single circuit board is suitable for configuring a plurality of batteries such as 2 strings, 3 strings, 4 strings and 5 strings by adopting a circuit structure and a configurable dial switch design. The invention simplifies the production flow and reduces the material management cost and the stock pressure. Meanwhile, the flexibility of the product is obviously improved, the configuration of different battery strings can be completed only by simple dial switch adjustment, and a circuit board is not required to be replaced or elements are not required to be welded again. This not only accelerates the delivery and circulation speed of the product, but also improves the versatility and adaptability of the product. In addition, the design of the invention also ensures the reliability and safety of battery protection, can effectively realize various protection functions such as overvoltage, undervoltage, over temperature, low temperature, overcurrent, short circuit and the like, and ensures the safe use of the battery module.

The foregoing description is only an overview of the technical solution of the present invention, and in order to make the technical means of the present invention more clearly understood, it can be implemented according to the content of the specification, and the following detailed description of the preferred embodiments of the present invention will be given with reference to the accompanying drawings.

Drawings

FIG. 1 is a circuit diagram of a flexible configuration of the number of strings of detected lithium batteries according to an embodiment of the present invention;

fig. 2 is a flowchart of a method for flexibly configuring the number of strings of detected lithium batteries according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent.

As shown in fig. 1 and 2, the present invention provides the following preferred embodiments:

Example 1

In order to solve the problem that the traditional lithium battery protection circuit lacks flexibility, the embodiment further optimizes a circuit structure capable of flexibly configuring the number of the detected lithium battery strings. The circuit mainly comprises an integrated chip, a dial switch and four resistors.

Specifically, the integrated chip is used for realizing the protection function of lithium batteries with different serial numbers. In practical application, a plurality of lithium battery protection chips commonly used in the market, such as BQ77908 of TI company or LTC6803 series chips of Ana l og Dev i ces company, can be selected. The chips generally integrate overvoltage, undervoltage, overcurrent and other protection functions, and can meet the protection requirements of 2-5 strings of lithium batteries.

Further, the dial switch is an element for realizing flexible configuration. The present embodiment employs a dial switch having at least four positions, each having two gear positions, ON and OFF. This design allows for flexible configuration of 2, 3, 4, and 5 strings of batteries with different switch combinations. In selecting a particular model, it is contemplated to use a D IP type dial switch, such as the common CTS218 series or APEM NDS series, etc., which has good reliability and durability.

Further, the circuit also comprises four resistors R1, R2, R3 and R4. The resistors are used for changing the level states of the terminals of the integrated chips SEL1 and SEL2 through different combinations of the resistors and the dial switch, so that the configuration of batteries with different serial numbers is realized. One end of the resistor R1 is connected to the SEL1 end of the integrated chip, one ends of R2 and R3 are connected to the SEL2 end, and one end of R4 is connected to both the SEL1 and SEL2 ends. The connection mode enables the level of the SEL1 and the level of the SEL2 to be flexibly controlled by changing the state of the dial switch, and further configures the chip to work in different serial number modes.

It should be understood that the selection of the resistance values of resistors R1, R2, R3 and R4 is critical to the proper operation of the system. In general, the resistance values of these resistors should be determined according to the specific requirements of the selected integrated chip. For example, if a chip is used that requires a set mode of operation by pulling up or pulling down resistors, typical values for these resistors may be in the range of 10k omega to 100k omega. Specific resistance value selection also needs to consider the power consumption requirement and the anti-interference capability of the system.

It can be understood that the four positions of the dial switch are respectively connected with the other ends of R1, R2, R3 and R4, and the connection mode enables the connection of the resistors to a circuit to be flexibly controlled by changing the state of the switch. For example, when a certain switch position is in an ON state, the corresponding resistor is connected into the circuit; conversely, when the switch is in the OFF state, the corresponding resistor is disconnected from the circuit. This design allows the circuit configuration to be changed by a simple switching operation, thereby accommodating batteries of different serial numbers.

The benefit of this embodiment is that by employing such a flexible configurable circuit design, the versatility and adaptability of the product is greatly improved. The same circuit board can be adjusted by a simple dial switch to adapt to 2 strings, 3 strings, 4 strings or 5 strings of lithium batteries, so that the production flow is simplified, the stock pressure is reduced, and the flexibility of products is improved. In addition, the design is convenient for field debugging and maintenance, and technicians can quickly adjust the circuit configuration according to actual requirements without replacing or redesigning the circuit board.

Through the design of the embodiment, the problem that different circuit boards need to be manufactured for batteries with different serial numbers in the traditional circuit design is solved, and a simple, efficient and low-cost solution is provided. The design idea can be widely applied to various scenes needing to adapt to various battery configurations, such as the fields of portable electronic equipment, electric tools, small electric vehicles and the like, and brings remarkable economic benefits and technical advantages for the design and production of the products.

Example two

In order to solve the specific implementation problem when configuring the 2-string lithium battery, the embodiment further optimizes the port design of the integrated chip and the configuration mode of the dial switch.

