Battery management system, control method, battery device and vehicle

Abstract

The invention provides a battery management system, a control method, a battery device and a vehicle, and belongs to the technical field of batteries. The battery management system provided by the invention comprises a main control loop and a plurality of branch control loops, the main control loop comprises a main loop relay for controlling the on-off of the main control loop; the plurality of branch control loops are connected with the plurality of battery modules in a one-to-one correspondence manner and are connected to the main control loop in a parallel connection manner, and each branch control loop in the plurality of branch control loops comprises a branch relay for controlling the on-off of the corresponding branch control loop; wherein the branch relays are normally-closed relays, control signals used for controlling the normally-closed relays to be switched on or switched off are pulse signals, and the branch relays are configured to be switched on after the main loop relay is switched off, so that the multiple battery modules are still electrically connected after the batteries stop supplying power to the outside. Therefore, circulation balance among the plurality of branch control loops can be realized, the voltage difference among the plurality of branch control loops can be eliminated, and the battery performance can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery management system, a control method, a battery device and a vehicle. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] The cruising range and charging time are the core issues of electric vehicles. Compared with the traditional charging mode, battery swapping technology can replace batteries in a short time, which not only improves time efficiency but also reduces cruising range anxiety. During the battery swapping process, the battery circuit will be connected and disconnected, which is not conducive to the battery's performance. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the background technology. To this end, one object of the present application is to provide a battery management system, a control method, a battery device and a vehicle to improve battery performance.

[0005] The embodiment of the first aspect of the present application provides a battery management system. The battery management system provided by the present application is used to control a battery, the battery includes a plurality of battery modules, and the battery management system includes a main control circuit and a plurality of branch control circuits; the main control circuit includes a main circuit relay for controlling the on and off of the main control circuit; the plurality of branch control circuits are connected to the plurality of battery modules one by one, and are connected to the main control circuit in parallel, and each of the plurality of branch control circuits includes a branch relay for controlling the on and off of the corresponding branch control circuit; wherein the branch relay is a normally closed relay, and the control signal for controlling the normally closed relay to be closed or opened is a pulse signal, and the branch relay is configured to remain closed after the main circuit relay is opened, so that the plurality of battery modules remain electrically connected after the battery stops supplying power to the outside.

[0006] In the technical solution of the embodiment of the present application, the battery management system includes a main control circuit and multiple branch control circuits. After the main circuit relay is disconnected, the branch relay is set to remain in a closed state so that the multiple battery modules are electrically connected. In this way, it is beneficial to achieve the circulation balance of the branch control circuit and reduce the influence of the pressure difference between the branches, thereby improving the stability and reliability of the battery during the charging and discharging process and improving the battery performance. In addition, by realizing the circulation effect between the branch control circuits, the situation in which the battery is damaged by the pulse current during the battery replacement process to the relay and the battery can be reduced to improve the battery replacement efficiency, and reduce the probability of the branch relay being unable to be closed due to the excessive pressure difference between the battery branches. In addition, the branch relay is set as a normally closed relay and the control signal is set as a pulse signal, so that there is no need to continuously provide the branch relay with power to keep it closed, thereby simplifying the control of the branch relay and the complexity of the circuit, and reducing the power consumption of the battery management system.

[0007] In some embodiments, the branch relay is a magnetic relay. The magnetic relay has a simple structure and high reliability. By setting the branch relay as a magnetic relay, the controllability of the battery management system can be improved, and additional power consumption and production costs can be effectively reduced.

[0008] In some embodiments, the branch relay is configured to be disconnected in a controlled manner when the self-test result of the battery module of the branch control circuit in which it is located fails, or when the battery needs to be replaced. Through the self-test operation, the normal operation of the battery management system can be effectively verified, and faults can be prevented and the possibility of the expansion of the fault range can be reduced, thereby improving the reliability of the battery management system.

[0009] In some embodiments, the battery management system further includes a controller, the controller includes a main control unit for controlling the main control loop, and a plurality of branch control units arranged in one-to-one correspondence with the plurality of branch control loops and used to control the corresponding branch relays, the main control unit is signal-connected with the plurality of branch control units; wherein the main control unit is configured to receive external instructions, and control the main loop relay to close or open according to the external instructions, and send control signals to the plurality of branch control units; each of the plurality of branch control units is configured to control the corresponding branch relay to close or open based on the control signal sent by the main control unit. Realizing control of the battery management system through the controller is beneficial to energy management and optimization of the entire system, and is beneficial to fault diagnosis and processing, and is further beneficial to realizing the circulation function of the branch control loop, improving the reliability of the battery management system and improving battery performance.

[0010] In some embodiments, the main control unit is further configured to perform a self-check on the battery status in response to receiving an external instruction, and send a control signal to the multiple branch control units based on the external instruction and the self-check result. The main control unit controls the multiple branch control units based on the external instruction and the self-check result, which is beneficial to the energy management and optimization of the entire system, thereby realizing the circulation of the branch control loop, reducing the pressure difference of each branch control loop, and improving the stability and reliability of the battery management system.

