Battery management system

Abstract

A battery management system, comprising a battery module (1), a power supply test unit (2), a temperature measurement unit (3), a controller (4), a logic processing unit (5), a latch unit (6), a switch driving unit (7) and a charge / discharge execution unit (8); the controller (4) transmits a switch control instruction to the latch unit (6) and transmits a first communication signal to the logic processing unit (5); the logic processing unit (5) acquires power supply information of the controller (4) by means of the power supply test unit (2), acquires temperature information of the controller (4) by means of the temperature measurement unit (3), and transmits a first enable signal or a second enable signal to the latch unit (6) on the basis of the first communication signal, the power supply information and the temperature information; the first enable signal is used for controlling the latch unit (6) to receive the switch control instruction and transmit same to the switch driving unit (7), so as to drive on and off of the charge / discharge execution unit (8); the second enable signal is used for controlling the latch unit (6) to stop receiving the switch control instruction, so as to maintain the switch driving unit (7) in a state of driving on and off of the charge / discharge execution unit (8). In the present application, the charge / discharge control of the system does not undergo abrupt changes when the controller (4) fails.

Description

A battery management system TECHNICAL FIELD

[0001] The present application relates to the technical field of battery management, in particular to a battery management system. BACKGROUND

[0002] Lithium ion batteries are widely used in the energy storage field due to their high energy density, large charge-discharge rate and long cycle life, such as being applied in new energy electric vehicles as energy storage devices of new energy electric vehicles. However, lithium ion batteries have poor safety, and therefore, in order to prevent dangerous overcharging or overdischarging of the battery, the voltage, temperature and other information of the battery need to be monitored in real time, and the operation of the battery system needs to be effectively managed, which requires the use of a battery management system (BMS, BATTERY MANAGEMENT SYSTEM).

[0003] The battery management system mainly controls the on-off of MOS tubes or relays through a controller to control the charge-discharge circuit of the battery. However, due to the possibility of controller failure or program runaway, once these faults occur, the commands issued by the controller will be out of control, and the MOS tubes or relays will lose control instantaneously, which may pose a safety risk. For example, during the operation of a vehicle, when the controller is operating normally, the MOS tubes or relays are in an on state, and when the controller fails, the commands issued by the controller cause the MOS tubes or relays to suddenly turn off, at which time the vehicle will instantaneously lose power and a dangerous event will occur.

[0004] In order to deal with this situation, the prior art usually adopts a protection scheme of adding a controller to improve the safety of the system through two controllers. However, this method is more expensive and more complex to design, and the protection effect of other protection schemes is also not ideal. Therefore, in the battery management system, there is an urgent need to design a scheme that has good protection effect, simple design and low cost to solve the problem of sudden change in the charge-discharge control of the battery when the controller fails, thereby causing a safety accident. SUMMARY

[0005] In order to solve the problem of sudden change in the charge-discharge control of the battery when the controller fails in the battery management system, thereby causing a safety accident, the present application provides a battery management system.

[0006] The battery management system provided by the present application adopts the following technical scheme: the battery management system comprises a battery module, a power supply detection unit and a temperature detection unit, and further comprises a controller, a logic processing unit, a latch unit, a switch driving unit and a charge-discharge execution unit connected in sequence; the charge-discharge execution unit is connected in a charge-discharge circuit of the battery module; the power supply detection unit, the temperature detection unit and the latch unit are connected with the controller.

[0007] The controller is configured to send a switch control instruction to the latch unit and periodically send a first communication signal to the logic processing unit.

[0008] The logic processing unit is configured to acquire power information of the controller through the power detection unit and acquire temperature information of the controller through the temperature detection unit.

[0009] The logic processing unit is further configured to send a first enable signal or a second enable signal to the latch unit based on the first communication signal, the power information and the temperature information of the controller.

[0010] The latch unit is configured to receive and latch the switch control instruction sent by the controller based on the first enable signal and deliver the switch control instruction to the switch driving unit; and the switch driving unit drives the charge-discharge execution unit based on the switch control instruction to realize charge-discharge control of the battery module; or,

[0011] The latch unit is configured to stop receiving the switch control instruction sent by the controller based on the second enable signal and output the switch control instruction latched in the latch unit to the switch driving unit to make the switch driving unit maintain the on-off driving state of the charge-discharge execution unit.

[0012] According to the above technical solution, the logic processing unit acquires the power information and the temperature information of the controller, directly communicates with the controller, and sends a first enable signal or a second enable signal to the latch control unit after analysis and processing based on the three aspects of information, wherein the first enable signal controls the latch unit to receive and latch the switch control instruction output by the current controller and then deliver the switch control instruction to the next stage; and the second enable signal controls the latch unit to stop receiving the switch control instruction output by the controller and makes the switch driving unit maintain the on-off control of the charge-discharge execution unit. Through such a design, when the controller fails or the program runs abnormally due to abnormal operation, or the controller is affected by the power supply or temperature, the latch unit will not change the output state due to the abnormality of the controller, the switch driving unit can also maintain the current on-off driving state of the charge-discharge execution unit, the on-off of the charge-discharge execution unit is maintained in the original state, and the battery module can maintain the charge-discharge state. At this time, the charge-discharge control of the battery module will not change abruptly, and the charge-discharge state of the battery module will not change abruptly, thereby effectively avoiding safety accidents. In addition, the power supply and temperature are detected, and the safety of the battery management system is improved in all directions. Moreover, no additional controller is needed in the battery management system, which reduces the cost and system design complexity and achieves good protection effect.

