Pure electric light truck insulation function detection method based on peripherals

Abstract

The invention discloses a peripheral-based pure electric light truck insulation function detection method, which adaptively develops an insulation function detection strategy on the basis of the existing communication network architecture, and comprises the following steps of: after electrification, sending a first instruction to a battery management system by a peripheral to enable the battery management system to enter a detection process; then, the peripheral sends a second instruction to request to be connected with the vehicle-end high-voltage loop, and the vehicle-mounted insulation detection function is closed; after the execution result of the second instruction is received, the peripheral executes high-voltage loop insulation detection and outputs an insulation value; after the peripheral detection is qualified, a third instruction is sent to request a charging relay to be closed, a heating relay is disconnected, and a vehicle-mounted insulation detection function is started; the peripheral executes detection to judge whether the vehicle-mounted insulation detection function is normal or not; and after the vehicle-mounted insulation detection function is judged to be normal, the peripheral sends a fourth instruction for ending the detection process and enabling the vehicle to recover to the vehicle high-voltage state. Whether the high-voltage loop insulation function and the vehicle-mounted insulation function of the pure electric light truck work normally or not is detected.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a peripheral-based pure electric light truck insulation function detection method. Background Art

[0002] The safety of the high-voltage system of new energy logistics vehicles is one of the core concerns of vehicle manufacturers. Failure of high-voltage insulation can lead to serious consequences and losses, such as electric shock to people, abnormal battery discharge leading to fire accidents in vehicles and cargo, etc. Summary of the invention

[0003] In view of the above, the present invention aims to provide a pure electric light truck insulation function detection method based on peripherals to solve the above-mentioned technical problems.

[0004] The technical solution adopted by the present invention is as follows:

[0005] The present invention provides a method for detecting the insulation function of a pure electric light truck based on an external device, which includes:

[0006] After the external insulation detection device and the battery management system are powered on, the external insulation detection device sends a first instruction to the battery management system; the first instruction is used to trigger the battery management system to enter a detection process based on the external insulation detection device;

[0007] The external insulation detection device sends a second instruction to the battery management system according to a preset period; the second instruction is used to request to connect the vehicle-end high-voltage circuit and turn off the vehicle-mounted insulation detection function;

[0008] After executing the second instruction, the battery management system feeds back the execution result of the second instruction to the external insulation detection device;

[0009] After receiving the feedback of the execution result of the second instruction, the external insulation detection device performs the insulation detection of the vehicle high-voltage circuit and outputs the insulation detection value;

[0010] After the external insulation detection device passes the detection, a third instruction is sent to the battery management system; the third instruction is used to request to keep the charging relay closed, disconnect the heating relay, and turn on the vehicle insulation detection function;

[0011] After receiving the feedback of the execution result of the third instruction, the external insulation detection device performs detection to determine whether the vehicle-mounted insulation detection function is normal;

[0012] After determining that the vehicle-mounted insulation detection function is normal, the external insulation detection device sends a fourth instruction to the battery management system, and the fourth instruction is used to end the detection process and restore the vehicle to a vehicle high-voltage state.

[0013] In at least one possible implementation, after executing the second instruction, the battery management system feeds back the execution result of the second instruction to the external insulation detection device, including: if the charging relay is configured in the battery pack, the battery management system directly drives and executes closing the heating relay, closing the charging relay, and turning off the on-board insulation detection function; and directly replies to the execution status of the second instruction of the external insulation detection device.

[0014] In at least one possible implementation, after executing the second instruction, the battery management system feeds back the execution result of the second instruction to the external insulation detection device, including: if the charging relay is configured in the high-voltage box, the battery management system executes closing the heating relay, requests the high-voltage box to close the charging relay, and turns off the on-board insulation detection function, and temporarily replies to the external insulation detection device through the intermediate instruction;

[0015] After the high-voltage box receives the battery management system's request for the charging relay to close, and completes the closing and feeds back the charging relay closing status, the battery management system replies to the execution status of the second instruction of the external insulation detection device.

