Battery charging and discharging control circuit, method and device and vehicle

Abstract

The invention relates to a battery charging and discharging control circuit, method and device and a vehicle, and relates to the technical field of computers. The battery charging and discharging control circuit comprises a plurality of single batteries, a plurality of first switches, a plurality of second switches and a controller, the plurality of single batteries are connected in series and / or in parallel; each single battery in the plurality of single batteries is connected with one first switch, and each single battery is connected with the corresponding first switch and one second switch; the plurality of first switches and the plurality of second switches are connected with the controller; the states of the first switches and the states of the second switches are determined based on the charging and discharging states of the battery charging and discharging control circuit and the equalization control requirements of the single batteries. Therefore, by adjusting the states of the first switches and the second switches corresponding to the plurality of single batteries, the equalization control of the plurality of single batteries is realized, the equalization control cost of the plurality of single batteries is reduced, and the equalization control efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of computer technology, and in particular to the field of battery pack charging and discharging technology, and specifically to a battery charging and discharging control circuit, method, device and vehicle. Background Art

[0002] A power battery is a battery pack composed of multiple single cells connected in parallel and in series. The energy charged and discharged by the power battery pack mainly depends on the consistency of all the single cells. Analogous to the barrel effect, the better the consistency of the power battery pack, the smaller the difference between its internal single cells, and the closer the energy that can be charged and discharged is to the theoretical value. Conversely, the worse the consistency of the power battery pack, the greater the difference between its internal single cells, and the energy that can be charged and discharged is far lower than the theoretical value. Therefore, it is necessary to keep the difference between all the single cells in the power battery pack within a certain range through balancing control.

[0003] At present, the mainstream balancing control schemes include passive balancing and active balancing. Passive balancing is to discharge the high-voltage single battery with a small current, and consume the energy of the single battery in the form of heat through resistance heat, so that the voltage of the high-voltage single battery is reduced, and the difference between the single battery and other single batteries is narrowed. Active balancing is to balance in the form of energy transfer, and realize high-voltage charging to low-voltage through energy storage components such as capacitors and inductors, and balance the differences between single batteries in the power battery pack. However, passive balancing is less efficient, takes a long time, and needs to consider the risk of overtemperature caused by resistance heat. Active balancing is only suitable for power battery packs with more parallel connections and fewer strings.

[0004] In the related art, CN103532189B proposes to collect the voltage value of the single battery in the battery pack in real time, and start the balancing when the difference between the voltage value of a certain battery and the lowest voltage value of the single battery exceeds the threshold. The control circuit adjusts the frequency of the power switch tube corresponding to the unbalanced single battery according to the size of the voltage difference, so that the single battery with a larger difference obtains a larger balancing current. This method uses the frequency of the power switch tube for balancing, which is inefficient and time-consuming. CN110936850A proposes that after determining the battery to be balanced, the controller instructs the driving connector to align with the first contact corresponding to the battery to be balanced through a work instruction, and the connector connects the first contact to construct a balancing circuit, so that the motor battery balances the battery to be balanced. When the battery to be balanced meets the conditions for terminating balancing, the motor battery is disconnected from the battery to be balanced, and the balancing of the battery to be balanced is terminated. This method requires the motor battery to construct a balancing circuit for the battery to be balanced separately, which is costly. Therefore, how to quickly balance the differences between the internal single batteries of the power battery is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The present application provides a battery charge and discharge control circuit, method, device and vehicle to at least solve the technical problems of low efficiency and high cost of differential balancing control between internal single cells of power batteries in related technologies. The technical solution of the present application is as follows:

[0006] According to a first aspect of the present application, a battery charge and discharge control circuit is provided, which includes: a plurality of single cells, a plurality of first switches, a plurality of second switches and a controller; the plurality of single cells are connected in series and / or in parallel; each of the plurality of single cells is connected to a first switch, and each single cell and the corresponding first switch are connected to a second switch; the plurality of first switches and the plurality of second switches are both connected to the controller; the states of the plurality of first switches and the states of the plurality of second switches are determined based on the charge and discharge state of the battery charge and discharge control circuit and the balance control requirements of the plurality of single cells.

[0007] According to a second aspect of the present application, a battery charge and discharge control method is provided, which is applied to a battery charge and discharge control circuit; the method comprises: determining a target single cell battery that needs to be balanced controlled in the battery charge and discharge control circuit; when the battery charge and discharge control circuit is charging or discharging, adjusting a first switch of the target single cell battery from a closed state to an open state, and adjusting a second switch of the target single cell battery from an open state to a closed state, wherein the first switches of other single cells in the battery charge and discharge control circuit except the target single cell battery continue to remain in a closed state, and the second switches continue to remain in an open state.

[0008] According to the above technical means, when the battery charge and discharge control circuit is charging or discharging, the states of the first switch and the second switch of the target single cell are adjusted, and the target single cell's balanced charging circuit or balanced discharging circuit is obtained by adjusting the original charge and discharge circuit of the battery charge and discharge control circuit, and the target single cell is balanced controlled, without adding a dedicated balanced circuit of the target single cell on the basis of the original charge and discharge circuit of the battery charge and discharge control circuit, the cost is low, and the rapid balanced control of the target single cell is realized, and the efficiency is high. In addition, there is no need to perform balanced control through resistance heating, which avoids the energy consumption and thermal risk of the battery charge and discharge control circuit, ensures that all single cells in the battery charge and discharge control circuit can work in the best state, improves the energy utilization efficiency of the battery charge and discharge control circuit, avoids overcharging or over-discharging of the target single cell, and prolongs the service life of the battery charge and discharge control circuit.

[0009] In a possible implementation, determining a target single cell that needs to be balanced controlled in a battery charge and discharge control circuit includes: acquiring a voltage value of each single cell in the battery charge and discharge control circuit; determining a state of charge of each single cell based on the voltage value of each single cell; and determining a target single cell from the battery charge and discharge control circuit based on the state of charge of each single cell.

[0010] According to the above technical means, by monitoring the voltage value of each single cell, the state of each single cell in the battery charge and discharge control circuit is understood, thereby determining the charge state of each single cell, identifying the target single cell that needs to be balanced controlled in the battery charge and discharge control circuit, and accurately determining the target single cell so as to balance the target single cell and ensure the overall performance and life of the battery charge and discharge control circuit.

[0011] In another possible implementation, the charge state of each single cell is determined based on the voltage value of each single cell, including: for each single cell, based on the correspondence between the voltage and the charge state of the single cell, determining the charge state corresponding to the voltage value of the single cell.

[0012] According to the above technical means, based on the correspondence between the voltage and the state of charge of the single cell, the state of charge of the single cell can be accurately determined, so that the charge and discharge state of each single cell can be detected through the state of charge of each single cell in the battery charge and discharge control circuit, which helps to accurately identify abnormal target single cells in the battery charge and discharge control circuit, and balance the target single cells to avoid damage to the target single cells due to overcharging or discharging, ensure the consistency and stability of the battery charge and discharge control circuit, and improve the overall performance and reliability of the battery charge and discharge control circuit.

[0013] In another possible implementation, based on the state of charge of each single cell, a target single cell is determined from a battery charge and discharge control circuit, including: based on the state of charge of each single cell, determining a state of charge difference between a maximum state of charge and a minimum state of charge among the states of charge of all single cells in the battery charge and discharge control circuit; when the state of charge difference is greater than a balanced state of charge difference, determining a target single cell from a single cell corresponding to the maximum state of charge and a single cell corresponding to the minimum state of charge.

[0014] According to the above technical means, the life of a battery charge and discharge control circuit generally depends on the single cell in the worst condition in the battery charge and discharge control circuit. The target single cell is determined by the maximum state of charge and the minimum state of charge of all single cells in the battery charge and discharge control circuit, so as to perform balanced control on the target single cell, reduce the difference between single cells in the battery charge and discharge control circuit, and extend the service life of the battery charge and discharge control circuit.