[0011] In some embodiments, the external instruction is a high-voltage instruction issued by the on-board controller; the main control unit is further configured to: in response to receiving the high-voltage instruction, perform a self-test on the battery status; in response to the self-test result being passed, control the main circuit relay to close, and issue a control instruction for instructing each of the multiple branch control units to close the branch relay. The main control unit controls the main circuit relay based on the self-test result and controls the branch relay through the branch control unit to achieve high voltage, which is beneficial to the energy management and optimization of the entire system, reduces the probability of failure, and further improves battery performance.

[0012] In some embodiments, the external instruction is a high-voltage lowering instruction issued by the vehicle controller; the main control unit is further configured to: in response to receiving the high-voltage lowering instruction, perform a self-check on the battery status; and in response to the self-check result being passed, control the main circuit relay to disconnect; wherein the branch relay in each branch control circuit of the multiple branch control circuits remains closed. In this way, it is conducive to realizing the circulation of the branch control circuit, reducing the pressure difference between the branches, and better exerting the battery capacity.

[0013] In some embodiments, the external instruction includes a high voltage lowering instruction issued by the vehicle controller; the main control unit is further configured to: in response to receiving the high voltage lowering instruction, perform a self-test on the battery status; and in response to a self-test failure result, issue a control instruction for instructing to disconnect the branch relay to the branch control unit corresponding to the branch control circuit where the battery module that failed the self-test is located. Disconnecting the branch relay by the self-test failure result can reduce the probability of failure and improve the reliability and safety of the battery management system.

[0014] In some embodiments, the main control unit is further configured to: in response to a self-test result of failing, send a control instruction to the vehicle controller for instructing to limit the output power. Limiting the output power by the self-test failure result is conducive to improving the flexibility and reliability of the battery management system, reducing energy loss, and improving energy utilization efficiency.

[0015] In some embodiments, the external instruction is a high-voltage lowering instruction issued by an external battery exchange device; the main control unit is further configured to: in response to receiving the high-voltage lowering instruction, control the main circuit relay to disconnect, and issue a high-voltage lowering instruction to each of the multiple branch control units. The main control unit receives the high-voltage lowering instruction issued by the external battery exchange device, thereby controlling the disconnection of the main circuit relay and indirectly controlling the branch relay, which is beneficial to the energy management and optimization of the entire system and improves battery performance.

[0016] An embodiment of the second aspect of the present application provides a control method for a battery management system, which is applied to the battery management systems of some of the above-mentioned embodiments, and the control method includes: obtaining external instructions; the external instructions include lower high voltage instructions or lower high voltage instructions; based on the external instructions, controlling the main circuit relay to close or open, and / or the branch relay to close or open.

[0017] An embodiment of a third aspect of the present application provides a battery device, which includes the battery management system in the above embodiment.

[0018] An embodiment of the fourth aspect of the present application provides a vehicle, which includes the battery device in the above embodiment, or the battery management system in the above embodiment.

[0019] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0021] Figure 1 A schematic diagram of the structure of a vehicle according to some embodiments of the present application; Figure 2 A schematic diagram of the exploded structure of a battery according to some embodiments of the present application; Figure 3 A simplified schematic diagram of a battery management system according to some embodiments of the present application; Figure 4 This is one of the flow charts of the battery management system of some embodiments of the present application; Figure 5 This is a second flowchart of a battery management system according to some embodiments of the present application; Figure 6This is a flowchart of a battery management system according to some embodiments of the present application; Figure 7 This is a flowchart of a control method for a battery management system according to some embodiments of the present application.

[0022] Description of reference numerals: Vehicles 1000; Battery 100, controller 200, motor 300, battery management system 400; Box body 10, first part 11, second part 12; Battery cell 20; Battery module 30, main control circuit 40, main circuit relay 41, main circuit positive relay 411, main circuit negative relay 412, main control unit 42, branch control circuit 50, branch relay 51, branch positive relay 511, branch negative relay 512, branch control unit 52. DETAILED DESCRIPTION

[0023] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0025] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0026] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0028] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0029] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0030] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0031] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0032] Power batteries are generally composed of multiple battery cells, where multiple battery cells are connected in series to form a battery unit, and multiple battery units are connected in parallel to form a battery device that can supply power to the outside. During the process of external charging and discharging of the battery device, due to performance differences between the battery cells, or differences in the wiring conditions of the branches where the battery modules are located, the ambient temperature, etc., there will be inconsistencies in the voltage and current between different branches of the battery.

[0033] In some cases, when charging a battery with differences in voltage and current between branches, it will lead to uneven battery charging and reduced charging efficiency. If the battery with differences in voltage and current between branches supplies power to the outside, the output voltage will be unstable and the output power will be reduced due to inconsistent battery discharge depth. In addition, the differences in voltage and current between battery branches will affect the overall performance of the battery, including but not limited to shortening the battery life and increasing safety risks.

[0034] In other cases, when the equipment needs to be replaced, the temperature difference causes the difference in the resistance of the battery cells, resulting in the difference in the current between the battery branches. Because the actual charging current of a branch exceeds the branch charging request current, the battery system prompts a charging over-limit fault and produces a "jump gun" phenomenon, and the battery replacement system cannot be fully charged. In addition, in this case, there are also large differences in the voltage between the battery branches, which will prevent the branch relay from closing smoothly.

