BMS relay simulation device

Abstract

The utility model relates to a BMS relay simulation device. The device comprises a fault injection control unit, a first relay and a second relay. The common end of the first relay is used for connecting a high-voltage power supply, the normally-closed end of the first relay is suspended, the normally-open end of the first relay is connected with the common end of the second relay, the normally-open end of the second relay is suspended, and the normally-closed end of the second relay is used for connecting a high-voltage detection module; according to the scheme, the principle is simple and easy to implement, the fault injection control unit only needs to send out a signal for changing the state of the first relay or the second relay according to the applied logic, the error probability is reduced, faults can be detected timely and accurately, and corresponding protection actions can be executed.

Description

Technical Field

[0001] The utility model belongs to the technical field of power battery control for electric vehicles, and in particular relates to a BMS relay simulation device. Background Art

[0002] The vehicle-mounted power battery control system (BMS, Battery Control System) is responsible for collecting the voltage and temperature information inside and outside the battery pack, and also controls various actuators to make the battery work in a safe and reliable environment, such as various relays. The relays in the BMS system are divided into charging relays, heating relays, and discharge relays. Regardless of the type of relay, its working principle is similar. Usually, the relay is in the normally open end when it is not working, and the common end and the normally open end are connected. When the relay enters the working state, the BMS switches to the normally closed end through the high-level drive coil, and the common end is connected to the normally closed end. If the positive pole of the high-voltage power supply (HV, High Voltage) is connected to the common end as the output, and the acquisition end of the high-voltage detection module (HVU, High Voltage Unit) of the BMS is connected to the normally closed end, when the BMS does not output a high level, the relay remains at the normally open end, and the HVU end cannot detect HV, then the BMS determines that the relay is not closed; when the BMS outputs a high level, the relay switches to the normally closed end, and the HVU detects HV at this time, then the BMS determines that the relay is closed. There are two failure states in actual relays, namely, sticking state and closing fault. The so-called sticking state means that after the relay is closed, the high-level output of the BMS becomes low-level, but the relay does not switch from the normally closed end to the normally open end; similarly, the closing fault means that the BMS controls the relay to close while the relay remains open. In the test environment, the tester must not only verify the normal control logic of the BMS for the relay, but also create a failure scenario to verify whether the BMS can accurately and timely detect the fault and perform the corresponding protection action. The Chinese utility model patent "A relay diagnostic test device and hardware-in-the-loop test system device" (authorization announcement number CN217360213U) discloses a relay diagnostic test device and a hardware-in-the-loop test system device. During the fault diagnosis test, the output signal of the ECU electronic control device is ignored, and the fault injector is controlled to drive the simulated relay to open and close to generate an open circuit fault and a sticking fault; in order to realize the "ignore" function, the common method is to set up complex software logic to achieve it, and "complex software logic" increases the probability of error, which may cause errors or problems in the fault simulation, so it is necessary to find a more stable relay fault test method. Utility Model Content

[0003] The utility model aims to provide a BMS relay simulation device to solve the problem of unstable relay fault testing.

[0004] In order to solve the above technical problems, the utility model provides a BMS relay simulation device, including a fault injection control unit, a first relay and a second relay; the common end of the first relay is used to connect to a high-voltage power supply, the normally closed end of the first relay is suspended, the normally open end of the first relay is connected to the common end of the second relay, the normally open end of the second relay is suspended, and the normally closed end of the second relay is used to connect to a high-voltage detection module;

[0005] One end of the coil control loop where the coil of the first relay is located is connected to the fault injection control unit, so that the control loop where the coil of the first relay is located is controlled to be turned on by the fault injection control unit;

[0006] One end of the control loop where the coil of the second relay is located is connected to the fault injection control unit, and the high-voltage end of the control loop where the coil of the second relay is located is also used to connect to the BMS, so that the control loop where the coil of the second relay is located is controlled to be turned on by the fault injection control unit or the BMS.

[0007] Furthermore, the high voltage end of the control loop where the coil of the second relay is located is connected to the fault injection control unit.

[0008] The beneficial effects of the above technical solution are as follows: the utility model is an improved invention, which is used in conjunction with the first relay and the second relay, and the fault injection unit sends instructions to control the first relay and the second relay to change their states, which can be normally open and normally closed, and the BMS sends instructions to control the second relay, thereby simulating the failure scenarios of the two BMS relays, namely, the adhesion fault and the closing fault. Among them, the adhesion fault is that the fault injection unit makes the first relay in the normally open state (that is, the state in which the common end and the normally open end of the first relay are connected), and when the BMS sends a low level to the coil of the second relay, the fault injection unit makes the second relay in the normally closed state (that is, the state in which the common end and the normally closed end of the second relay are connected), so that the high-voltage power supply and the high-voltage detection module are connected; the closing fault is that the fault injection unit makes the first relay in the normally closed state (that is, the state in which the common end and the normally closed end of the first relay are connected), and when the BMS sends a high level to the coil of the second relay, the high-voltage power supply and the high-voltage detection module are always disconnected. The fault state of the relay is simulated by two relay hardware. The principle of the scheme is simple and easy to implement. The fault injection control unit only needs to change the state of the first relay or the second relay according to the application logic, which reduces the probability of error and facilitates timely and accurate fault detection and execution of corresponding protection actions. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a connection diagram of an embodiment of a BMS relay simulation device of the utility model;

