Insulation detection circuit and method

Abstract

The invention provides an insulation detection circuit and method. The insulation detection circuit comprises a to-be-detected high-voltage power supply and a load. A first end of the load is connected with the positive electrode of the to-be-detected high-voltage power supply, and a second end of the load is connected with the negative electrode of the to-be-detected high-voltage power supply. The insulation detection circuit further comprises a first switch S1, a second switch S2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8. After the technical scheme is adopted, the insulation resistance value of the high-voltage power supply working with the load can be simply and accurately measured, the measurement error caused by the fluctuation of the voltage of the high-voltage power supply along with the load is avoided, and the possible problem that the change ground dead zone of the insulation resistance value cannot be detected when the insulation resistances of the positive electrode and the negative electrode of the high-voltage battery are simultaneously changed is also avoided.

Description

technical field [0001] The invention relates to the field of insulation detection, in particular to an insulation detection circuit and method. Background technique [0002] The measurement of the insulation resistance of the high-voltage power supply directly affects the safe operation of the high-voltage system. When the measured insulation resistance is lower than a certain safety value, it is necessary to disconnect the circuit in time to ensure safety. If the measured value of the insulation resistance is larger than the actual value, It will cause the circuit to be disconnected by misoperation, which is not conducive to the stable operation of the circuit. If the measured value of the insulation resistance is smaller than the actual value, it will cause the actual insulation resistance to be lower than the safe value and not be discovered in time, which will bring potential safety hazards. . The existing insulation detection method is that the first resistor, the firs...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the above-mentioned technical defects, the object of the present invention is to provide an insulation detection circuit and method, which can accurately measure the insulation resistance value of the high-voltage power supply under the working state through a simple circuit, and solve the problem of insulation caused by the fluctuation of the high-voltage power supply voltage with the load. The technical problem that the deviation between the measured insulation resistance value and the actual value is too large also avoids the dead zone problem that may occur when the insulation resistance of the positive and negative electrodes of the high-voltage battery changes at the same time.

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