[0035] In order to solve the problem of uneven current in multiple branches of the above-mentioned multi-branch battery exchange system, so as to better exert the battery capacity, the present application provides a battery management system, a control method, a battery device and a vehicle. The battery management system provided by the present application is used to control the battery, and the battery includes multiple battery modules. The battery management system includes a main control circuit and multiple branch control circuits; the main control circuit includes a main circuit relay that controls the on and off of the main control circuit; the multiple branch control circuits are connected to the multiple battery modules one by one, and are connected to the main control circuit in parallel. Each of the multiple branch control circuits includes a branch relay that controls the on and off of the corresponding branch control circuit; wherein the branch relay is configured to remain closed after the main circuit relay is disconnected, so that the multiple battery modules remain electrically connected. This is conducive to achieving circulating current balance between multiple branch control circuits, eliminating the pressure difference of multiple branch control circuits, and improving battery performance.

[0036] The battery management system disclosed in the embodiment of the present application can be used in, but not limited to, electrical devices such as vehicles, ships or aircraft. The battery management system disclosed in the embodiment of the present application can be used for battery charge and discharge management.

[0037] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0038] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0039] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application. Vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0040] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0041] Please refer to Figure 2 , Figure 2 Schematic diagram of the exploded structure of the battery provided for some embodiments of the present application. The battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is contained in the box 10. Among them, the box 10 is used to provide a storage space for the battery cell 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second part 12 can be a hollow structure with one end open, the first part 11 can be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 can also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 can be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0042] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0043] Each battery cell 20 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0044] The embodiment of the present application provides a battery management system 400, which is used to control a battery, and the battery includes a plurality of battery modules 30. The battery management system 400 includes a main control circuit 40 and a plurality of branch control circuits 50; the main control circuit 40 includes a main circuit relay 41 for controlling the on and off of the main control circuit 40; the plurality of branch control circuits 50 are connected to the plurality of battery modules 30 in a one-to-one correspondence, and are connected to the main control circuit 40 in parallel, and each of the plurality of branch control circuits 50 includes a branch relay 51 for controlling the on and off of the corresponding branch control circuit 50; wherein the branch relay 51 is a normally closed relay, and the control signal for controlling the normally closed relay to be closed or opened is a pulse signal, and the branch relay 51 is configured to remain closed after the main circuit relay 41 is opened, so that the plurality of battery modules 30 remain electrically connected after the battery stops supplying power to the outside.

[0045] The battery management system 400 (BMS) is an electronic system that monitors and manages the operating status of rechargeable batteries (including single batteries and battery packs). The core functions of the battery management system 400 are to protect the battery from exceeding its safe operating range, monitor the battery's voltage, temperature and current in real time, generate and report relevant data, control the battery's operating environment, and ensure battery balance, thereby achieving safe, stable and efficient operation of the battery system.

[0046] The battery module 30 is an independent unit in the battery system, which is usually composed of multiple battery cells 20 connected in series. Multiple battery modules 30 are connected in parallel to form a battery, which can be a power battery for a vehicle device. As a component of the battery 100, the performance of the battery module 30 directly affects the cruising range, charging speed and safety performance of the vehicle device.

[0047] like Figure 3 The schematic diagram of the battery management system 400 of some embodiments of the present application is shown, and the corresponding battery includes three parallel battery modules 30. In some embodiments, the battery management system 400 may include a main control circuit 40 and multiple branch control circuits 50, wherein the branch control circuit 50 is directly electrically connected to the battery module 30, and the three battery modules 30 are respectively connected in parallel to the main control circuit 40 through the branch control circuit 50.

[0048] The main control circuit 40 is responsible for the core functions of the battery system. In some cases, it is responsible for the charge and discharge management of the battery 100, the detection and control of the battery status, and the communication with other vehicle systems. The branch control circuit 50 is responsible for the subdivision of the battery system, such as detecting the voltage and temperature of the battery module 30 of the corresponding branch, the parameter detection and function management of the individual battery cells in the battery module 30. The branch control circuit 50 will collect and report the status data of the battery module 30 and the internal battery cells for further processing and decision-making by the main control circuit 40. Among them, multiple branch control circuits 50 are connected to multiple battery modules 30 in a one-to-one correspondence, indicating that each battery module 30 is electrically connected to a specific branch control circuit 50 and each branch control circuit 50 can realize the control of a specific battery module 30. It should be supplemented that, in some other embodiments, the specific positions and quantities of the main circuit relay 41 and the branch relay 51 and the number of branch control circuits 50 can be the same as those of the main circuit relay 41 and the branch relay 51. Figure 3 The illustrated embodiments are different, to which the present application is not restricted.

[0049] A relay is a commonly used electrical control device used to control the opening or closing of a specific circuit through an electromagnetic or electronic signal. A relay usually consists of an electromagnetic coil and one or more contacts, wherein the electromagnetic coil generates a magnetic field after the current is turned on, causing the contacts to close or open, thereby controlling the flow of current in the circuit. The main function of a relay is to control the on and off of a circuit, thereby realizing functions such as remote control, automatic control, current amplification, protection, and safety isolation of the circuit. A normally closed relay refers to a relay whose switch or contact remains closed (i.e. connected) when no external force (which may be applied voltage, current, or mechanical force) is applied. A pulse signal is a transient signal that generally generates an extremely high energy peak in a very short time (such as nanoseconds or microseconds), and is usually composed of a very short voltage or current.

