A power battery system for eliminating circulating current impact, its control method, and a vehicle

Abstract

The present invention provides a power battery system for eliminating circulating current impact, its control method, and a vehicle, belonging to the technical field of power batteries. The system includes: a battery management system and at least two parallel-connected battery pack modules connected between two high-voltage output busbars. The battery pack module includes a battery pack, a branch bus contactor connected in series with the battery pack, a branch voltage equalizing contactor and a voltage equalizing resistor connected in parallel with the branch bus contactor, and a voltage sensor. The voltage sensor is used to detect the voltage of the voltage equalizing resistor. The battery management system is used to generate a control signal based on the voltage. The branch bus contactor and the branch voltage equalizing contactor respond to the control signal to conduct or cut off, performing passive equalization processing on the battery pack to eliminate circulating current impact. The present invention discharges the battery pack through the voltage equalizing resistor, ensuring the consistency between battery packs and improving the performance and service life of the power battery system.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and particularly relates to a power battery system for eliminating circulating current impact, a control method thereof, and a vehicle. Background Art

[0002] Currently, electric vehicles usually use rechargeable lithium-ion batteries as energy storage elements in the power battery system. To meet the voltage requirements for the normal operation of the whole vehicle, about 200 battery cells are usually connected in series to form a battery pack branch in the power battery system, and multiple battery pack branches are connected in parallel to obtain a large enough total capacity and output the voltage required by the high-voltage system of the whole vehicle. After multiple groups of battery branches are connected in series, due to reasons such as different temperatures of batteries arranged at different positions, differences in self-discharge of batteries, and differences in battery performance attenuation, circulating current will occur between the parallel battery packs. To avoid the above situation, branch contactors for controlling the on / off of each branch are added to each group of battery branches, so that the parallel state between each branch can be disconnected when the power battery system is not working, which can effectively prevent the above-mentioned circulating current from occurring between each branch when the batteries are stored. However, in such a state, the open-circuit voltages of each battery pack branch may have a large difference after being stored for a certain period of time.

[0003] To solve the above technical problems, Patent CN202311702216.8 provides a parallel battery pack anti-circulating current circuit and a control method thereof. The parallel battery pack anti-circulating current circuit is used between two parallel battery packs. A current-limiting circuit is provided between the positive or negative poles of the parallel battery packs. The current-limiting circuit includes a switching tube, an inductor, and an anti-reverse diode arranged along the current direction. By setting the above-mentioned controllable current-limiting circuit between the parallel battery packs, it is expected to prevent excessive circulating current from occurring between the parallel branch battery packs. Patent CN202310267678.5 discloses a method for preventing circulating current in parallel battery clusters. Each battery in each battery cluster is connected to a pre-charge circuit and an anti-reverse diode respectively to suppress the circulating current between clusters at the beginning of power-on and the circulating current during charge and discharge. That is, the prior art all avoids the occurrence of circulating current through anti-reverse diodes, but the voltages between the battery pack branches of each branch are still unbalanced, and the consistency of the battery pack branches in the power battery system cannot be guaranteed, resulting in a reduction in the performance of the power battery system.

[0004] Therefore, there is an urgent need to provide a power battery system for eliminating circulating current impact, a control method thereof, and a vehicle, which can ensure the consistency of each branch battery pack while eliminating the circulating current, so as to improve the performance and service life of the power battery system. Summary of the Invention

[0005] In view of this, it is necessary to provide a power battery system for eliminating circulating current impact, its control method, and a vehicle, so as to solve the technical problem in the prior art that the consistency of branch battery packs is not considered when eliminating the circulating current impact, resulting in the decline of the performance and service life of the power battery system.

