Fault diagnosis method, diagnosis device and diagnosis device for battery relay

Abstract

The invention discloses a fault diagnosis method, a diagnosis device and a diagnosis device for a battery relay, and relates to the technical field of battery fault diagnosis. The method comprises the steps that a relay control instruction is responded, a positive-end relay and a negative-end relay of a battery are controlled through corresponding control loops, one of the positive-end relay control loop and the negative-end relay control loop is high-side control, and the other one of the positive-end relay control loop and the negative-end relay control loop is low-side control; fault diagnosis is carried out on the positive end relay according to the relay control instruction, the feedback information of the positive end relay control loop and the outer side voltage; and performing fault diagnosis on the negative end relay according to the relay control instruction, the feedback information of the negative end relay control loop and the outside voltage. According to the method, fault diagnosis is carried out on the relays according to corresponding control instructions, loop feedback and outer voltage based on heterogeneous unilateral control of the positive-end relays and the negative-end relays, and the fault diagnosis coverage is improved.

Description

Technical Field

[0001] This application relates to the field of fault diagnosis technology, and in particular to a fault diagnosis method for a battery relay, a fault diagnostic tool for a battery relay, a computer-readable storage medium, a fault diagnosis device for a battery relay, and a vehicle. Background Technology

[0002] Battery management systems (BMS) play a crucial role in electric and hybrid vehicles, managing the battery's charging and discharging process and ensuring safety. Relays, as important components controlling the high-voltage circuit, are used to connect and disconnect the high-voltage circuit under normal operating conditions, and to disconnect it in abnormal situations to protect the battery and vehicle electrical system from overload, short circuits, or further malfunctions that could lead to thermal runaway.

[0003] In related technologies, relay products with low failure rates are selected to meet high-level functional safety requirements, but this method increases the complexity of the system and the application cost. Summary of the Invention

[0004] This application aims to solve the technical problems mentioned in the background. Therefore, the first objective of this application is to propose a fault diagnosis method for battery relays, which, based on heterogeneous unilateral control of the positive and negative relays, enables fault monitoring of both the positive and negative relays. This reduces the fault diagnosis cost and control circuit design complexity of battery relays while meeting high functional safety requirements.

[0005] The second objective of this application is to provide a fault diagnostic tool for battery relays.

[0006] The third objective of this application is to provide a computer-readable storage medium.

[0007] The fourth objective of this application is to provide a fault diagnosis device for a battery relay.

[0008] The fifth objective of this application is to propose a vehicle.

[0009] To achieve the above objectives, a first aspect of this application proposes a fault diagnosis method for a battery relay. The battery relay includes a positive terminal relay corresponding to the positive terminal of the battery and a negative terminal relay corresponding to the negative terminal of the battery. The method includes: responding to a relay control command, controlling the positive terminal relay through a first control circuit corresponding to the positive terminal relay, and controlling the negative terminal relay through a second control circuit corresponding to the negative terminal relay, wherein one of the first control circuit and the second control circuit is a high-side control circuit and the other is a low-side control circuit; acquiring feedback information from the first control circuit and / or the external voltage of the positive terminal relay, and performing fault diagnosis on the positive terminal relay based on the relay control command, the feedback information from the first control circuit, and the external voltage of the positive terminal relay; acquiring feedback information from the second control circuit and / or the external voltage of the negative terminal relay, and performing fault diagnosis on the negative terminal relay based on the relay control command, the feedback information from the second control circuit, and the external voltage of the negative terminal relay.

[0010] According to the battery relay fault diagnosis method of this application embodiment, the battery relay includes a positive terminal relay and a negative terminal relay. Responding to a relay control command, the positive terminal relay is controlled through a first control loop, and the negative terminal relay is controlled through a second control loop. One of the first and second control loops is a high-side control, and the other is a low-side control. Feedback information from the first and second control loops and / or the external voltages of the positive and negative terminal relays are acquired. Fault diagnosis is performed on the positive and negative terminal relays based on the relay control command, feedback information, and external voltages. Therefore, this method, based on heterogeneous unilateral control of the positive and negative terminal relays, achieves fault monitoring of both relays, reducing the fault diagnosis cost and control loop design complexity of the battery relay while meeting high functional safety requirements.

[0011] In addition, the battery relay fault diagnosis method according to the above embodiments of this application may also have the following additional technical features: According to one embodiment of this application, the fault diagnosis method for the battery relay further includes: generating a multi-point alarm signal and controlling the battery to enter a degradation mode when it is determined that the positive terminal relay is in a fault abnormal state based on the fault diagnosis result of the positive terminal relay and the negative terminal relay is in a fault abnormal state based on the fault diagnosis result of the negative terminal relay; and generating a latent fault alarm signal when it is determined that the positive terminal relay is in a fault abnormal state based on the fault diagnosis result of the positive terminal relay or the negative terminal relay is in a fault abnormal state based on the fault diagnosis result of the negative terminal relay.

[0012] According to one embodiment of this application, the fault diagnosis method for the battery relay further includes: abnormal fault states including relay sticking fault and / or control circuit abnormality.

[0013] According to one embodiment of this application, when the first control loop is a low-side control loop, the first control loop includes a controllable switch, and the feedback information of the first control loop is the output current of the controllable switch. Fault diagnosis of the positive terminal relay is performed based on the relay control command, the feedback information of the first control loop, and the external voltage of the positive terminal relay, including: determining the state of the target relay according to the relay control command; determining that the positive terminal relay has a control loop abnormality when the target relay is in a closed state and the output current of the controllable switch is less than or equal to a preset current threshold, or when the target relay is in an open state and the output current of the controllable switch is greater than a preset current threshold; and determining that the positive terminal relay has a sticking fault when the target relay is in a closed state, the output current of the controllable switch is less than or equal to a preset current threshold, and the external voltage of the positive terminal relay is greater than a preset voltage threshold, or when the target relay is in an open state, the output current of the controllable switch is less than or equal to a preset current threshold, and the external voltage of the positive terminal relay is less than a preset voltage threshold.