[0015] In another possible implementation, the target single cell is the single cell corresponding to the charge state corresponding to the largest difference between the first difference and the second difference; the first difference is the difference between the maximum charge state and the average charge state of all single cells in the battery charge and discharge control circuit; the second difference is the difference between the minimum charge state and the average value.

[0016] According to the above technical means, by determining the difference between the state of charge and the average state of charge, the target single cell is determined by the maximum difference method, so that the target single cell with the largest difference between the state of charge and the average state of charge in the battery charge and discharge control circuit can be balanced and controlled, thereby optimizing the performance of the entire battery charge and discharge control circuit, ensuring the balance of each single cell in the battery charge and discharge control circuit, and improving the energy utilization efficiency of the entire battery charge and discharge control circuit.

[0017] In another possible implementation, the method further includes: after the charging or discharging time of the battery charge and discharge control circuit reaches the balancing control time, adjusting the first switch of the target single cell from an open state to a closed state, and adjusting the second switch of the target single cell from a closed state to an open state.

[0018] According to the above technical means, after the charging or discharging time of the battery charge and discharge control circuit reaches the balancing control time, it indicates that the current charge state of the target single cell has reached the average charge state of the battery charge and discharge control circuit, and the target single cell does not need to be balanced controlled. By adjusting the first switch and the second switch of the target single cell, the balancing circuit of the target single cell is restored to the normal charging and discharging circuit of the battery charge and discharge control circuit, thereby achieving precise balancing control of the target single cell, reducing the inconsistency between the single cells in the battery charge and discharge control circuit, and ensuring that all single cells in the battery charge and discharge control circuit are charged and discharged at a similar rate, thereby improving the energy utilization efficiency of the battery charge and discharge control circuit.

[0019] In another possible implementation, the method further includes: determining the balancing control duration based on the difference between the state of charge of the target single battery and the average value, and the current value of the battery charge and discharge control circuit.

[0020] According to the above technical means, the balancing control time required for the target single cell is accurately determined through the difference between the charge state of the target single cell and the average value, as well as the current value of the battery charge and discharge control circuit, ensuring that the target single cell has enough time for balancing, avoiding over-balancing or under-balancing, and improving the efficiency of the balancing control process.

[0021] In yet another possible implementation, the method further includes: performing balancing control on the target single battery when the battery charge and discharge control circuit is not performing charging or discharging.

[0022] According to the above technical means, when the battery charge and discharge control circuit is not charging or discharging, the target single cell is balanced and controlled to adjust the difference in charge state between the single cells in the battery charge and discharge control circuit, maintain the consistency of the battery charge and discharge control circuit, and extend the service life of the battery charge and discharge control circuit. And when the battery charge and discharge control circuit is not charging or discharging, the balanced control can ensure that all single cells are in the best state before the battery charge and discharge control circuit actually works, thereby improving the overall energy utilization efficiency.

[0023] In another possible implementation, each single cell is connected to the passive balancing circuit via a third switch, and the passive balancing circuit includes at least one resistor; performing balancing control on the target single cell includes: adjusting the third switch of the target single cell from an open state to a closed state, wherein the third switches of other single cells except the target single cell in the battery charge and discharge control circuit continue to remain in an open state, and the first switches and the second switches of all single cells in the battery charge and discharge control circuit remain in an open state.

[0024] According to the above technical means, static balancing control is performed on the target single cell battery separately through the third switch of the target single cell battery, which reduces the energy waste caused by balancing control, improves the efficiency of the balancing control process, reduces energy loss, and shortens the balancing time, which helps to maintain the consistency of all single cells in the battery charge and discharge control circuit, ensure the overall performance and life of the battery charge and discharge control circuit, and improve the safety of the battery charge and discharge control circuit.

[0025] According to a third aspect provided by the present application, a battery charge and discharge control device is provided, which is applied to a battery charge and discharge control circuit; the device includes: a determination module and an adjustment module; the determination module is used to determine a target single cell battery that needs to be balanced controlled in the battery charge and discharge control circuit; the adjustment module is used to adjust the first switch of the target single cell battery from a closed state to an open state, and the second switch of the target single cell battery from an open state to a closed state when the battery charge and discharge control circuit is charging or discharging, wherein the first switches of other single cells in the battery charge and discharge control circuit except the target single cell battery continue to remain in a closed state, and the second switches continue to remain in an open state.

[0026] In a possible implementation, the determination module is specifically used to obtain the voltage value of each single cell in the battery charge and discharge control circuit; determine the charge state of each single cell based on the voltage value of each single cell; and determine the target single cell from the battery charge and discharge control circuit based on the charge state of each single cell.

[0027] In another possible implementation manner, the determination module is specifically configured to determine, for each single cell, the state of charge corresponding to the voltage value of the single cell based on the corresponding relationship between the voltage and the state of charge of the single cell.

[0028] In another possible implementation, the determination module is specifically used to determine the charge state difference between the maximum charge state and the minimum charge state of all the single cells in the battery charge and discharge control circuit based on the charge state of each single cell; when the charge state difference is greater than the balanced charge state difference, determine the target single cell from the single cell corresponding to the maximum charge state and the single cell corresponding to the minimum charge state.

[0029] In another possible implementation, the target single cell is the single cell corresponding to the charge state corresponding to the largest difference between the first difference and the second difference; the first difference is the difference between the maximum charge state and the average charge state of all single cells in the battery charge and discharge control circuit; the second difference is the difference between the minimum charge state and the average value.

[0030] In another possible implementation, the adjustment module is further used to adjust the first switch of the target single cell battery from an open state to a closed state, and the second switch of the target single cell battery from a closed state to an open state after the charging or discharging time of the battery charge and discharge control circuit reaches a balancing control time.

[0031] In yet another possible implementation, the determination module is further configured to determine the balancing control duration based on a difference between the state of charge of the target single battery and the average value, and a current value of the battery charge and discharge control circuit.

[0032] In yet another possible implementation, the device further includes: a control module, configured to perform balancing control on the target single battery when the battery charge and discharge control circuit is not charging or discharging.

[0033] In another possible implementation, each single cell is connected to the passive balancing circuit via a third switch, and the passive balancing circuit includes at least one resistor; a control module is specifically used to adjust the third switch of the target single cell from an open state to a closed state, wherein the third switches of other single cells except the target single cell in the battery charge and discharge control circuit continue to remain in an open state, and the first switches and the second switches of all single cells in the battery charge and discharge control circuit remain in an open state.

[0034] According to the fourth aspect provided by the present application, a vehicle is provided, comprising: a processor; a memory for storing processor executable instructions; wherein the processor is configured to execute instructions to implement the method of the above-mentioned second aspect and any possible implementation manner thereof.

[0035] According to the fifth aspect provided by the present application, a computer-readable storage medium is provided. When the instructions in the computer-readable storage medium are executed by the processor of the vehicle, the vehicle is enabled to execute the method in the above-mentioned second aspect and any possible implementation method thereof.

[0036] According to the sixth aspect provided by the present application, a computer program product is provided, the computer program product comprising computer instructions, and when the computer instructions are executed on a vehicle, the vehicle executes the method of the above-mentioned second aspect and any possible implementation manner thereof.

[0037] Therefore, the above technical features of the present application have the following beneficial effects:

[0038] (1) When the battery charge and discharge control circuit is charging or discharging, the states of the first switch and the second switch of the target single cell are adjusted, and the target single cell is balanced by adjusting the original charge and discharge circuit of the battery charge and discharge control circuit to obtain the balanced charging circuit or balanced discharge circuit of the target single cell, and the target single cell is balanced. There is no need to add a dedicated balanced circuit for the target single cell on the basis of the original charge and discharge circuit of the battery charge and discharge control circuit, which is low in cost and realizes rapid balanced control of the target single cell with high efficiency. In addition, there is no need to perform balanced control through resistance heating, which avoids energy consumption and thermal risks of the battery charge and discharge control circuit, ensures that all single cells in the battery charge and discharge control circuit can work in the best state, improves the energy utilization efficiency of the battery charge and discharge control circuit, avoids overcharging or overdischarging of the target single cell, and prolongs the service life of the battery charge and discharge control circuit.