[0010] Figure 2 This is a normal disconnection schematic diagram of an embodiment of a BMS relay simulation device of the utility model;

[0011] Figure 3 This is a normal closing schematic diagram of an embodiment of a BMS relay simulation device of the utility model;

[0012] Figure 4 This is a schematic diagram of a sticking fault of an embodiment of a BMS relay simulation device of the utility model;

[0013] Figure 5 It is a schematic diagram of a closing fault of a BMS relay simulation device embodiment of the utility model;

[0014] Figure 6 It is a high-level connection diagram of a fault injection control unit of an embodiment of a BMS relay simulation device of the utility model;

[0015] Figure 7 It is a low-level connection diagram of a fault injection control unit of an embodiment of a BMS relay simulation device of the utility model. DETAILED DESCRIPTION

[0016] The utility model focuses on providing a BMS relay simulation device, which is characterized by comprising a fault injection control unit, a first relay and a second relay; the common end of the first relay is used to connect to a high-voltage power supply, the normally closed end of the first relay is suspended, the normally open end of the first relay is connected to the common end of the second relay, the normally open end of the second relay is suspended, and the normally closed end of the second relay is used to connect to a high-voltage detection module;

[0017] One end of the coil control loop where the coil of the first relay is located is connected to the fault injection control unit, so that the control loop where the coil of the first relay is located is controlled to be turned on by the fault injection control unit;

[0018] One end of the control loop where the coil of the second relay is located is connected to the fault injection control unit, and the high-voltage end of the control loop where the coil of the second relay is located is also used to connect the BMS, so that the control loop where the coil of the second relay is located is controlled by the fault injection control unit or the BMS to be turned on. The utility model uses the first relay and the second relay in conjunction, and the fault injection unit issues an instruction to control the first relay and the second relay to change their states, which can be specifically a normally open state and a normally closed state, and the BMS issues an instruction to control the second relay, thereby simulating the failure scenarios of the two BMS relays, namely, the adhesion fault and the closing fault. Among them, the adhesion fault is that the fault injection unit makes the first relay in the normally open state (i.e., the state where the common end and the normally open end of the first relay are connected), and when the BMS sends a low level to the coil of the second relay, the fault injection unit makes the second relay in the normally closed state (i.e., the state where the common end and the normally closed end of the second relay are connected), so that the high-voltage power supply and the high-voltage detection module are turned on; the closing fault is that the fault injection unit makes the first relay in the normally closed state (i.e., the state where the common end and the normally closed end of the first relay are connected), and when the BMS sends a high level to the coil of the second relay, the high-voltage power supply and the high-voltage detection module are always disconnected. The fault state of the relay is simulated by two relay hardware. The principle of the scheme is simple and easy to implement. The fault injection control unit only needs to change the state of the first relay or the second relay according to the application logic, which reduces the probability of error and facilitates timely and accurate fault detection and execution of corresponding protection actions.

[0019] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0020] BMS relay simulation device embodiment:

[0021] A BMS relay simulation device of the present embodiment includes a fault injection control unit (FIU, FaultInjection Unit), a first relay K1 and a second relay K2; the common end of the first relay K1 is used to connect to a high-voltage power supply, the normally closed end (state 1) of the first relay K1 is suspended, the normally open end (state 0) of the first relay K1 is connected to the common end of the second relay K2, the normally open end (state 0) of the second relay K2 is suspended, and the normally closed end (state 1) of the second relay K2 is used to connect to a high-voltage detection module; one end of the coil control loop where the coil of the first relay is located is connected to the fault injection control unit, so that the control loop where the coil of the first relay is located is controlled to be turned on by the fault injection control unit;

[0022] One end of the control loop where the coil of the second relay is located is connected to the fault injection control unit, and the high voltage end of the control loop where the coil of the second relay is located is also used to connect to the BMS, so that the control loop where the coil of the second relay is located is controlled to be turned on by the fault injection control unit or the BMS. Figure 1 At this time, the BMS and the fault injection control unit FIU are both connected to the high voltage end of the second relay coil, and the second relay coil is controlled by a high level. Figure 6 shown.