[0006] On the one hand, to solve the above technical problem, the present invention provides a power battery system for eliminating circulating current impact, including: a battery management system and at least two parallel-connected battery pack modules connected between two high-voltage output buses. The battery pack module includes a battery pack, a branch bus contactor connected in series with the battery pack, a branch voltage equalizing contactor and an equalizing resistor connected in parallel with the branch bus contactor, and a voltage sensor. The branch voltage equalizing contactor is a normally closed contactor;

[0007] The voltage sensor is used to detect the voltage of the equalizing resistor;

[0008] The battery management system is used to be woken up in response to the voltage, obtain the voltage difference between the battery pack modules, and generate a control signal based on the voltage;

[0009] The branch bus contactor and the branch voltage equalizing contactor are turned on and off in response to the control signal to perform passive equalization processing on the battery pack and eliminate the circulating current impact.

[0010] In a possible implementation, the battery pack includes a plurality of series-connected battery cells, and the number of battery cells in each battery pack is the same.

[0011] In a possible implementation, the battery cell includes a battery core and an equalizing resistor connected in parallel with the battery core.

[0012] In a possible implementation, the resistance value of the equalizing resistor is less than the resistance value of the equalizing resistor.

[0013] In a possible implementation, the power battery system for eliminating circulating current impact further includes a current sensor connected in series with the battery pack, and the current sensor is used to detect the current flowing through the battery pack.

[0014] On the other hand, the present invention also provides a control method for a power battery system for eliminating circulating current impact, which is used to control the power battery system for eliminating circulating current impact in any of the above possible implementation manners. The method includes:

[0015] Obtain the voltages of a plurality of equalizing resistors in a plurality of battery packs;

[0016] When any one of the voltages is greater than the voltage threshold, the battery management system is woken up, and the branch voltages of each battery pack module are obtained based on the battery management system;

[0017] Determine the branch voltage difference between every two of the battery pack modules based on the branch voltage, and determine whether the branch voltage difference is greater than a first threshold;

[0018] When the branch voltage difference is greater than the first threshold, determine a target battery pack among the multiple battery packs based on the battery management system, and control the branch voltage equalization contactors in the target battery pack to close and the branch bus contactors to open, and perform passive equalization on the target battery pack through the voltage equalization resistors in the target battery pack.

[0019] In a possible implementation, the battery pack includes a plurality of series-connected battery cells, and the battery cell includes a battery core and an equalization resistor connected in parallel with the battery core. Then, the power battery method for eliminating circulating current impact further includes:

[0020] When the branch voltage difference is less than or equal to the first threshold, determine whether the branch voltage difference is greater than a second threshold; the first threshold is greater than the second threshold;

[0021] When the branch voltage difference is less than the first threshold and greater than the second threshold, determine a target battery cell based on the battery management system;

[0022] Determine a first battery pack module including the target battery cell;

[0023] Control both the branch bus contactor and the branch voltage equalization contactor of the first battery pack module to open, and perform equalization processing on the target battery cell through the equalization resistor.

[0024] In a possible implementation, the battery pack module further includes a second battery pack module that does not include the target battery cell. Then, after performing equalization processing on the target battery cell through the equalization resistor, it further includes:

[0025] Obtain the voltage to be evaluated of the first battery pack module after passive equalization and the reference voltage of the second battery pack module, and when the target voltage difference between the voltage to be evaluated and the reference voltage is less than or equal to the second threshold, control the branch bus contactors in the first battery pack module and the second battery pack module to close and the branch voltage equalization contactors to open, and supply power to an external load based on the power battery system for eliminating circulating current impact.

[0026] In a possible implementation, the first threshold is 10V and the second threshold is 3V.

[0027] On the other hand, the present invention further provides a vehicle, including a power battery system and a controller;

[0028] The power battery system is a power battery system for eliminating circulating current impact as described in any one of the possible implementations above;

[0029] The controller includes a memory and a processor, wherein:

[0030] The memory is used to store programs;

[0031] The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the control method of the power battery system for eliminating circulating current impact described in any one of the possible implementations above.