The integrated chip in this embodiment includes VDD terminals and VSS terminals in addition to SEL1 and SEL2 terminals. The VDD terminal is typically connected to the positive power supply of the system, while the VSS terminal is connected to the ground or negative power supply of the system. The presence of these two ports provides a stable operating voltage and reference level for the chip.

Further, when the system needs to be configured to adapt to 2 strings of lithium batteries, the setting mode of the dial switch is as follows: the first position and the fourth position are placed in an OFF state, and the second position and the third position are placed in an ON state. This configuration allows the SEL2 signal to be connected to the VSS terminal through resistor R4, while the SEL1 signal is also connected to the VSS terminal through resistor R4.

It should be appreciated that this configuration actually pulls both the SEL1 and SEL2 signals low to ground. In many lithium battery protection chips, the level combination of the SEL1 and SEL2 terminals is used to indicate in which battery string mode the chip should operate. When both signals are low, it is typically indicated that the chip should operate in a 2-string battery protection mode.

It will be appreciated that resistor R4 in this configuration not only provides a pull-down path for the SEL1 and SEL2 signals, but also serves as a current limiting protection. R4 with proper resistance is selected to ensure that the signal can be reliably pulled down and the output port of the chip cannot bear excessive current. Typically, the pull-down resistance in such applications may range from 10k omega to 100k omega depending on the characteristics of the integrated chip used.

Further, an important feature of this arrangement is its simplicity and reliability. By using a single resistor R4 to control both the SEL1 and SEL2 signals, the number of components in the circuit is reduced, improving the reliability of the system, and reducing the cost. In addition, the design has good anti-interference capability, because both signals are firmly pulled to the ground level and are not easily affected by external electromagnetic interference.

The embodiment has the advantages that the quick and reliable configuration of the protection mode of the 2-string lithium battery is realized through simple dial switch operation and ingenious circuit design. The design not only simplifies the operation flow, but also improves the adaptability and flexibility of the system. Technicians can quickly adjust the system configuration in the field according to actual needs without having to replace or redesign the circuit board. In addition, the standardized design method also greatly simplifies the production and inventory management flow, and is beneficial to improving the production efficiency and reducing the cost.

Example III

In order to solve the specific requirements when configuring 3 strings of lithium batteries, the present embodiment further optimizes the configuration mode and signal connection strategy of the dial switch.

In this embodiment, when the system needs to be configured to accommodate 3 strings of lithium batteries, the setting manner of the dial switch is as follows: the first position is placed in an ON state, the second position is placed in an OFF state, the third position is placed in an OFF state, and the fourth position is placed in an ON state. This unique configuration allows the SEL2 signal to be connected to VDD terminal through resistor R2, while the SEL1 signal is connected to VSS terminal through resistor R4.

It is to be appreciated that this configuration actually pulls the SEL2 signal high to VDD level while simultaneously pulling the SEL1 signal low to VSS level. In many lithium battery protection chips, the level combination of the SEL1 and SEL2 terminals is used to indicate in which battery string mode the chip should operate. When SEL2 is high and SEL1 is low, it is typically indicated that the chip should operate in 3-string battery protection mode.

It will be appreciated that resistors R2 and R4 play a critical role in this configuration. R2 is used as a pull-up resistor to pull up the SEL2 signal to the VDD level; and R4 acts as a pull-down resistor pulling the SEL1 signal low to VSS level. R2 and R4 with proper resistance values are selected to ensure that signals can be reliably pulled high or low, and that the input/output ports of the chip cannot bear excessive current. Typically, the pull-up and pull-down resistance values in such applications may range from 10k omega to 100k omega depending on the characteristics of the integrated chip used and the power consumption requirements of the system.

Further, this configuration can achieve more accurate level control by controlling SEL2 and SEL1 signals respectively using different resistors (R2 and R4). Not only improves the reliability of the system, but also enhances the adaptability to different chip models. For example, some chips require more stringent input level requirements, which can be easily met by adjusting the resistance values of R2 and R4.

The design of this embodiment also allows for the tamper resistance of the circuit. Since the SEL2 and SEL1 signals are pulled to different levels (VDD and VSS), respectively, this configuration has a stronger immunity to interference than if both signals were pulled to the same level. This is because it is often difficult for external noise to affect both high and low level signals, thereby improving the stability of the system in complex electromagnetic environments.

It should be noted that in practice, the voltage selection at VDD and VSS terminals should generally be matched to the operating voltage of the system, and take into account the normal operating voltage range of 3 strings of lithium batteries. For example, if a 3.3V logic level chip is used, VDD requires a voltage regulator circuit to provide a stable 3.3V voltage, ensuring proper operation of the chip even in the event of battery voltage fluctuations.