[0050] In some examples, the battery management system 400 of an embodiment of the present application is applied to a vehicle device, and the main circuit relay 41 and the branch relay 51 can be closed when the upper voltage is high to enable the battery to supply power or charge to the outside. When the lower voltage is high, after the main circuit relay 41 receives a disconnect instruction and disconnects, the branch relay 51 remains in a normally closed state when no separate disconnect instruction is received, thereby maintaining the connectivity between multiple branches in the battery. The branch relay 51 will only disconnect when it receives a pulse signal indicating disconnection.

[0051] The main circuit relay 41 is used to control the on and off of the main control circuit 40, and the branch circuit relay 51 is used to control the on and off of the branch control circuit 50. In some embodiments, the main circuit relay 41 includes a main circuit positive relay 411 and a main circuit negative relay 412, and the branch circuit relay 51 includes a branch positive relay 511 and a branch negative relay 512.

[0052] In the embodiment of the present application, after the main circuit relay 41 is disconnected, it does not mean that the branch relay 51 located in the branch control circuit 50 will also be disconnected when the main circuit relay 41 is disconnected. On the contrary, the branch relay 51 can still remain in a closed state to maintain a closed circuit between multiple battery modules 30, so that internal multi-branch current sharing can still be achieved even after the battery is under high voltage.

[0053] The battery management system 400 of the embodiment of the present application includes a main control circuit 40 and multiple branch control circuits 50. After the main circuit relay 41 is disconnected, the branch relay 51 is set to remain in a closed state so that the multiple battery modules 30 are electrically connected. In this way, it is conducive to achieving the circulation balance of the branch control circuit 50, reducing the influence of the pressure difference between the branches, thereby improving the stability and reliability of the battery during the charging and discharging process, and improving the battery performance. In addition, by realizing the circulation effect between the branch control circuits 50, the battery 100 can be reduced in the process of power exchange due to the pulse current. The situation of damage to the relay and the battery can be reduced to improve the power exchange efficiency, and reduce the probability of the branch relay being unable to be closed due to the excessive pressure difference between the battery branches. In addition, the branch relay 51 is set as a normally closed relay and the control signal is set as a pulse signal, so that there is no need to continuously provide the branch relay with power to keep it closed, thereby simplifying the control of the branch relay 51 and the complexity of the circuit, and reducing the power consumption of the battery management system.

[0054] According to some embodiments of the present application, the branch relay 51 is a magnetic relay.

[0055] A magnetic relay is an electromechanical component that uses an input signal (voltage or current) to generate electromagnetic force in the electromagnet core to attract the armature, thereby causing the contact to operate to achieve opening, closing, or switching control. The input signal does not need to be maintained continuously. When the relay needs to be disconnected, the voltage or current signal can be enabled to directly trigger the relay to disconnect. The other states are maintained by the magnetic relay.

[0056] The magnetic relay has a simple structure and high reliability. By setting the branch relay 51 as a magnetic relay, in addition to improving the controllability of the battery management system 400, it can also effectively reduce additional power consumption and production costs.

[0057] According to some embodiments of the present application, the branch relay 51 is configured to be controlled to be disconnected when the self-test result of the battery module 30 of the branch control loop 50 in which it is located fails, or when the battery needs to be replaced.

[0058] Self-test refers to the process in which the battery system (including single cells, battery modules or battery packs) automatically tests its own key parameters and performance indicators through built-in detection circuits and related algorithms. These parameters include but are not limited to the battery's voltage, current, temperature, internal resistance, capacity, and battery's state of health (SOH) and state of charge (SOC). The purpose of battery self-test is to promptly detect possible problems with the battery, such as performance degradation and potential faults, so as to ensure the safe and reliable operation of the battery system.

[0059] In some embodiments, when the battery management system 400 receives an upper high voltage instruction or a lower high voltage instruction, it will perform a self-inspection on each battery module and each auxiliary function module of the battery according to a preset fault list. If one or more of the fault lists are triggered, it means that the self-inspection fails, otherwise it means that the self-inspection passes. The fault list may include but is not limited to abnormal voltage or temperature of the battery cell 20, abnormal total current or total voltage of the battery, insulation fault and communication fault. Among them, the abnormal voltage of the battery cell 20 refers to the undervoltage of the battery cell 20 or the abnormal voltage collection, and the abnormal temperature of the battery cell 20 refers to its temperature exceeding or less than the normal range value; the total current or total voltage of the battery pack refers to the abnormal current or voltage of the main control circuit 40; insulation fault refers to the situation that the battery device cannot work normally during use due to the degradation of the insulation performance of the battery 100 or other electrical equipment; communication fault refers to the inability to communicate or unstable communication between the battery management system 400 and the external control unit, or even the inability to communicate or unstable communication of the control unit inside the battery management system 400.

[0060] In some embodiments, when the self-test result fails, the branch relay 51 in the branch control loop 50 where the faulty battery module is located will receive a disconnection instruction and disconnect the branch control loop 50 .