[0016] In at least one possible implementation, the external insulation detection device performs detection to determine whether the vehicle-mounted insulation detection function is normal, including: connecting a resistor through a line action to successively lower the insulation resistance between DC+ and DC- and the electrical platform, and detecting a single-point insulation value by the vehicle-mounted insulation detection function;

[0017] When it is detected that the single-point insulation value is lower than the preset standard, determine whether to report the corresponding fault code or the instrument displays the insulation fault light;

[0018] If yes, it is determined that the on-board insulation detection function is normal.

[0019] In at least one possible implementation, the detection method further includes: after receiving the first instruction, if the message is lost, the battery management system exits the detection process;

[0020] Alternatively, after entering the detection process based on the external insulation detection device, if the preset timing time is exceeded, the detection process is forced to exit.

[0021] In at least one possible implementation method, the detection method also includes: before the external insulation detection device sends the first instruction, confirming that the high-voltage main circuit is closed and determining whether the established conditions are met, the established conditions include at least one of the following: no limit fault, no low voltage abnormal fault alarm, no heating relay fault alarm, no insulation fault, and no heating high-side control short-to-ground short-power fault.

[0022] Compared with the prior art, the main design concept of the present invention is to adapt and develop an insulation function detection strategy based on the existing communication network architecture, specifically including: after power-on, the peripheral sends a first instruction to the battery management system to enable it to enter a detection process based on the peripheral; the peripheral sends a second instruction to the battery management system according to a preset period to request to connect the vehicle-end high-voltage circuit and turn off the vehicle-mounted insulation detection function; after receiving the feedback of the execution result of the second instruction, the peripheral performs the vehicle high-voltage circuit insulation detection and outputs the insulation value; after determining that the peripheral detection is qualified, sending a third instruction to the battery management system to request the charging relay to close, the heating relay to disconnect, and the vehicle-mounted insulation detection function to start; after receiving the feedback of the execution result of the third instruction, the peripheral performs a test to determine whether the vehicle-mounted insulation detection function is normal; after determining that the vehicle-mounted insulation detection function is normal, the peripheral sends a fourth instruction to the battery management system to end the detection process and restore the vehicle to the vehicle high-voltage state. The insulation function detection strategy proposed in the present invention is independent of the vehicle OBD diagnostic CAN channel. It sets specific messages and test procedures in the current power CAN network or the CAN network where the on-board insulation diagnostic node is located, so as to detect whether the high-voltage circuit insulation and on-board insulation function of the pure electric logistics vehicle are working normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0024] Figure 1 A schematic diagram of a method for detecting the insulation function of a pure electric light truck based on a peripheral device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0026] The present invention proposes an embodiment of a method for detecting the insulation function of a pure electric light truck based on an external device. Specifically, Figure 1 shown, including:

[0027] Step S1: After the external insulation detection device and the battery management system are powered on, the external insulation detection device sends a first instruction to the battery management system; the first instruction is used to trigger the battery management system to enter a detection process based on the external insulation detection device;

[0028] The external insulation detection device TESTER mentioned here is a safety insulation component detection device that can be calibrated periodically to ensure that the detection accuracy meets the standard requirements. It integrates IMD (insulation detection module) and adjustable resistance circuit, and comes with a DC charging plug. The wiring harness at the end of the plug is connected to the inside of TESTER.

[0029] Because of the IMD integrated inside TESTER, it can detect whether the insulation of the vehicle's high-voltage circuit meets the vehicle's factory standards and output a digital insulation value; the circuit is set inside TESTER, and an adjustable resistor is set between DC+, DC- and the power platform to lower the resistance value of the vehicle's high-voltage system DC+ and DC- to test the on-board insulation detection (generally integrated inside the BMS battery management system) function. Specifically, the IMD (insulation detection module) uses a double bridge method and sets three detection pins, which are directly connected to the DC+ / DC- and the power platform; the adjustable resistance circuit is set between DC+ and the power platform, and between DC- and the power platform. The control end of the adjustable resistor is connected to TESTER, and TESTER can adjust the resistance value through the control circuit.