The embodiment has the advantage that the 3-string lithium battery protection mode is quickly, reliably and accurately configured through the carefully designed dial switch configuration and the resistor network. The design not only simplifies the operation flow, but also improves the adaptability and the reliability of the system. Technicians can quickly adjust the system configuration in the field according to actual needs without having to replace or redesign the circuit board. In addition, the standardized design method also greatly simplifies the production and test flow, and is beneficial to improving the quality and consistency of products.

By the design of the embodiment, the problem that a special circuit is required to be designed for 3 strings of batteries in the traditional method is solved, and a flexible, efficient and low-cost solution is provided. The design idea can be widely applied to various scenes needing to adapt to various battery configurations, such as the fields of portable medical equipment, industrial control equipment, intelligent home systems and the like, and brings remarkable technical advantages and economic benefits for the design and production of the products.

Example IV

Similarly, in order to solve the specific requirements when configuring 4 strings of lithium batteries, the present embodiment further optimizes the configuration mode and the signal connection strategy of the dial switch, so as to implement a more efficient and flexible battery protection system.

In this embodiment, when the system needs to be configured to accommodate the 4-string lithium battery, the setting manner of the dial switch is as follows: the first position is placed in an OFF state, the second position is placed in an ON state, the third position is placed in an ON state, and the fourth position is placed in an OFF state. This unique configuration allows the SEL2 signal to be connected to the VSS terminal through resistor R4, while the SEL1 signal is connected to the VDD terminal through resistor R1.

It is to be appreciated that this configuration actually pulls the SEL2 signal low to VSS level while simultaneously pulling the SEL1 signal high to VDD level. In many lithium battery protection chips, the level combination of the SEL1 and SEL2 terminals is used to indicate in which battery string mode the chip should operate. When SEL2 is low and SEL1 is high, it is typically indicated that the chip should operate in a 4-string battery protection mode.

It will be appreciated that resistors R1 and R4 play a critical role in this configuration. R1 is used as a pull-up resistor to pull up the SEL1 signal to the VDD level; and R4 acts as a pull-down resistor pulling the SEL2 signal low to VSS level. R1 and R4 with proper resistance values are selected to ensure that signals can be reliably pulled high or low, and that the input/output ports of the chip cannot bear excessive current. Typically, the pull-up and pull-down resistance values in such applications may range from 10k omega to 100k omega depending on the characteristics of the integrated chip used and the power consumption requirements of the system.

Example five

In order to solve the special requirements of 5 strings of lithium batteries in configuration, the embodiment further optimizes the setting strategy and signal path selection of the dial switch so as to realize accurate protection and monitoring under higher voltage.

In this embodiment, when the system needs to adapt to 5 strings of lithium batteries, the configuration of the dial switch is as follows: the first position is placed in an ON state, the second position is placed in an OFF state, the third position is placed in an ON state, and the fourth position is placed in an OFF state. This unique combination allows the SEL2 signal to be connected to the VDD terminal through the R2 resistor, while the SEL1 signal is also connected to the VDD terminal through the R1 resistor.

It should be appreciated that this configuration is actually pulling the SEL2 and SEL1 signals to VDD levels simultaneously. In advanced lithium battery protection chips, the simultaneous high level of the SEL1 and SEL2 terminals generally indicates that the chip should operate in a 5-string battery protection mode. In this mode, the voltage detection and protection thresholds inside the chip are automatically adjusted to accommodate the operating voltage range of the 5-string lithium battery.

It will be appreciated that the R1 and R2 resistors in this configuration act as pull-up resistors, reliably pulling the SEL1 and SEL2 signals up to the VDD level. The appropriate R1 and R2 resistances are chosen to ensure that the signal is pulled high steadily, but also to account for the higher voltages and currents that a 5-string battery system can face. In such high voltage applications, the resistance values of R1 and R2 may be relatively large, e.g., in the range of 50kΩ to 200kΩ, to limit the current through these resistors while ensuring signal stability.

Further, a significant feature of this arrangement is its adaptability to high pressure systems. The rated voltage of the 5-string lithium battery can reach 18.5V to 21V, so the VDD power supply can need a specially designed step-down circuit to provide stable logic level voltage (such as 3.3V or 5V) to the protection chip and the control circuit. The step-down circuit not only can process higher input voltage, but also has good transient response capability so as to cope with voltage fluctuation in the process of charging and discharging the battery.

The design of this embodiment also allows for the safety and reliability of the high voltage system. Since the total voltage of a 5-string lithium battery system is high, the withstand voltage range of many common electronic components can be exceeded, and therefore additional protection measures are required in the design. For example, transient voltage suppression diodes (TVS) may be added on SEL1 and SEL2 signal lines to prevent high voltage spikes from damaging the chip. At the same time, special care is required for the layout and routing of the circuit board to ensure adequate isolation and safety distance between the high voltage section and the low voltage control circuit.

It should be noted that the complexity of a Battery Management System (BMS) may be significantly increased in a 5-string battery configuration. In addition to basic overcharge and overdischarge protection, a finer cell balancing function is also required. This requires the addition of special equalization circuitry or chips in addition to the main protection chip to ensure consistent performance and life of the 5 cells during long term use.