[0013] In one specific implementation, the battery management system further comprises a reset control unit; the reset control unit is connected to the controller;

[0014] The controller is configured to periodically send a second communication signal to the reset control unit;

[0015] The reset control unit is configured to determine the operating status of the controller based on the second communication signal, and send a reset instruction to the controller based on the determination result of the operating status of the controller;

[0016] The controller is configured to perform a reset operation based on the reset instruction.

[0017] By using the above technical solution, through the cooperation of the reset control unit and the latch unit, the danger caused by the sudden change of the system state is avoided, and the self-recovery of the controller is realized.

[0018] In one specific implementation, the battery management system further comprises a voltage conversion unit; the voltage conversion unit is connected to the controller, the power detection unit and the temperature detection unit respectively; the voltage conversion unit is further connected between the battery module and the external device;

[0019] The controller is configured to periodically send a third communication signal to the voltage conversion unit;

[0020] The voltage conversion unit is configured to obtain the power information of the controller through the power detection unit, and obtain the temperature information of the controller through the temperature detection unit;

[0021] The voltage conversion unit is configured to perform a shutdown action based on the third communication signal, the power information and the temperature information of the controller, and cut off the connection between the battery module and the external device.

[0022] By using the above technical solution, the power and temperature information of the controller are obtained by the voltage conversion unit, and the voltage conversion unit directly communicates with the controller. By summarizing the information in three aspects, when the controller runs abnormally, the controller temperature is abnormal or the controller power is abnormal, the system can be directly shut down, and the connection between the battery module and the external device is cut off, thereby further improving the protection of the battery management system and ensuring the safety of the system.

[0023] In one specific implementation, a first delay time t1' is preset in the logic processing unit. If the logic processing unit does not receive the first communication signal sent by the controller within the first delay time t1', the logic processing unit determines that the controller runs abnormally;

[0024] The second delay time t2' is preset in the reset control unit, and if the reset control unit does not receive the second communication signal sent by the controller within the second delay time t2', the reset control unit determines that the controller is abnormal;

[0025] The third delay time t3' is preset in the voltage conversion unit, and if the voltage conversion unit does not receive the third communication signal sent by the controller within the third delay time t3', the voltage conversion unit determines that the controller is abnormal;

[0026] The size relationship among the first delay time t1', the second delay time t2' and the third delay time t3' is t3'>t2'>t1'.

[0027] By adopting the above technical scheme, when the controller is abnormal, the latch operation is first performed, the logical processing unit can find it in time, and the latch path is used to avoid the sudden change of the control of the battery module charging and discharging; when the controller is still abnormal after the latch, the reset operation is performed, the reset control unit resets the controller, the controller recovers to normal after the reset, and the latch unit can gain time for the reset operation of the controller during the signal latch process; however, if the controller is still abnormal after the reset operation, it indicates that the controller is damaged at this time, and the reset operation cannot recover, if other systems find the fault of the battery management system at this time and then stop, a long time may have passed, and danger may occur, therefore, the voltage conversion unit in the rear stage performs decision, cuts off the connection between the battery module and the external equipment, the voltage conversion unit stops when the controller is abnormal and cannot recover, the safety of the product and the person is ensured, the all-around protection of the battery management system is realized, and the voltage conversion unit can further manage and protect the battery module.

[0028] In a specific implementation, the logical processing unit is configured to determine the running state of the controller based on the first communication signal, determine the power supply state of the controller based on the power supply information, and determine the temperature state of the controller based on the temperature information.

[0029] If the controller is normal, the power supply of the controller is normal, and the temperature of the controller is normal, the logical processing unit sends a first enable signal to the latch unit.

[0030] If any of the following conditions occurs: the controller is abnormal, the power supply of the controller is in a first power supply abnormal state, and the temperature of the controller is in a first temperature abnormal state, the logical processing unit sends a second enable signal to the latch unit.

[0031] By adopting the technical scheme, when any one of the following situations occurs: the controller is abnormal, the power supply of the controller is in the first power supply abnormal condition, and the temperature of the controller is in the first temperature abnormal condition, it is indicated that the controller is abnormal or is possibly abnormal due to the power supply or the temperature, and therefore the logic processing unit controls the latch unit to stop receiving the switch control instruction output by the controller, so as to achieve the latching purpose.

[0032] In a specific implementable solution, the voltage conversion unit is configured to determine the operation condition of the controller based on the third communication signal, determine the power supply condition of the controller based on the power supply information, and determine the temperature condition of the controller based on the temperature information.

[0033] If any one of the following situations occurs: the controller is abnormal, the power supply of the controller is in the second power supply abnormal condition, and the temperature of the controller is in the second temperature abnormal condition, the voltage conversion unit performs a shutdown action to cut off the connection between the battery module and the external device.

[0034] By adopting the technical scheme, when any one of the following situations occurs: the controller is abnormal, the power supply of the controller is in the second power supply abnormal condition, and the temperature of the controller is in the second temperature abnormal condition, it is indicated that the controller is possibly damaged and cannot normally process signals, and therefore the voltage conversion unit directly cuts off the connection between the battery module and the external device, so as to maximize the system safety.

[0035] In a specific implementable solution, the battery management system further comprises a voltage lifting unit; the voltage lifting unit is connected between the switch driving unit and the charge-discharge execution unit.

[0036] The voltage lifting unit is configured to enhance the on-off driving capability of the switch driving unit on the charge-discharge execution unit.

[0037] By adopting the technical scheme, when the driving capability of the switch driving unit cannot drive the charge-discharge execution unit, the voltage lifting unit enhances the driving capability of the switch driving unit.

[0038] In a specific implementable solution, the battery management system further comprises an analog front-end chip; the analog front-end chip is connected with the battery module and the controller respectively.

