Dual insulation detection method and system for high-voltage system of electric vehicle and computer storage medium

Abstract

The invention discloses a dual insulation detection method and system for an electric vehicle high-voltage system and a computer storage medium, and the method comprises the steps: after a vehicle is powered on at low voltage and a vehicle controller is awakened, the vehicle controller is used for transmitting an insulation detection instruction to a first insulation detection module and a second insulation detection module; a first insulation detection module and a second insulation detection module judge whether insulation detection values of respective positions are larger than a first set threshold value and a second set threshold value respectively, and a vehicle controller reads the insulation detection values of the first insulation detection module and the second insulation detection module and calculates the absolute value of the difference value of the insulation detection values of the first insulation detection module and the second insulation detection module. Judging whether the absolute value is smaller than a set value; when the vehicle has an insulation fault, whether the insulation fault is a battery insulation fault or a load end insulation fault can be distinguished, and the maintenance convenience of the vehicle is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle insulation monitoring, and in particular relates to a double insulation detection method, system and computer storage medium for a high voltage system of an electric vehicle. Background Art

[0002] In the prior art, new energy vehicles generally use a power battery BMS system to monitor the insulation performance of the vehicle, such as Figure 1 As shown, after waking up, the BMS continuously monitors the insulation performance of the vehicle's high-voltage system. If an insulation fault is detected, an insulation fault alarm message is issued, and the vehicle is limited in power or the high voltage is lowered according to the vehicle control strategy and the insulation fault level to ensure safety. This solution has the following disadvantages: 1. When an insulation system fault occurs in the vehicle, the insulation detection system can only issue an insulation fault alarm message and limit the power or lower the high voltage of the vehicle according to the insulation fault level and the vehicle control strategy; it is impossible to distinguish whether the insulation fault occurs at the load end or the power battery, and the power battery and the high-voltage load need to be checked one by one, which is extremely inconvenient to check the vehicle insulation fault; 2. Since the vehicle's high-voltage system has only one insulation detection module, when the insulation detection module itself fails to detect and causes inaccurate detection, it is impossible to directly determine whether the insulation fault is caused by the insulation detection module itself or the vehicle's high-voltage system has an insulation fault.

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

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

[0005] Another object of the present invention is to provide a double insulation detection system for a high voltage system of an electric vehicle.

[0006] Another object of the present invention is to provide a computer-readable storage medium.

[0007] The technical solution of the present invention to solve the technical problem is: A double insulation detection method for a high voltage system of an electric vehicle comprises the following steps: 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; 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 a first set threshold value. If so, execute step S3.1; if not, execute 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 the set value. If so, a control instruction is sent to turn off the first insulation detection module, turn on the second insulation detection module, and turn on the vehicle to high voltage; after the set time is reached, a control instruction is sent to turn off the second insulation detection module and turn on the first insulation detection module; execute step S4.1; if not, report an insulation detection fault, and control the vehicle not to allow high voltage; S3.2: The first insulation detection module and the second insulation detection module respectively determine whether the insulation detection value of their respective positions is greater than the second set threshold value. If so, an insulation detection fault is reported, and the vehicle controller sends a control instruction to turn off the first insulation detection module, turn on the second insulation detection module, and put the vehicle on high voltage; after the set time is reached, the vehicle controller sends a control instruction to turn off the second insulation detection module and turn on the first insulation detection module; execute step S4.2; if not, report an insulation detection fault, and control the vehicle not to allow 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 insulation detection values, and determines whether the absolute value is less than the set value; if so, the vehicle maintains the current state; executes step S5; if not, reports an insulation detection fault, the vehicle runs at limited power, and after reaching the set speed, the vehicle lowers the high voltage; 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, reports an insulation detection fault and the vehicle runs at limited power; if not, reports an insulation detection fault and the vehicle runs at limited power. After reaching the set speed, the vehicle lowers the high voltage; S5: The first insulation detection module determines whether the insulation detection value of the location is greater than the first set threshold value. If so, the vehicle maintains the current state; if not, execute step S6; S6: The first insulation detection module determines whether the insulation detection value at the location is greater than the second set threshold value. If so, an insulation detection fault is reported and the vehicle runs at limited power; if not, an insulation detection fault is reported and the vehicle runs at limited power. After reaching the set speed, the vehicle lowers the high voltage.

[0008] 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.

[0009] The first set threshold is 500Ω / V, and the second set threshold is 100Ω / V.

[0010] The set time is that the insulation detection cycle reaches 20 cycles.

[0011] The set vehicle speed is 5KM / H.

[0012] The set value is 10% of an average value calculated based on the insulation detection value of the first insulation detection module and the insulation detection value of the second insulation detection module.