[0032] The beneficial effects of the present invention are as follows: the power battery system for eliminating circulating current impact provided by the present invention, by setting a voltage-equalizing resistor, controls the on-off of the branch bus contactor and the branch voltage-equalizing contactor when the voltage difference between the battery packs is large, and realizes the equalization of the battery packs through the voltage-equalizing resistor, that is, makes the voltage difference between the battery packs smaller, and avoids the generation of circulating current. In addition, the battery packs of each branch are discharged through the voltage-equalizing resistor in each battery pack module, which ensures the consistency of the power between the battery packs, avoids the generation of circulating current from the fundamental cause, and can improve the performance and service life of the power battery system.

[0033] Furthermore, compared with the anti-reverse diode in the prior art, the voltage-equalizing resistor in the present invention has a simpler structure and lower cost, thereby reducing the structural complexity and cost of the power battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic structural diagram of an embodiment of a power battery system for eliminating circulating current impact provided by the present invention;

[0036] Figure 2 A schematic diagram of the structure of a battery cell according to an embodiment of the present invention;

[0037] Figure 3 A schematic flow chart of an embodiment of a control method for a power battery system for eliminating circulating current impact provided by the present invention;

[0038] Figure 4 A schematic flow chart of another embodiment of a control method for a power battery system for eliminating circulating current impact provided by the present invention;

[0039] Figure 5 This is a schematic diagram of the overall implementation process of the control method for a power battery system that eliminates circulating current impact provided by the present invention;

[0040] Figure 6 This is a schematic structural diagram of an embodiment of a vehicle provided by the present invention. Detailed implementation manners

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0042] It should be understood that the schematic drawings are not drawn to actual scale. The flowcharts used in the present invention illustrate the operations implemented according to some embodiments of the present invention. It should be understood that the operations in the flowchart may not be implemented in sequence, and steps without logical context relationships may be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present invention. Some of the block diagrams shown in the drawings are functional entities, and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor systems and / or microcontroller systems.

[0043] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present invention. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0044] The present invention provides a power battery system that eliminates circulating current impact, its control method, and a vehicle, which will be described separately below.

[0045] Figure 1 This is a schematic structural diagram of an embodiment of a power battery system that eliminates circulating current impact provided by the present invention, as Figure 1As shown in the figure, the power battery system 10 for eliminating circulating current impact includes: a battery management system 200 and at least two parallel-connected battery pack modules 100 connected between two high-voltage output busbars 11. The battery pack module 100 includes a battery pack 110, a branch bus contactor 120 connected in series with the battery pack 110, a branch voltage equalizing contactor 130 and a voltage equalizing resistor 140 connected in parallel with the branch bus contactor 120, and a voltage sensor 150. The branch voltage equalizing contactor 130 is a normally-closed contactor;

[0046] The voltage sensor 150 is used to detect the voltage of the voltage equalizing resistor 140;

[0047] The battery management system 200 is used to be woken up in response to the voltage, obtain the voltage difference between the battery pack modules 100, and generate a control signal based on the voltage;

[0048] The branch bus contactor 120 and the branch voltage equalizing contactor 130 are turned on and off in response to the control signal to perform passive equalization processing on the battery pack 110 and eliminate the circulating current impact.

[0049] Among them, one end of each voltage equalizing resistor 140 is connected with equal potential, and the other end is connected to the branch voltage equalizing contactor 130.

[0050] It should be noted that: since a circulating current will be generated only when the voltage difference between the battery pack modules 100 is greater than a certain threshold, when the circulating current appears, a voltage difference will be generated across the voltage equalizing resistor 140, that is: the voltage sensor 150 will detect the voltage. However, when the circulating current is small, that is: when the voltage detected by the voltage sensor 150 is small, the power battery system 10 for eliminating the circulating current impact will perform self-balancing and there is no need for passive equalization. Therefore, the battery management system 200 is used to be woken up and obtain the voltage difference between the battery pack modules 100 when the voltage is greater than a certain voltage threshold, and generate a control signal based on the voltage.

[0051] In an example of the present invention, as Figure 1 shown, the number of the battery pack modules 100 is 3, that is: the power battery system 10 for eliminating the circulating current impact is constituted by 3 parallel-connected battery pack modules.