[0039] The analog front-end chip is configured to collect battery operation information of the battery module and output the battery operation information to the controller; the battery operation information comprises single-cell voltage, total-cell voltage, and single-cell temperature.

[0040] The controller is configured to determine whether the voltages of the single battery cells in the battery module are balanced based on the battery operation information, and if not, the controller sends a balancing instruction to the analog front-end chip, and the analog front-end chip performs a voltage balancing action based on the balancing instruction to balance the voltages of the single battery cells in the battery module.

[0041] The controller is further configured to determine whether the battery module has an overvoltage or overtemperature risk based on the battery operation information, and if so, the controller performs a corresponding protection action.

[0042] By using the above technical solution, the battery operation information is collected by the analog front-end chip and output to the controller, the controller sends a balancing instruction, the analog front-end chip performs balancing processing on the battery module, the charging and discharging of the battery cells in the battery module are balanced, and the service life of the battery module is improved; at the same time, the controller realizes protection processing on the battery module, and the system safety is improved.

[0043] In a specific implementation, the latch unit includes a shift register; the shift register includes a first enable pin, a signal input pin, and a signal output pin.

[0044] The shift register receives the first enable signal or the second enable signal output by the logic processing unit through the first enable pin, receives the switch control instruction output by the controller through the signal input pin, and transmits the switch control instruction to the switch driving unit through the signal output pin.

[0045] By using the above technical solution, the latch function is realized through the connection and design of the shift register.

[0046] In a specific implementation, the reset control unit includes a reset control chip; the reset control chip includes a communication pin and a reset control pin.

[0047] The reset control chip receives the second communication signal output by the controller through the communication pin, and sends a reset instruction to the controller through the reset control pin.

[0048] By using the above technical solution, the reset function is realized through the connection and design of the reset control chip.

[0049] In summary, the technical solution of the present application has at least the following beneficial technical effects:

[0050] 1、Through the logic processing unit, the power information and temperature information of the controller are acquired, and the logic processing unit is directly communicated with the controller. When the controller is faulty or the program runs out of control to cause abnormal operation, or the controller is affected by the power supply or temperature, the logic processing unit controls the latch unit, so that the latch unit will not change the output state due to the abnormality of the controller, and the switch driving unit can also maintain the current on-off driving state of the charge-discharge execution unit, so that the charge-discharge control of the battery module will not change suddenly, thereby effectively avoiding safety accidents. In addition, the detection of the power supply and temperature is combined to comprehensively improve the safety of the battery management system. Moreover, no additional controller is needed in the battery management system, thereby reducing the cost and system design complexity and achieving good protection effect.

[0051] 2、When the controller is abnormal, the latch operation is first performed, which is timely found by the logic processing unit and avoids the sudden change of the control of the battery module through the latch path. When the controller is still abnormal after the latch, the reset operation is performed, the controller is reset through the reset control unit, and the latch unit can gain time for the reset operation of the controller during the signal latch process. However, if the controller is still abnormal after the reset operation, it indicates that the controller is damaged at this time, and the reset operation cannot be restored. If the other system discovers the fault of the battery management system at this time and then stops, a long time may have passed, and danger may occur. Therefore, the voltage conversion unit at the rear stage performs decision-making to cut off the connection between the battery module and the external equipment, thereby comprehensively protecting the battery management system. BRIEF DESCRIPTION OF DRAWINGS

[0052] Fig. 1 is a schematic diagram of the overall structure of the battery management system in the embodiment of the application;

[0053] Fig. 2 is a schematic diagram of the first connection mode of the battery management system in the embodiment of the application;

[0054] Fig. 3 is a schematic diagram of the second connection mode of the battery management system in the embodiment of the application;

[0055] Fig. 4 is a schematic diagram of the connection of the shift register in the embodiment of the application;

[0056] Fig. 5 is a schematic diagram of the connection of the reset control chip in the embodiment of the application.

[0057] Marked with the following figures: 1, battery module; 2, power detection unit; 3, temperature detection unit; 4, controller; 5, logic processing unit; 6, latch unit; 61, shift register; 7, switch driving unit; 8, charge-discharge execution unit; 9, reset control unit; 91, reset control chip; 10, voltage conversion unit; 11, voltage lifting unit; 12, analog front-end chip. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0059] The battery management system provided by the embodiments of the present application comprises a battery module 1, a power detection unit 2 and a temperature detection unit 3, and further comprises a controller 4, a logic processing unit 5, a latch unit 6, a switch driving unit 7 and a charge-discharge execution unit 8 connected in sequence; the charge-discharge execution unit 8 is connected in a charge-discharge loop of the battery module 1; the power detection unit 2, the temperature detection unit 3 and the latch unit 6 are connected with the controller 4.

[0060] The controller 4 is configured to send a switch control instruction to the latch unit 6, and periodically send a first communication signal to the logic processing unit 5.

[0061] The logic processing unit 5 is configured to acquire power information of the controller 4 through the power detection unit 2, and acquire temperature information of the controller 4 through the temperature detection unit 3.

[0062] The logic processing unit 5 is further configured to send a first enable signal or a second enable signal to the latch unit 6 based on the first communication signal, the power information and the temperature information of the controller 4 after analysis and processing.

[0063] The latch unit 6 is configured to receive and latch the switch control instruction sent by the controller 4 based on the first enable signal, and deliver the switch control instruction to the switch driving unit 7; the switch driving unit 7 drives the charge-discharge execution unit 8 to be on or off based on the switch control instruction, so as to realize charge-discharge control of the battery module 1; or,

[0064] The latch unit 6 is configured to stop receiving the switch control instruction sent by the controller 4 based on the second enable signal, and output the switch control instruction latched in the latch unit 6 to the switch driving unit 7, so that the switch driving unit 7 keeps the on-off driving state of the charge-discharge execution unit 8.