[0039] (2) By monitoring the voltage value of each single cell, the state of each single cell in the battery charge and discharge control circuit is understood, thereby determining the charge state of each single cell, identifying the target single cell that needs to be balanced in the battery charge and discharge control circuit, and accurately determining the target single cell so as to balance the target single cell and ensure the overall performance and life of the battery charge and discharge control circuit.

[0040] (3) Based on the correspondence between the voltage and the state of charge of the single cell, the state of charge of the single cell can be accurately determined, so that the charge and discharge state of each single cell can be detected through the charge state of each single cell in the battery charge and discharge control circuit, which helps to accurately identify abnormal target single cells in the battery charge and discharge control circuit, and balance the target single cells to avoid damage to the target single cells due to overcharging or discharging, thereby ensuring the consistency and stability of the battery charge and discharge control circuit and improving the overall performance and reliability of the battery charge and discharge control circuit.

[0041] (4) The life of a battery charge and discharge control circuit generally depends on the worst single cell in the battery charge and discharge control circuit. The target single cell is determined by the maximum and minimum state of charge of all single cells in the battery charge and discharge control circuit, so as to perform balanced control on the target single cell, reduce the difference between single cells in the battery charge and discharge control circuit, and extend the life of the battery charge and discharge control circuit.

[0042] (5) By determining the difference between the state of charge and the average state of charge and adopting the maximum difference method to determine the target single cell, the target single cell with the largest difference between the state of charge and the average state of charge in the battery charge and discharge control circuit can be balanced and controlled, thereby optimizing the performance of the entire battery charge and discharge control circuit, ensuring the balance of each single cell in the battery charge and discharge control circuit, and improving the energy utilization efficiency of the entire battery charge and discharge control circuit.

[0043] (6) After the charging or discharging time of the battery charge and discharge control circuit reaches the balancing control time, it indicates that the current charge state of the target single cell has reached the average charge state of the battery charge and discharge control circuit, and the target single cell does not need to be balanced. By adjusting the first switch and the second switch of the target single cell, the balancing circuit of the target single cell is restored to the normal charging and discharging circuit of the battery charge and discharge control circuit, thereby achieving precise balancing control of the target single cell, reducing the inconsistency between the single cells in the battery charge and discharge control circuit, and ensuring that all the single cells in the battery charge and discharge control circuit are charged and discharged at a similar rate, thereby improving the energy utilization efficiency of the battery charge and discharge control circuit.

[0044] (7) The balancing control time required for the target single cell is accurately determined by the difference between the charge state of the target single cell and the average value, as well as the current value of the battery charge and discharge control circuit, to ensure that the target single cell has enough time for balancing, to avoid over-balancing or under-balancing, and to improve the efficiency of the balancing control process.

[0045] (8) When the battery charge and discharge control circuit is not charging or discharging, the target single cell is balanced to adjust the charge state difference between the single cells in the battery charge and discharge control circuit, maintain the consistency of the battery charge and discharge control circuit, and extend the service life of the battery charge and discharge control circuit. In addition, when the battery charge and discharge control circuit is not charging or discharging, the balanced control can ensure that all single cells are in the best state before the battery charge and discharge control circuit actually works, thereby improving the overall energy utilization efficiency.

[0046] (9) Static balancing control is performed on the target single cell battery separately through the third switch of the target single cell battery, thereby reducing energy waste caused by balancing control, improving the efficiency of the balancing control process, reducing energy loss, and shortening the balancing time, which helps to maintain the consistency of all single cells in the battery charge and discharge control circuit, ensure the overall performance and life of the battery charge and discharge control circuit, and improve the safety of the battery charge and discharge control circuit.

[0047] It should be noted that the technical effects brought about by any implementation method in the first aspect and the third aspect to the sixth aspect can refer to the technical effects brought about by the corresponding implementation method in the second aspect, and will not be repeated here.

[0048] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0050] Figure 1 is a structural schematic diagram of a battery charging and discharging control system according to an exemplary embodiment;

[0051] Figure 2 is a schematic diagram of a battery charge and discharge control circuit according to an exemplary embodiment;

[0052] Figure 3 is a schematic diagram of a charging and discharging current path of a battery charging and discharging control circuit according to an exemplary embodiment;

[0053] Figure 4is a flow chart of a battery charging and discharging control method according to an exemplary embodiment;

[0054] Figure 5 is a schematic diagram of a target single cell balancing control current path according to an exemplary embodiment;

[0055] Figure 6 is a flow chart of another battery charging and discharging control method according to an exemplary embodiment;

[0056] Figure 7 is a flow chart of another battery charging and discharging control method according to an exemplary embodiment;

[0057] Figure 8 is a flow chart of another battery charging and discharging control method according to an exemplary embodiment;

[0058] Fig. 9 is a flow chart of another battery charging and discharging control method according to an exemplary embodiment;

[0059] Fig.10 is a block diagram of a battery charge and discharge control device according to an exemplary embodiment;

[0060] Fig.11 is a block diagram of a vehicle according to an exemplary embodiment. DETAILED DESCRIPTION

[0061] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0062] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0063] The power battery of a vehicle can be simply understood as a battery pack composed of multiple single cells connected in parallel and in series, where parallel connection affects the capacity of the power battery and series connection affects the voltage of the power battery. The energy charged and discharged by the power battery pack mainly depends on the consistency of all single cells. Analogous to the barrel effect, the better the consistency of the power battery pack, the smaller the difference between its internal single cells, and the closer the energy that can be charged and discharged is to the theoretical value. Conversely, the worse the consistency of the power battery pack, the greater the difference between its internal single cells, and the energy that can be charged and discharged is far lower than the theoretical value. Therefore, it is necessary to keep the difference between all single cells in the power battery pack within a certain range through balancing control.

[0064] Balancing control is to keep the differences between all the cells in the power battery pack within a certain range through some methods. The current mainstream balancing solutions are passive balancing and active balancing. Passive balancing is to discharge the high-voltage cells with a small current, and consume the power of the cells in the form of heat through resistance heat, so that the voltage of the high-voltage cells is reduced and the difference with other cells is reduced. Active balancing is to balance by transferring power, and realize high-voltage charging to low-voltage through energy storage components such as capacitors and inductors, so as to balance the inconsistency between cells. However, passive balancing is low-cost and low-efficiency, and it is necessary to consider the risk of over-temperature caused by resistance heat. The balancing current is generally at the mA level, and the balancing time is long, for example: from dozens of hours to several days. Active balancing is only suitable for power battery packs with more parallel connections and fewer strings.

[0065] In the related art, the balanced maintenance of the power battery pack is achieved through the cooperation of the charger, the discharger, the charge and discharge port, the switch array, the balanced control unit, the switch controller, etc. The specific implementation method is to monitor the voltage at both ends of each single cell through the balanced control unit and transmit the voltage information to the single chip microcomputer. The single chip microcomputer controls the switch array to make the positive and negative poles of the single cell that needs to be balanced and the positive and negative ends of the charge and discharge port connected to form a charging or discharging circuit, so as to balance the charge or discharge of the single cell. When the balanced single cell voltage reaches the target value, the single chip microcomputer controls the switch array to disconnect the positive and negative poles of the balanced single cell from the positive and negative ends of the charge and discharge port, and stops charging or discharging. However, this method needs to add a circuit specifically for balanced charging or balanced discharge of a single cell on the basis of the original charge and discharge circuit of the power battery. The energy released during the balanced discharge process is an additional consumption and is only applicable to the balanced maintenance of the power battery pack under static conditions. Therefore, how to quickly balance the differences between the internal single cells of the power battery is a technical problem that needs to be solved urgently.