[0052] To ensure the consistency of the power battery system 10 for eliminating the circulating current impact, the quantity and specifications of the electrical components in each battery pack module 100 are kept consistent. For example: the resistance values of the voltage equalizing resistors 140 in each battery pack module 100 are the same.

[0053] Compared with the prior art, the power battery system 10 for eliminating circulating current impact provided by the embodiment of the present invention controls the on / off of the branch bus contactor 120 and the branch voltage equalizing contactor 130 by setting the voltage equalizing resistor 140 when the voltage difference between the battery pack modules 100 is large, so as to realize the equalization process of the battery packs 110 through the voltage equalizing resistor 140, that is: the voltage difference between the battery packs 110 is small, avoiding the generation of circulating current. Moreover, the battery packs 110 of each branch are discharged through the voltage equalizing resistor 140 in each battery pack module 100, ensuring the consistency of the power of each battery pack 110, fundamentally avoiding the generation of circulating current, and improving the performance and service life of the power battery system.

[0054] Furthermore, the voltage equalizing resistor 140 in the embodiment of the present invention has a simpler structure and lower cost compared with the anti-reverse diode in the prior art. Therefore, the structural complexity and cost of the power battery system are reduced.

[0055] To avoid poor consistency of the power battery system 10 for eliminating circulating current impact due to the inconsistency of the number and specifications of the battery packs 110, in some embodiments of the present invention, as Figure 1 shown, the battery pack 110 includes a plurality of serially connected battery cells 111, and the number of battery cells 111 in each battery pack 110 is the same.

[0056] Moreover, the specifications of each battery cell 111, such as: battery capacity, etc. are the same.

[0057] The embodiment of the present invention ensures the consistency of each battery pack 110 by ensuring that at least two parallel-connected battery packs 110 are completely the same, thereby realizing the basic balance of each battery pack 110 and avoiding the generation of circulating current impact.

[0058] Since when the consistency between each battery pack module 100 is good, the consistency between multiple battery cells 111 inside a single battery pack module 100 may be poor, thus causing a decline in the performance and service life of the power battery. To ensure the consistency of each battery cell 111 inside the battery pack 110, in some embodiments of the present invention, as Figure 2 shown, the battery cell 111 includes an electric core 1111 and an equalizing resistor 1112 connected in parallel with the electric core 1111.

[0059] The embodiment of the present invention can perform equalization processing on each electric core 1111 based on the equalizing resistor 1112 by setting the equalizing resistor 1112 connected in parallel with the electric core 1111, so as to make multiple battery cells 111 consistent, thereby further improving the performance and service life of the power battery. Furthermore, the embodiment of the present invention improves the diversity of the equalization processing method for the power battery system 10 for eliminating circulating current impact by setting the equalizing resistor 1112.

[0060] In some embodiments of the present invention, to achieve different granularities during equalization processing, the resistance value of the equalizing resistor 1112 is smaller than the resistance value of the voltage equalizing resistor 140.

[0061] By setting different resistance values for the equalizing resistor 1112 and the voltage equalizing resistor 140, different granularities of equalization processing methods can be provided. Specifically: when the voltage difference is large, the voltage difference can be quickly eliminated through the voltage equalizing resistor 140, that is, the equalization speed is increased. However, since the adjustment amount of the voltage equalizing resistor 140 is large each time, when the voltage difference is small, it is difficult to eliminate the voltage difference by adjusting the voltage equalizing resistor 140. At this time, the adjustment is carried out through the equalizing resistor 1112. Since the resistance value of the equalizing resistor 1112 is small, its adjustment speed is slow, but the adjustment accuracy is high, and the voltage difference can be accurately eliminated.

[0062] Since a current will be generated when there is a circulating current between different battery pack modules 100, to avoid misjudging whether a circulating current occurs when the voltage sensor 150 fails or is damaged, in some embodiments of the present invention, as Figure 1 shown, the power battery system 10 for eliminating the impact of circulating current further includes a current sensor 160 connected in series with the battery pack 110. The current sensor 160 is used to detect the current flowing through the battery pack 110, and wakes up the battery management system 200 based on the current detected by the current sensor 160.