[0061] In other embodiments, when the battery needs to be replaced, that is, in the battery replacement mode, the battery replacement station sends a "lower high voltage instruction" to the battery management system 400 through a communication protocol (which may be a Bluetooth protocol), and the battery management system 400 controls the branch relay 51 to disconnect to facilitate battery replacement.

[0062] Through the self-check operation, the normal operation of the battery management system 400 can be effectively verified, and faults can be prevented and the possibility of the expansion of the fault range can be reduced, thereby improving the reliability of the battery management system 400.

[0063] According to some embodiments of the present application, the battery management system 400 also includes a controller, which includes a main control unit 42 for controlling the main control loop 40, and multiple branch control units 52 arranged in a one-to-one correspondence with multiple branch control loops 50 and used to control corresponding branch relays 51, and the main control unit 42 is signal-connected to the multiple branch control units 52; wherein the main control unit 42 is configured to receive external instructions, and control the main loop relay 41 to close or open according to the external instructions, and send control signals to the multiple branch control units 52; each of the multiple branch control units 52 is configured to control the corresponding branch relay 51 to close or open based on the control signal sent by the main control unit 42.

[0064] The controller can also be called a battery management unit (BMU), which is a basic unit of the battery management system 400 and is responsible for monitoring and managing the status of the battery 100. The controller includes a main control unit 42 (Module Battery Management Unit, MBMU) and a branch control unit 52 (System Battery Management Unit, SBMU), which can respectively realize on-off control of the main control loop 40 and multiple branch control loops 50.

[0065] The main control unit 42 is responsible for comprehensive monitoring of the entire battery system, formulation of charging and discharging strategies, and communication with external systems. It obtains key parameters of each battery module (or battery cell) in real time, such as voltage, current, temperature and other information. For example, in the battery system of an electric vehicle, the main control unit 42 will continuously monitor data from each battery module to ensure that the battery system operates in a safe and efficient state. The main control unit 42 will also formulate corresponding charging and discharging strategies based on the overall state of the battery system and external requirements (such as the power requirements of the vehicle or the charging / discharging plan of the energy storage system). In addition, the main control unit 42 is the communication hub between the battery system and external devices (such as the vehicle's motor controller, charging pile or battery swap station). It sends the status information of the battery system to external devices, and receives instructions from external devices and performs corresponding operations.

[0066] The branch control unit 52 is mainly responsible for detailed monitoring of a single battery module (or a small portion of battery cells), including collecting various parameter data (such as voltage, temperature, etc.) of the batteries within its management range, and transmitting these data to the main control unit 42. The branch control unit 52 also receives instructions from the main control unit 42 and executes these instructions within the local range it manages. At the same time, it feeds back the results of the instruction execution to the main control unit 42.

[0067] In an embodiment of the present application, when the main control unit 42 issues an upper high voltage instruction to the branch control unit 52, the branch control unit 52 controls the branch relay 51 to close; and when the main control unit 42 issues a lower high voltage instruction to the branch control unit 52, the branch control unit 52 controls the branch relay 51 to open.

[0068] Controlling the battery management system 400 through the controller is beneficial to energy management and optimization of the entire system, and is beneficial to fault diagnosis and processing, and is further beneficial to realizing the circulation function of the branch control loop 50, improving the reliability of the battery management system and improving battery performance.

[0069] According to some embodiments of the present application, the main control unit 42 is further configured to perform a self-check on the battery status in response to receiving an external instruction, and send a control signal to the plurality of branch control units 52 based on the external instruction and the self-check result.

[0070] like Figure 4 and Figure 5As shown, in some embodiments, the external instruction received by the main control unit 42 may be an upper high voltage instruction or a lower high voltage instruction. After receiving the external instruction, the main control unit 42 will perform a self-inspection on the battery according to a preset fault list. If the result of the self-inspection of the main control unit 42 is passed, that is, there is no fault, the MBMU will send a control signal to multiple SBMUs, and the multiple SBMUs will control the closing and opening of the corresponding multiple branch relays 51.

[0071] The main control unit 42 controls multiple branch control units based on external instructions and self-test results, which is beneficial to the energy management and optimization of the entire system, thereby realizing the circulation of the branch control loop 50, reducing the pressure difference of each branch control loop 50, and improving the stability and reliability of the battery management system 400.

[0072] According to some embodiments of the present application, the external instruction is a high-voltage instruction issued by the vehicle-mounted controller; the main control unit 42 is also configured to: in response to receiving the high-voltage instruction, perform a self-check on the battery status; in response to the self-check result being a pass, control the main circuit relay 41 to close, and issue a control instruction for instructing the closing of the branch relay 51 to each of the multiple branch control units 52.

[0073] The vehicle control unit (VCU) is the core control unit of new energy vehicles. It is responsible for vehicle mode and energy management, drive control, safety management, high-voltage system power management, fault diagnosis and processing, etc.