[0014] According to one embodiment of this application, when the second control loop is a high-side control loop, the second control loop includes a high-side driver chip, and the feedback information of the second control loop is the output level of the high-side driver chip. Fault diagnosis of the negative relay is performed based on the relay control command, the feedback information of the second control loop, and the external voltage of the negative relay. This includes: determining the target relay state and the target level corresponding to the target relay state based on the relay control command; determining that the negative relay has a control loop abnormality when the output level of the high-side driver chip does not match the target level; and determining that the negative relay has an adhesion fault when the target relay state is closed, the output level of the high-side driver chip is the target level corresponding to the closed state, and the external voltage of the negative relay is greater than a preset voltage threshold, or when the target relay state is open, the output level of the high-side driver chip is the target level corresponding to the open state, and the external voltage of the negative relay is less than a preset voltage threshold.

[0015] To achieve the above objectives, a second aspect of this application provides a fault diagnostic tool for a battery relay, including a memory, a processor, and a fault diagnostic program for the battery relay stored in the memory and executable on the processor. When the processor executes the fault diagnostic program for the battery relay, it implements the aforementioned fault diagnostic method for the battery relay.

[0016] According to the battery relay fault diagnostic device of the present application embodiment, when the processor executes the battery relay fault diagnosis program, the battery relay fault diagnosis method is implemented. Based on the above-mentioned battery relay fault diagnosis method, the fault diagnosis cost of battery relay and the complexity of control circuit design are reduced while meeting the requirements of high functional safety level.

[0017] To achieve the above objectives, a third aspect of this application provides a computer-readable storage medium storing a fault diagnosis program for a battery relay, which, when executed by a processor, implements the aforementioned fault diagnosis method for the battery relay.

[0018] According to the embodiments of this application, a computer-readable storage medium storing a fault diagnosis program for a battery relay stored thereon implements the aforementioned fault diagnosis method for a battery relay when executed by a processor. Based on the aforementioned fault diagnosis method for a battery relay, the fault diagnosis cost of the battery relay and the complexity of the control circuit design are reduced while meeting the requirements of a high functional safety level.

[0019] To achieve the above objectives, a fourth aspect of this application provides a fault diagnosis device for a battery relay. The battery relay includes a positive terminal relay corresponding to the positive terminal of the battery and a negative terminal relay corresponding to the negative terminal of the battery. The device includes: a control module, configured to control the positive terminal relay through a first control circuit corresponding to the positive terminal relay and control the negative terminal relay through a second control circuit corresponding to the negative terminal relay in response to a relay control command, wherein one of the first control circuit and the second control circuit is a high-side control circuit and the other is a low-side control circuit; a first acquisition module, configured to acquire feedback information from the first control circuit and / or the external voltage of the positive terminal relay; a second acquisition module, configured to acquire feedback information from the second control circuit and / or the external voltage of the negative terminal relay; and a fault diagnosis module, configured to perform fault diagnosis on the positive terminal relay based on the relay control command, the feedback information from the first control circuit, and the external voltage of the positive terminal relay, and to perform fault diagnosis on the negative terminal relay based on the relay control command, the feedback information from the second control circuit, and the external voltage of the negative terminal relay.

[0020] According to the battery relay fault diagnosis device of this application embodiment, the control module responds to the relay control command, controls the positive relay through a first control loop corresponding to the positive relay, and controls the negative relay through a second control loop corresponding to the negative relay. One of the first and second control loops is a high-side control loop, and the other is a low-side control loop. A first acquisition module acquires feedback information from the first control loop and / or the external voltage of the positive relay, and a second acquisition module acquires feedback information from the second control loop and / or the external voltage of the negative relay. The fault diagnosis module performs fault diagnosis on the positive relay based on the relay control command, the feedback information from the first control loop, and the external voltage of the positive relay, and performs fault diagnosis on the negative relay based on the relay control command, the feedback information from the second control loop, and the external voltage of the negative relay. Therefore, this device, based on heterogeneous unilateral control of the positive and negative relays, achieves fault monitoring of both the positive and negative relays, reducing the fault diagnosis cost and control loop design complexity of the battery relay while meeting high functional safety requirements.

[0021] To achieve the above objectives, a fifth aspect of this application provides a vehicle comprising: a power battery; a battery relay, including a positive terminal relay corresponding to the positive terminal of the power battery and a negative terminal relay corresponding to the negative terminal of the power battery; and a battery management system, configured to, in response to a relay control command, control the positive terminal relay via a first control circuit corresponding to the positive terminal relay and control the negative terminal relay via a second control circuit corresponding to the negative terminal relay, wherein one of the first and second control circuits is a high-side control circuit and the other is a low-side control circuit, and to acquire feedback information from the first control circuit and / or the external voltage of the positive terminal relay, and to perform fault diagnosis on the positive terminal relay based on the relay control command, the feedback information from the first control circuit, and the external voltage of the positive terminal relay, and to acquire feedback information from the second control circuit and / or the external voltage of the negative terminal relay, and to perform fault diagnosis on the negative terminal relay based on the relay control command, the feedback information from the second control circuit, and the external voltage of the negative terminal relay.

[0022] In addition, the vehicle according to the above embodiments of this application may also have the following additional technical features: According to one embodiment of this application, the battery management system is further configured to: when it is determined that the positive terminal relay is in a normal state based on the fault diagnosis result of the positive terminal relay and the negative terminal relay is in a normal state based on the fault diagnosis result of the negative terminal relay, acquire the operating data of the power battery; when the operating data of the battery exceeds a preset allowable range, disconnect the positive terminal relay through the first control circuit and the second control circuit corresponding to the positive terminal relay, and disconnect the negative terminal relay through the first control circuit and the second control circuit corresponding to the negative terminal relay.