[0066] In view of the above problems, the present application proposes a battery charge and discharge control method, in which, when the battery charge and discharge control circuit is charging or discharging, the states of the first switch and the second switch of the target single cell are adjusted, and the target single cell is balanced by adjusting the original charge and discharge circuit of the battery charge and discharge control circuit. The target single cell is balanced and controlled, and there is no need to add a dedicated balanced circuit of the target single cell on the basis of the original charge and discharge circuit of the battery charge and discharge control circuit. The cost is low, and the rapid balanced control of the target single cell is achieved with high efficiency. In addition, there is no need to perform balanced control through resistance heating, which avoids the energy consumption and thermal risk of the battery charge and discharge control circuit, ensures that all single cells in the battery charge and discharge control circuit can work in the best state, improves the energy utilization efficiency of the battery charge and discharge control circuit, avoids overcharging or over-discharging of the target single cell, and prolongs the service life of the battery charge and discharge control circuit.

[0067] For ease of understanding, the battery charging and discharging control method provided by the present application is specifically introduced below with reference to the accompanying drawings.

[0068] Figure 1 is a structural schematic diagram of a battery charging and discharging control system according to an exemplary embodiment. Figure 1 As shown, the battery charge and discharge control system 100 includes: a battery pack 101 and an external load or charging device 102 , the battery pack 101 includes: a charge and discharge port 1011 , a series-parallel circuit single battery 1012 , a first switch module 1013 , a second switch module 1014 and a control module 1015 .

[0069] In some embodiments, the charge and discharge port 1011, the series-parallel loop single battery 1012, the first switch module 1013, the second switch module 1014 and the external load or charging device 102 form a current loop. The first switch module 1013 is connected to the control module 1015 and the series-parallel loop single battery 1012, respectively, and the second switch module 1014 is connected to the control module 1015 and the series-parallel loop single battery 1012, respectively. The series-parallel loop single battery 1012 is connected to the first switch module 1013, the second switch module 1014 and the charge and discharge port 1011, respectively. The control module 1015 controls the opening and closing of the first switch module 1013 and the second switch module 1014 to form different current loops inside the battery pack 101.

[0070] In other embodiments, the control module 1015 can monitor the voltage, current, and temperature of the series-parallel loop single battery 1012 in real time. The control module 1015 may include a vehicle controller, a control circuit of a motor controller, and a battery management circuit, and the vehicle controller, the control circuit of the motor controller, and the battery management circuit may be connected via a controller area network (CAN), a local area network (LAN), or other communication methods. Different modules in the control module 1015 control the conduction and disconnection of the first switch module 1013 and the second switch module 1014 according to the information obtained, so that the first switch module 1013, the second switch module 1014, the series-parallel loop single battery 1012, and the external load or charging device 102 form different current loops.

[0071] In some other embodiments, the first switch module 1013 can make the series-parallel loop single battery 1012, the second switch module 1014, the charge and discharge port 1011 and the external load or charging device 102 form a current loop according to the control signal sent by the control module 1015.

[0072] In some other embodiments, the second switch module 1014 can make the first switch module 1013 , the series-parallel loop single battery 1012 , the charge and discharge port 1011 and the external load or charging device 102 form a current loop according to the control signal sent by the control module 1015 .

[0073] In some other embodiments, the series-parallel circuit single battery 1012 can be a battery pack composed of all types of single batteries connected in series and parallel, such as lithium-ion batteries, nickel-hydrogen batteries, lead-acid batteries, sodium-sulfur batteries, and supercapacitors.

[0074] In some other embodiments, the charge and discharge port 1011 is an interface for the battery pack 101 to output energy to the outside or to input energy from an external charging device.

[0075] In some other embodiments, the external load or charging device 102 may be an electric drive or motor for driving the vehicle when the battery pack 101 is in a discharging state, and may be a charging pile or other charging equipment when the battery pack 101 is in a charging state.

[0076] It should be noted that the control module 1015, the first switch module 1013, the series-parallel circuit single battery 1012, and the charge and discharge port 1011 constitute the conventional charge and discharge circuit of the battery pack 101, that is, when the balancing control is not turned on, all the single batteries in the battery pack 101 participate in the current circuit of charging and discharging. The control module 1015 changes the current circuit of the battery pack 101 during the charging and discharging process by controlling the first switch module 1013 and the second switch module 1014, and indirectly controls the charge and discharge capacity of the target single battery that needs to be balanced. When the target single battery in the battery pack 101 is balanced, the target single battery in the battery pack 101 does not participate in the current circuit of charging and discharging of the battery pack.

[0077] Figure 2 is a schematic diagram of a battery charge and discharge control circuit according to an exemplary embodiment. Figure 2 As shown, the battery charge and discharge control circuit includes: multiple single batteries U1, U2,..., Un, multiple first switches K11, K12,..., K1n, multiple second switches K21, K22,..., K2n and a controller C1.

[0078] Wherein, a plurality of single cells are connected in series and / or in parallel. Each of the plurality of single cells is connected to a first switch, and each single cell and the corresponding first switch are connected to a second switch. The plurality of first switches and the plurality of second switches are both connected to a controller. The states of the plurality of first switches and the states of the plurality of second switches are determined based on the charge and discharge states of the battery charge and discharge control circuit and the balance control requirements of the plurality of single cells.

[0079] In some embodiments, the series-parallel circuit single battery 1012 is generally composed of a number of single batteries connected in series and parallel. The characteristic of the single battery is that it has only one positive electrode and one negative electrode. Figure 2 The single cells are represented by U1, U2, . . . , Un respectively. The first switch module 1013 is composed of a first switch connected in series with all the single cells, such as Figure 2 The second switch module 1014 is composed of a second switch connected in parallel with all the single cells, such as Figure 2 Among them, K21, K22,..., K2n.

[0080] It should be understood that a first switch is arranged in the battery charge and discharge control circuit to connect multiple single cells in the battery charge and discharge control circuit. By closing the first switches of multiple single cells, a charge and discharge loop of the battery charge and discharge control circuit is constructed. When the battery charge and discharge control circuit does not need to be charged and discharged, the multiple first switches can be disconnected to isolate the multiple single cells, thereby avoiding charging and discharging between the multiple single cells in the battery charge and discharge control circuit when charging and discharging is not required, thereby improving the safety of the battery charge and discharge control circuit.

[0081] It should also be understood that a second switch is arranged in the battery charge and discharge control circuit. When the battery charge and discharge control circuit is charging and discharging, multiple second switches are in an open state, so that multiple single cells participate in the charge and discharge circuit. By closing the second switch of the target single cell, the target single cell is isolated from the charge and discharge circuit, thereby achieving balanced control of the target single cell.

[0082] In some embodiments, the first end of K11 in the first switch module 1013 is connected to the negative electrode of the single cell U1, and the second end of K11 in the first switch module 1013 is connected to the positive electrode of the single cell U2. The first end of K12 in the first switch module 1013 is connected to the negative electrode of the single cell U2, ..., the first end of K1n in the first switch module 1013 is connected to the negative electrode of the single cell Un, and the second end of K1n in the first switch module 1013 is connected to the negative electrode of the charge and discharge port 1011. The first end of K21 in the second switch module 1014 is connected to the positive electrode of the single cell U1, and the second end of K21 in the second switch module 1014 is connected to the negative electrode of the single cell U1, that is, the positive electrode of the single cell U2. The first end of K22 in the second switch module 1014 is connected to the positive electrode of the single cell U2, that is, the negative electrode of the single cell U1,..., the first end of K2n in the second switch module 1014 is connected to the positive electrode of the single cell Un, that is, the negative electrode of the single cell Un-1, and the second end of K2n in the second switch module 1014 is connected to the negative electrode of the charge and discharge port 1011.