[0030] In addition, TESTER can also be configured with a Bluetooth device for sending and receiving vehicle and TESTER messages. The Bluetooth receiver is plugged into the vehicle's OBD diagnostic port, and the vehicle's EVCAN transmits messages through the on-board gateway. Bluetooth sends and receives vehicle EVCAN messages through the EVCANH / L terminals defined in the OBD, allowing TESTER messages to be transmitted between the vehicle and the vehicle.

[0031] After entering the detection process based on the first instruction, the conditional judgment of exiting the detection process can also be considered. Here, the present invention provides some preferred embodiments, for example, the detection method also includes: after receiving the first instruction, if the message is lost (such as lost for 5 seconds), the battery management system exits the detection process; or, after entering the detection process based on the external insulation detection device, if the preset timing time is exceeded, the detection process is forced to exit.

[0032] Of course, the reasons why the detection process fails to complete smoothly and exits abnormally may also be any of the following: receiving a power-off command from the VCU, all wake-up sources are lost, baseline failure, low-voltage power supply abnormal alarm, heating circuit relay failure, internal communication failure, etc.

[0033] Step S2, the external insulation detection device sends a second instruction to the battery management system according to a preset period, wherein the second instruction is used to request to connect the vehicle-end high-voltage circuit and turn off the vehicle-mounted insulation detection function;

[0034] Step S3: After executing the second instruction, the battery management system feeds back the execution result of the second instruction to the external insulation detection device;

[0035] Specifically, the external insulation detection device sends the second instruction message to the BMS according to a preset cycle (50ms or other cycle). For example, the message is 00 00 00 00 00 00 00 01, and its main interpretation can be expanded to request the heating relay to be closed, the charging relay to be closed, and the on-board insulation detection to be closed. It should be noted here that in the process of executing the insulation detection process based on the peripheral, the heating relay is in forced control mode, that is, according to the requirements of the detection process, it is forced to close, disconnect, and other operations. After the BMS receives the request from TESTER, it closes the heating relay, closes the charging relay, and turns off the insulation detection function, and then feeds back the execution status to TESTER. Based on different high-voltage system architectures, in actual operation, it can be specifically divided into the following two situations:

[0036] (1) If the charging relay is configured in the battery pack, the BMS will directly drive and execute closing the heating relay, closing the charging relay, and turning off the on-board insulation detection function; after that, it will directly reply 00 00 00 00 00 00 0001, which means that the TESTER is informed that the BMS has currently controlled the vehicle-side high-voltage circuit to be connected and turned off the on-board insulation detection function.

[0037] (2) If the charging relay is configured in the high-voltage box, the BMS closes the heating relay, requests the high-voltage box to close the charging relay, and turns off the on-board insulation detection function, and replies to TESTER through an intermediate command, such as the message 0000 00 00 00 00 00 03; after that, after the high-voltage box receives the BMS request to close the charging relay, and the closing is completed and the charging relay closing status is fed back, it replies to TESTER 00 00 00 00 00 00 00 01, which informs TESTER that the BMS has currently controlled the vehicle-end high-voltage circuit to be connected and turned off the on-board insulation detection function.

[0038] Step S4: after receiving the feedback of the execution result of the second instruction, the external insulation detection device performs the insulation detection of the vehicle high-voltage circuit and outputs the insulation detection value;

[0039] After receiving the message 00 00 00 00 00 00 00 01 from BMS, TESTER starts to perform insulation test after a delay of 200ms to detect the insulation value of the current vehicle high-voltage circuit and display it digitally on the TESTER screen.