[0023] According to the vehicle embodiment of this application, the battery management system responds to a relay control command by controlling the positive relay through a first control circuit corresponding to the positive relay and controlling the negative relay through a second control circuit corresponding to the negative relay. One of the first and second control circuits is a high-side control circuit, and the other is a low-side control circuit. The system acquires feedback information from the first control circuit and / or the external voltage of the positive relay, and performs fault diagnosis on the positive relay based on the relay control command, the feedback information from the first control circuit, and the external voltage of the positive relay. Similarly, it acquires feedback information from the second control circuit and / or the external voltage of the negative relay, and performs fault diagnosis on the negative relay based on the relay control command, the feedback information from the second control circuit, and the external voltage of the negative relay. This reduces the fault diagnosis cost of the battery relay and the complexity of the control circuit design while meeting high functional safety requirements, thereby improving the vehicle's operational stability. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the architecture of a battery system according to a specific embodiment of this application; Figure 2 This is a flowchart of a battery relay fault diagnosis method according to some embodiments of this application; Figure 3 This is a flowchart of a battery relay fault diagnosis method according to a specific embodiment of this application; Figure 4 This is a block diagram of a fault diagnostic device for a battery relay according to some embodiments of this application; Figure 5 This is a connection diagram of a fault diagnosis device for a battery relay according to some embodiments of this application; Figure 6 This is a block diagram of a vehicle according to some embodiments of this application. Detailed Implementation

[0025] The following describes in detail, with reference to the accompanying drawings, a battery relay fault diagnosis method, a battery relay fault diagnostic tool, a computer-readable storage medium, a battery relay fault diagnosis device, and a vehicle according to embodiments of this application.

[0026] Battery management systems (BMS) play a crucial role in electric and hybrid vehicles, managing the battery's charging and discharging processes and ensuring safety. Relays, as vital components controlling the high-voltage circuit, are used to connect and disconnect the high-voltage circuit under normal operating conditions, and to disconnect it in abnormal situations to protect the battery and vehicle's electrical system from overload, short circuits, or further malfunctions that could lead to thermal runaway. Due to these roles in the BMS, relays are responsible for executing the main safety mechanisms at the system level within functional safety requirements.

[0027] In related technologies, in order to meet high-level functional safety requirements, in addition to selecting relay products with low failure rates, bilateral high / low side control is implemented for the low-voltage control circuits of the positive and negative relays. Although this improves safety performance, it increases the complexity and cost of the system.

[0028] To address the aforementioned technical problems, this application proposes a fault diagnosis method for battery relays. This method is based on heterogeneous unilateral control of the positive and negative relays to achieve fault diagnosis of both the positive and negative relays, thereby meeting high functional safety requirements and reducing the cost of fault diagnosis and the complexity of control circuit design for battery relays.

[0029] The fault diagnosis method for the battery relay according to the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0030] In some embodiments of this application, the battery relay includes a positive terminal relay corresponding to the positive terminal of the battery and a negative terminal relay corresponding to the negative terminal of the battery.

[0031] Specifically, refer to Figure 1 As shown, a battery system typically consists of battery modules, high-voltage accessories (current sensors, relays), and a battery management system (BMS). Within a battery module, cells are electrically connected via series and parallel connections. These connections between modules establish a voltage platform and capacity level that meets the vehicle's requirements. Cell voltage is typically acquired by the BMS's analog front-end voltage acquisition circuit, while temperature is usually acquired by the BMS's analog front-end acquisition circuit in conjunction with a temperature sensor. The BMS can control the positive, negative, pre-charge, fast-charge positive, and fast-charge negative relays to disconnect and connect the battery system circuits. Upon detecting a battery system malfunction, the BMS can disconnect the battery system from external high-voltage connections via relays.

[0032] Figure 2This is a flowchart of a fault diagnosis method for a battery relay according to some embodiments of this application.

[0033] Reference Figure 2 The battery relay fault diagnosis method of this application embodiment includes the following steps: S1, in response to the relay control command, controls the positive relay through the first control circuit corresponding to the positive relay, and controls the negative relay through the second control circuit corresponding to the negative relay. One of the first control circuit and the second control circuit is the high-side control circuit, and the other circuit is the low-side control circuit.

[0034] Specifically, refer to Figure 1 The positive terminal relay corresponding to the positive terminal of the battery can be a positive relay, a pre-charge relay, or a fast-charge positive relay. The negative terminal relay corresponding to the negative terminal of the battery can be a negative relay or a fast-charge negative relay. Each relay corresponds to a separate control circuit. The first control circuit includes the positive relay control circuit, the pre-charge relay control circuit, and the fast-charge positive relay control circuit; the second control circuit includes the negative relay control circuit and the fast-charge negative relay control circuit.

[0035] The relay control commands include relay closing control commands and relay opening control commands. In response to the relay closing control command, the battery management system controls the positive relay through a first control loop, changing the positive relay from an open state to a closed state. Then, through a second control loop, it controls the negative relay, changing the negative relay from an open state to a closed state, thus connecting the battery system circuit. Conversely, in response to the relay opening control command, the battery management system controls the positive relay through the first control loop, restoring it from a closed state to an open state. Then, through the second control loop, it controls the negative relay, restoring it from a closed state to an open state, thus disconnecting the battery system circuit.

[0036] The high-side control circuit and the low-side control circuit control the opening and closing of the relay contacts on the high-voltage side by controlling the energization of the relay coil on the low-voltage side, thereby controlling the conduction or disconnection of the battery system circuit. Specifically, the high-side control circuit controls the energization of the relay coil by controlling the connection between the high-potential side of the relay coil and the power supply; the low-side control circuit controls the energization of the relay coil by controlling the connection between the ground potential side of the relay coil and the ground terminal.

[0037] When the first control loop is a high-side control loop, the second control loop is a low-side control loop. In this case, the positive relay control loop, the pre-charge relay control loop, and the fast-charge positive relay control loop are all high-side control loops, while the negative relay control loop and the fast-charge negative relay control loop are all low-side control loops. Conversely, when the first control loop is a low-side control loop, the second control loop is a high-side control loop. In this case, the positive relay control loop, the pre-charge relay control loop, and the fast-charge positive relay control loop are all low-side control loops, while the negative relay control loop and the fast-charge negative relay control loop are all high-side control loops. Thus, the positive and negative relays are controlled based on a heterogeneous single-side control strategy.

[0038] S2, obtain feedback information from the first control loop and / or the external voltage of the positive terminal relay, and perform fault diagnosis on the positive terminal relay based on the relay control command, the feedback information from the first control loop, and the external voltage of the positive terminal relay.

[0039] Specifically, the feedback information of the first control loop refers to the feedback information of the switching element or driver chip used in the first control loop, and the external voltage of the positive terminal relay refers to the voltage across the contacts of the positive terminal relay. Fault diagnosis of the positive terminal relay is performed based on the control command of the positive terminal relay, the feedback information of the first control loop, and the external voltage of the positive terminal relay. For example, the presence of a control loop malfunction can be determined by combining the relay control command and the feedback information of the first control loop; the presence of a contact sticking fault in the positive terminal relay can also be determined by combining the relay control command and the external voltage of the positive terminal relay.

[0040] S3, obtain feedback information from the second control loop and / or the external voltage of the negative terminal relay, and perform fault diagnosis on the negative terminal relay based on the relay control command, the feedback information from the second control loop, and the external voltage of the negative terminal relay.

[0041] Specifically, the feedback information of the second control loop refers to the feedback information of the switching element or driver chip used in the second control loop, and the external voltage of the negative relay refers to the voltage across the contacts of the negative relay. Fault diagnosis of the negative relay is performed based on the control command of the negative relay, the feedback information of the first control loop, and the external voltage of the negative relay. For example, the presence of a control loop malfunction can be determined by combining the relay control command and the feedback information of the second control loop; the presence of a contact sticking fault in the negative relay can be determined by combining the relay control command and the external voltage of the negative relay.

[0042] In some embodiments of this application, the fault diagnosis method for the battery relay further includes: generating a multi-point alarm signal and controlling the battery to enter a degradation mode when it is determined that the positive relay is in a faulty state based on the fault diagnosis result of the positive relay and the negative relay is in a faulty state based on the fault diagnosis result of the negative relay; and generating a latent fault alarm signal when it is determined that the positive relay is in a faulty state based on the fault diagnosis result of the positive relay or the negative relay is in a faulty state based on the fault diagnosis result of the negative relay.

[0043] In other words, when the fault diagnosis results determine that both the positive and negative relays are in a faulty state, a multi-point alarm signal is generated and the battery is controlled to enter a degraded mode; when the fault diagnosis results determine that either the positive or negative relay is in a faulty state, a latent fault alarm signal is generated.

[0044] Among them, multi-point alarm signals and latent fault alarm signals will be transmitted through Figure 1 The vehicle controller transmits the information to the vehicle's instrument panel or central control screen, displaying it as a warning light or text prompt to remind the driver to identify the type of fault and take further action.

[0045] Controlling the battery to enter degrade mode can include reducing the battery's input / output power, reducing the battery's charging and discharging current, limiting the battery's peak power, and reducing the battery's available power range. By implementing the above degrade and power reduction operations, potential risks caused by relay failures are avoided, and high-level functional safety requirements can be met.

[0046] In addition, if the fault diagnosis results determine that both the positive and negative relays are in normal condition, further diagnosis can be made to determine whether there are faults in the power system that violate safety functions, such as high-voltage interlock circuit faults, insulation resistance faults, high-voltage sampling circuit faults, etc. If there are any of the above faults that violate functional safety requirements, the positive and negative relays should be disconnected at the same time to enter a safe state; if there are no such faults that violate functional safety requirements, no operation is required.

[0047] In some embodiments of this application, the fault diagnosis method for the battery relay further includes: abnormal fault states including relay sticking faults and / or control circuit abnormalities.

[0048] Specifically, relay sticking fault refers to the phenomenon where, after a disconnect command is issued, the relay contacts fail to separate properly due to an abnormality and remain closed, causing the circuit to remain energized. Control circuit abnormality refers to the abnormality of the relay circuit in the first or second control circuit due to various reasons. For example, in a low-voltage control circuit, there are some basic components required for control, including resistors and capacitors. If these components fail due to a short circuit, the relay's control pin will remain in a constantly active state, that is, the relay's control pin will remain continuously active, always maintaining a high or low level, making it impossible to switch the relay coil on or off based on the relay control command.

[0049] In some embodiments of this application, when the first control loop is a low-side control loop, the first control loop includes a controllable switch, and the feedback information of the first control loop is the output current of the controllable switch. Fault diagnosis of the positive terminal relay is performed based on the relay control command, the feedback information of the first control loop, and the external voltage of the positive terminal relay. This includes: determining the state of the target relay based on the relay control command; determining that the positive terminal relay has a control loop abnormality when the target relay is in a closed state and the output current of the controllable switch is less than or equal to a preset current threshold, or when the target relay is in an open state and the output current of the controllable switch is greater than a preset current threshold; and determining that the positive terminal relay has a sticking fault when the target relay is in a closed state, the output current of the controllable switch is less than or equal to a preset current threshold, and the external voltage of the positive terminal relay is greater than a preset voltage threshold, or when the target relay is in an open state, the output current of the controllable switch is less than or equal to a preset current threshold, and the external voltage of the positive terminal relay is less than a preset voltage threshold.

[0050] Specifically, when the first control loop is a low-side control loop, the controllable switch of the first control loop is connected in series between the relay coil and ground. The controllable switch can be a transistor, MOSFET, or other similar device. The main control chip of the battery management system collects the output current of the controllable switch and combines it with the target relay state indicated by the relay control command to determine the feedback information of the first control loop. It is understood that, to ensure power supply safety, the positive and negative relays are normally open relays, meaning the relay contacts are initially open and close after energization.

[0051] When the target relay is in the closed state, the controllable switch needs to be closed via the first control circuit to energize the relay coil. The magnetic field generated by the energized coil then activates the relay armature, causing the relay contacts to actuate and close the positive relay. A preset current threshold is used to determine if the relay coil is energized. This threshold can be determined based on the minimum operating current of the positive relay under normal coil energization. For example, the preset current threshold can be set slightly lower than the measured minimum holding current of the relay under normal conditions. During fault monitoring, if the output current of the controllable switch is less than or equal to the preset current threshold, the coil is considered not energized, which does not match the target relay's state requirement, indicating a control circuit abnormality in the positive relay. If the output current of the controllable switch is greater than the preset current threshold, the coil is considered energized, matching the target relay's state requirement, indicating a normal control circuit for the positive relay. The process for determining a control circuit abnormality in the positive relay is as follows: When the target relay is in the open state, the controllable switch needs to be opened via the first control circuit to de-energize the relay coil, thereby causing the relay armature to move the relay contacts back to the open state. At this time, if the output current of the controllable switch is less than or equal to the preset current threshold, the coil is considered to be in the de-energized state, matching the target relay state requirement, and the control circuit of the positive relay is normal; if the output current of the controllable switch is greater than the preset current threshold, the coil is considered to be energized, which does not match the target relay state requirement, and the control circuit of the positive relay is abnormal.

[0052] Assuming the control circuit of the positive relay is normal, the actual contact state of the positive relay is further identified based on its external voltage. If the actual contact state of the positive relay matches the state of the target relay, the positive relay contacts are considered normal; otherwise, the positive relay may have contact adhesion issues. It is understood that the external voltage of the relay is the voltage across the relay contacts. When the contacts are closed, the external voltage is lower; when the contacts are open, the external voltage is higher. The process for determining a positive relay adhesion fault is as follows: If the target relay is in a closed state and the output current of the controllable switch is less than or equal to the preset current threshold, the control circuit of the positive relay is considered to be normal. At this time, if the external voltage of the positive relay is greater than the preset voltage threshold, the contact is considered to be in an open state, which does not match the state of the target relay, and the positive relay is considered to have a sticking fault. If the external voltage of the positive relay is less than the preset voltage threshold, the contact is considered to be in a closed state, which matches the state of the target relay, and the positive relay is considered to have no sticking fault and the contact is in a normal state.

[0053] If the target relay is in the open state and the output current of the controllable switch is less than or equal to the preset current threshold, the control circuit of the positive relay is determined to be normal. At this time, if the external voltage of the positive relay is greater than the preset voltage threshold, the contact is considered to be in the open state, which matches the state of the target relay; if the external voltage of the positive relay is less than the preset voltage threshold, the contact is considered to be in the closed state, which does not match the state of the target relay, and the positive relay is considered to have a sticking fault.

[0054] In some embodiments of this application, when the second control loop is a high-side control loop, the second control loop includes a high-side driver chip, and the feedback information of the second control loop is the output level of the high-side driver chip. Fault diagnosis of the negative relay is performed based on the relay control command, the feedback information of the second control loop, and the external voltage of the negative relay. This includes: determining the target relay state and the target level corresponding to the target relay state based on the relay control command; determining that the negative relay has a control loop abnormality when the output level of the high-side driver chip does not match the target level; and determining that the negative relay has an adhesion fault when the target relay state is closed, the output level of the high-side driver chip is the target level corresponding to the closed state, and the external voltage of the negative relay is greater than a preset voltage threshold, or when the target relay state is open, the output level of the high-side driver chip is the target level corresponding to the open state, and the external voltage of the negative relay is less than a preset voltage threshold.

[0055] Specifically, when the second control loop is a high-side control loop, the second control loop includes a high-side driver chip to control the on and off of the coil, and the output level of the driver chip is collected as feedback information for the second control loop.

[0056] The target relay state includes a closed state and an open state, and the target level includes a high level and a low level, corresponding to the target relay state. For example, the target level corresponding to the closed state is a high level, and the target level corresponding to the open state is a low level. By comparing the output level of the driver chip with the target level, it is determined whether there is a control loop abnormality. That is, when the output level of the high-side driver chip does not match the target level, it is considered that there is a control loop abnormality in the negative relay; when the output level of the high-side driver chip matches the target level, the control loop of the negative relay is considered normal.

[0057] Once it is determined that the control circuit of the negative relay is in a normal state, the actual contact state of the negative relay is further identified by combining the external voltage of the negative relay to determine whether contact sticking has occurred. The specific judgment process is as follows: When the target relay is in a closed state and the output level of the high-side driver chip is the target level corresponding to the closed state, the control circuit of the negative relay is considered normal. At this time, if the external voltage of the negative relay is less than the preset voltage threshold, it is determined that the contacts of the negative relay are in a closed state, which matches the state of the target relay, and the negative relay is in a normal state. If the external voltage of the negative relay is greater than the preset voltage threshold, it is determined that the contacts of the negative relay are in an open state, which does not match the state of the target relay, and the negative relay has a sticking fault.

[0058] When the target relay is in the open state and the output level of the high-side driver chip is the target level corresponding to the open state, the control circuit of the negative relay is considered to be normal. At this time, if the external voltage of the negative relay is less than the preset voltage threshold, it is determined that the contacts of the negative relay are in the closed state, which does not match the state of the target relay, and the negative relay has a sticking fault. If the external voltage of the negative relay is greater than the preset voltage threshold, it is determined that the contacts of the negative relay are in the open state, which matches the state of the target relay, and the negative relay is in a normal state.

[0059] As a specific embodiment of this application, such as Figure 3 As shown, the fault diagnosis method for this battery relay may include the following steps: S101, in response to a relay control command, controls the positive terminal relay through a first control circuit and the negative terminal relay through a second control circuit. The first control circuit uses low-side control, and the second control circuit uses high-side control.

[0060] S102, obtain the feedback information of the first control loop and the external voltage of the positive terminal relay, and obtain the feedback information of the second control loop and the external voltage of the negative terminal relay.

[0061] S103, perform fault diagnosis on the positive terminal relay based on the control command of the positive terminal relay, the feedback information of the first control circuit, and the external voltage of the positive terminal relay.

[0062] S104 performs fault diagnosis on the negative terminal relay based on the control command of the negative terminal relay, the feedback information of the second control circuit, and the external voltage of the negative terminal relay.

[0063] S105, determine if there is a sticking fault in the positive terminal relay and / or an abnormality in the control circuit. If yes, proceed to step S106; otherwise, proceed to step S107.

[0064] S106, determine whether the negative terminal relay has a sticking fault and / or a control circuit abnormality. If yes, proceed to step S108; otherwise, proceed to step S109.

[0065] S107, determine if there is a sticking fault in the negative terminal relay and / or an abnormality in the control circuit. If yes, proceed to step S109; otherwise, proceed to step S110.

[0066] S108 generates multi-point alarm signals and controls the battery to enter degradation mode.

[0067] S109 generates a latent fault alarm signal.

[0068] S110, determine if there is a fault that violates functional safety requirements. If yes, proceed to step S111; otherwise, proceed to step S112.

[0069] S111, simultaneously disconnects the relays at both positive and negative ends to enter a safe state.

[0070] S112, no operation is performed.

[0071] The battery relay fault diagnosis method provided in this embodiment utilizes a heterogeneous approach where each of the positive and negative relays monitors only one side. Specifically, all relays on the positive side control only the low-side drive (or high-side drive), and the relays on the negative side control only the high-side drive (or low-side drive). This redundancy between the positive and negative relays allows for heterogeneous redundancy through the selection of different types of relays. This enables functional safety decomposition of single-point faults (such as relays failing to disconnect) at the relay disconnection requirement level, while failures of both positive and negative relays together constitute a two-point fault. Furthermore, the individual relays enhance control loop anomaly diagnosis and system-level adhesion diagnosis, both contributing to the diagnosis of latent faults in the two-point fault scenario, thus improving diagnostic coverage. Based on the diagnosis of both two-point and latent faults, high-level functional safety requirements can be met. Compared to homogeneous single-side relay control schemes, this method offers a higher level of functional safety; compared to dual-side dual-control relay control schemes, it is more cost-effective.

[0072] In summary, the battery relay fault diagnosis method according to the embodiments of this application includes a positive terminal relay and a negative terminal relay. Responding to a relay control command, the positive terminal relay is controlled through a first control loop, and the negative terminal relay is controlled through a second control loop. One of the first and second control loops is a high-side control, and the other is a low-side control. Feedback information from the first and second control loops and / or the external voltages of the positive and negative terminal relays are acquired. Fault diagnosis is then performed on the positive and negative terminal relays based on the relay control command, feedback information, and external voltages. Therefore, this method, based on heterogeneous unilateral control of the positive and negative terminal relays, achieves fault monitoring of both relays, reducing the fault diagnosis cost and control loop design complexity of the battery relay while meeting high functional safety requirements.

[0073] Corresponding to the above embodiments, this application also proposes a fault diagnostic tool for battery relays.

[0074] Reference Figure 4 The battery relay fault diagnostic device 200 of this application includes a memory 210, a processor 220, and a battery relay fault diagnostic program stored in the memory 210 and executable on the processor 220. When the processor executes the battery relay fault diagnostic program, it implements the above-mentioned battery relay fault diagnosis method.

[0075] According to the battery relay fault diagnostic device of the present application embodiment, when the processor executes the battery relay fault diagnosis program, the battery relay fault diagnosis method is implemented. Based on the above-mentioned battery relay fault diagnosis method, the fault diagnosis cost of battery relay and the complexity of control circuit design are reduced while meeting the requirements of high functional safety level.

[0076] Corresponding to the above embodiments, this application also proposes a computer-readable storage medium storing a fault diagnosis program for a battery relay, which, when executed by a processor, implements the above-described fault diagnosis method for the battery relay.

[0077] According to the embodiments of this application, a computer-readable storage medium storing a fault diagnosis program for a battery relay stored thereon implements the aforementioned fault diagnosis method for a battery relay when executed by a processor. Based on the aforementioned fault diagnosis method for a battery relay, the fault diagnosis cost of the battery relay and the complexity of the control circuit design are reduced while meeting the requirements of a high functional safety level.

[0078] Corresponding to the above embodiments, this application also proposes a fault diagnosis device for a battery relay, wherein the battery relay includes a positive terminal relay disposed corresponding to the positive terminal of the battery and a negative terminal relay disposed corresponding to the negative terminal of the battery.

[0079] Reference Figure 5 The battery relay fault diagnosis device 300 of this application embodiment includes: a control module 310, a first acquisition module 320, a second acquisition module 330, and a fault diagnosis module 340.

[0080] The control module 310 is used to respond to relay control commands by controlling the positive relay through a first control loop corresponding to the positive relay and controlling the negative relay through a second control loop corresponding to the negative relay. One of the first and second control loops is a high-side control loop, and the other is a low-side control loop. The first acquisition module 320 is used to acquire feedback information from the first control loop and / or the external voltage of the positive relay. The second acquisition module 330 is used to acquire feedback information from the second control loop and / or the external voltage of the negative relay. The fault diagnosis module 340 is used to diagnose faults in the positive relay based on the relay control commands, the feedback information from the first control loop, and the external voltage of the positive relay, and to diagnose faults in the negative relay based on the relay control commands, the feedback information from the second control loop, and the external voltage of the negative relay.

[0081] According to one embodiment of this application, the fault diagnosis module 340 is further configured to generate a multi-point alarm signal and control the battery to enter a degradation mode when it is determined that the positive terminal relay is in a fault abnormal state based on the fault diagnosis result of the positive terminal relay and the negative terminal relay is in a fault abnormal state based on the fault diagnosis result of the negative terminal relay; and generate a latent fault alarm signal when it is determined that the positive terminal relay is in a fault abnormal state based on the fault diagnosis result of the positive terminal relay or the negative terminal relay is in a fault abnormal state based on the fault diagnosis result of the negative terminal relay.

[0082] According to one embodiment of this application, the fault abnormality includes relay sticking fault and / or control circuit abnormality.

[0083] According to one embodiment of this application, the fault diagnosis module 340 is further configured to, when the first control loop is a low-side control loop, the first control loop includes a controllable switch, and the feedback information of the first control loop is the output current of the controllable switch, perform fault diagnosis on the positive terminal relay based on the relay control command, the feedback information of the first control loop, and the external voltage of the positive terminal relay. Specifically, it is configured to, determine the state of the target relay based on the relay control command, and determine that the positive terminal relay has a control loop abnormality when the target relay is in a closed state and the output current of the controllable switch is less than or equal to a preset current threshold, or when the target relay is in an open state and the output current of the controllable switch is greater than a preset current threshold; and determine that the positive terminal relay has an adhesion fault when the target relay is in a closed state, the output current of the controllable switch is less than or equal to a preset current threshold, and the external voltage of the positive terminal relay is greater than a preset voltage threshold, or when the target relay is in an open state, the output current of the controllable switch is less than or equal to a preset current threshold, and the external voltage of the positive terminal relay is less than a preset voltage threshold.

[0084] According to one embodiment of this application, the fault diagnosis module 340 is further configured to, when the second control loop is a high-side control loop, the second control loop includes a high-side driver chip, and the feedback information of the second control loop is the output level of the high-side driver chip, perform fault diagnosis on the negative terminal relay based on the relay control command, the feedback information of the second control loop, and the external voltage of the negative terminal relay. Specifically, it is configured to: determine the target relay state and the target level corresponding to the target relay state based on the relay control command; determine that the negative terminal relay has a control loop abnormality when the output level of the high-side driver chip does not match the target level; determine that the negative terminal relay has an adhesion fault when the target relay state is closed, the output level of the high-side driver chip is the target level corresponding to the closed state, and the external voltage of the negative terminal relay is greater than a preset voltage threshold, or when the target relay state is open, the output level of the high-side driver chip is the target level corresponding to the open state, and the external voltage of the negative terminal relay is less than a preset voltage threshold.

[0085] It should be noted that the above explanation of the embodiments and beneficial effects of the fault diagnosis method for battery relays also applies to the fault diagnosis device for battery relays in the embodiments of this application. To avoid redundancy, it will not be elaborated in detail here.

[0086] In summary, the battery relay fault diagnosis device of this application, through a control module responding to relay control commands, controls the positive relay via a first control loop corresponding to the positive relay and the negative relay via a second control loop corresponding to the negative relay. One of the first and second control loops is a high-side control loop, and the other is a low-side control loop. A first acquisition module acquires feedback information from the first control loop and / or the external voltage of the positive relay, and a second acquisition module acquires feedback information from the second control loop and / or the external voltage of the negative relay. The fault diagnosis module performs fault diagnosis on the positive relay based on the relay control commands, the feedback information from the first control loop, and the external voltage of the positive relay, and performs fault diagnosis on the negative relay based on the relay control commands, the feedback information from the second control loop, and the external voltage of the negative relay. Therefore, this device, based on heterogeneous unilateral control of the positive and negative relays, achieves diagnostic coverage that meets high functional safety requirements through a diagnostic strategy, reducing the fault diagnosis cost of the battery relay and the complexity of the control loop design.

[0087] Corresponding to the above embodiments, this application also proposes a vehicle.

[0088] Reference Figure 6 The vehicle 400 in this application embodiment includes: a power battery 410, a battery relay 420, and a battery management system 430.

[0089] The battery relay 420 includes a positive terminal relay corresponding to the positive terminal of the power battery and a negative terminal relay corresponding to the negative terminal of the power battery. The battery management system 430 is used to respond to relay control commands by controlling the positive terminal relay through a first control circuit corresponding to the positive terminal relay and controlling the negative terminal relay through a second control circuit corresponding to the negative terminal relay. One of the first control circuit and the second control circuit is a high-side control circuit and the other is a low-side control circuit. The system also acquires feedback information from the first control circuit and / or the external voltage of the positive terminal relay, and performs fault diagnosis on the positive terminal relay based on the relay control commands, the feedback information from the first control circuit, and the external voltage of the positive terminal relay. Similarly, the system acquires feedback information from the second control circuit and / or the external voltage of the negative terminal relay, and performs fault diagnosis on the negative terminal relay based on the relay control commands, the feedback information from the second control circuit, and the external voltage of the negative terminal relay.

[0090] In some embodiments of this application, the battery management system 430 of the vehicle is further configured to: acquire the operating data of the power battery when it is determined that the positive terminal relay is in a normal state based on the fault diagnosis result of the positive terminal relay and the negative terminal relay is in a normal state based on the fault diagnosis result of the negative terminal relay; and disconnect the positive terminal relay through the first control circuit and the second control circuit corresponding to the positive terminal relay when the operating data of the battery exceeds a preset allowable range, and disconnect the negative terminal relay through the first control circuit and the second control circuit corresponding to the negative terminal relay.

[0091] According to the vehicle embodiment of this application, the battery management system responds to a relay control command by controlling the positive relay through a first control circuit corresponding to the positive relay and controlling the negative relay through a second control circuit corresponding to the negative relay. One of the first and second control circuits is a high-side control circuit, and the other is a low-side control circuit. The system acquires feedback information from the first control circuit and / or the external voltage of the positive relay, and performs fault diagnosis on the positive relay based on the relay control command, the feedback information from the first control circuit, and the external voltage of the positive relay. Similarly, it acquires feedback information from the second control circuit and / or the external voltage of the negative relay, and performs fault diagnosis on the negative relay based on the relay control command, the feedback information from the second control circuit, and the external voltage of the negative relay. This reduces the fault diagnosis cost of the battery relay and the complexity of the control circuit design while meeting the diagnostic coverage requirements of a high functional safety level.

[0092] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0093] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0094] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0096] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0097] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A fault diagnosis method for a battery relay, characterized in that, The battery relay includes a positive terminal relay corresponding to the positive terminal of the battery and a negative terminal relay corresponding to the negative terminal of the battery. The method includes: In response to a relay control command, the positive terminal relay is controlled through a first control circuit corresponding to the positive terminal relay, and the negative terminal relay is controlled through a second control circuit corresponding to the negative terminal relay. One of the first control circuit and the second control circuit is a high-side control circuit, and the other circuit is a low-side control circuit. Obtain feedback information from the first control loop and / or the external voltage of the positive terminal relay, and perform fault diagnosis on the positive terminal relay based on the relay control command, the feedback information from the first control loop, and the external voltage of the positive terminal relay. Obtain feedback information from the second control loop and / or the external voltage of the negative terminal relay, and perform fault diagnosis on the negative terminal relay based on the relay control command, the feedback information from the second control loop, and the external voltage of the negative terminal relay.