[0083] It should be understood that the switches in the first switch module 1013 are all in a closed state by default, and the switches in the second switch module 1014 are all in an open state by default, that is, the series-parallel circuit single cells 1011 are sequentially connected in series to form a normal charging and discharging current loop, and the current passes through all single cells U1, U2,..., Un. When a switch in the first switch module 1013 is disconnected, a local open circuit is formed, and a new current loop excluding the target single cell can be formed by cooperating with the conduction and disconnection of the second switch module 1014.

[0084] Figure 3 is a schematic diagram of a charging and discharging current path of a battery charging and discharging control circuit according to an exemplary embodiment. Figure 3As shown, when the battery pack 101 does not need to be balanced controlled, the battery pack 101 performs conventional charging and discharging as follows: all switches K21, K22, . . . , K2n in the second switch module 1014 remain in an open state, and all switches K11, K12, . . . , K1n in the first switch module 1013 remain in a closed state. The specific current loop is composed of U1, K11, U2, K12, . . . , Un and K1n. The actual charging or discharging current is calculated according to Figure 3 Flow in the direction indicated by the arrow.

[0085] It should be noted that the system structure, battery charge and discharge control circuit, and application scenario described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person of ordinary skill in the art can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0086] In some embodiments, the executor of the battery charge and discharge control method provided in the embodiments of the present application can be the battery pack itself, the control module of the battery charge and discharge control circuit, or the battery charge and discharge control device, or the battery management system (BMS), etc., any device or equipment that can control the first switch, the second switch, and the third switch of the single cell in the battery charge and discharge control circuit, and this application does not impose any restrictions on this.

[0087] Figure 4 is a flow chart of a battery charging and discharging control method according to an exemplary embodiment. Figure 4 As shown, the battery charge and discharge control method includes the following steps:

[0088] S401, determining a target single battery cell that needs to be balanced in a battery charge and discharge control circuit.

[0089] Among them, the battery charge and discharge control circuit includes a plurality of single cells, each of which is provided with a first switch and a second switch, the first switch is connected in series with the single cell, and the second switch is connected in parallel with the single cell and the first switch of the single cell. The battery charge and discharge control circuit is a device composed of a plurality of single cells connected in series, in parallel or in series and in parallel, and the battery charge and discharge control circuit is used to store and release electrical energy. The power battery charge and discharge control circuit can also provide power for the vehicle. Balance control is a control strategy adopted in a system composed of multiple related units to achieve performance balance and stable operation between units, so as to ensure that the performance of each unit remains at a relatively consistent level, and to avoid the performance degradation of individual units affecting the performance of the entire system.

[0090] Exemplarily, by acquiring the voltage value of each single cell in the battery, the state of charge of each single cell is determined based on the voltage value of each single cell. The state of charge represents the ratio of the remaining charge in the battery to the rated capacity of the battery. Based on the state of charge of each single cell, the target single cell with inconsistent remaining power in the battery charge and discharge control circuit can be determined.

[0091] S402 , when the battery charge and discharge control circuit is charging or discharging, adjusting the first switch of the target single cell from the closed state to the open state, and adjusting the second switch of the target single cell from the open state to the closed state.

[0092] Wherein, the first switches of the other single cells except the target single cell in the battery charge and discharge control circuit continue to remain in a closed state, and the second switches continue to remain in an open state.

[0093] Exemplarily, after determining the target single cell in the battery charge and discharge control circuit, when the battery charge and discharge control circuit is charging or discharging, the target single cell is balanced and controlled. The first switch of the target single cell can be adjusted from a closed state to an open state, and the second switch of the target single cell can be adjusted from an open state to a closed state, thereby isolating the target single cell from the conventional charge and discharge circuit of the battery charge and discharge control circuit, and charging and discharging other single cells in the battery charge and discharge control circuit except the target single cell, so that the charge state of the target single cell is consistent with the charge state of other single cells in the battery charge and discharge control circuit except the target single cell.

[0094] Specifically, when the battery charge and discharge control circuit is charging, the charge state of the target single cell is higher than the charge state of other single cells in the battery charge and discharge control circuit, indicating that the target single cell has too much remaining power and is overcharged. The target single cell is isolated from the conventional charge and discharge circuit of the battery charge and discharge control circuit, and other single cells in the battery charge and discharge control circuit except the target single cell are charged until the charge state of the target single cell is consistent with the charge state of other single cells in the battery charge and discharge control circuit.

[0095] Specifically, when the battery charge and discharge control circuit is discharging, the charge state of the target single cell is lower than the charge state of other single cells in the battery charge and discharge control circuit, indicating that the remaining power of the target single cell is too low and the target single cell is over-discharged. By isolating the target single cell from the conventional charge and discharge circuit of the battery charge and discharge control circuit, the other single cells in the battery charge and discharge control circuit except the target single cell are discharged until the charge state of the target single cell is consistent with the charge state of other single cells in the battery charge and discharge control circuit. This ensures that the charge state of all single cells in the battery charge and discharge control circuit remains consistent.

[0096] It should be understood that when the battery charge and discharge control circuit is charging or discharging, the states of the first switch and the second switch of the target single cell are adjusted, and the original charge and discharge circuit of the battery charge and discharge control circuit is adjusted to obtain the balanced charging circuit or balanced discharge circuit of the target single cell, and the target single cell is balanced. There is no need to add a dedicated balanced circuit of the target single cell on the basis of the original charge and discharge circuit of the battery charge and discharge control circuit, and the cost is low. Rapid balanced control of the target single cell is achieved with high efficiency. In addition, there is no need to perform balanced control through resistance heating, which avoids energy consumption and thermal risks of the battery charge and discharge control circuit, ensures that all single cells in the battery charge and discharge control circuit can work in the best state, improves the energy utilization efficiency of the battery charge and discharge control circuit, avoids overcharging or overdischarging of the target single cell, and prolongs the service life of the battery charge and discharge control circuit.

[0097] As an example, Figure 5 FIG. 1 is a schematic diagram of a target single cell balancing control current path according to an exemplary embodiment. Figure 5 As shown, when the target single cell needs to be balanced, it is assumed here that the single cell U2 needs to be balanced. The implementation method of dynamic balancing is: adjusting K12 in the first switch module 1013 from the closed state to the open state, and the other first switches remain in the closed state, adjusting K22 in the second switch module 1014 from the open state to the closed state, and the other second switches remain in the open state. The actual charging or discharging current of the balancing circuit of the target single cell is as follows: Figure 5 Flow in the direction indicated by the arrow.

[0098] In some embodiments, the state of charge of each single cell is determined by the voltage value of each single cell in the battery charge and discharge control circuit, thereby determining the target single cell. Figure 6 As shown, the above step S401 can be specifically implemented as the following steps S4011-S4013:

[0099] S4011. Obtain the voltage value of each single battery in the battery charge and discharge control circuit.

[0100] Exemplarily, the real-time voltage value across all single cells in the battery charge and discharge control circuit is monitored in real time by a voltage sensor in the charging or discharging state, or the voltage of each single cell is determined by the voltage division principle of multiple single cells in the battery charge and discharge control circuit, or the voltage value of each single cell is obtained from the battery management system.

[0101] S4012: Determine the state of charge of each single cell based on the voltage value of each single cell.

[0102] Among them, the state of charge is the ratio of the remaining charge in the battery to the rated capacity of the battery, which can be used to accurately control the charging and discharging process of the battery.

[0103] Exemplarily, the state of charge of each single cell can be determined based on the mapping relationship between the voltage value and the state of charge of the single cell, or by measuring the charge and discharge current and time of each single cell and integrating the current to determine the remaining power of each single cell to determine the state of charge, or by estimating the state of charge of each single cell through a Kalman filter.

[0104] S4013: Based on the state of charge of each single cell, determine the target single cell from the battery charge and discharge control circuit.