The embodiment has the advantage that the rapid, reliable and accurate configuration of the protection mode of the 5-string lithium battery is realized through the carefully designed dial switch configuration and the resistor network. The design not only simplifies the operation flow of the high-voltage system, but also improves the adaptability and the safety of the system. Technicians can quickly adjust the system configuration in the field according to actual needs without having to replace or redesign the circuit board. In addition, the standardized design method greatly simplifies the production and test flow, and is beneficial to improving the quality and consistency of products, especially when processing high-pressure systems.

Example six

In order to solve the problems of comprehensive monitoring and safety management in a lithium battery protection system, the embodiment further optimizes the circuit structure, refines the design of each functional module, and realizes the comprehensive monitoring and protection of the working state of the lithium battery.

In this embodiment, the core circuit capable of flexibly configuring the number of battery strings further includes key components such as a power management unit, a temperature sensor, a current detection circuit, and a voltage detection circuit. These components work in concert with the integrated chip to form a complete battery management system.

It should be understood that the power management unit not only provides stable operating voltage for the integrated chip, but also takes charge of power sequence control of the whole system. In practical applications, a high-efficiency, low-noise switching regulator such as TPS62xxx series of TI or ADP2xxx series of Ana l og Devi ces may be selected as the core of the power management unit. The chip generally has a wide input voltage range, high conversion efficiency and good transient response characteristic, and can well adapt to voltage change of the lithium battery in the charge and discharge processes.

Further, the temperature sensor is selected and designed by considering the sensitivity of the lithium battery to temperature change, and high-precision digital temperature sensors such as LM35 series of T I or DS18B20 of Maxim can be adopted. These sensors have good linearity and fast response time, and are capable of accurately capturing small changes in battery temperature. At the same time, the arrangement position of the temperature sensor is also critical, and the temperature sensor should be usually close to the battery cell as much as possible to obtain the most accurate temperature data.

It will be appreciated that high accuracy current detection is not only necessary for over-current protection, but also to implement the basis for battery state estimation and life prediction. In practical designs, a scheme using a shunt resistor in combination with a high-precision operational amplifier, such as a current detection application specific integrated circuit employing an I NA226 of Texas I nstruments, may be considered. The chip is usually integrated with a high-precision ADC and a digital interface, can be directly communicated with a main control chip, and simplifies the system design.

Further, the voltage detection circuit is the last line of defense for ensuring the safe use of the battery. For a multi-string battery system, it is necessary to monitor the voltage of each single battery and the total voltage of the entire battery pack at the same time. This can be achieved by using a special battery monitoring IC, such as the LTC6804 series of Ana l og Devi ces or the bq76940 series of TI. The chips are generally integrated with multiple paths of high-precision ADCs, can monitor voltages of up to 12 battery cells at the same time, have built-in equalization functions, and are beneficial to prolonging the service life of the battery pack.

Further, the data interaction and control logic between these functional modules also needs to be carefully designed. For example, when the temperature sensor detects an abnormality in the battery temperature, it is necessary to rapidly control the power MOSFET in the current detection circuit by the integrated chip to shut off the charge-discharge circuit. Meanwhile, the data of the voltage detection circuit also needs to be fed back to the integrated chip in real time so as to respond to the overcharge or overdischarge state in time. Such complex interaction logic typically needs to be implemented within an integrated chip or coordinated by an external microcontroller.

The embodiment has the advantage that by integrating the functional modules of power management, temperature monitoring, current detection, voltage detection and the like, a comprehensive, accurate and quick-response battery management system is constructed. The design can not only effectively prevent potential safety hazards such as battery overcharge, overdischarge, overcurrent and overtemperature, but also provide a reliable data base for battery state estimation and life prediction through accurate data acquisition.

Example seven

In order to solve various safety risks faced by the lithium battery in the use process, the embodiment further optimizes the internal structure of the integrated chip, refines the design of various protection function modules, and realizes all-round and multi-layer safety protection of the lithium battery.

The integrated chip in this embodiment integrates an overvoltage protection module, an undervoltage protection module, an over-temperature protection module, a low-temperature protection module, an over-current protection module, and a short-circuit protection module. These modules work cooperatively to form a comprehensive battery protection system.

It is understood that the overvoltage protection module can rapidly cut off the charging loop when the voltage exceeds a preset threshold value by accurately monitoring the voltage of the battery in the charging process of the lithium battery, so as to prevent potential safety hazards caused by overcharging of the battery. In practical design, the overvoltage protection module can adopt a high-precision comparator circuit to realize millivolt-level voltage detection precision in cooperation with an external sampling resistor network. Meanwhile, in order to avoid false triggering, a certain hysteresis voltage and delay time are usually set.

Further, the under-voltage protection module is mainly aimed at the discharging process of the battery. It is understood that overdischarge may seriously impair the performance and life of a lithium battery. The under-voltage protection module cuts off a discharge loop when the voltage drops below a safety threshold by continuously monitoring the battery voltage, and protects the battery from overdischarging. This module may use a circuit configuration similar to overvoltage protection, but the threshold settings and response times may be different to accommodate different discharge characteristics.