[0013] A double insulation detection system for a high voltage system of an electric vehicle using a double insulation detection method for a high voltage system of an electric vehicle, comprising: The vehicle controller is used 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 ​​of the two, and determine whether the absolute value is less than a set value; the vehicle controller sends a control instruction to turn off the first insulation detection module, turn on the second insulation detection module, and apply high voltage to the vehicle; after the set time is reached, the vehicle controller sends a control instruction to turn off the second insulation detection module and turn on the first insulation detection module; A first insulation detection module, used to detect the insulation value of the location and send the insulation detection value to the vehicle controller; A second insulation detection module, used to detect the insulation value of the location and send the insulation detection value to the vehicle controller; The communication module is used to realize data communication among the vehicle controller, the first insulation detection module and the second insulation detection module.

[0014] 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.

[0015] A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, a device where the computer-readable storage medium is located executes a double insulation detection method for a high-voltage system of an electric vehicle.

[0016] The beneficial effects of the present invention are as follows: by setting the first insulation detection module and the second insulation detection module, when the vehicle is powered on at low voltage and the vehicle controller is awakened, the vehicle controller is used to send insulation detection instructions to the first insulation detection module and the second insulation detection module respectively; the first insulation detection module and the second insulation detection module respectively determine whether the insulation detection values ​​of their respective locations are greater than the first set threshold value and the second set threshold value, and 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 insulation detection values ​​of the two, and determines whether the absolute value is less than the set value. When an insulation fault occurs in the vehicle, it can be distinguished whether the insulation fault is a battery insulation fault or a load-end insulation fault, thereby improving the convenience of vehicle maintenance; two sets of insulation systems of vehicles of the same specification are tested and verified to avoid the problem of being unable to identify the false alarm insulation value when the insulation detection module itself has a detection fault or a detection error, thereby improving the safety factor of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a single insulation detection system in the prior art; Figure 2 is a flow chart of the insulation detection method of the present invention; Figure 3 Schematic diagram of a double insulation detection system of the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0019] Embodiment 1: like Figure 1 As shown, the present invention discloses a double insulation detection method for a high voltage system of an electric vehicle, comprising the following steps: 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 set at the power battery BMS end, and the second insulation detection module is set at the high-voltage load end.

[0020] 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 a first set threshold value. If so, execute step S3.1; if not, execute step S3.2; wherein the first set threshold value is 500Ω / V.

[0021] 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 insulation detection values ​​of the two, and determines whether the absolute value is less than the set value. If so, a control instruction is sent to turn off the first insulation detection module, turn on the second insulation detection module, and put the vehicle on high voltage; after the set time is reached, a control instruction is sent to turn off the second insulation detection module and turn on the first insulation detection module; execute step S4.1; if not, report an insulation detection fault and control the vehicle not to allow high voltage; wherein the set value is 10% of the average value calculated based on 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 cycle reaches 20 cycles, that is, the second insulation detection module performs 20 tests. At this time, the insulation detection of the second insulation detection module is not only for the high-voltage load end, but also includes the insulation detection of the power battery BMS end. When the insulation detection cycle reaches 20 cycles, the first insulation detection module also performs insulation detection on the power battery BMS end and the high-voltage load end at the same time.

[0022] S3.2: The first insulation detection module and the second insulation detection module respectively determine whether the insulation detection value of their respective locations is greater than the second set threshold value. If so, an insulation detection fault is reported, and the vehicle controller sends a control instruction to turn off the first insulation detection module, turn on the second insulation detection module, and put the vehicle on high voltage; after the set time is reached, the vehicle controller sends a control instruction to turn off the second insulation detection module and turn on the first insulation detection module; execute step S4.2; if not, an insulation detection fault is reported, and the vehicle is controlled not to be allowed to be on high voltage; wherein the second set threshold value is 100Ω / V. At this time, the insulation detection fault reported by the first insulation detection module is a power battery insulation detection fault, and the insulation detection fault reported by the second insulation detection module is a high-voltage load insulation detection fault.

[0023] 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 so, the vehicle maintains the current state; executes step S5; if not, reports an insulation detection fault, the vehicle runs at limited power, and after reaching the set speed, the vehicle lowers the high voltage; wherein the set speed is 5KM / H, and the insulation detection fault reported at this time is an insulation detection function failure. The absolute value of the difference between the insulation detection values ​​of the two is calculated as the difference between the insulation detection value of the second detection module within 20 cycles and the detection value of the current corresponding cycle of the first insulation detection module.