[0105] Exemplarily, based on the state of charge of each single cell, the single cells with obviously outlier state of charge in the battery charge and discharge control circuit can be screened out and determined as target single cells that need to be balanced controlled. For example: determine the state of charge difference between the maximum state of charge and the minimum state of charge among the states of charge of all single cells in the battery charge and discharge control circuit, that is, the maximum state of charge difference in the battery charge and discharge control circuit, so as to compare the state of charge of the single cell corresponding to the maximum state of charge difference with the average state of charge of the battery charge and discharge control circuit, and determine the single cell with the largest difference as the target single cell.

[0106] It should be understood that by monitoring the voltage value of each single cell and understanding the state of each single cell in the battery charge and discharge control circuit, the charge state of each single cell can be determined, and the target single cell that needs to be balanced controlled in the battery charge and discharge control circuit can be identified. This enables accurate determination of the target single cell so that the target single cell can be balanced controlled, thereby ensuring the overall performance and life of the battery charge and discharge control circuit.

[0107] In other embodiments, the state of charge corresponding to the voltage value of the single cell may be determined based on the correspondence between the voltage and the state of charge of the single cell. Therefore, the above step S4012 may be specifically implemented as follows: for each single cell, based on the correspondence between the voltage and the state of charge of the single cell, the state of charge corresponding to the voltage value of the single cell is determined.

[0108] Among them, the open circuit voltage data of the single cell under different charge states can be obtained through experimental testing, and then the corresponding relationship between the voltage and charge state of the single cell can be established through data fitting, or the corresponding relationship between the voltage and charge state of the single cell can be determined by the ampere-hour integration method or the equivalent circuit model.

[0109] Exemplarily, multiple batteries in a battery charge and discharge control circuit are generally batteries of the same specification and model. Therefore, for each single cell in the battery charge and discharge control circuit, the charge state corresponding to the voltage value of each single cell can be queried based on the correspondence between the voltage and charge state of the battery of the specification and model.

[0110] It should be understood that based on the correspondence between the voltage and the state of charge of the single cell, the state of charge of the single cell can be accurately determined, so that the charge and discharge state of each single cell can be detected through the charge state of each single cell in the battery charge and discharge control circuit, which helps to accurately identify abnormal target single cells in the battery charge and discharge control circuit, and balance the target single cells to avoid damage to the target single cells due to overcharging or discharging, ensure the consistency and stability of the battery charge and discharge control circuit, and improve the overall performance and reliability of the battery charge and discharge control circuit.

[0111] In some embodiments, the charge state difference between the maximum charge state and the minimum charge state of all the single cells in the battery charge and discharge control circuit can be determined, thereby determining the target single cell from the single cell corresponding to the maximum charge state and the single cell corresponding to the minimum charge state. Figure 7 As shown, the above step S4013 can be specifically implemented as the following steps S4013a-S4013b:

[0112] S4013a, based on the state of charge of each single battery, determine the state of charge difference between the maximum state of charge and the minimum state of charge among the states of charge of all single batteries in the battery charge and discharge control circuit.

[0113] Exemplarily, based on the state of charge of each single cell, the single cells with the largest state of charge and the smallest state of charge in the battery charge and discharge control circuit can be screened, and the state of charge difference between the maximum state of charge and the minimum state of charge can be determined, that is, the maximum state of charge difference in the battery charge and discharge control circuit, and the maximum state of charge difference represents the single cell with the most inconsistent state of charge in the battery charge and discharge control circuit.

[0114] S4013b: When the state of charge difference is greater than the balanced state of charge difference, determine a target single cell from the single cells corresponding to the maximum state of charge and the single cells corresponding to the minimum state of charge.

[0115] The target single cell is the single cell corresponding to the state of charge corresponding to the largest difference between the first difference and the second difference; the first difference is the difference between the maximum state of charge and the average state of charge of all single cells in the battery charge and discharge control circuit; the second difference is the difference between the minimum state of charge and the average value. The balanced state of charge difference is determined according to the specification attributes of the single cells in the battery charge and discharge control circuit, indicating the maximum state of charge difference allowed in the battery charge and discharge control circuit. If the balanced state of charge difference is exceeded, it means that the single cells in the battery charge and discharge control circuit are inconsistent.

[0116] Exemplarily, when the state of charge difference is greater than the balanced state of charge difference, it indicates that the state of charge consistency of the single cells in the battery charge and discharge control circuit is poor, and it is necessary to perform balanced control on the single cells in the battery charge and discharge control circuit. Since the single cells corresponding to the maximum state of charge and the single cells corresponding to the minimum state of charge are the causes of the poor consistency of the state of charge of the single cells in the battery charge and discharge control circuit, the target single cell having the largest difference between the state of charge and the average state of charge is determined from the single cells corresponding to the maximum state of charge and the single cells corresponding to the minimum state of charge.

[0117] It should be understood that the life of a battery charge and discharge control circuit generally depends on the worst single cell in the battery charge and discharge control circuit. The target single cell is determined by the maximum state of charge and the minimum state of charge of all single cells in the battery charge and discharge control circuit, so as to perform balanced control on the target single cell, reduce the difference between single cells in the battery charge and discharge control circuit, and extend the service life of the battery charge and discharge control circuit.

[0118] In some other embodiments, after the first switch of the target single cell is adjusted from the closed state to the open state, and the second switch of the target single cell is adjusted from the open state to the closed state for the equalization control time, the equalization control of the target single cell is completed, and the first switch and the second switch of the target single cell need to be restored to the default state. Figure 8As shown, the battery charging and discharging control method provided in the embodiment of the present application also includes the following steps:

[0119] S403: After the charging or discharging time of the battery charge and discharge control circuit reaches the balancing control time, the first switch of the target single cell is adjusted from the open state to the closed state, and the second switch of the target single cell is adjusted from the closed state to the open state.

[0120] The balancing control duration indicates the duration for which the target single battery cell needs to be subjected to balancing control.

[0121] Exemplarily, after the charging or discharging time of the battery charge and discharge control circuit reaches the balancing control time, the balancing control of the target single cell battery has been completed, and the charge state of the target single cell battery has been consistent with the charge state of other single cells in the battery charge and discharge control circuit. Therefore, the first switch and the second switch of the target single cell battery can be restored to the default state, that is, the first switch of the target single cell battery is adjusted from the open state to the closed state, and the second switch of the target single cell battery is adjusted from the closed state to the open state.

[0122] It should be understood that after the charging or discharging time of the battery charge and discharge control circuit reaches the balancing control time, it indicates that the current charge state of the target single cell has reached the average charge state of the battery charge and discharge control circuit, and the target single cell does not need to be balanced controlled. By adjusting the first switch and the second switch of the target single cell, the balancing circuit of the target single cell is restored to the normal charging and discharging circuit of the battery charge and discharge control circuit, thereby achieving precise balancing control of the target single cell, reducing the inconsistency between the single cells in the battery charge and discharge control circuit, and ensuring that all single cells in the battery charge and discharge control circuit are charged and discharged at a similar rate, thereby improving the energy utilization efficiency of the battery charge and discharge control circuit.

[0123] In some other embodiments, the required equalization control time of the target single cell can be determined by the difference between the state of charge of the target single cell and the average state of charge. Therefore, the battery charge and discharge control method provided in the embodiment of the present application also includes the following steps: determining the equalization control time based on the difference between the state of charge of the target single cell and the average value, and the current current value of the battery charge and discharge control circuit.

[0124] Exemplarily, the difference between the charge state of the target single cell and the average value can be determined, so as to determine how long it takes for the target battery to be consistent with other single cells in the battery charge and discharge control circuit based on the difference and the current charging current or discharging current of the battery charge and discharge control circuit, thereby determining the balancing control duration of the target battery.

[0125] It should be understood that the balancing control time required for the target single cell is accurately determined by the difference between the charge state of the target single cell and the average value, as well as the current value of the battery charge and discharge control circuit, ensuring that the target single cell has enough time for balancing, avoiding over-balancing or under-balancing, and improving the efficiency of the balancing control process.