[0065] In the above process, the switch control instruction sent by the controller 4 has weak driving capability and cannot directly drive the charge-discharge execution unit 8, so the switch driving unit 7 is used to drive the charge-discharge execution unit 8. The logic processing unit 5 can be built by using logic gate circuits, or can be built by using logic gate circuits combined with chips with processing functions, which can be designed by the person skilled in the art.

[0066] Since the power supply and temperature of the controller 4 will affect the performance of the controller 4 when being abnormal, and may cause the controller 4 to run failure and fail to correctly process information, the battery management system of the embodiment acquires the power supply information and temperature information of the controller through the logic processing unit 5, and also directly communicates with the controller 4, and according to the information of the three aspects, after analysis and processing, sends a first enable signal or a second enable signal to the latch control unit, wherein the first enable signal is to control the latch unit 6 to receive the switch control instruction output by the current controller 4 and latch, and then pass the switch control instruction to the next stage; the second enable signal is to control the latch unit 6 to stop receiving the switch control instruction output by the controller 4, so that the switch driving unit 7 keeps the on-off control of the charge-discharge execution unit 8;

[0067] Through such a design, when the controller 4 fails or the program runs abnormally due to runaway, or the controller 4 is affected by the power supply or temperature, the logic processing unit 5 controls the latch unit 6, so that the latch unit 6 will not change the output state due to the abnormality of the controller 4, and the switch driving unit 7 can also keep the current on-off driving state of the charge-discharge execution unit 8, and the on-off of the charge-discharge execution unit 8 is maintained in the original state, and the battery module 1 can keep the charge-discharge state, so that the charge-discharge control of the battery module 1 will not change suddenly, and the charge-discharge state of the battery module 1 will not change suddenly, thereby effectively avoiding safety accidents, and the detection of the power supply and temperature is combined, and the safety of the battery management system is improved in all directions; and no additional controller is needed in the battery management system, which reduces the cost and system design complexity, and achieves good protection effect.

[0068] In a possible implementation, the logic processing unit 5 is configured to determine the running state of the controller 4 based on the first communication signal, determine the power supply state of the controller 4 based on the power supply information, and determine the temperature state of the controller 4 based on the temperature information.

[0069] If the controller 4 runs normally, the power supply of the controller 4 is normal, and the temperature of the controller 4 is normal, the logic processing unit 5 sends a first enable signal to the latch unit 6.

[0070] If any of the following conditions occurs: the controller 4 runs abnormally, the power supply of the controller 4 is in a first power supply abnormal state, and the temperature of the controller 4 is in a first temperature abnormal state, it indicates that the current controller 4 has been abnormal or its processing function may have been affected by the temperature or power supply, and the logic processing unit 5 sends a second enable signal to the latch unit 6, so that the latch unit 6 stops receiving the switch control instruction output by the controller 4.

[0071] The first power abnormality condition represents a power abnormality and an abnormal time not exceeding a first time threshold; specifically, the power abnormality includes one or more of overvoltage, overcurrent, voltage fluctuation, current fluctuation, and power noise exceeding a preset noise threshold; and the first temperature abnormality condition represents a temperature exceeding a first temperature threshold.

[0072] The first enable signal is a signal satisfying a latch trigger condition of the latch unit 6, and the second enable signal is a signal not satisfying the latch trigger condition of the latch unit 6.

[0073] Therefore, when any of the following conditions occurs: the controller 4 is running abnormally, the power supply of the controller 4 is in the first power abnormality condition, and the temperature of the controller 4 is in the first temperature abnormality condition, it indicates that the controller 4 is abnormal or may be abnormal due to the power supply or temperature, and therefore the logic processing unit 5 controls the latch unit 6 to stop receiving the switch control instruction output by the controller 4, achieving the latching purpose.

[0074] Further, the controller 4 serves as the brain of the battery management system, is responsible for receiving detected various data, and issues execution instructions through calculation and analysis of the data. The controller 4 can use a microprocessor (MCU), a digital signal processor (DSP), etc.

[0075] In a possible implementation, referring to FIG. 1, the battery management system further includes a reset control unit 9; the reset control unit 9 is connected to the controller 4.

[0076] The controller 4 is configured to periodically send a second communication signal to the reset control unit 9.

[0077] The reset control unit 9 is configured to determine the running state of the controller 4 based on the second communication signal, and send a reset instruction to the controller 4 based on a determination result of the running state of the controller 4; specifically, when the reset control unit 9 determines that the controller 4 is running abnormally, the reset control unit 9 sends the reset instruction to the controller 4.

[0078] The controller 4 is configured to perform a reset operation based on the reset instruction.

[0079] Therefore, through the cooperation of the reset control unit 9 and the latch unit 6, the danger caused by sudden changes in the system state is avoided, and the self-recovery of the controller 4 is achieved.

[0080] In a possible implementation, with reference to FIG. 1, the battery management system further comprises a voltage conversion unit 10; the voltage conversion unit 10 is connected with the controller 4, the power detection unit 2 and the temperature detection unit 3 respectively; and the voltage conversion unit 10 is further connected between the battery module 1 and an external device, so as to realize energy interaction between the battery module 1 and the external device during charging and discharging of the battery module 1.

[0081] The controller 4 is configured to periodically send a third communication signal to the voltage conversion unit 10.

[0082] The voltage conversion unit 10 is configured to acquire power information of the controller 4 through the power detection unit 2, and to acquire temperature information of the controller 4 through the temperature detection unit 3.