[0040] Step S5: After the external insulation detection device passes the detection, a third instruction is sent to the battery management system, wherein the third instruction is used to request to keep the charging relay closed, disconnect the heating relay, and turn on the vehicle-mounted insulation detection function;

[0041] After TESTER detects that the insulation is qualified, it sends 00 00 00 00 00 00 00 04, which corresponds to the request to disconnect the heating relay and turn on the on-board insulation detection (keep the charging relay closed); after receiving the message from TESTER, BMS executes the corresponding action after a delay of 200ms, mainly disconnecting the heating relay and turning on the on-board insulation detection function, and then replies with the message 0000 00 00 00 00 00 04.

[0042] Step S6: After receiving the feedback of the execution result of the third instruction, the external insulation detection device performs a test to determine whether the vehicle-mounted insulation detection function is normal;

[0043] After receiving the reply message, TESTER delays 200ms, connects the resistor through the line action, lowers the insulation resistance between DC+ and the electrical platform, detects the single-point insulation value, and determines whether the on-board insulation detection function is normal. Furthermore, similarly, the insulation resistance between DC- and the electrical platform is lowered, the single-point insulation value is detected, and the on-board insulation detection function is determined whether it is normal. It should be emphasized here that in order to ensure high voltage safety, the insulation resistance value of DC+ / DC- to the electrical platform should not be lowered at the same time. When the on-board insulation function detects that the single-point insulation value is lower than the preset standard, check whether the corresponding fault code is reported or the instrument displays the insulation fault light. If so, it is determined that the on-board insulation detection function is normal.

[0044] Step S7: After determining that the vehicle-mounted insulation detection function is normal, the external insulation detection device sends a fourth instruction to the battery management system, and the fourth instruction is used to end the detection process and restore the vehicle to a high-voltage state.

[0045] After TESTER or the operator detects that the on-board insulation function is normal, the message 00 00 00 00 0000 00 06 is sent, corresponding to the request for the heating relay to be disconnected, the charging relay to be disconnected, and the on-board insulation detection to be turned on; the BMS receives the above instructions, executes the end of the insulation detection process, and returns to the vehicle high-voltage state; and accordingly, the execution result is fed back to TESTER.

[0046] Based on the above embodiments, it can also be added that before the first instruction is sent by the external insulation detection device, it is confirmed that the high-voltage main circuit is closed and it is determined whether the established conditions are met. The established conditions include at least one of the following: no limit fault, no low-voltage abnormal fault alarm, no heating relay fault alarm, no insulation fault, and no heating high-side control short-to-ground short-power fault (short circuit).

[0047] To sum up, the main design concept of the present invention is to adapt and develop an insulation function detection strategy based on the existing communication network architecture, specifically including: after power-on, the peripheral sends a first instruction to the battery management system to enable it to enter a detection process based on the peripheral; the peripheral sends a second instruction to the battery management system according to a preset period to request to connect the vehicle-end high-voltage circuit and turn off the vehicle-mounted insulation detection function; after receiving the feedback of the execution result of the second instruction, the peripheral performs the vehicle high-voltage circuit insulation detection and outputs the insulation value; after determining that the peripheral detection is qualified, sending a third instruction to the battery management system to request the charging relay to close, the heating relay to disconnect, and the vehicle-mounted insulation detection function to start; after receiving the feedback of the execution result of the third instruction, the peripheral performs a test to determine whether the vehicle-mounted insulation detection function is normal; after determining that the vehicle-mounted insulation detection function is normal, the peripheral sends a fourth instruction to the battery management system to end the detection process and restore the vehicle to the vehicle high-voltage state. The insulation function detection strategy proposed in the present invention is independent of the vehicle OBD diagnostic CAN channel. It sets specific messages and test procedures in the current power CAN network or the CAN network where the on-board insulation diagnostic node is located, so as to detect whether the high-voltage circuit insulation and on-board insulation function of the pure electric logistics vehicle are working normally.

[0048] If the expressions expressing orientation are mentioned in the embodiments of the present invention, they are relative concepts based on the embodiments. In addition, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, wherein a, b, c can be single or multiple.