[0063] In the embodiments of the present invention, by setting the current sensor 160 to collect the current flowing through each battery pack 110, it is possible to determine whether a circulating current has occurred based on the current difference between the battery packs 110, increasing the diversity of the judgment methods for whether a circulating current is generated, and further increasing the diversity of the methods for eliminating the impact of circulating current.

[0064] Furthermore, the current collected by setting the current sensor 160 can also be collected by the battery management system 200. Through this current, the battery management system 200 can determine the target battery pack.

[0065] In the specific embodiments of the present invention, when the currents of the three battery packs 110 are 5A, 7A, and -12A respectively, the target battery pack is the battery pack generating a current of -12A. When the currents of the three battery packs 110 are -21A, 4A, and 17A respectively, the target battery pack is the battery pack generating a current of -21A.

[0066] The embodiments of the present invention also provide a control method for a power battery system for eliminating the impact of circulating current, which is used to control the power battery system 10 for eliminating the impact of circulating current in any of the above embodiments, as Figure 3 shown, the control method for the power battery system for eliminating the impact of circulating current includes:

[0067] S301. Obtain the voltages of multiple equalizing resistors 140 in multiple battery packs 110;

[0068] S302. When any one of the voltages is greater than the voltage threshold, the battery management system 200 is awakened, and the branch voltages of each battery pack module 100 are obtained based on the battery management system 200;

[0069] S303. Determine the branch voltage differences between every two battery pack modules 100 based on the branch voltages, and determine whether the branch voltage differences are greater than the first threshold;

[0070] S304. When the branch voltage difference is greater than the first threshold, determine the target battery pack among the multiple battery packs 110 based on the battery management system 200, and control the branch equalizing contactor 130 in the target battery pack to close and the branch bus contactor 120 to open, and perform passive equalization on the target battery pack through the equalizing resistor 140 in the target battery pack.

[0071] Specifically, the branch including the equalizing resistor in the target battery pack forms a discharge loop with two high-voltage output buses 11. On this discharge loop, the voltage in the target battery pack is equalized through the equalizing resistor 140 of the target battery pack to eliminate the circulating current.

[0072] Among them, the voltage threshold and the first threshold can be set or adjusted according to the actual application scenario or empirical values. In a specific embodiment of the present invention, the first threshold is 10V.

[0073] Since the resistance value of the equalizing resistor 140 is relatively large, its adjustment step for the voltage difference is relatively large. In a specific embodiment, if the voltage difference is 2V, but when adjusted through the equalizing resistor 140, the voltage difference adjusted by each adjustment step is 3V, then the 2V voltage difference cannot be eliminated by adjusting through the equalizing resistor 140. To solve this technical problem, in some embodiments of the present invention, as Figure 4 shown, the power battery method for eliminating the circulating current impact further includes:

[0074] S401. When the branch voltage difference is less than or equal to the first threshold, determine whether the branch voltage difference is greater than the second threshold; the first threshold is greater than the second threshold;

[0075] S402. When the branch voltage difference is less than the first threshold and greater than the second threshold, determine the target battery cell based on the battery management system 200;

[0076] S403. Determine the first battery pack module including the target battery cell;

[0077] S404. Control both the branch bus contactor 120 and the branch equalizing contactor 130 of the first battery pack module to open, and perform equalization processing on the target battery cell through the equalizing resistor 1112.

[0078] Specifically, the battery cell 1111 of the target battery cell and the balancing resistor 1112 form a loop. In this loop, the battery cell 1111 of the target battery cell is discharged through the balancing resistor 1112 to achieve circulation elimination.

[0079] In the embodiment of the present invention, by setting the balancing resistor 1112 with a resistance value smaller than that of the voltage equalizing resistor 140 to adjust the voltage difference, a small-range adjustment of the voltage difference can be achieved, improving the adjustment accuracy. Moreover, through the balancing resistor 1112, the equalization process of the battery cell 111 can also be realized, further improving the consistency of each battery cell 111.