[0074] like Figure 4 As shown, the VCU sends a "high voltage command" to the control unit 42 (i.e., MBMU). After receiving the "high voltage command", the MBMU will trigger a self-test. During the self-test, a fault list will be called. The object content of the fault list can be a battery cell, a battery pack, insulation performance, or the communication status inside or outside the battery management system 400. If the self-test passes, that is, there is no fault, the MBMU will control the main circuit relay 41 to close to achieve the conduction of the main control circuit 40. At the same time, the MBMU will send a "high voltage command" to the SBMU to control the branch relay 51 to close to achieve the conduction of the corresponding multiple branch control circuits.

[0075] The main control unit 42 controls the main circuit relay 41 based on the self-test result and controls the branch circuit relay 51 through the branch control unit 52 to achieve high voltage, which is beneficial to the energy management and optimization of the entire system, reduces the probability of failure, and further improves battery performance.

[0076] According to some embodiments of the present application, the external instruction is a lower high voltage instruction issued by the vehicle-mounted controller; the main control unit 42 is also configured to: in response to receiving the lower high voltage instruction, perform a self-check on the battery status; and in response to the self-check result being passed, control the main circuit relay 41 to disconnect; wherein the branch relay 51 in each branch control circuit 50 in the multiple branch control circuits 50 remains closed.

[0077] like Figure 5 As shown, after receiving the "lower high voltage command" from the VCU, the MBMU will trigger a self-test. During the self-test, a fault list will be called. The object content of the fault list can be a battery cell, a battery pack, insulation performance, or the communication status inside or outside the battery management system 400. If the self-test passes, that is, there is no fault, the MBMU controls the main circuit relay 41 to disconnect to disconnect the main control circuit 40. It should be noted that the MBMU will not issue a control instruction to each branch control unit 52 in the multiple SBMUs to instruct the closing of the branch relay 51. In this case, the branch relay 51 in each branch control circuit 50 in the multiple branch control circuits 50 remains in a closed state.

[0078] After the main control unit 42 receives the high voltage command, the branch relay 51 remains closed when the main circuit relay 41 is disconnected, so that the multiple battery modules 30 are electrically connected. This is conducive to realizing the circulation of the branch control circuit 50, reducing the pressure difference between the branches, and better exerting the battery capacity.

[0079] According to some embodiments of the present application, the external instruction includes a lower high voltage instruction issued by the vehicle-mounted controller; the main control unit 42 is also configured to: in response to receiving the lower high voltage instruction, perform a self-inspection of the battery status; in response to the self-inspection result being failed, issue a control instruction for instructing to disconnect the branch circuit relay 51 to the branch control unit 52 corresponding to the branch control circuit 50 where the battery module 30 that failed the self-inspection is located.

[0080] like Figure 5 As shown, after receiving the "lower high voltage command" from the VCU, the MBMU will trigger a self-check. Based on the result of the self-check failure, the corresponding SBMU will control the branch relay 51 it controls to disconnect. It should be understood that this process does not affect the electrical connection of the branch control circuit 50 without faults.

[0081] By disconnecting the branch relay 51 when the self-test fails, the probability of failure can be reduced and the reliability and safety of the battery management system 400 can be improved.

[0082] According to some embodiments of the present application, the main control unit 42 is further configured to: in response to a self-test result being a failure, send a control instruction for instructing to limit the output power to the on-board controller.

[0083] like Figure 5 As shown, the result of the failure of the self-test result may be that all of the multiple branch control loops 50 are faulty, or some of the multiple branch control loops 50 are faulty, and the MBMU sends a control instruction for instructing to disconnect the branch relay 51 to the SBMU corresponding to the faulty branch control loop 50, so that the faulty branch control loop 50 is disconnected. In addition, the MBMU sends a control instruction for instructing to limit the output power to the VCU to support the reduced number of branch control loops 50.

[0084] Limiting the output power by the self-test failure result is beneficial to improving the flexibility and reliability of the battery management system 400, and is beneficial to reducing energy loss and improving energy utilization efficiency.

[0085] According to some embodiments of the present application, the external instruction is a lower high voltage instruction issued by an external battery exchange device; the main control unit 42 is also configured to: in response to receiving the lower high voltage instruction, control the main circuit relay 41 to disconnect, and issue a lower high voltage instruction to each of the multiple branch control units 52.

[0086] like Figure 6 As shown, the external battery swapping device may be a battery swapping station. In some embodiments, the battery swapping station first establishes a communication connection with the battery management system 400 (which may be a Bluetooth communication connection). Then, based on the communication connection between the battery swapping station and the battery management system 400, the battery swapping station sends a "lower high voltage instruction" to the battery management system 400. Finally, in response to the "lower high voltage instruction" sent by the battery swapping station, the MBMU controls the main circuit relay 41 to disconnect and further sends a "lower high voltage instruction" to the SBMU. The SBMU responds to the "lower high voltage instruction" sent by the MBMU to disconnect the branch circuit relay 51.

[0087] The main control unit 42 receives the high-voltage lowering instruction issued by the external battery replacement equipment, thereby controlling the disconnection of the main circuit relay 41 and the indirect control branch relay 51, which is beneficial to the energy management and optimization of the entire system and improves the battery performance.

[0088] An embodiment of the present application provides a control method for a battery management system, which is applied to a battery management system 400 of some embodiments of the present application, and the control method includes: S61, obtaining an external instruction; the external instruction includes an upper high voltage instruction or a lower high voltage instruction; S62, based on the external instruction, controlling the main circuit relay 41 to close or open, and / or the branch relay 51 to close or open.