[0083] The voltage conversion unit 10 is configured to perform a shutdown action and cut off the connection between the battery module 1 and the external device, based on the third communication signal, the power information and the temperature information of the controller 4, and through analysis and processing.

[0084] The external device is, for example, a load; the voltage conversion unit 10 can be a power conversion system (PCS) or a direct current chopper; the power conversion system can convert direct current into alternating current to supply power to an alternating current load, or convert alternating current into direct current to charge the battery module 1; and the direct current chopper is a direct current to direct current converter, which is used for voltage regulation of direct current and can convert fixed direct current voltage into variable direct current voltage.

[0085] Therefore, the voltage conversion unit 10 acquires the power and temperature information of the controller 4 and directly communicates with the controller 4, and through summarizing the information of the three aspects, the voltage conversion unit 10 can directly shut down and cut off the connection between the battery module 1 and the external device when the controller 4 runs abnormally, the temperature of the controller 4 is abnormal or the power of the controller 4 is abnormal, so as to further improve the protection of the battery management system and ensure the safety of the system.

[0086] In a possible implementation, the voltage conversion unit 10 is configured to determine the running state of the controller 4 based on the third communication signal, determine the power state of the controller 4 based on the power information, and determine the temperature state of the controller 4 based on the temperature information.

[0087] If any of the following conditions occurs: the controller 4 runs abnormally, the power of the controller 4 is in a second power abnormal state, and the temperature of the controller 4 is in a second temperature abnormal state, the voltage conversion unit 10 performs a shutdown action and cuts off the connection between the battery module 1 and the external device.

[0088] The second power abnormality condition represents that the power supply is abnormal and the abnormal time exceeds the first time threshold; and the second temperature abnormality condition represents that the temperature exceeds the second temperature threshold. It can be understood that the second temperature threshold is greater than the first temperature threshold.

[0089] Through such a design, when any of the following conditions occurs, it indicates that the controller 4 is very likely to be damaged and unable to normally process signals, and even the processing of other signals in the system will also be problematic: the controller 4 runs abnormally, the power supply of the controller 4 is in the second power abnormality condition, and the temperature of the controller 4 is in the second temperature abnormality condition. Therefore, the voltage conversion unit 10 directly cuts off the connection between the battery module 1 and the external device, thereby maximizing the safety of the system.

[0090] That is, when the power supply is abnormal and the abnormal time is long, which has exceeded the first time threshold, and the temperature is abnormal and has exceeded the second temperature threshold, the abnormality of the system is relatively serious at this time, the controller 4 is very likely to be damaged and unable to normally process signals, and the output switch control instruction can also be incorrect, and the processing of other signals can also be problematic. Therefore, the voltage conversion unit 10 directly cuts off the connection between the battery module 1 and the external device.

[0091] In a possible implementation, the controller 4 is configured to periodically send a first communication signal to the logic processing unit 5 based on a first time interval t1.

[0092] The controller 4 is configured to periodically send a second communication signal to the reset control unit 9 based on a second time interval t2.

[0093] The controller 4 is configured to periodically send a third communication signal to the voltage conversion unit 10 based on a third time interval t3.

[0094] Preferably, the relationship among the first time interval t1, the second time interval t2, and the third time interval t3 is t1=t2=t3. For example, all are 1 s.

[0095] Further, a first delay time t1’ is preset in the logic processing unit 5. If the logic processing unit 5 does not receive the first communication signal sent by the controller 4 within the first delay time t1’, the logic processing unit 5 determines that the controller 4 runs abnormally.

[0096] The second delay time t2' is preset in the reset control unit 9, and if the reset control unit 9 does not receive the second communication signal sent by the controller 4 within the second delay time t2', the reset control unit 9 judges that the controller 4 is abnormal. That is, after the reset control unit 9 receives the second communication signal sent by the controller 4 this time, if the reset control unit 9 still does not identify the second communication signal sent by the controller 4 next time within the second delay time t2', the reset control unit 9 judges that the controller 4 is abnormal.

[0097] The third delay time t3' is preset in the voltage conversion unit 10, and if the voltage conversion unit 10 does not receive the third communication signal sent by the controller 4 within the third delay time t3', the voltage conversion unit 10 judges that the controller 4 is abnormal. That is, after the voltage conversion unit 10 receives the third communication signal sent by the controller 4 this time, if the voltage conversion unit 10 still does not identify the third communication signal sent by the controller 4 next time within the third delay time t3', the voltage conversion unit 10 judges that the controller 4 is abnormal.

[0098] Preferably, the size relationship between the first delay time t1', the second delay time t2' and the third delay time t3' is t3'>t2'>t1'; for example, t3' is 5s, t2' is 1.6s, and t1' is 1s.

[0099] Through such a setting, when the controller 4 is abnormal, the latch operation is performed first, which is discovered in time by the logic processing unit 5, and through this latch path, the sudden change of the control of the battery module charging and discharging is avoided.

[0100] When the controller is still abnormal after the latch, the reset operation is performed, the controller 4 is reset by the reset control unit 9, the controller 4 recovers to normal after the reset, and the latch unit 6 can gain time for the reset operation of the controller 4 during the signal latching process.

[0101] However, if the controller 4 is still abnormal after the reset operation, it means that the controller 4 is damaged at this time, and the reset operation cannot recover. If other systems discover the failure of the battery management system at this time and then stop, a long time may have passed, and danger may occur. Therefore, the voltage conversion unit 10 at the rear stage makes a decision to cut off the connection between the battery module 1 and the external equipment, so that when the controller 4 is abnormal and cannot recover itself, the voltage conversion unit 10 stops itself, ensuring the safety of products and persons, realizing the all-round protection of the battery management system, and the voltage conversion unit 10 can realize further management and protection of the battery module 1.