[0080] In a specific embodiment of the present invention, the second threshold is 3V.

[0081] It should be noted that when the voltage difference is less than the second threshold, the circulating current does not affect the power battery system. Therefore, in some embodiments of the present invention, if the battery pack module further includes a second battery pack module that does not include the target battery cell, then after step S404, it further includes:

[0082] Obtain the voltage to be evaluated of the first battery pack module after passive equalization and the reference voltage of the second battery pack module, and when the target voltage difference between the voltage to be evaluated and the reference voltage is less than or equal to the second threshold, control the branch bus contactor 120 in the first battery pack module and the second battery pack module to close, and the branch voltage equalizing contactor 130 to open, and supply power to the external load based on the power battery system 10 that eliminates the circulating current impact.

[0083] That is: the power battery system with a voltage difference less than the second threshold can directly supply power to the external load.

[0084] To verify that no circulating current is generated when the voltage difference is less than the second threshold, in some embodiments of the present invention, the voltage difference is set to be less than the second threshold, and the circulating current is detected after parallel connection for 1 hour, and the circulating current is 0A; the circulating current is detected again after parallel connection for 24 hours, and the circulating current is also 0A. This shows that no circulating current is generated when the voltage difference is less than the second threshold, and no equalization process is required.

[0085] In summary, in some embodiments of the present invention, as Figure 5 shown, the control method of the power battery system that eliminates the circulating current impact is specifically as follows:

[0086] S501. Detect the branch voltage difference between multiple battery packs;

[0087] S502. Judge whether the branch voltage difference is less than or equal to the second threshold and the first threshold;

[0088] S503. When the branch voltage difference is less than or equal to the second threshold, the circulating current of multiple parallel battery pack modules is self-balanced. When the circulating current drops to zero, the power battery system based on eliminating the circulating current impact supplies power to the external load;

[0089] S504. When the branch voltage difference is greater than the second threshold and less than the first threshold, the battery management system is woken up passively, and the target battery pack with a larger circulating current is determined, and the target battery cell in the target battery pack is identified. The target battery cell is the battery cell with the highest voltage in the target battery pack; then passive equalization is performed on the target battery cell, and it is determined whether the voltage difference between the target battery pack after passive equalization processing and other battery packs is less than or equal to the second threshold. When it is less than or equal to, it is processed in the same way as when the voltage difference is less than or equal to the second threshold;

[0090] S505. When the voltage difference is greater than or equal to the first threshold, the battery management system is woken up passively, and the target battery pack with a larger circulating current is determined. The branch voltage equalization contactors of the target battery pack are closed, and the branch bus contactors are disconnected. Passive equalization is performed on the entire target battery pack based on the equalization resistors, and it is determined whether the voltage difference between the target battery pack after passive equalization processing and other battery packs is less than the first threshold. When it is less than, it is processed in the same way as when the voltage difference is greater than the second threshold and less than the first threshold.

[0091] The embodiment of the present invention uses the equalization resistors 140 and the balancing resistors 1112 to provide an equalization method for the battery packs 110 and the battery cells 111, achieving the consistency between different battery packs 110 and different battery cells 111 in the same battery pack, effectively controlling the circulating current of the power battery system, and at the same time extending the service life of the power battery system.

[0092] Moreover, the voltage difference after passive equalization processing is detected twice to prevent the battery cell with a higher voltage in the branch of the battery pack being passively charged from being passively overcharged in the scenario with circulating current, further improving the performance and service life of the power battery system.

[0093] As Figure 6 shown, the present invention also correspondingly provides a vehicle 600. The vehicle includes a power battery system 601 and a controller 602. The power battery system is the power battery system for eliminating the circulating current impact in any one of the above embodiments. The controller 602 includes a processor 6021, a memory 6022, and a display 6023. Figure 6 Only some components of the controller 602 are shown, but it should be understood that it is not required to implement all the shown components, and more or fewer components can be alternatively implemented.