[0089] like Figure 7 The control method of the battery management system of some embodiments of the present application is shown, and the control method of the battery management system is used to control the battery management system.

[0090] In S61, the "upper high voltage instruction" can be issued by the VCU, and the "lower high voltage instruction" can be sent by the VCU and the external power exchange device, where the external instruction is sent to the MBMU. In S62, the MBMU will perform corresponding operations on the main circuit relay 41 and the branch relay 51 based on the external instruction.

[0091] If the VCU sends a "high voltage command" to the MBMU, the MBMU will trigger a self-test after receiving the "high voltage command". During the self-test, a fault list will be called. The object content of the fault list can be the battery cell 20, the battery pack, the insulation performance, or the communication status inside or outside the battery management system 400. If the self-test passes, that is, there is no fault, the MBMU will control the main circuit relay 41 to close to achieve the conduction of the main control circuit 40, and at the same time, the MBMU will send a "high voltage command" to the SBMU to control the branch relay 51 to close to achieve the conduction of the corresponding multiple branch control circuits.

[0092] When the MBMU receives the "lower high voltage command" from the VCU, it will trigger a self-check. If the self-check passes, that is, there is no fault, the MBMU controls the main circuit relay 41 to disconnect to disconnect the main control circuit 40. It should be noted that the MBMU will not issue a control instruction for instructing each branch control unit 52 in the multiple SBMUs to close the branch relay 51. In this case, the branch relay 51 in each branch control circuit 50 in the multiple branch control circuits 50 remains in a closed state.

[0093] If the external battery replacement device sends a "lower high voltage command" to the battery management system 400, the MBMU responds to the "lower high voltage command" sent by the battery replacement station, the MBMU controls the main circuit relay 41 to disconnect and further sends a "lower high voltage command" to the SBMU, and the SBMU responds to the "lower high voltage command" sent by the MBMU to disconnect the branch circuit relay 51.

[0094] In this way, after the main circuit relay 41 is disconnected, the branch circuit relay 51 is set to remain in a closed state, so that the multiple battery modules 30 are electrically connected. This is conducive to achieving the circulation balance of the branch control circuit 50, eliminating the pressure difference of multiple branch control circuits, improving the battery performance, and better exerting the battery capacity.

[0095] Embodiments of the present application provide a battery device, including a battery management system 400 of some embodiments of the present application.

[0096] In addition to the battery management system 400 of the embodiment of the present application, the battery device may also include a battery module composed of multiple battery cells connected in series and in parallel, a thermal management system responsible for maintaining the battery operating within an optimal temperature range to ensure the performance and life of the battery, an electrical system for internal and external electrical connections of the battery system, and a structural member for support. The effects of the battery device of the embodiment of the present application are not repeated here.

[0097] Embodiments of the present application provide a vehicle, including a battery device according to some embodiments of the present application, or a battery management system 400 according to some embodiments of the present application.

[0098] The vehicle provided in the embodiment of the present application includes not only a battery device or a battery management system 400, but also an electric motor for providing power, an electronic control system for providing power output and control, a steering system, a braking system, a suspension system, a lighting system, and a body structure. The effects of the vehicle in the embodiment of the present application are not described in detail.

[0099] like Figure 3 As shown, a battery management system 400 of an embodiment of the present application is used to control a battery, wherein the battery includes a plurality of battery modules 30. The battery management system 400 includes a main control circuit 40, a plurality of branch control circuits 50, a main circuit relay 41, a branch circuit relay 51 and a controller.

[0100] The main control circuit 40 includes a main circuit relay 41 for controlling the on / off of the main control circuit 40, and a plurality of branch control circuits 50 are connected to the plurality of battery modules 30 in a one-to-one correspondence, and are connected to the main control circuit 40 in parallel, and each of the plurality of branch control circuits 50 includes a branch relay 51 for controlling the on / off of the corresponding branch control circuit 50. Among them, the main circuit relay 41 includes a main circuit positive relay 411 and a main circuit negative relay 412, and the branch relay 51 includes a branch positive relay 511 and a branch negative relay 512, and the branch relay 51 is a magnetic attraction relay.

[0101] The controller includes a main control unit 42 (MBMU) for controlling the main control loop 40, and a plurality of branch control units 52 (SBMU) arranged in one-to-one correspondence with the plurality of branch control loops 50 and for controlling the corresponding branch relays 51, and the main control unit 42 is signal-connected to the plurality of branch control units 52; wherein the main control unit 42 is configured to receive external instructions, and control the main loop relay 41 to close or open according to the external instructions, and send control signals to the plurality of branch control units 52; each of the plurality of branch control units 52 is configured to control the corresponding branch relay 51 to close or open based on the control signal sent by the main control unit 42.

[0102] The following is a partial logic example of the battery management system 400 according to an embodiment of the present application. Figure 4-6 As shown: (I) If the external command is a "high voltage command" issued by the vehicle controller (VCU), the main control unit 42 performs a self-check on the battery status after receiving the "high voltage command"; and in response to the self-check result being passed, controls the main circuit relay 41 to close, and issues a control command for instructing each of the multiple branch control units 52 to close the branch circuit relay 51. The self-check content is one or more of abnormal battery cell voltage or temperature, abnormal battery pack total current or voltage, insulation fault, and communication fault.

