A dual insulation detection method, system and computer storage medium for a high-voltage system of an electric vehicle

Abstract

The application discloses a kind of double insulation detection method, system and computer storage medium of electric vehicle high pressure system, in vehicle low voltage, vehicle controller wakes up, and insulation detection instruction is sent to first insulation detection module, second insulation detection module using vehicle controller respectively;After first insulation detection module, second insulation detection module respectively judges whether the insulation detection value of respective position is greater than first set threshold value, second set threshold value, vehicle controller reads the insulation detection value of first insulation detection module, second insulation detection module respectively, calculates the absolute value of the difference of two insulation detection values, judges whether the absolute value is less than set value.The insulation fault of vehicle can be distinguished whether battery insulation fault or load end insulation fault when insulation fault occurs, and the convenience of vehicle maintenance is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vehicle insulation monitoring, and particularly relates to a double insulation detection method and system for a high-voltage system of an electric vehicle and a computer storage medium. BACKGROUND

[0002] In the prior art, a new energy vehicle generally uses a power battery BMS system to monitor the insulation performance of the vehicle, as shown in the prior art. Figure 1 After the BMS is woken up, the insulation performance of the high-voltage system of the vehicle is continuously monitored, if an insulation fault is detected, an insulation fault alarm information is sent out, and the vehicle is processed with limited power or high-voltage according to the vehicle control strategy and the insulation fault level to ensure safety. This scheme has the following disadvantages: 1. When the vehicle has an insulation system fault, the insulation detection system can only send out an insulation fault alarm information and process the vehicle with limited power or high-voltage according to the insulation fault level and the vehicle control strategy; it cannot distinguish whether the insulation fault occurs at the load end or the power battery, and it is extremely inconvenient to check the insulation fault of the vehicle; 2. Since the vehicle high-voltage system has only one insulation detection module, when the insulation detection module itself has a detection fault leading to inaccurate detection, it cannot directly determine whether the insulation fault is caused by the insulation detection module itself or the vehicle high-voltage system has an insulation fault.

[0003] A new insulation detection method is needed to solve the above technical problems. SUMMARY

[0004] The purpose of the present application is to provide a double insulation detection method for a high-voltage system of an electric vehicle, which can solve the technical problems that the insulation detection system in the prior art cannot automatically distinguish the fault area and cannot ensure the accuracy of the reported insulation fault.

[0005] The purpose of the present application is also to provide a double insulation detection system for a high-voltage system of an electric vehicle.

[0006] The purpose of the present application is also to provide a computer readable storage medium.

[0007] The technical solution of the present application to solve the technical problems is as follows:

[0008] A double insulation detection method for a high-voltage system of an electric vehicle, comprising the following steps:

[0009] S1: The vehicle is powered on at low voltage, the vehicle controller is woken up, and the vehicle controller sends insulation detection instructions to the first insulation detection module and the second insulation detection module, respectively;

[0010] S2: The first insulation detection module and the second insulation detection module respectively judge whether the insulation detection value at the position where each of them is located is greater than the first set threshold value, if yes, step S3.1 is executed; if no, step S3.2 is executed;

[0011] S3.1: The vehicle controller reads the insulation detection value of each of the first insulation detection module and the second insulation detection module, calculates the absolute value of the difference between the two insulation detection values, judges whether the absolute value is less than the set value, if yes, sends a control instruction to make the first insulation detection module close, the second insulation detection module open and the vehicle high voltage; after reaching the set time, sends a control instruction to make the second insulation detection module close and the first insulation detection module open; step S4.1 is executed; if no, reports an insulation detection fault, and controls the vehicle not to allow high voltage;

[0012] S3.2: The first insulation detection module and the second insulation detection module respectively judge whether the insulation detection value at the position where each of them is located is greater than the second set threshold value, if yes, reports an insulation detection fault, and the vehicle controller sends a control instruction to make the first insulation detection module close, the second insulation detection module open and the vehicle high voltage; after reaching the set time, the vehicle controller sends a control instruction to make the second insulation detection module close and the first insulation detection module open; step S4.2 is executed; if no, reports an insulation detection fault, and controls the vehicle not to allow high voltage;