Further, the over-temperature protection module and the low-temperature protection module jointly ensure that the lithium battery works in a safe temperature range. The two modules can use a precise analog front-end circuit to realize rapid and accurate temperature detection by matching with an external temperature sensor. When the temperature exceeds the preset range, the modules trigger corresponding protection mechanisms, such as cutting off the charge-discharge loop or reducing the charge-discharge current.

It is understood that the overcurrent protection module and the short-circuit protection module play an important role in preventing the battery from being damaged by a large current. Over-current protection is typically achieved using a current sense resistor in combination with a high speed comparator, while short circuit protection may use a faster sense circuit, such as a hall sensor or dedicated current sense I C. These modules not only require fast response capability, but also have an automatic recovery function to cope with transient high current or short circuit conditions.

Further, a cooperative mechanism between these protection modules is explained. For example, upon detecting an over-current condition, the chip may first attempt to limit current, and if the condition persists, trigger a complete disconnect; and when a short circuit is detected, the circuit needs to be immediately cut off. This multi-level protection strategy requires complex logic control circuitry to support, which can be implemented using a state machine or microcontroller core.

The design of this embodiment also allows for flexible adaptation for different battery string configurations. Through the setting of an external dial switch, the integrated chip can dynamically adjust the threshold value and response characteristic of each protection module so as to adapt to 2 to 5 strings of lithium battery packs with different configurations. This flexibility is not only manifested in voltage-dependent protection, but also in parameter adjustment of temperature and current protection.

It should be noted that to ensure security in extreme cases, these protection modules may also be equipped with redundant designs or hardware locking mechanisms. For example, overvoltage protection can be achieved by both software comparison and hardware comparator to prevent single point failure; and after some key protection triggers, external intervention may be required to recover to prevent repeated entry into dangerous states.

The embodiment has the advantage that the lithium battery is comprehensively, accurately and rapidly protected by integrating various protection function modules. The design not only greatly improves the use safety of the battery, but also enables the same chip to be suitable for various battery configurations through a flexible configuration mode, and greatly improves the universality and the production efficiency of products. Through the design of this embodiment, solved the problem that traditional battery protection circuit function is single, adaptability is poor, provided a comprehensive, intelligent, configurable battery protection solution.

Example eight

In order to solve the problem that the traditional lithium battery protection circuit lacks flexibility and universality, the embodiment further optimizes the battery string number configuration method, and refines specific steps of the configuration process so as to realize quick, accurate and flexible configuration of lithium batteries with different string numbers.

As shown in fig. 2, the method for flexibly configuring the number of the detected lithium battery strings comprises the following steps:

s100, providing an integrated chip for protecting lithium batteries with different serial numbers.

S200, providing a dial switch, wherein the dial switch comprises at least four positions, and each position has two gears of ON and OFF.

And S300, respectively connecting the four positions of the dial switch with four resistors R1, R2, R3 and R4.

S400, different connection modes are formed between R1, R2, R3 and R4 and the SEL1 end and the SEL2 end of the integrated chip by adjusting different position combinations of the dial switch, so that flexible configuration of batteries of 2 strings, 3 strings, 4 strings and 5 strings is realized.

In this embodiment, a highly integrated protection chip is provided, which has the capability of adapting to a configuration of 2 to 5 strings of lithium batteries. It should be appreciated that such integrated chips are typically fabricated using advanced CMOS processes, with complex analog circuitry and digital logic integrated therein, and capable of dynamically adjusting their internal parameters and protection thresholds based on external configuration signals. For example, a chip such as LTC6811 of Texas I nstruments's BQ77915 or Ana l og Devi ces may be selected as the core protection unit. The chip not only has high-precision voltage and current detection capability, but also is internally provided with an advanced equalization algorithm and a communication interface, thereby providing a hardware foundation for flexible configuration and intelligent management of the system.

Further, this embodiment introduces a four-bit dip switch. It will be appreciated that the choice of dial switch has an important impact on the reliability and ease of use of the system. In practical applications, high reliability dip switches such as the TDA04 series of C & K or the SSCL series of ALPS may be considered. These switches generally have good mechanical life (typically up to 10,000 or more switching operations) and electrical performance and are capable of stable operation in harsh environments. Meanwhile, in order to improve the intuitiveness of operation and prevent misoperation, clear silk-screen marks can be added near the dial switch, and even the design with a dust cover is considered.

It will be appreciated that. The dial switches at four positions are respectively connected with four precision resistors R1, R2, R3 and R4. The choice of these resistances is critical, and usually thin film resistances or metal film resistances with a precision of less than 1% and a low temperature coefficient should be used. For example, MMA series or Panason ic ERA series precision resistors of Vi shay can be selected. The selection of the resistance value needs to comprehensively consider the factors such as the working voltage range of the system, the impedance characteristic of the input end of the chip, the anti-interference capability and the like. Typically, the resistance of these resistors may be between a few kiloohms and a few tens of kiloohms to ensure signal integrity while achieving min imi zer power consumption.