[0094] In some embodiments, the processor 6021 may be a central processing unit (CPU), a microprocessor, or other data processing chips, which are used to run the program code stored in the memory 6022 or process data, such as the control method of the power battery system for eliminating circulating current impact in the present invention.

[0095] In some embodiments of the present invention, the processor 6021 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 6021 may be local or remote. In some embodiments, the processor 6021 may be implemented on a cloud platform. In one embodiment, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination of the above.

[0096] In some embodiments, the memory 6022 may be an internal storage unit of the controller 602, such as the hard disk or memory of the controller 602. In some other embodiments, the memory 6022 may also be an external storage device of the controller 602, such as a plug-in hard disk equipped on the controller 602, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc.

[0097] Furthermore, the memory 6022 may also include both the internal storage unit of the controller 602 and the external storage device. The memory 6022 is used to store the application software installed in the controller 602 and various types of data.

[0098] In some embodiments, the display 6023 may be an LED display, a liquid crystal display, a touch liquid crystal display, and an OLED (Organic Light-Emitting Diode) toucher, etc. The display 6023 is used to display the information of the controller 602 and to display a visual user interface. The components 6021 - 6023 of the controller 602 communicate with each other through a system bus.

[0099] In some embodiments of the present invention, when the processor 6021 executes the control program of the power battery system for eliminating circulating current impact in the memory 6022, the following steps may be implemented:

[0100] Control the branch bus contactor to disconnect, and obtain the voltages of multiple equalizing resistors in multiple battery packs;

[0101] When any one of the voltages is greater than the voltage threshold, the battery management system is awakened, and the branch voltages of each battery pack module are obtained based on the battery management system;

[0102] Determine the branch voltage difference between two battery pack modules based on the branch voltage, and determine whether the branch voltage difference is greater than a first threshold;

[0103] When the branch voltage difference is greater than the first threshold, determine the target battery pack and non-target battery packs among the multiple battery packs based on the battery management system, and control the branch equalizing contactors in the target battery pack to open and the branch bus contactors to close, and control the branch equalizing contactors in the non-target battery packs to close and the branch bus contactors to open, and perform passive equalization on the target battery pack through the equalizing resistors in the non-target battery packs.

[0104] It should be understood that when the processor 6021 executes the control program of the power battery system for eliminating circulating current shock in the memory 6022, in addition to the above functions, other functions can also be realized. For specific details, reference can be made to the description of the embodiments of the control method of the power battery system for eliminating circulating current shock above.

[0105] Furthermore, in the embodiments of the present invention, the type of the controller 602 mentioned is not specifically limited. The controller 602 can be a portable vehicle such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, a laptop computer, etc. Exemplary embodiments of the portable vehicle include, but are not limited to, portable vehicles equipped with IOS, android, Microsoft or other operating systems. The above portable vehicle can also be other portable vehicles. It should also be understood that in some other embodiments of the present invention, the controller 602 may not be a portable vehicle, but a desktop computer having a touch-sensitive surface (such as a touch panel).

[0106] Correspondingly, the embodiments of the present invention also provide a computer-readable storage medium. The computer-readable storage medium is used to store computer-readable programs or instructions. When the programs or instructions are executed by a processor, the steps or functions in the control method of the power battery system for eliminating circulating current shock provided in the above method embodiments can be realized.

[0107] Those skilled in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware (such as a processor, a controller, etc.) through a computer program. The computer program can be stored in a computer-readable storage medium. Among them, the computer-readable storage medium is a disk, an optical disk, a read-only memory or a random access memory, etc.