[0024] 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, reports an insulation detection fault and the vehicle runs at limited power; if not, reports an insulation detection fault and the vehicle runs at limited power. After reaching the set speed, the vehicle lowers the high voltage; S5: The first insulation detection module determines whether the insulation detection value of the location is greater than the first set threshold value. If so, the vehicle maintains the current state; if not, execute step S6; S6: The first insulation detection module determines whether the insulation detection value at the location is greater than the second set threshold value. If so, an insulation detection fault is reported and the vehicle runs at limited power; if not, an insulation detection fault is reported and the vehicle runs at limited power. After reaching the set speed, the vehicle lowers the high voltage.

[0025] Generally, in practical applications, the insulation resistance value is between 100Ω / V and 500Ω / V, which is called a primary 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 secondary 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. When the vehicle speed drops to no more than the set speed, the vehicle is subjected to high voltage treatment.

[0026] Embodiment 2: like Figure 2 As shown, 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 comprises: a vehicle controller, a first insulation detection module, a second insulation detection module, and a communication module, wherein 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.

[0027] The vehicle controller is used 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 ​​of the two, and determine whether the absolute value is less than a set value; the vehicle controller sends a control instruction to turn off the first insulation detection module, turn on the second insulation detection module, and apply high voltage to the vehicle; after the set time is reached, the vehicle controller sends a control instruction to turn off the second insulation detection module and turn on the first insulation detection module; A first insulation detection module, used to detect the insulation value of the location and send the insulation detection value to the vehicle controller; A second insulation detection module, used to detect the insulation value of the location and send the insulation detection value to the vehicle controller; The communication module is used to realize data communication among the vehicle controller, the first insulation detection module and the second insulation detection module.

[0028] Embodiment 3: A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, a device where the computer-readable storage medium is located executes a double insulation detection method for a high-voltage system of an electric vehicle.

[0029] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

Claims

1. A double insulation detection method for a high voltage system of an electric vehicle, characterized in that: The following steps are involved: 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; 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 a first set threshold value. If so, execute step S3.1; if not, execute 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 the set value. If so, a control instruction is sent to turn off the first insulation detection module, turn on the second insulation detection module, and turn on the vehicle to high voltage; after the set time is reached, a control instruction is sent to turn off the second insulation detection module and turn on the first insulation detection module; execute step S4.1; if not, report an insulation detection fault, and control the vehicle not to allow high voltage; S3.2: The first insulation detection module and the second insulation detection module respectively determine whether the insulation detection value of their respective positions is greater than the second set threshold value. If so, an insulation detection fault is reported, and the vehicle controller sends a control instruction to turn off the first insulation detection module, turn on the second insulation detection module, and put the vehicle on high voltage; after the set time is reached, the vehicle controller sends a control instruction to turn off the second insulation detection module and turn on the first insulation detection module; execute step S4.2; if not, report an insulation detection fault, and control the vehicle not to allow 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 insulation detection values, and determines whether the absolute value is less than the set value; if so, the vehicle maintains the current state; executes step S5; if not, reports an insulation detection fault, the vehicle runs at limited power, and after reaching the set speed, the vehicle lowers the high voltage; 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, reports an insulation detection fault and the vehicle runs at limited power; if not, reports an insulation detection fault and the vehicle runs at limited power. After reaching the set speed, the vehicle lowers the high voltage; S5: The first insulation detection module determines whether the insulation detection value of the location is greater than the first set threshold value. If so, the vehicle maintains the current state; if not, execute step S6; S6: The first insulation detection module determines whether the insulation detection value at the location is greater than the second set threshold value. If so, an insulation detection fault is reported and the vehicle runs at limited power; if not, an insulation detection fault is reported and the vehicle runs at limited power. After reaching the set speed, the vehicle lowers the high voltage.

2. The double insulation detection method of the electric vehicle high voltage system according to claim 1 is characterized in that: 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.

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

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

5. The double insulation detection method of the electric vehicle high voltage system according to claim 1, characterized in that: The set vehicle speed is 5KM / H.

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

7. A double insulation detection system for a high voltage system of an electric vehicle using a double insulation detection method for a high voltage system of an electric vehicle, characterized in that: include: The vehicle controller is used 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 the set value; the vehicle controller sends a control instruction to turn off the first insulation detection module, turn on the second insulation detection module, and apply high voltage to the vehicle; after the set time is reached, the vehicle controller sends a control instruction to turn off the second insulation detection module and turn on the first insulation detection module; A first insulation detection module, used to detect the insulation value of the location and send the insulation detection value to the vehicle controller; A second insulation detection module, used to detect the insulation value of the location and send the insulation detection value to the vehicle controller; The communication module is used to realize data communication among the vehicle controller, the first insulation detection module and the second insulation detection module.

8. The double insulation detection method of the electric vehicle high voltage system according to claim 7, characterized in that: 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.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the device where the computer-readable storage medium is located executes the method according to any one of claims 1 to 6.

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