Further, the combination of different positions of the dial switch and the connection mode of the resistor network determine the configuration flexibility of the system. It should be understood that by adjusting different positions of the dial switch, various connection combinations of R1, R2, R3, R4 and SEL1 and SEL2 terminals of the integrated chip may be realized. This design allows the user to change the system configuration by simple switching operations without changing the hardware circuitry. For example, when configured as a 2-string battery, it may be desirable to place the first and second positions of the dial switch in the ON position, while the other positions remain OFF; when configured as a 5 string battery, it may be desirable to put all four positions ON.

It will be appreciated that the SEL1 and SEL2 ports may be connected to an analog multiplexer or ADC inside the integrated chip, with the current configuration state being determined by detecting the voltage values of the two ports. Multiple voltage thresholds may be provided inside the chip to distinguish between different configuration combinations. For example, the voltage of the SEL1 port may be divided into four sections, corresponding to configurations of 2 to 5 strings, respectively, while the SEL2 port may be used to further subdivide or verify the configuration.

Further, in order to improve the reliability and anti-interference capability of the system, filter capacitors and protection diodes may be added to the SEL1 and SEL2 ports. The filter capacitor is helpful to suppress high-frequency interference, and the protection diode can prevent the chip from being damaged by transient high voltage such as electrostatic discharge (ESD). The choice of these additional components also requires caution, for example, GRM series multilayer ceramic capacitors of Murata and VESD series ESD protection diodes of Vi shay can be used.

Further, the design of the present embodiment also takes into account the reliability and safety of the configuration process. For example, a configuration locking mechanism may be incorporated into the system that requires the user to perform a specific confirmation operation (e.g., pressing a reset button or sending a specific instruction) after changing the dial switch settings to prevent unexpected configuration changes. Meanwhile, the system can perform self-checking when being started, verify whether the current configuration is valid, and enter a safety mode and send out a warning if invalid configuration is detected.

It should be noted that although the present embodiment mainly discusses the configuration of 2 to 5 strings of batteries, this design concept can be further extended. By increasing the number of digits of the dip switch or employing a more complex coding scheme, a more serial number configuration can theoretically be supported. For example, up to 64 different configuration combinations can be implemented using a 6-bit dip switch, providing feasibility for future product upgrades and extensions.

The benefit of this embodiment is that a high degree of flexibility and configurability of the battery protection system is achieved by a simple and smart hardware design. The design not only greatly improves the universality of products and reduces the number of SKUs (stock keeping units) required by different battery string number configurations, but also brings remarkable convenience for production, stock management and after-sale service.

The method solves the problems of complex configuration and poor adaptability of the traditional battery protection circuit, and provides a simple, visual and reliable battery string number configuration scheme. The thought of flexible configuration can be widely applied to the fields of various portable electronic devices, electric tools, new energy storage systems and the like, and provides a more universal and easily managed power protection solution for the products. Meanwhile, due to the adoption of a standardized configuration interface, the method reserves an expansion space for new battery technology and more complex battery management requirements which can occur in the future, and ensures long-term competitiveness and sustainable development of products.

Example nine

In order to solve various safety risks faced by the lithium battery in the use process, the embodiment further optimizes and refines the protection function of the integrated chip, and realizes an omnibearing and multi-layer safety protection strategy for the lithium battery.

In this embodiment, the integrated chip is designed as a multifunctional protection center, and integrates multiple protection mechanisms such as overvoltage protection, undervoltage protection, over-temperature protection, low-temperature protection, overcurrent protection, and short-circuit protection. It will be appreciated that such a highly integrated design not only improves the reliability of the system, but also greatly reduces the complexity of the peripheral circuitry, which is beneficial to improving product consistency and production efficiency.

Further, the overvoltage protection function ensures safe charging of the lithium battery. It can be understood that the high-precision comparator circuit can be adopted in the integrated chip, and the voltage detection precision of millivolt level can be realized by matching with an external precision resistor voltage division network. For example, a super-high speed comparator such as a TLV3201 of Texas I nstruments can be used, the response time of the super-high speed comparator can reach nanosecond level, and the protection can be triggered quickly when the voltage suddenly changes. The threshold value of the overvoltage protection is usually set taking into account the chemical characteristics and safety margin of the battery, for example, for a lithium ion battery with a nominal voltage of 3.7V, the cell overvoltage protection threshold value can be set between 4.25V and 4.35V.

Further, the undervoltage protection function is mainly aimed at the discharging process. It should be noted that overdischarge may seriously affect the life and performance of a lithium battery. The integrated chip may use a circuit structure similar to overvoltage protection, but the threshold settings and response times may be different. For example, for a 3.7V lithium battery, the under-voltage protection threshold may be set between 2.5V and 3.0V. In order to avoid false triggering, the chip can also set a certain hysteresis voltage and delay time, which can be realized by an internal digital logic circuit.