[0102] In a possible implementation, with reference to FIG. 1, the battery management system further includes a voltage lifting unit 11; the voltage lifting unit 11 is connected between the switch driving unit 7 and the charging / discharging execution unit 8;

[0103] The voltage lifting unit 11 is configured to enhance the on-off driving capability of the switch driving unit 7 on the charging / discharging execution unit 8.

[0104] The voltage lifting unit 11 can use a charge pump scheme, a boost circuit scheme, or other schemes, which are not limited in the application.

[0105] Therefore, when the driving capability of the switch driving unit 7 cannot drive the on-off of the charging / discharging execution unit 8, the driving capability of the switch driving unit 7 is enhanced by the voltage lifting unit 11, and the system operation stability is improved.

[0106] In a possible implementation, with reference to FIGS. 2 and 3, the battery management system further includes an analog front-end chip 12, which is connected with the battery module 1 and the controller 4 respectively.

[0107] The communication mode between the analog front-end chip 12 and the controller 4 includes but is not limited to UART, SPI, I2C, and the like; the battery module 1 can use a lithium ion battery, a sodium ion battery, or other types of batteries. The battery module 1 can include one battery cell or any series and parallel combination of multiple battery cells. According to the number of battery cells in the battery module 1, the number of analog front-end chips 12 can be one or a plurality of series, and the function of the analog front-end chip 12 can also be realized by discrete components.

[0108] The analog front-end chip 12 is configured to collect battery operation information of the battery module 1 and output the battery operation information to the controller 4; the battery operation information includes single-cell voltage, total-cell voltage, single-cell temperature, and the like.

[0109] The controller 4 is configured to determine, based on the battery operation information, whether the voltages of the single cells in the battery module 1 are balanced, and if not, the controller 4 sends a balancing instruction to the analog front-end chip 12, and the analog front-end chip 12 performs a voltage balancing action based on the balancing instruction, so that the voltages of the single cells in the battery module 1 are balanced and tend to be consistent.

[0110] The controller 4 is further configured to determine, based on the battery operation information, whether the battery module 1 has an overvoltage or overtemperature risk, and if so, the controller 4 performs a corresponding protection action.

[0111] In the embodiment of the present application, the controller 4 divides each single battery cell into a high-voltage battery cell and a low-voltage battery cell based on the voltage of each single battery cell, and sends an equalization command to the analog front-end chip 12, which can perform passive equalization; the passive equalization specifically refers to that the analog front-end chip 12 controls the high-voltage battery cell to discharge to the resistor connected to the high-voltage battery cell, so as to reduce the voltage of the high-voltage battery cell.

[0112] Therefore, by collecting the battery operation information by the analog front-end chip 12 and outputting the battery operation information to the controller 4, the controller 4 can realize equalization processing of the battery module 1, ensure the charge and discharge balance of the battery cells in the battery module 1, and improve the service life of the battery module; at the same time, the controller 4 can realize protection processing of the battery module 1, and improve the system safety.

[0113] In a possible implementation, with reference to FIG. 2 or FIG. 3, the battery management system includes a resistor R1 connected in the charge and discharge circuit of the battery module 1; the controller 4 is connected to both ends of the resistor R1; specifically, the resistor R1 can be connected between the battery module 1 and the charge and discharge execution unit 8.

[0114] The controller 4 acquires the charge and discharge current of the battery module 1 by collecting the voltage at both ends of the resistor R1, and determines whether the battery module 1 has an overcurrent risk based on the charge and discharge current; if the battery module 1 has an overcurrent risk, the controller 4 performs corresponding protection actions.

[0115] Further, the controller 4 is further configured to calculate the remaining capacity of the battery module 1 based on the charge and discharge current of the battery module 1.

[0116] Therefore, the controller 4 acquires the charge and discharge current of the battery module 1 by collecting the voltage at both ends of the resistor R1 connected in the battery charge and discharge circuit, and performs protection in time when there is an overcurrent risk, thereby further improving the safety of the system.

[0117] In a possible implementation, with reference to FIG. 2 or FIG. 3, the charge and discharge execution unit 8 includes a discharge controllable switch Q1, a charge controllable switch Q2, a pre-charge controllable switch Q3, and a resistor R2.

[0118] The discharge controllable switch Q1 and the charge controllable switch Q2 are connected in series in the charge and discharge circuit of the battery module 1; the pre-charge controllable switch Q3 and the resistor R2 are connected in series to form a pre-charge structure, and the pre-charge structure is connected in parallel to the charge controllable switch Q2.

[0119] The on-off control of the switch driving unit 7 on the charge and discharge execution unit 8 will be specifically described as follows:

[0120] When the battery module 1 is in a discharging state, the switch driving unit 7 controls the on-off of the discharging controllable switch Q1 based on the switch control instruction, to realize the on-off control of the charging and discharging execution unit 8.

[0121] When the battery module 1 is in a charging state, the switch driving unit 7 controls the on-off of the charging controllable switch Q2 based on the switch control instruction, to realize the on-off control of the charging and discharging execution unit 8.

[0122] When the battery module 1 is in a pre-charging state, the switch driving unit 7 controls the on-off of the pre-charging controllable switch Q3 based on the switch control instruction, to realize the on-off control of the charging and discharging execution unit 8; wherein the pre-charging state represents that the battery module 1 is charging for the voltage conversion unit 10; specifically, the battery module 1 is pre-charging for the capacitor element in the voltage conversion unit 10, and through the pre-charging process, the overcurrent phenomenon in the circuit can be avoided, and the elements in the circuit are effectively protected.