[0013] S4.1: The vehicle controller reads the insulation detection value of each of the first insulation detection module and the second insulation detection module, calculates the absolute value of the difference between the two insulation detection values, judges whether the absolute value is less than the set value; if yes, the vehicle remains in the current state; step S5 is executed; if no, reports an insulation detection fault, and the vehicle runs at limited power, and after reaching the set speed, the vehicle is de-energized;

[0014] S4.2: The vehicle controller reads the insulation detection value of each of the first insulation detection module and the second insulation detection module, calculates the absolute value of the difference between the two insulation detection values, judges whether the absolute value is less than the set value; if yes, reports an insulation detection fault, and the vehicle runs at limited power; if no, reports an insulation detection fault, and the vehicle runs at limited power, and after reaching the set speed, the vehicle is de-energized;

[0015] S5: The first insulation detection module judges whether the insulation detection value at the position where it is located is greater than the first set threshold value, if yes, the vehicle remains in the current state; if no, step S6 is executed;

[0016] S6: The first insulation detection module judges whether the insulation detection value at the position where it is located is greater than the second set threshold value, if yes, reports an insulation detection fault, and the vehicle runs at limited power; if no, reports an insulation detection fault, and the vehicle runs at limited power, and after reaching the set speed, the vehicle is de-energized.

[0017] The first insulation detection module is arranged at the power battery BMS end, and the second insulation detection module is arranged at the high-voltage load end.

[0018] The first set threshold value is 500Ω / V, and the second set threshold value is 100Ω / V.

[0019] The set time is 20 cycles of the insulation detection period.

[0020] The set vehicle speed is 5KM / H.

[0021] The set value is 10% of the average value calculated according to the insulation detection value of the first insulation detection module and the insulation detection value of the second insulation detection module.

[0022] A double insulation detection system of an electric vehicle high-voltage system adopting a double insulation detection method of the electric vehicle high-voltage system, comprising:

[0023] A vehicle controller is configured to send an insulation detection instruction to the first insulation detection module and the second insulation detection module, read the insulation detection values of the first insulation detection module and the second insulation detection module, calculate the absolute value of the difference between the insulation detection values, and determine whether the absolute value is less than a set value; the vehicle controller sends a control instruction to make the first insulation detection module closed, the second insulation detection module opened, and the vehicle high-voltage; after a set time is reached, the vehicle controller sends a control instruction to make the second insulation detection module closed and the first insulation detection module opened.

[0024] The first insulation detection module is configured to detect the insulation value at the location and send the insulation detection value to the vehicle controller.

[0025] The second insulation detection module is configured to detect the insulation value at the location and send the insulation detection value to the vehicle controller.

[0026] A communication module is configured to realize data communication between the vehicle controller, the first insulation detection module, and the second insulation detection module.

[0027] The first insulation detection module is arranged at the power battery BMS end, and the second insulation detection module is arranged at the high-voltage load end.

[0028] A computer readable storage medium stores a computer program, and the computer program is executed by a processor to make a device in which the computer readable storage medium is located execute a double insulation detection method of an electric vehicle high-voltage system.

[0029] The beneficial effects of the present application are: by setting the first insulation detection module and the second insulation detection module, when the vehicle is powered on at low voltage, the vehicle controller sends insulation detection instructions to the first insulation detection module and the second insulation detection module respectively after the vehicle controller wakes up; the first insulation detection module and the second insulation detection module respectively judge whether the insulation detection value at the position where each is located is greater than the first set threshold value and the second set threshold value, the vehicle controller reads the insulation detection value of the first insulation detection module and the second insulation detection module respectively, calculates the absolute value of the difference between the two insulation detection values, and judges whether the absolute value is less than the set value. When the vehicle has an insulation fault, it can be distinguished whether the insulation fault is a battery insulation fault or a load end insulation fault, and the convenience of vehicle maintenance is improved; the two sets of insulation systems of the same specification vehicle are detected and checked, avoiding the problem that when the insulation detection module itself fails or has a detection error, the insulation value cannot be identified and false positives are avoided, and the safety factor of the vehicle is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic diagram of a single insulation detection system in the prior art;