Further, the over-temperature protection and the low-temperature protection form a temperature safety protection mechanism together. It can be understood that the integrated chip can use a high-precision analog front-end circuit, such as an ADS1115 of Texas I nstruments and other 16-bit ADCs, and can be matched with an external NTC thermistor to realize the temperature detection precision of +/-1 ℃. The over-temperature protection threshold is typically set between 50 ℃ and 60 ℃, while the low-temperature protection threshold may be between 0 ℃ and 10 ℃, depending on the chemical characteristics and application scenario of the battery.

Further, overcurrent protection and short-circuit protection are important mechanisms for preventing the battery from being damaged by a large current. Over-current protection is typically achieved using a current sense resistor in combination with a high speed comparator, while short circuit protection may use a faster sense circuit, such as a hall sensor or a dedicated current sense IC. For example, it is contemplated to use Al l egro ACS712 series hall effect current sensors with response times up to 5 mus that can effectively detect instantaneous large currents. The threshold value of the overcurrent protection needs to be set taking into account the maximum safe discharge current of the battery, typically 1C to 3C of rated capacity, while the short-circuit protection needs to respond in a shorter time, and the threshold value can be set to 2 to 5 times that of the overcurrent protection.

It should be understood that these protection functions do not operate in isolation, but rather form a coordinated protection network. For example, upon detecting an over-current condition, the chip may first attempt to limit current, and if the condition persists, trigger a complete disconnect; and when a short circuit is detected, the circuit needs to be immediately cut off. This multi-level protection strategy requires complex logic control circuitry to support, which can be implemented using a state machine or microcontroller core. For example, it is possible to consider the use of a low-power microcontroller of the ARM Cortex-M0+ series, such as the STM32L0 series, as the control core of the chip, implementing complex protection logic and communication functions.

The design of this embodiment also allows for flexible adaptation for different battery string configurations. Through the setting of an external dial switch, the integrated chip can dynamically adjust the threshold value and response characteristic of each protection module so as to adapt to 2 to 5 strings of lithium battery packs with different configurations. This flexibility is not only manifested in voltage-dependent protection, but also in parameter adjustment of temperature and current protection. For example, for a 5 string battery configuration, the overvoltage protection threshold may be set at 21.75V (4.35 v×5), while a 2 string configuration may be set at 8.7V (4.35 v×2).

To further improve the reliability of the system, the present embodiment may also introduce redundancy design and self-diagnostic functionality. For example, critical protection functions may be implemented by both analog circuitry and digital algorithms to prevent single point failure; the system can also perform self-checking regularly to verify the functional integrity of each protection module. Furthermore, to cope with extreme cases, some critical protection triggers require external intervention to recover, which can be achieved by setting a hardware locking mechanism.

The embodiment has the advantage that the lithium battery is comprehensively, accurately and quickly protected by integrating various protection functions. The design not only greatly improves the use safety of the battery, but also enables the same chip to be suitable for various battery configurations through a flexible configuration mode, and greatly improves the universality and the production efficiency of products.

Examples ten

In order to solve the problems of incomplete information acquisition, insufficient precision, poor real-time performance and the like in the traditional lithium battery management system, the embodiment further optimizes and refines a battery state monitoring method, and realizes high-precision and real-time monitoring of the temperature, current and voltage of the lithium battery.

In this embodiment, the battery state monitoring system is designed as a multi-dimensional and high-precision data acquisition network, and integrates multiple sensing mechanisms such as temperature monitoring, current monitoring and voltage sampling. It should be appreciated that such an all-round monitoring not only provides accurate data support for battery protection functions, but also lays a solid foundation for advanced functions of the battery management system (e.g., residual capacity estimation, health status estimation, etc.).

Further, temperature detection ensures safe operation of the lithium battery. It will be appreciated that the present system may employ a high precision NTC (negative temperature coefficient) thermistor as the temperature sensor. For example, a Murata NCP18WF104 series NTC thermistor can be selected, which can reach a tolerance of + -1% at 25 ℃ and a temperature coefficient of 4300K, and can provide high-precision temperature monitoring in the range of-40 ℃ to 125 ℃. In order to further improve the detection precision, the system can adopt Wheatstone bridge circuit configuration, and combines a high-resolution ADC (such as 24-bit AD 7124-8) to realize the temperature resolution of 0.1 ℃. The temperature signal is transmitted to the integrated chip through the special analog input channel after being conditioned, and the digital signal processing unit in the chip can carry out filtering and calibration on the temperature data so as to eliminate the influence of environmental noise and sensor errors.