[0123] Wherein, the discharging controllable switch Q1, the charging controllable switch Q2 and the pre-charging controllable switch Q3 can adopt MOS tube or relay. When the battery module 1 is in a charging state, the switch driving unit 7 drives the on-off of the charging controllable switch Q2 to realize the charging control of the battery module 1; when the battery module 1 is in a discharging state, the switch driving unit 7 drives the discharging controllable switch Q1 to realize the discharging control of the battery module 1; when the battery module 1 is in a pre-charging state, the switch driving unit 7 drives the pre-charging controllable switch Q3 to realize the pre-charging control of the voltage conversion unit 10.

[0124] Further, with reference to FIG. 2 and FIG. 3, the battery management system of the application has two connection modes, FIG. 2 shows a circuit diagram in which the charging and discharging execution unit 8 is connected to the low-voltage side, i.e. the negative side of the battery module 1, and FIG. 3 shows a circuit diagram in which the charging and discharging execution unit 8 is connected to the high-voltage side, i.e. the positive side of the battery module 1.

[0125] As shown in FIG. 2, when the charging and discharging execution unit 8 is connected to the low-voltage side, the voltage lifting unit 11 is not needed at this time, and the switch driving unit 7 can directly drive the charging and discharging execution unit 8; as shown in FIG. 3, when the charging and discharging execution unit 8 is connected to the high-voltage side, and the discharging controllable switch Q1 and the charging controllable switch Q2 in the charging and discharging execution unit 8 adopt NMOS tube, at this time the voltage for driving the NMOS tube needs to be higher than the voltage of the battery module 1, therefore the voltage lifting unit 11 is used to enhance the driving ability of the switch driving unit 7.

[0126] In a possible implementation, referring to FIG. 4, the latch unit 6 comprises a shift register 61; the shift register comprises a first enable pin, a signal input pin and a signal output pin;

[0127] The shift register 61 receives the first enable signal or the second enable signal output by the logic processing unit 5 through the first enable pin, receives the switch control instruction output by the controller 4 through the signal input pin, and transmits the switch control instruction to the switch driving unit 7 through the signal output pin.

[0128] Specifically, in combination with FIG. 4, the first enable pin is a LATCH_CLOCK pin and a SHIFT_CLOCK pin, the signal input pin is an A pin, and the signal output pin is a QA pin and a QB pin.

[0129] The shift register 61 receives the first enable signal output by the controller 4 through the LATCH_CLOCK pin and the SHIFT_CLOCK pin, receives the switch control instruction output by the controller 4 through the A pin, and transmits the switch control instruction to the switch driving unit 7 through the QA pin and the QB pin.

[0130] The shift register 61 can be a 74HC595 chip, or can be built with a flip-flop circuit or other chips, which is not limited in the present application.

[0131] Therefore, the shift register 61 receives the first enable signal output by the controller 4 through the LATCH_CLOCK pin and the SHIFT_CLOCK pin, when the logic processing unit 5 outputs the first enable signal and meets the latch trigger condition of the shift register 61, the shift register 61 receives the switch control instruction through the A pin and transmits the switch control instruction to the switch driving unit 7 through the QA pin and the QB pin; when the logic processing unit 5 outputs the second enable signal and does not meet the latch trigger condition of the shift register 61, the output of the QA pin and the QB pin of the shift register 61 cannot be changed, that is, the shift register 61 keeps the previous output, realizing the latch function.

[0132] In a possible implementation, referring to FIG. 5, the reset control unit 9 comprises a reset control chip 91; the reset control chip 91 comprises a communication pin and a reset control pin;

[0133] The reset control chip 91 receives the second communication signal output by the controller 4 through the communication pin, and sends a reset instruction to the controller 4 through the reset control pin.

[0134] Further, the reset control pin is also connected with a voltage of 3.3V, and a resistor is further connected between the reset control pin and the controller 4; one end of the resistor connected with the controller 4 is connected with the ground through a capacitor in series;

[0135] Specifically, the communication pin is a WD I pin, and the reset control pin is a RESET pin; the reset control chip 91 receives the second communication signal output by the controller 4 through the WD I pin, and sends a reset instruction to the controller 4 through the RESET pin.

[0136] Wherein, the reset control chip 91 can adopt a watchdog chip SP706SE, or other chips, which are not limited by the present application.

[0137] Therefore, when the controller 4 operates normally, the reset control chip 91 receives the correct second communication signal in time, and the reset control chip 91 does not output the reset instruction at this time; when the controller 4 operates abnormally, the reset control chip 91 cannot receive the correct second communication signal in time, and the reset control chip 91 outputs the reset instruction at this time, so that the controller 4 is reset, and the controller 4 starts to work normally again.