[0031] Figure 2 is a flowchart of the insulation detection method of the present application;

[0032] Figure 3 is a schematic diagram of the dual insulation detection system of the present application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0034] Embodiment 1:

[0035] As shown in Figure 1 , the present application discloses a dual insulation detection method for a high-voltage system of an electric vehicle, comprising the following steps:

[0036] S1: The vehicle is powered on at low voltage, the vehicle controller wakes up, and the vehicle controller sends insulation detection instructions to the first insulation detection module and the second insulation detection module respectively; the first insulation detection module is arranged at the power battery BMS end, and the second insulation detection module is arranged at the high-voltage load end.

[0037] S2: The first insulation detection module and the second insulation detection module respectively judge whether the insulation detection value at the position where each is located is greater than the first set threshold value, if yes, step S3.1 is executed; if no, step S3.2 is executed; wherein the first set threshold value is 500Ω / V.

[0038] S3.1: The vehicle controller reads the insulation detection values of the first insulation detection module and the second insulation detection module respectively, calculates the absolute value of the difference between the two insulation detection values, judges whether the absolute value is less than a set value, if yes, sends a control instruction to make the first insulation detection module close, the second insulation detection module open and the vehicle high voltage; after reaching a set time, sends a control instruction to make the second insulation detection module close, the first insulation detection module open; executes step S4.1; if not, reports an insulation detection fault, and controls the vehicle not to allow high voltage; wherein the set value is 10% of the average value calculated according to the insulation detection value of the first insulation detection module and the insulation detection value of the second insulation detection module. The set time is that the insulation detection period reaches 20 cycles, that is, the second insulation detection module detects 20 times, at this time, the insulation detection of the second insulation detection module not only includes the insulation detection of the high voltage load end, but also includes the insulation detection of the power battery BMS end. When the insulation detection period reaches 20 cycles, the first insulation detection module also insulates the power battery BMS end and the high voltage load end.

[0039] S3.2: The first insulation detection module and the second insulation detection module respectively judge whether the insulation detection value of the position where each is located is greater than a second set threshold, if yes, reports an insulation detection fault, and the vehicle controller sends a control instruction to make the first insulation detection module close, the second insulation detection module open and the vehicle high voltage; after reaching a set time, the vehicle controller sends a control instruction to make the second insulation detection module close, the first insulation detection module open; executes step S4.2; if not, reports an insulation detection fault, and controls the vehicle not to allow high voltage; wherein the second set threshold is 100Ω / V. At this time, the insulation detection fault reported by the first insulation detection module is the power battery insulation detection fault, and the insulation detection fault reported by the second insulation detection module is the high voltage load insulation detection fault.

[0040] S4.1: The vehicle controller reads the insulation detection values of the first insulation detection module and the second insulation detection module respectively, calculates the absolute value of the difference between the two insulation detection values, judges whether the absolute value is less than a set value; if yes, the vehicle remains in the current state; executes step S5; if not, reports an insulation detection fault, and the vehicle runs at a limited power, and after reaching a set speed, the vehicle is high voltage; wherein the set speed is 5KM / H, at this time, the reported insulation detection fault is an insulation detection function fault. The calculation of the absolute value of the difference between the two insulation detection values is the difference between the insulation detection value of the second detection module and the detection value of the corresponding period of the first insulation detection module within 20 cycles.