[0108] The above has introduced in detail a power battery system for eliminating circulating current impact, its control method, and a vehicle provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A power battery system for eliminating circulation shock, characterized in that: include: A battery management system and at least two parallel battery pack modules connected between two high-voltage output busbars, wherein the battery pack module includes a battery pack, a branch bus contactor connected in series with the battery pack, a branch voltage-equalizing contactor and a voltage-equalizing resistor connected in parallel with the branch bus contactor, and a voltage sensor, wherein the branch voltage-equalizing contactor is a normally closed contact contactor; The voltage sensor is used to detect the voltage of the voltage balancing resistor; The battery management system is used to be awakened in response to the voltage, and obtain the voltage difference between the battery pack modules, and generate a control signal based on the voltage; The branch bus contactor and the branch voltage balancing contactor are switched on and off in response to the control signal, and the battery pack is passively balanced to eliminate circulating current impact; The battery pack includes a plurality of battery cells connected in series, wherein the battery cells include a battery cell and a balancing resistor connected in parallel with the battery cell; When the voltage difference is greater than a first threshold, passively balancing the battery pack based on the voltage balancing resistor; When the voltage difference is less than the first threshold and greater than the second threshold, passively balancing the single battery based on the balancing resistor; When the voltage difference is less than or equal to the second threshold, the circulating currents of the multiple battery modules are self-balanced; The first threshold is 10V, and the second threshold is 3V.

2. The power battery system for eliminating circulating current impact according to claim 1, characterized in that: The number of battery cells in each of the battery packs is the same.

3. The power battery system for eliminating circulating current shock according to claim 2, characterized in that: The resistance value of the balancing resistor is smaller than the resistance value of the voltage balancing resistor.

4. The power battery system for eliminating circulating current shock according to claim 1, characterized in that: The power battery system for eliminating circulating current impact further includes a current sensor connected in series with the battery pack, and the current sensor is used to detect the current flowing through the battery pack.

5. A control method for a power battery system for eliminating circulating current impact, characterized in that: A method for controlling a power battery system for eliminating circulating current shock according to any one of claims 1 to 4, the method comprising: Acquire multiple voltages of multiple voltage balancing resistors in multiple battery packs; When any of the voltages is greater than a voltage threshold, the battery management system is awakened, and the branch voltage of each of the battery modules is obtained based on the battery management system; Determine a branch voltage difference between two of the battery modules based on the branch voltage, and determine whether the branch voltage difference is greater than a first threshold; When the branch voltage difference is greater than the first threshold, a target battery group among multiple battery groups is determined based on the battery management system, and the branch equalizing contactor in the target battery group is controlled to close and the branch bus contactor is disconnected, and the target battery group is passively balanced through the equalizing resistor in the target battery group.

6. The control method for a power battery system for eliminating circulating current impact according to claim 5, characterized in that: The battery pack includes a plurality of battery cells connected in series, and the battery cells include a battery cell and a balancing resistor connected in parallel with the battery cell. The power battery method for eliminating circulating current impact also includes: When the branch voltage difference is less than or equal to the first threshold, determining whether the branch voltage difference is greater than a second threshold; When the branch voltage difference is less than the first threshold value and greater than the second threshold value, determining a target battery cell based on the battery management system; determining a first battery pack module including the target battery cell; The branch bus contactor and the branch voltage balancing contactor of the first battery module are controlled to be disconnected, and the target battery cell is balanced through the balancing resistor.

7. The control method for a power battery system for eliminating circulating current impact according to claim 6, characterized in that: The battery pack module further includes a second battery pack module that does not include the target battery cell, and after the target battery cell is equalized by the equalizing resistor, the battery pack module further includes: Obtain the voltage to be evaluated of the first battery pack module and the reference voltage of the second battery pack module after passive balancing, and when the target voltage difference between the voltage to be evaluated and the reference voltage is less than or equal to a second threshold, control the branch bus contactors in the first battery pack module and the second battery pack module to close and the branch voltage equalizing contactors to disconnect, and supply power to the external load based on the power battery system for eliminating circulating current shock.

8. A vehicle, characterized in that: Including power battery system and controller; The power battery system is a power battery system for eliminating circulating current impact as described in any one of claims 1 to 4; The controller includes a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the control method of the power battery system for eliminating circulating current impact as described in any one of claims 5 to 7 above.

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