[0049] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings, but the above is only a preferred embodiment of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched into a variety of equivalent schemes by those skilled in the art without departing from or changing the design ideas and technical effects of the present invention; therefore, the present invention is not limited to the scope of implementation shown in the drawings, and all changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification and drawings, should be within the protection scope of the present invention.

Claims

1. A method for detecting the insulation function of a pure electric light truck based on peripherals, characterized in that: include: After the external insulation detection device and the battery management system are powered on, the external insulation detection device sends a first instruction to the battery management system; The first instruction is used to trigger the battery management system to enter a detection process based on an external insulation detection device; The external insulation detection device sends a second instruction to the battery management system according to a preset period; The second instruction is used to request to connect the vehicle-end high-voltage circuit and turn off the vehicle-mounted insulation detection function; After executing the second instruction, the battery management system feeds back the execution result of the second instruction to the external insulation detection device; After receiving the feedback of the execution result of the second instruction, the external insulation detection device performs the insulation detection of the vehicle high-voltage circuit and outputs the insulation detection value; After the external insulation detection device passes the detection, a third instruction is sent to the battery management system; the third instruction is used to request to keep the charging relay closed, disconnect the heating relay, and turn on the vehicle insulation detection function; After receiving the feedback of the execution result of the third instruction, the external insulation detection device performs detection to determine whether the vehicle-mounted insulation detection function is normal; After determining that the vehicle-mounted insulation detection function is normal, the external insulation detection device sends a fourth instruction to the battery management system, and the fourth instruction is used to end the detection process and restore the vehicle to a vehicle high-voltage state.

2. The method for detecting the insulation function of a pure electric light truck based on peripheral equipment according to claim 1 is characterized in that: After executing the second instruction, the battery management system feeds back the execution result of the second instruction to the external insulation detection device, including: if the charging relay is configured in the battery pack, the battery management system directly drives and executes closing the heating relay, closing the charging relay, and closing the vehicle-mounted insulation detection function; and directly replies to the execution status of the second instruction of the external insulation detection device.

3. The method for detecting the insulation function of a pure electric light truck based on peripheral equipment according to claim 1 is characterized in that: After executing the second instruction, the battery management system feeds back the execution result of the second instruction to the external insulation detection device, including: if the charging relay is configured in the high-voltage box, the battery management system executes closing the heating relay, requests the high-voltage box to close the charging relay, and turns off the vehicle-mounted insulation detection function, and temporarily replies to the external insulation detection device through the intermediate instruction; After the high-voltage box receives the battery management system's request for the charging relay to close, and completes the closing and feeds back the charging relay closing status, the battery management system replies to the execution status of the second instruction of the external insulation detection device.

4. The method for detecting the insulation function of a pure electric light truck based on peripheral equipment according to claim 1 is characterized in that: The detection performed by the external insulation detection device to determine whether the vehicle-mounted insulation detection function is normal includes: connecting the resistor through the line action, successively lowering the insulation resistance between DC+ and DC- and the electrical platform respectively, and detecting the single-point insulation value by the vehicle-mounted insulation detection function; When it is detected that the single-point insulation value is lower than the preset standard, determine whether to report the corresponding fault code or the instrument displays the insulation fault light; If yes, it is determined that the on-board insulation detection function is normal.

5. The method for detecting the insulation function of a pure electric light truck based on a peripheral device according to any one of claims 1 to 4, characterized in that: The detection method further includes: after receiving the first instruction, if the message is lost, the battery management system exits the detection process; Alternatively, after entering the detection process based on the external insulation detection device, if the preset timing time is exceeded, the detection process is forced to exit.

6. The method for detecting the insulation function of a pure electric light truck based on a peripheral device according to any one of claims 1 to 4, characterized in that: The detection method also includes: before the external insulation detection device sends the first instruction, confirming that the high-voltage main circuit is closed and judging whether the established conditions are met, the established conditions include at least one of the following: no limit fault, no low voltage abnormal fault alarm, no heating relay fault alarm, no insulation fault, and no heating high side control short ground short power supply fault.

Images