[0041] S4.2: The vehicle controller reads the insulation detection values of the first insulation detection module and the second insulation detection module respectively, calculates the absolute value of the difference between the two insulation detection values, and determines whether the absolute value is less than a set value; if yes, an insulation detection fault is reported, and the vehicle is limited in power; if no, an insulation detection fault is reported, the vehicle is limited in power, and the vehicle is powered off after reaching a set speed;

[0042] S5: The first insulation detection module determines whether the insulation detection value at the location is greater than a first set threshold value; if yes, the vehicle remains in the current state; if no, step S6 is performed;

[0043] S6: The first insulation detection module determines whether the insulation detection value at the location is greater than a second set threshold value; if yes, an insulation detection fault is reported, and the vehicle is limited in power; if no, an insulation detection fault is reported, the vehicle is limited in power, and the vehicle is powered off after reaching a set speed.

[0044] In general, in actual applications, the insulation resistance value is between 100Ω / V and 500Ω / V, which is called a first-level insulation fault, at this time the vehicle insulation fault is reported, and the vehicle controller limits the power of the vehicle according to the vehicle control strategy; the insulation resistance value is not greater than 100Ω / V, which is called a second-level insulation fault, at this time the vehicle insulation fault is reported, and the vehicle controller limits the power of the vehicle according to the vehicle control strategy, and powers off the vehicle when the vehicle speed is not greater than a set speed.

[0045] Embodiment 2:

[0046] As shown in Figure 2 A double insulation detection system of an electric vehicle high-voltage system adopting a double insulation detection method of an electric vehicle high-voltage system, comprising: a vehicle controller, a first insulation detection module, a second insulation detection module, and a communication module; the first insulation detection module is arranged at the power battery BMS end, and the second insulation detection module is arranged at the high-voltage load end. The power battery BMS supplies power to the high-voltage load end, and the first insulation detection module and the second insulation detection module can complete mutual verification of insulation detection.

[0047] The vehicle controller is used for sending an insulation detection instruction to the first insulation detection module and the second insulation detection module; reading the insulation detection values of the first insulation detection module and the second insulation detection module respectively, calculating the absolute value of the difference between the two insulation detection values, and determining whether the absolute value is less than a set value; the vehicle controller sends a control instruction to make the first insulation detection module close, the second insulation detection module open, and the vehicle powered on; after a set time, the vehicle controller sends a control instruction to make the second insulation detection module close and the first insulation detection module open;

[0048] The first insulation detection module is used for detecting the insulation value at the location and sending the insulation detection value to the vehicle controller;

[0049] A second insulation detection module is configured to detect an insulation value of a location and send the insulation detection value to the vehicle controller.

[0050] A communication module is configured to realize data communication among the vehicle controller, the first insulation detection module and the second insulation detection module.

[0051] Embodiment 3

[0052] A computer readable storage medium stores a computer program, and the computer program is executed by a processor to make a device where the computer readable storage medium is located execute a double insulation detection method of a high-voltage system of an electric vehicle.

[0053] All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative labor are within the protection scope of the present application.

Claims

1. A method for detecting double insulation in a high-voltage system of an electric vehicle, characterized in that, Includes the following steps: S1: The vehicle is powered on at low voltage, the vehicle controller is awakened, and the vehicle controller sends insulation detection commands to the first insulation detection module and the second insulation detection module respectively. S2: The first insulation detection module and the second insulation detection module respectively determine whether the insulation detection value at their respective locations is greater than the first set threshold. If yes, proceed to step S3.1; if no, proceed to step S3.

2. S3.1: The vehicle controller reads the insulation detection values ​​of the first insulation detection module and the second insulation detection module, calculates the absolute value of the difference between the two insulation detection values, and determines whether the absolute value is less than a set value. If so, it sends a control command to shut down the first insulation detection module, turn on the second insulation detection module, and allow the vehicle to access high voltage. After the set time is reached, it sends a control command to shut down the second insulation detection module and turn on the first insulation detection module, and executes step S4.

1. If not, it reports an insulation detection fault and prevents the vehicle from accessing high voltage. S3.2: The first insulation detection module and the second insulation detection module respectively determine whether the insulation detection value at their respective locations is greater than the second set threshold. If so, an insulation detection fault is reported, and the vehicle controller sends a control command to shut down the first insulation detection module, turn on the second insulation detection module, and connect the vehicle to high voltage. After a set time is reached, the vehicle controller sends a control command to shut down the second insulation detection module and turn on the first insulation detection module, and executes step S4.

2. If not, an insulation detection fault is reported, and the vehicle is prevented from connecting to high voltage. S4.1: The vehicle controller reads the insulation detection values ​​of the first insulation detection module and the second insulation detection module, calculates the absolute value of the difference between the two insulation detection values, and determines whether the absolute value is less than the set value; if yes, the vehicle maintains the current state and executes step S5; if no, an insulation detection fault is reported, the vehicle operates with limited power, and after reaching the set speed, the vehicle is de-energized. S4.2: The vehicle controller reads the insulation detection values ​​of the first insulation detection module and the second insulation detection module, calculates the absolute value of the difference between the two insulation detection values, and determines whether the absolute value is less than the set value; if so, it reports an insulation detection fault and the vehicle operates with limited power; if not, it reports an insulation detection fault, the vehicle operates with limited power, and after reaching the set speed, the vehicle de-energizes. S5: The first insulation detection module determines whether the insulation detection value at the current location is greater than the first set threshold. If yes, the vehicle maintains its current state; otherwise, proceed to step S6. S6: The first insulation detection module determines whether the insulation detection value at the current location is greater than the second set threshold. If yes, it reports an insulation detection fault and the vehicle operates with limited power. If no, it reports an insulation detection fault, the vehicle operates with limited power, and the vehicle is de-energized after reaching the set speed.

2. The method for detecting double insulation in a high-voltage system of an electric vehicle according to claim 1, characterized in that, The first insulation detection module is located at the power battery BMS end, and the second insulation detection module is located at the high-voltage load end.

3. The method for detecting double insulation in a high-voltage system of an electric vehicle according to claim 1, characterized in that, The first set threshold is 500Ω / V, and the second set threshold is 100Ω / V.

4. The method for detecting double insulation in a high-voltage system of an electric vehicle according to claim 1, characterized in that, The set time is when the insulation detection cycle reaches 20 cycles.

5. The method for detecting double insulation in a high-voltage system of an electric vehicle according to claim 1, characterized in that, The set speed is 5 km / h.

6. The method for detecting double insulation in a high-voltage system of an electric vehicle according to claim 1, characterized in that, The set value is 10% of the average value calculated based on the insulation detection values ​​of the first insulation detection module and the second insulation detection module.

7. A double insulation detection system for a high-voltage system of an electric vehicle, employing the double insulation detection method for a high-voltage system of an electric vehicle according to any one of claims 1-6, characterized in that, include: The vehicle controller is used to send insulation detection commands to the first insulation detection module and the second insulation detection module. The system reads the insulation detection values ​​of the first insulation detection module and the second insulation detection module, calculates the absolute value of the difference between the two insulation detection values, and determines whether the absolute value is less than a set value. The vehicle controller sends a control command to turn off the first insulation detection module, turn on the second insulation detection module, and connect the vehicle to high voltage. After the set time is reached, the vehicle controller sends a control command to turn off the second insulation detection module and turn on the first insulation detection module. The first insulation detection module is used to detect the insulation value at its location and send the insulation detection value to the vehicle controller. The second insulation detection module is used to detect the insulation value at its location and send the insulation detection value to the vehicle controller. The communication module is used to enable data communication between the vehicle controller, the first insulation detection module, and the second insulation detection module.

8. The dual insulation detection system for the high-voltage system of an electric vehicle according to claim 7, characterized in that, The first insulation detection module is located at the power battery BMS end, and the second insulation detection module is located at the high-voltage load end.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it causes the device containing the computer-readable storage medium to perform the method of any one of claims 1-6.

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