[0138] The above are the preferred embodiments of the present application, which do not limit the protection scope of the present application, so that: any equivalent changes made according to the structure, shape, principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A battery management system, characterized by: The battery management system comprises a battery module (1), a power detection unit (2) and a temperature detection unit (3), and further comprises a controller (4), a logic processing unit (5), a latch unit (6), a switch driving unit (7) and a charging and discharging execution unit (8) connected in sequence; the charging and discharging execution unit (8) is connected in a charging and discharging circuit of the battery module (1); the power detection unit (2), the temperature detection unit (3) and the latch unit (6) are connected with the controller (4); The controller (4) is configured to send a switch control instruction to the latch unit (6), and periodically send a first communication signal to the logic processing unit (5) based on a first time interval t1; The logic processing unit (5) is configured to acquire power information of the controller (4) through the power detection unit (2), and acquire temperature information of the controller (4) through the temperature detection unit (3); The logic processing unit (5) is further configured to send a first enable signal or a second enable signal to the latch unit (6) based on the first communication signal, the power information and the temperature information of the controller (4); The latch unit (6) is configured to receive and latch the switch control instruction sent by the controller (4) based on the first enable signal, and deliver the switch control instruction to the switch driving unit (7); the switch driving unit (7) drives the charging and discharging execution unit (8) to be on or off based on the switch control instruction, so as to realize charging and discharging control of the battery module (1); or, The latch unit (6) is configured to stop receiving the switch control instruction sent by the controller (4) based on the second enable signal, and output the switch control instruction latched in the latch unit (6) to the switch driving unit (7), so that the switch driving unit (7) maintains the on-off driving state of the charging and discharging execution unit (8); The battery management system further comprises a reset control unit (9); the reset control unit (9) is connected with the controller (4); The controller (4) is configured to periodically send a second communication signal to the reset control unit (9) based on a second time interval t2; The reset control unit (9) is configured to judge the running state of the controller (4) based on the second communication signal, and send a reset instruction to the controller (4) based on the judgment result of the running state of the controller (4); The controller (4) is configured to perform a reset operation based on the reset instruction; The battery management system further comprises a voltage conversion unit (10); the voltage conversion unit (10) is connected with the controller (4), the power detection unit (2) and the temperature detection unit (3) respectively; the voltage conversion unit (10) is further connected between the battery module (1) and an external device; The controller (4) is configured to periodically send a third communication signal to the voltage conversion unit (10) based on a third time interval t3; The voltage conversion unit (10) is configured to acquire power supply information of the controller (4) through the power supply detection unit (2), and to acquire temperature information of the controller (4) through the temperature detection unit (3); The voltage conversion unit (10) is configured to perform a shutdown action to cut off the connection between the battery module (1) and the external device based on the third communication signal, the power supply information and the temperature information of the controller (4); t1=t2=t3; The logic processing unit (5) is preset with a first delay time t1', and if the logic processing unit (5) does not receive the first communication signal sent by the controller (4) within the first delay time t1', the logic processing unit (5) determines that the controller (4) is abnormal. The reset control unit (9) is preset with a second delay time t2', and if the reset control unit (9) does not receive the second communication signal sent by the controller (4) within the second delay time t2', the reset control unit (9) determines that the controller (4) is abnormal. The voltage conversion unit (10) is preset with a third delay time t3', and if the voltage conversion unit (10) does not receive the third communication signal sent by the controller (4) within the third delay time t3', the voltage conversion unit (10) determines that the controller (4) is abnormal. The size relationship between the first delay time t1', the second delay time t2' and the third delay time t3' is t3'>t2'>t1'.

2. The battery management system of claim 1, wherein, The logic processing unit (5) is configured to determine the running state of the controller (4) based on the first communication signal, determine the power supply state of the controller (4) based on the power supply information, and determine the temperature state of the controller (4) based on the temperature information. If the controller (4) is normal, the power supply of the controller (4) is normal, and the temperature of the controller (4) is normal, the logic processing unit (5) sends a first enable signal to the latch unit (6). If any of the following conditions occurs: the controller (4) is abnormal, the power supply of the controller (4) is in a first power supply abnormal state, and the temperature of the controller (4) is in a first temperature abnormal state, the logic processing unit (5) sends a second enable signal to the latch unit (6).

3. The battery management system of claim 1, wherein, The voltage conversion unit (10) is configured to determine the running state of the controller (4) based on the third communication signal, determine the power supply state of the controller (4) based on the power supply information, and determine the temperature state of the controller (4) based on the temperature information. If any of the following conditions occurs: the controller (4) is abnormal, the power supply of the controller (4) is in a second power supply abnormal state, and the temperature of the controller (4) is in a second temperature abnormal state, the voltage conversion unit (10) performs a shutdown action to cut off the connection between the battery module (1) and the external device.

4. The battery management system of claim 1, wherein, The voltage lifting unit (11) is connected between the switch driving unit (7) and the charge-discharge executing unit (8). The voltage lifting unit (11) is used for enhancing the on-off driving capability of the switch driving unit (7) to the charge-discharge executing unit (8).

5. The battery management system of claim 1, wherein: The analog front-end chip (12) is connected with the battery module (1) and the controller (4) respectively. The analog front-end chip (12) is used for collecting battery operation information of the battery module (1) and outputting the battery operation information to the controller (4), wherein the battery operation information includes single cell voltage, total cell voltage and single cell temperature. The controller (4) is used for judging whether the voltages of single cells in the battery module (1) are balanced based on the battery operation information, and if not, the controller (4) sends a balancing instruction to the analog front-end chip (12), and the analog front-end chip (12) performs a voltage balancing action based on the balancing instruction, so that the voltages of single cells in the battery module (1) reach balance. The controller (4) is also used for judging whether the battery module (1) has overvoltage or overtemperature risk based on the battery operation information, and if so, the controller (4) performs a corresponding protection action.

6. The battery management system of claim 1, wherein: The latch unit (6) includes a shift register (61), and the shift register includes a first enable pin, a signal input pin and a signal output pin. The shift register (61) receives a first enable signal or a second enable signal output by the logic processing unit (5) through the first enable pin, receives a switch control instruction output by the controller (4) through the signal input pin, and delivers the switch control instruction to the switch driving unit (7) through the signal output pin.

7. The battery management system of claim 1, wherein: The reset control unit (9) includes a reset control chip (91), and the reset control chip (91) includes a communication pin and a reset control pin. The reset control chip (91) receives a second communication signal output by the controller (4) through the communication pin, and sends a reset instruction to the controller (4) through the reset control pin.

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