Further, current monitoring is another important indicator for evaluating the operating state and safety of a battery. This embodiment may employ a high precision hall effect current sensor such as the ACS770 series of Al l egro. Such sensors have high linearity (typically 0.1%) and low temperature drift (40 ppm/°c) and are capable of accurately measuring bi-directional currents from-100A to +100A. In order to adapt to different battery configurations and application scenes, the system is provided with a signal conditioning circuit with switchable gain, and the measuring range is dynamically adjusted through control signals of the integrated chip. The current signal may be conditioned for digitization by a 16-bit or higher resolution ADC (e.g., T I ADS 8860) and then transmitted to the integrated chip via the SPI or I2C interface. The complex current integration algorithm can be realized in the chip and is used for accurately calculating the charge and discharge capacity of the battery.

Further, voltage detection is a fundamental function of battery management systems. The embodiment can adopt a high-impedance and high-precision resistor voltage division network and combines a precision operational amplifier (such as OPA188 of T I) to construct a multichannel voltage sampling circuit. In order to adapt to 2 to 5 strings of lithium battery packs with different configurations, the system is designed with a Programmable Gain Amplifier (PGA), and the gain is dynamically adjusted by the control signal of the integrated chip so as to ensure that the optimal measurement accuracy can be obtained under different battery string numbers. The voltage signal can be digitized with high precision by 24 bits de lta-s igma ADC (such as MAX11214 of Max im) to realize the resolution of microvolts. It should be noted that to ensure accuracy of long-term measurements, the system also includes a self-calibration mechanism that periodically calibrates the measurement channels using an internal reference voltage source.

Further, the three signal acquisitions are not independent, but rather synchronous sampling is achieved through well-designed timing control. It will be appreciated that the integrated chip may employ a high performance Digital Signal Processor (DSP) core, such as the C2000 series T I, to enable real-time acquisition and processing of multiple signals. Through synchronous sampling, the system can accurately capture the behavior characteristics of the battery under the transient working condition, and a reliable data base is provided for advanced algorithms (such as impedance spectrum analysis, state estimation and the like).

In order to improve the anti-interference capability and reliability of the system, the present embodiment may also employ a plurality of advanced techniques. For example, differential signaling techniques may be used in the signaling path in combination with common mode chokes and TVS diodes to effectively suppress electromagnetic interference and transient overvoltage. In the software layer, an anomaly detection algorithm can be implemented, and potential erroneous data is identified and filtered by analyzing the time-domain and frequency-domain characteristics of the signal.

The design of this embodiment also allows for flexibility and scalability of the system. Through modularized hardware design and configurable software architecture, the system can be easily adapted to lithium batteries of different types and specifications. For example, the temperature detection module may support parallel connection of up to 16 temperature sensors to meet the monitoring needs of a large battery pack; the current detection module may be reserved with an external shunt interface to support the measurement requirements of higher accuracy or greater range.

The embodiment has the advantage of providing comprehensive and accurate data support for the battery management system through high-precision, multidimensional and real-time battery state monitoring. The design not only greatly improves the reliability and the accuracy of battery protection, but also lays a solid foundation for realizing advanced battery management functions.

Claims

1. A circuit for flexibly configuring the number of strings of lithium batteries to be detected, said circuit comprising:

2. The circuit for flexibly configuring the number of strings of lithium batteries to be detected according to claim 1, wherein said integrated chip further comprises a VDD terminal and a VSS terminal;

3. The circuit of claim 2, wherein when configured as a 3-string battery, the dial switch is turned ON in a first position, OFF in a second position, OFF in a third position, and ON in a fourth position, such that the SEL2 signal is connected to VDD through R2 and the SEL1 signal is connected to VSS through R4.

4. The circuit of claim 2, wherein when configured as a 4-string battery, the dial switch has a first position ON, a second position ON, a third position ON, and a fourth position OFF, such that the SEL2 signal is connected to VSS via R4 and the SEL1 signal is connected to VDD via R1.

5. The circuit of claim 2, wherein when configured as a 5-string battery, the dial switch is turned ON in a first position, turned OFF in a second position, turned ON in a third position, and turned OFF in a fourth position, such that the SEL2 signal is coupled to VDD via R2 and the SEL1 signal is coupled to VDD via R1.

6. The circuit for flexibly configuring the number of detected lithium battery strings according to claim 1, characterized in that the circuit further comprises:

The power management unit is used for supplying power to the integrated chip;

7. The circuit of claim 6, wherein the integrated chip comprises an overvoltage protection module, an undervoltage protection module, an overtemperature protection module, a low temperature protection module, an overcurrent protection module, and a short circuit protection module.

8. A method of flexibly configuring the number of strings of detected lithium batteries using the circuit of any one of claims 1 to 7, the method comprising the steps of:

And R1, R2, R3 and R4 form different connection modes with the SEL1 end and the SEL2 end of the integrated chip by adjusting different position combinations of the dial switch.

9. The method for flexibly configuring the number of strings of detected lithium batteries according to claim 8, wherein the process for providing an integrated chip for protecting lithium batteries with different numbers of strings comprises the steps of:

10. The method of flexibly configuring the number of detected lithium battery strings according to claim 9, further comprising the steps of: