High voltage interlock circuit and detection method thereof

1. A high voltage interlock circuit comprising:

a first switching module, one terminal of the first switching module being connected to a first power supply, and the other terminal of the first switching module being connected to one terminal of a high voltage component module and a first power ground;

a second switching module comprises a first driving unit and a first switching unit arranged in isolation, the first driving unit being used to drive the first switching unit to close, a current input terminal of the first driving unit being connected to the other terminal of the high voltage component module, one terminal of the first switching unit being connected to a second power supply, and the other terminal of the first switching unit being connected to a second power ground;

a third switching module comprises a second driving unit and a second switching unit arranged in isolation, the second driving unit being used to drive the second switching unit to close, a current output terminal of the second driving unit being connected to the other terminal of the high voltage component module, one terminal of the second switching unit being connected to a third power supply, and the other terminal of the second switching unit being connected to the second power ground;

a fourth switching module, one terminal of the fourth switching module being connected to a fourth power supply, and the other terminal of the fourth switching module being connected to a current output terminal of the first driving unit, a current input terminal of the second driving unit and the first power ground;

a controller, configured to control the first switching module and the fourth switching module to close alternately, obtain a first detection result at one terminal of the first switching unit and a second detection result at one terminal of the second switching unit, and determine a fault of the high voltage component module based on the first detection result and the second detection result.

2. The high voltage interlock circuit of claim 1 , wherein the first driving unit and/or the second driving unit are light emitting elements;

the first switching unit and/or the second switching unit are optical switches.

3. The high voltage interlock circuit of claim 2 , wherein the light emitting elements are photodiodes;

the optical switches are metal oxide semiconductor field effect transistors or photoelectric triodes.

4. The high voltage interlock circuit of claim 1 , wherein the controller is specifically configured to:

determine that the high voltage component module has a short-connected power supply fault, under a condition that the first detection result is less than a first preset voltage threshold and the second detection result is greater than a second preset voltage threshold when the first switching module is closed, and both the first detection result and the second detection result are greater than the second preset voltage threshold when the fourth switching module is closed;

determine that the high voltage component module has a short-connected power ground fault, under a condition that both the first detection result and the second detection result are greater than the second preset voltage threshold when the first switching module is closed, and the first detection result is greater than the second preset voltage threshold and the second detection result is less than the first preset voltage threshold when the fourth switching module is closed;

determine that the high voltage component module has an open circuit fault, under a condition that both the first detection result and the second detection result are greater than the second preset voltage threshold when the first switching module is closed, and both the first detection result and the second detection result are greater than the second preset voltage threshold when the fourth switching module is closed.

5. The high voltage interlock circuit of claim 1 , wherein the controller is further configured to control both the first switching module and the fourth switching module to be disconnected, obtain a third detection result at one terminal of the first switching unit and a fourth detection result at one terminal of the second switching unit, and determine the fault of the high voltage component module based on the third detection result and the fourth detection result.

6. The high voltage interlock circuit of claim 5 , wherein the controller is configured to determine that the high voltage component module has a short-connected power supply fault when the third detection result is less than a first preset voltage threshold and the fourth detection result is greater than a second preset voltage threshold.

7. The high voltage interlock circuit of claim 1 , further comprising:

a first current limiting module, arranged between the first switching module and the first power supply;

a second current limiting module, arranged between the second power supply and one terminal of the first switching unit;

a third current limiting module, arranged between the third power supply and one terminal of the second switching unit;

a fourth current limiting module, arranged between one terminal of the fourth switching module and the fourth power supply.

8. The high voltage interlock circuit of claim 1 , further comprising:

a first current limiting module, arranged between the other terminal of the first switching module and the first power ground;

a second current limiting module, arranged between the other terminal of the fourth switching module and the first power ground.

9. The high voltage interlock circuit of claim 1 , further comprising:

a first anti-reverse module, arranged between one terminal of the high voltage component module and the first power supply;

a second anti-reverse module, arranged between the fourth power supply and the second power ground.

10. A detection method for a high-voltage interlock circuit, applied to the high voltage interlock circuit of claim 1 , the method comprising:

controlling the first switching module and the fourth switching module to close alternately;

obtaining the first detection result at one terminal of the first switching unit and the second detection result at one terminal of the second switching unit;

determining the fault of the high voltage component module based on the first detection result and the second detection result.

11. The method of claim 10 , wherein the determining the fault of the high voltage component module based on the first detection result and the second detection result comprises:

determining that the high voltage component module has a short-connected power supply fault, under a condition that the first detection result is less than a first preset voltage threshold and the second detection result is greater than a second preset voltage threshold when the first switching module is closed, and both the first detection result and the second detection result are greater than the second preset voltage threshold when the fourth switching module is closed;

determining that the high voltage component module has a short-connected power ground fault, under a condition that both the first detection result and the second detection result are greater than the second preset voltage threshold when the first switching module is closed, and the first detection result is greater than the second preset voltage threshold and the second detection result is less than the first preset voltage threshold when the fourth switching module is closed;

determining that the high voltage component module has an open circuit fault, under a condition that both the first detection result and the second detection result are greater than the second preset voltage threshold when the first switching module is closed, and both the first detection result and the second detection result are greater than the second preset voltage threshold when the fourth switching module is closed.

12. The method of claim 10 , further comprising:

controlling both the first switching module and the fourth switching module to be disconnected;

obtaining a third detection result at one terminal of the first switching unit and a fourth detection result at one terminal of the second switching unit;

determining the fault of the high voltage component module based on the third detection result and the fourth detection result.

13. The method of claim 12 , wherein the determining the fault of the high voltage component module based on the third detection result and the fourth detection result comprises:

determining that the high voltage component module has a short-connected power supply fault when the third detection result is less than a first preset voltage threshold and the fourth detection result is greater than a second preset voltage threshold.