[0103] (ii) If the external command is a "lower high voltage command" issued by the vehicle-mounted controller (VCU), the main control unit 42 performs a self-check on the battery status after receiving the "lower high voltage command"; in response to the self-check result being a pass, the main circuit relay 41 is controlled to be disconnected; wherein, the branch relay 51 in each branch control circuit 50 of the multiple branch control circuits 50 remains closed; in response to the self-check result being a fail, a control command for instructing the branch relay 51 to be disconnected is sent to the branch control unit 52 corresponding to the branch control circuit 50 where the battery module 30 that failed the self-check is located, and a control command for instructing the output power to be limited is sent to the vehicle-mounted controller.

[0104] (iii) If the external instruction is a "lower high voltage instruction" issued by an external battery swapping device (which may be a battery swapping station), the main control unit 42 controls the main circuit relay 41 to disconnect after receiving the "lower high voltage instruction", and sends a control instruction to each of the multiple branch control units 52 to instruct the branch circuit relay 51 to disconnect.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery management system, It is characterized in that The battery management system is used to control a battery, the battery includes a plurality of battery modules, and the battery management system includes: A main control circuit, including a main circuit relay for controlling the on and off of the main control circuit; A plurality of branch control loops, each of which is connected to the plurality of battery modules in a one-to-one correspondence and connected to the main control loop in parallel, each of which includes a branch relay for controlling the on / off of the corresponding branch control loop; Among them, the branch relay is a normally closed relay, and the control signal used to control the closing or opening of the normally closed relay is a pulse signal. The branch relay is configured to remain closed after the main circuit relay is disconnected, so that the multiple battery modules remain electrically connected after the battery stops supplying power to the outside.

2. The battery management system according to claim 1, It is characterized in that The branch relay is a magnetic relay.

3. The battery management system according to claim 2, It is characterized in that The branch relay is configured to be disconnected in a controlled manner when a self-test result of a battery module of the branch control loop in which the branch relay is located fails, or when the battery needs to be replaced.

4. The battery management system according to any one of claims 1 to 3, It is characterized in that Also includes: A controller, comprising a main control unit for controlling the main control loop, and a plurality of branch control units arranged in one-to-one correspondence with the plurality of branch control loops and for controlling corresponding branch relays, wherein the main control unit is signal-connected to the plurality of branch control units; Wherein, the main control unit is configured to receive external instructions, and control the main circuit relay to close or open according to the external instructions, and send control signals to the multiple branch control units; Each of the plurality of branch control units is configured to control the corresponding branch relay to close or open based on a control signal sent by the main control unit.

5. The battery management system according to claim 4, It is characterized in that The main control unit is further configured to perform a self-check on a battery status in response to receiving an external command, and to send a control signal to the plurality of branch control units based on the external command and a self-check result.

6. The battery management system according to claim 5, It is characterized in that The external command is a high voltage command issued by the vehicle controller. The main control unit is further configured to: in response to receiving the upper high voltage instruction, perform a self-check on the battery status; and In response to the self-test result being passed, the main circuit relay is controlled to be closed, and a control instruction for instructing to close the branch circuit relay is issued to each of the plurality of branch control units.

7. The battery management system according to claim 5, It is characterized in that The external command is a high voltage lowering command issued by the vehicle controller. The main control unit is further configured to: in response to receiving the lower high voltage instruction, perform a self-check on the battery status; and in response to a self-check result being a pass, control the main circuit relay to be disconnected; Wherein, the branch relay in each branch control loop of the multiple branch control loops remains closed.

8. The battery management system according to claim 5, It is characterized in that The external command includes a high voltage lowering command issued by the vehicle controller. The main control unit is further configured to: in response to receiving the lower high voltage instruction, perform a self-check on the battery status; and In response to a failure in the self-test result, a control instruction for instructing to disconnect the branch relay is sent to a branch control unit corresponding to the branch control circuit where the battery module that failed the self-test is located.

9. The battery management system according to claim 8, It is characterized in that The main control unit is further configured to: in response to a self-test result being a failure, send a control instruction for instructing to limit the output power to the on-board controller.

10. The battery management system according to claim 5, It is characterized in that The external command is a high voltage lowering command issued by an external battery replacement device. The main control unit is further configured to, in response to receiving the high-voltage lowering instruction, control the main circuit relay to be disconnected, and issue a high-voltage lowering instruction to each of the plurality of branch control units.

11. A control method for a battery management system, applied to the battery management system according to any one of claims 1 to 10, It is characterized in that The control method comprises: Obtaining an external instruction; the external instruction includes an upper high voltage instruction or a lower high voltage instruction; Based on the external command, the main circuit relay is controlled to be closed or opened, and / or the branch circuit relay is controlled to be closed or opened.

12. A battery device comprising the battery management system according to any one of claims 1 to 10.

13. A vehicle, comprising the battery device according to claim 12, or the battery management system according to any one of claims 1-10.

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