[0023] When simulating the normal disconnection working state, the fault injection control unit FIU issues an instruction to make the first relay K1 in the normally open state and the second relay K2 in the normally open state. Specifically, when the fault injection control unit FIU outputs a low level through the digital control line L1, the first relay K1 remains normally open (state 0), and the fault injection control unit FIU outputs a low level through the digital control line L2, and the second relay K2 remains normally open (state 0). The state of the second relay K2 is controlled by the BMS through the digital control line L3, so that when the BMS issues an instruction to the second relay K2 to keep it in the normally open state, the second relay K2 is in the normally open state, and the high-voltage power supply HV and the high-voltage detection module HVU are disconnected. Specifically, when the BMS outputs a low level through the digital control line L3, the high-voltage detection module HVU located at the normally closed end (state 1) of the second relay K2 cannot detect the high-voltage power supply HV, that is, the disconnection control of the relay is realized. Figure 2 shown.

[0024] When simulating the normal closed working state, the fault injection control unit FIU issues an instruction to make the first relay K1 normally open and the second relay K2 normally open. Specifically, when the fault injection control unit FIU outputs a low level through the digital control line L1, the first relay K1 remains normally open (state 0), and when the fault injection control unit FIU outputs a low level through the digital control line L2, the second relay K2 remains normally open (state 0). The state of the second relay K2 is controlled by the BMS through the digital control line L3, so that when the BMS issues an instruction to keep the second relay K2 in a normally closed state, the second relay K2 changes to a normally closed state, and the high-voltage power supply HV and the high-voltage detection module HVU are connected. Specifically, when the BMS outputs a high level through the digital control line L3, the high-voltage detection module HVU located at the normally closed end (state 1) of the second relay K2 is connected to the high-voltage power supply HV, that is, the closing control of the relay is realized. Figure 3 shown.

[0025] When simulating a sticking fault, the fault injection control unit FIU issues an instruction to make the first relay K1 normally open. Specifically, when the fault injection control unit FIU outputs a low level through the digital control line L1, the first relay K1 remains normally open (state 0), and the second relay K2 is normally closed. Specifically, when the fault injection control unit FIU outputs a high level through the digital control line L2, the second relay K2 remains normally closed (state 1), so that when the BMS issues an instruction to the second relay K2 to keep it normally open, the second relay K2 still remains normally closed, and the high-voltage power supply HV and the high-voltage detection module HVU are connected; specifically, the BMS outputs a low level through the digital control line L3, and the high-voltage detection module HVU located at the normally closed end (state 1) of the second relay K2 is always connected to the high-voltage power supply HV, that is, the sticking fault of the relay is realized. Specifically, Figure 4 shown.

[0026] When simulating a closing fault, the fault injection control unit FIU issues an instruction to make the first relay K1 in a normally closed state. Specifically, when the fault injection control unit FIU outputs a high level through the digital control line L1, the first relay K1 remains normally closed (state 1). When the BMS issues an instruction to the second relay K2 to keep it in a normally closed state, the high-voltage power supply HV and the high-voltage detection module HVU are disconnected. Specifically, the BMS outputs a high level through the digital control line L3, and the high-voltage detection module HVU located at the normally closed end (state 1) of the second relay K2 is always disconnected from the high-voltage power supply HV, that is, the closing fault of the relay is realized. Specifically, Figure 5 shown.

[0027] In summary, the system control state can be changed by controlling different combinations of the digital control lines L1 and L2 through the FIU control module, as shown in Table 1.

[0028] Table 1

[0029]

[0030] As another implementation, the fault injection control unit FIU may also be connected to the low voltage end of the second relay coil, such as Figure 7 As shown, at this time, the FIU controls the conduction of the second relay coil by outputting a low-level signal. When simulating the normal disconnection working state, normal closing working state, adhesion fault and closing fault of the relay, the specific principle is the same as the high-level control method. The difference is that the control of the second relay coil (that is, controlling the second relay from the normally open state to the normally closed state) is changed from high-level control to low-level control.

[0031] Specific implementation methods are given above, but the present invention is not limited to the described implementation methods. The basic idea of ​​the present invention is the above basic scheme. For ordinary technicians in this field, according to the teachings of the present invention, it does not require creative labor to design various deformed models, formulas, and parameters. Changes, modifications, substitutions, and variations of the implementation methods without departing from the principles and spirit of the present invention still fall within the scope of protection of the present invention.

Claims

1. A BMS relay simulation device, characterized in that: It includes a fault injection control unit, a first relay and a second relay; the common end of the first relay is used to connect to a high-voltage power supply, the normally closed end of the first relay is suspended, the normally open end of the first relay is connected to the common end of the second relay, the normally open end of the second relay is suspended, and the normally closed end of the second relay is used to connect to a high-voltage detection module; One end of the coil control loop where the coil of the first relay is located is connected to the fault injection control unit, so that the control loop where the coil of the first relay is located is controlled to be turned on by the fault injection control unit; One end of the control loop where the coil of the second relay is located is connected to the fault injection control unit, and the high-voltage end of the control loop where the coil of the second relay is located is also used to connect to the BMS, so that the control loop where the coil of the second relay is located is controlled to be turned on by the fault injection control unit or the BMS.

2. The BMS relay simulation device according to claim 1, characterized in that: The high voltage end of the control loop where the coil of the second relay is located is connected to the fault injection control unit.

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