[0126] In some other embodiments, when the battery charge and discharge control circuit is not charging or discharging, after determining the target single cell that needs to be balanced in the battery charge and discharge control circuit, static balanced control can be performed on the target single cell. Therefore, the battery charge and discharge control method provided in the embodiment of the present application also includes the following steps: when the battery charge and discharge control circuit is not charging or discharging, balanced control is performed on the target single cell.

[0127] For example, when the battery charge and discharge control circuit is not charging or discharging, the charge of the target single cell that needs to be balanced controlled in the battery charge and discharge control circuit cannot be adjusted through the charge and discharge circuit of the battery charge and discharge control circuit. Therefore, it is necessary to balance the target single cell itself, for example, by charging and discharging the target single cell through a resistor or charging device connected in series with the target single cell, so that the target single cell is consistent with other single cells in the battery charge and discharge control circuit. Alternatively, charge transfer can be achieved through energy storage components such as capacitors and inductors, so that the target single cell is consistent with other single cells in the battery charge and discharge control circuit.

[0128] It should be understood that when the battery charge and discharge control circuit is not charging or discharging, the target single cell is balanced to adjust the state of charge difference between the single cells in the battery charge and discharge control circuit, maintain the consistency of the battery charge and discharge control circuit, and extend the service life of the battery charge and discharge control circuit. And when the battery charge and discharge control circuit is not charging or discharging, the balanced control can ensure that all single cells are in the best state before the battery charge and discharge control circuit actually works, thereby improving the overall energy utilization efficiency.

[0129] In some other embodiments, each single cell is connected to a passive balancing circuit via a third switch, and the passive balancing circuit includes at least one resistor. The above-mentioned balancing control of the target single cell can be specifically implemented as follows: adjusting the third switch of the target single cell from an open state to a closed state.

[0130] The third switches of the other single cells except the target single cell in the battery charge and discharge control circuit continue to remain in the disconnected state, and the first switches and the second switches of all single cells in the battery charge and discharge control circuit remain in the disconnected state.

[0131] Exemplarily, the third switch of the target single cell battery can be adjusted from an open state to a closed state, and the charge in the target single cell battery can be discharged with a small current through at least one resistor of the passive balancing circuit. Heat is generated by the resistor and the charge of the target single cell battery is consumed in the form of heat until the charge state of the target single cell battery is consistent with the average charge state of the battery charge and discharge control circuit. The third switch of the target single cell battery can be adjusted from a closed state to an open state.

[0132] Specifically, the required discharge time of the target single cell battery can be determined by the resistance value of at least one resistor of the passive balancing circuit and the difference between the charge state of the target single cell battery and the average charge state of the battery charge and discharge control circuit, so that after the time length between the charge state of the target single cell battery and the average charge state of the battery charge and discharge control circuit is greater than the discharge time, the third switch of the target single cell battery is adjusted from a closed state to an open state.

[0133] It should be understood that static balancing control is performed on the target single cell battery separately through the third switch of the target single cell battery, which reduces the energy waste caused by balancing control, improves the efficiency of the balancing control process, reduces energy loss, and shortens the balancing time, which helps to maintain the consistency of all single cells in the battery charge and discharge control circuit, ensure the overall performance and life of the battery charge and discharge control circuit, and improve the safety of the battery charge and discharge control circuit.

[0134] Fig. 9 is a flow chart of another battery charge and discharge control method according to an exemplary embodiment. Fig. 9 As shown, the process includes the following steps: obtaining the voltage of the power battery pack in real time. Determining whether the power battery pack is in the process of charging and discharging. When the power battery pack is in the process of charging and discharging, calculating the dynamic SOC values ​​of all the cells. Determining whether the dynamic maximum SOC difference of the cell is greater than or equal to the threshold value. When the dynamic maximum SOC difference of the cell is greater than or equal to the threshold value, determining the target cell, estimating the balancing time, and starting dynamic balancing. Determining whether the dynamic balancing time is greater than the balancing time. When the dynamic balancing time is greater than the balancing time, balancing ends. When the dynamic balancing time is not greater than the balancing time, continue to determine whether the dynamic balancing time is greater than the balancing time until the dynamic balancing time is greater than the balancing time. When the dynamic maximum SOC difference of the cell is not greater than or equal to the threshold value, re-acquire the voltage of the power battery pack in real time. When the power battery pack is not in the process of charging and discharging, calculating the static SOC values ​​of all the cells, determining whether the static maximum SOC difference of the cell is greater than or equal to the threshold value. When the static maximum SOC difference of the cell is greater than or equal to the threshold value, executing other static balancing strategies. When the static maximum SOC difference of the cell is not greater than or equal to the threshold value, re-acquire the voltage of the power battery pack in real time.

[0135] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the method. In order to achieve the above functions, the battery charge and discharge control device or the vehicle includes a hardware structure and / or software module corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0136] The embodiments of the present application can exemplarily divide the functional modules of the battery charge and discharge control device or the vehicle according to the above method. For example, the battery charge and discharge control device or the vehicle may include various functional modules corresponding to the various functional divisions, or two or more functions may be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiments of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0137] Fig.10 is a block diagram of a battery charge and discharge control device according to an exemplary embodiment. Fig.10 The battery charge and discharge control device 1000 is used in a battery charge and discharge control circuit; the battery charge and discharge control device 1000 comprises: a determination module 1001 and an adjustment module 1002; the determination module 1001 is used to determine a target single cell that needs to be balanced controlled in the battery charge and discharge control circuit; the adjustment module 1002 is used to adjust the first switch of the target single cell from a closed state to an open state, and the second switch of the target single cell from an open state to a closed state when the battery charge and discharge control circuit is charging or discharging, wherein the first switches of other single cells except the target single cell in the battery charge and discharge control circuit continue to remain in a closed state, and the second switches continue to remain in an open state.

[0138] In a possible implementation, the determination module 1001 is specifically used to obtain the voltage value of each single cell in the battery charge and discharge control circuit; determine the charge state of each single cell based on the voltage value of each single cell; and determine the target single cell from the battery charge and discharge control circuit based on the charge state of each single cell.

[0139] In another possible implementation, the determination module 1001 is specifically configured to determine, for each single cell, the state of charge corresponding to the voltage value of the single cell based on the corresponding relationship between the voltage and the state of charge of the single cell.

[0140] In another possible implementation, the determination module 1001 is specifically used to determine the charge state difference between the maximum charge state and the minimum charge state among the charge states of all single cells in the battery charge and discharge control circuit based on the charge state of each single cell; when the charge state difference is greater than the balanced charge state difference, determine the target single cell from the single cell corresponding to the maximum charge state and the single cell corresponding to the minimum charge state.

[0141] In another possible implementation, the target single cell is the single cell corresponding to the charge state corresponding to the largest difference between the first difference and the second difference; the first difference is the difference between the maximum charge state and the average charge state of all single cells in the battery charge and discharge control circuit; the second difference is the difference between the minimum charge state and the average value.

[0142] In another possible implementation, the adjustment module 1002 is further used to adjust the first switch of the target single cell battery from an open state to a closed state, and the second switch of the target single cell battery from a closed state to an open state after the charging or discharging time of the battery charge and discharge control circuit reaches the balancing control time.

[0143] In yet another possible implementation, the determination module 1001 is further configured to determine the balancing control duration based on the difference between the state of charge of the target single battery and the average value, and the current value of the battery charge and discharge control circuit.

[0144] In yet another possible implementation, the device further includes: a control module 1003, where the control module 1003 is configured to perform balancing control on the target single battery when the battery charge and discharge control circuit is not charging or discharging.

[0145] In another possible implementation, each single cell is connected to the passive balancing circuit via a third switch, and the passive balancing circuit includes at least one resistor; the control module 1003 is specifically used to adjust the third switch of the target single cell from an open state to a closed state, wherein the third switches of other single cells except the target single cell in the battery charge and discharge control circuit continue to remain in an open state, and the first switches and the second switches of all single cells in the battery charge and discharge control circuit remain in an open state.

[0146] According to the above technical means, when the battery charge and discharge control circuit is charging or discharging, the states of the first switch and the second switch of the target single cell are adjusted, and the target single cell's balanced charging circuit or balanced discharging circuit is obtained by adjusting the original charge and discharge circuit of the battery charge and discharge control circuit, and the target single cell is balanced controlled, without adding a dedicated balanced circuit of the target single cell on the basis of the original charge and discharge circuit of the battery charge and discharge control circuit, the cost is low, and the rapid balanced control of the target single cell is realized, and the efficiency is high. In addition, there is no need to perform balanced control through resistance heating, which avoids the energy consumption and thermal risk of the battery charge and discharge control circuit, ensures that all single cells in the battery charge and discharge control circuit can work in the best state, improves the energy utilization efficiency of the battery charge and discharge control circuit, avoids overcharging or over-discharging of the target single cell, and prolongs the service life of the battery charge and discharge control circuit.

[0147] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0148] Fig.11 FIG. 1 is a block diagram of a vehicle according to an exemplary embodiment. Fig.11 As shown, vehicle 1100 includes, but is not limited to, a processor 1101 and a memory 1102 .

[0149] The memory 1102 is used to store executable instructions of the processor 1101. It can be understood that the processor 1101 is configured to execute instructions to implement the battery charge and discharge control method in the above embodiment.

[0150] It should be noted that those skilled in the art can understand that Fig.11 The vehicle structure shown in the figure does not constitute a limitation on the vehicle, and the vehicle may include Fig.11 More or fewer components may be shown, or certain components may be combined, or the components may be arranged differently.

[0151] The processor 1101 is the control center of the vehicle, which uses various interfaces and lines to connect various parts of the entire vehicle, and executes various functions of the vehicle and processes data by running or executing software programs and / or modules stored in the memory 1102, and calling data stored in the memory 1102, so as to monitor the vehicle as a whole. The processor 1101 may include one or more processing units. Optionally, the processor 1101 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, and application programs, etc., and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 1101.

[0152] The memory 1102 may be used to store software programs and various data. The memory 1102 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one functional module (such as a determination unit, a processing unit, etc.), etc. In addition, the memory 1102 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0153] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 1102 including instructions, and the above instructions can be executed by the processor 1101 of the vehicle 1100 to implement the battery charging and discharging control method in the above embodiment.

[0154] In actual implementation, Fig.10 The functions of the determination module 1001, the adjustment module 1002 and the control module 1003 in the embodiment can be obtained by Fig.11 The processor 1101 in the embodiment calls the computer program stored in the memory 1102 to implement. The specific execution process can refer to the description of the method part in the above embodiment, which will not be repeated here.

[0155] Optionally, the computer-readable storage medium may be a non-temporary computer-readable storage medium, for example, the non-temporary computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0156] In an exemplary embodiment, the present application also provides a computer program product including one or more instructions, which can be executed by the vehicle's processor 1101 to complete the battery charging and discharging control method in the above embodiment.

[0157] It should be noted that when the instructions in the above-mentioned computer-readable storage medium or one or more instructions in the computer program product are executed by the vehicle's processor, the various processes of the above-mentioned method embodiment are implemented, and the same technical effect as the above-mentioned method can be achieved. To avoid repetition, they will not be repeated here.

[0158] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0159] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0160] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0161] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0162] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the full classification part or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including a number of instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute the full classification part or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or CD and other media that can store program code.

[0163] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery charge and discharge control circuit, characterized in that: The battery charge and discharge control circuit comprises: a plurality of single cells, a plurality of first switches, a plurality of second switches and a controller; The plurality of single cells are connected in series and / or in parallel; Each of the plurality of single cells is connected to a first switch, and each of the single cells and the corresponding first switch are connected to a second switch; The multiple first switches and the multiple second switches are all connected to the controller; the states of the multiple first switches and the states of the multiple second switches are determined based on the charge and discharge state of the battery charge and discharge control circuit and the balance control requirements of the multiple single cells.

2. A battery charging and discharging control method, characterized in that: Applicable to the battery charge and discharge control circuit as claimed in claim 1; the method comprises: Determining a target single cell battery that needs to be balanced controlled in the battery charge and discharge control circuit; When the battery charge and discharge control circuit is charging or discharging, the first switch of the target single cell is adjusted from a closed state to an open state, and the second switch of the target single cell is adjusted from an open state to a closed state, wherein the first switches of other single cells in the battery charge and discharge control circuit except the target single cell continue to remain in a closed state, and the second switches continue to remain in an open state.

3. The method according to claim 2, characterized in that The step of determining a target single battery cell that needs to be balanced controlled in the battery charge and discharge control circuit includes: Obtaining the voltage value of each single battery in the battery charge and discharge control circuit; Determining the state of charge of each single cell based on the voltage value of each single cell; Based on the state of charge of each single cell, the target single cell is determined from the battery charge and discharge control circuit.

4. The method according to claim 3, characterized in that: The step of determining the state of charge of each single cell based on the voltage value of each single cell comprises: For each of the single cells, the state of charge corresponding to the voltage value of the single cell is determined based on the corresponding relationship between the voltage and the state of charge of the single cell.

5. The method according to claim 3, characterized in that: The step of determining the target single cell from the battery charge and discharge control circuit based on the charge state of each single cell comprises: Based on the state of charge of each single battery, determine the state of charge difference between the maximum state of charge and the minimum state of charge among the states of charge of all single batteries in the battery charge and discharge control circuit; In a case where the state of charge difference is greater than the balanced state of charge difference, the target single cell is determined from the single cell corresponding to the maximum state of charge and the single cell corresponding to the minimum state of charge.

6. The method according to claim 5, characterized in that The target single cell is a single cell corresponding to the state of charge corresponding to the largest difference between the first difference and the second difference; the first difference is the difference between the maximum state of charge and the average state of charge of all single cells in the battery charge and discharge control circuit; The second difference is a difference between the minimum state of charge and the average value.

7. The method according to claim 6, characterized in that The method further comprises: After the charging or discharging time of the battery charge and discharge control circuit reaches the balancing control time, the first switch of the target single cell is adjusted from the open state to the closed state, and the second switch of the target single cell is adjusted from the closed state to the open state.

8. The method according to claim 7, characterized in that The method further comprises: The balancing control duration is determined based on the difference between the state of charge of the target single battery and the average value, and the current value of the battery charge and discharge control circuit.

9. The method according to any one of claims 2 to 8, characterized in that: The method further comprises: When the battery charge and discharge control circuit is not performing charging or discharging, balancing control is performed on the target single battery.

10. The method according to claim 9, characterized in that Each of the single cells is connected to a passive balancing circuit via a third switch, and the passive balancing circuit includes at least one resistor; The performing balancing control on the target single battery includes: The third switch of the target single cell is adjusted from an open state to a closed state, wherein the third switches of other single cells except the target single cell in the battery charge and discharge control circuit continue to remain in an open state, and the first switches and the second switches of all single cells in the battery charge and discharge control circuit remain in an open state.

11. A battery charge and discharge control device, characterized in that: Applicable to the battery charge and discharge control circuit as claimed in claim 1; the device comprises: a determination module and an adjustment module; The determination module is used to determine the target single battery that needs to be balanced controlled in the battery charge and discharge control circuit; The adjustment module is used for adjusting the first switch of the target single cell from a closed state to an open state, and adjusting the second switch of the target single cell from an open state to a closed state when the battery charge and discharge control circuit is charging or discharging, wherein the first switches of other single cells in the battery charge and discharge control circuit except the target single cell continue to remain in a closed state, and the second switches continue to remain in an open state.

12. A vehicle, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method as claimed in any one of claims 2 to 10.

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