INSULATION DETECTION METHOD AND INSULATION DETECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an insulation detection method and an insulation detection device capable of detecting insulation in all vehicle traveling conditions. SOLUTION: An AC signal from an AC signal generation means 10 is applied to a DC power supply V via a detection resistor Rd and a coupling capacitor Cd, and a voltage amplitude variation component of the AC signal present at a connection point between the detection resistor Rd and the coupling capacitor Cd is detected by the detection means 10. The correction means 10 corrects a first voltage measurement value when the capacitor C is connected between a positive pole of the DC power supply V and a ground electric potential G and a second voltage measurement value when the capacitor C is connected between a negative pole of the DC power supply V and the ground electric potential G by a voltage measurement means 10 on the basis of the detected voltage amplitude variation component. A calculation means 10 calculates a ground fault resistance of the DC power supply on the basis of the first and second voltage measurement values after the correction and a both end voltage V0of the DC power supply V when the capacitor C is connected between the positive and negative poles of the DC power supply V by the voltage measurement means 10. COPYRIGHT: (C)2007,JPO&INPIT