2. The fault diagnosis method for a battery relay according to claim 1, characterized in that, Also includes: If the fault diagnosis results of the positive relay indicate that the positive relay is in a faulty state, and the fault diagnosis results of the negative relay indicate that the negative relay is in a faulty state, a multi-point alarm signal is generated, and the battery is controlled to enter a degraded mode. If the fault diagnosis result of the positive terminal relay determines that the positive terminal relay is in a faulty state, or if the fault diagnosis result of the negative terminal relay determines that the negative terminal relay is in a faulty state, a latent fault alarm signal is generated.

3. The fault diagnosis method for a battery relay according to claim 2, characterized in that, The fault conditions include relay sticking faults and / or control circuit abnormalities.

4. The fault diagnosis method for a battery relay according to claim 3, characterized in that, When the first control loop is a low-side control loop, the first control loop includes a controllable switch, and the feedback information of the first control loop is the output current of the controllable switch. Fault diagnosis of the positive terminal relay is performed based on the relay control command, the feedback information of the first control loop, and the external voltage of the positive terminal relay, including: The target relay state is determined according to the relay control command; If the target relay is in a closed state and the output current of the controllable switch is less than or equal to a preset current threshold, or if the target relay is in a closed state and the output current of the controllable switch is greater than the preset current threshold, it is determined that the control circuit of the positive terminal relay is abnormal. If the target relay is in a closed state, the output current of the controllable switch is less than or equal to the preset current threshold, and the external voltage of the positive terminal relay is greater than the preset voltage threshold, or if the target relay is in a closed state, the output current of the controllable switch is greater than or equal to the preset current threshold, and the external voltage of the positive terminal relay is less than the preset voltage threshold, then the positive terminal relay is determined to have the adhesion fault.

5. The fault diagnosis method for a battery relay according to claim 3, characterized in that, When the second control loop is a high-side control loop, the second control loop includes a high-side driver chip, and the feedback information of the second control loop is the output level of the high-side driver chip. Fault diagnosis of the negative terminal relay is performed based on the relay control command, the feedback information of the second control loop, and the external voltage of the negative terminal relay, including: The target relay state and the target level corresponding to the target relay state are determined according to the relay control command. If the output level of the high-side driver chip does not match the target level, it is determined that the control loop of the negative terminal relay is abnormal. If the target relay is in a closed state, the output level of the high-side driver chip is the target level corresponding to the closed state, and the external voltage of the negative relay is greater than a preset voltage threshold, or if the target relay is in a closed state, the output level of the high-side driver chip is the target level corresponding to the open state, and the external voltage of the negative relay is less than the preset voltage threshold, then the negative relay is determined to have the adhesion fault.

6. A fault diagnostic tool for a battery relay, characterized in that, The method includes a memory, a processor, and a fault diagnosis program for a battery relay stored in the memory and executable on the processor. When the processor executes the fault diagnosis program for the battery relay, it implements the fault diagnosis method for the battery relay according to any one of claims 1-5.

7. A computer-readable storage medium, characterized in that, It stores a fault diagnosis program for a battery relay, which, when executed by a processor, implements the fault diagnosis method for a battery relay according to any one of claims 1-5.

8. A fault diagnosis device for a battery relay, characterized in that, The battery relay includes a positive terminal relay corresponding to the positive terminal of the battery and a negative terminal relay corresponding to the negative terminal of the battery. The device includes: The control module is used to respond to relay control commands by controlling the positive terminal relay through a first control circuit corresponding to the positive terminal relay and controlling the negative terminal relay through a second control circuit corresponding to the negative terminal relay. One of the first control circuit and the second control circuit is a high-side control circuit, and the other circuit is a low-side control circuit. The first acquisition module is used to acquire feedback information of the first control loop and / or the external voltage of the positive terminal relay; The second acquisition module is used to acquire the feedback information of the second control loop and / or the external voltage of the negative terminal relay; The fault diagnosis module is used to diagnose faults in the positive terminal relay based on the relay control command, the feedback information of the first control loop, and the external voltage of the positive terminal relay, and to diagnose faults in the negative terminal relay based on the relay control command, the feedback information of the second control loop, and the external voltage of the negative terminal relay.

9. A vehicle, characterized in that, include: Power battery; The battery relay includes a positive terminal relay corresponding to the positive terminal of the power battery and a negative terminal relay corresponding to the negative terminal of the power battery. A battery management system is configured to respond to relay control commands by controlling the positive relay via a first control loop corresponding to the positive relay and controlling the negative relay via a second control loop corresponding to the negative relay, wherein one of the first and second control loops is a high-side control loop and the other is a low-side control loop; and to acquire feedback information from the first control loop and / or the external voltage of the positive relay, and perform fault diagnosis on the positive relay based on the relay control commands, the feedback information from the first control loop, and the external voltage of the positive relay; and to acquire feedback information from the second control loop and / or the external voltage of the negative relay, and perform fault diagnosis on the negative relay based on the relay control commands, the feedback information from the second control loop, and the external voltage of the negative relay.

10. The vehicle according to claim 9, characterized in that, The battery management system is further configured to, when determining that the positive terminal relay is in a normal state based on the fault diagnosis result of the positive terminal relay and the negative terminal relay is in a normal state based on the fault diagnosis result of the negative terminal relay, acquire the operating data of the power battery, and when the operating data of the battery exceeds a preset allowable range, disconnect the positive terminal relay through the first control circuit and the second control circuit corresponding to the positive terminal relay, and disconnect the negative terminal relay through the first control circuit and the second control circuit corresponding to the negative terminal relay.

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