INSULATION RESISTANCE MEASURING INSTRUMENT OF DC CIRCUIT, ELECTROSTATIC CAPACITANCE MEASURING INSTRUMENT, INSULATION RESISTANCE MEASURING METHOD AND ELECTROSTATIC CAPACITANCE MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To accurately and easily measure an insulation resistance and an electrostatic capacitance of a DC circuit to the ground in a live-wire state. SOLUTION: A ground resistors 3 is grounded at the positive/negative terminal of the DC circuit D. A stable voltage value for stabilizing a voltage between terminals of the ground resistor 3 is measured at the positive/negative terminal. The insulation resistances Rp, Rn are calculated, based on the stable voltage values. A transition duration (time constant) is measured, until the voltage between the terminals of the ground resistor 3 reaches a predetermined voltage. The electrostatic capacitance (Cp+Cn) is calculated, based on the transition duration and the insulation resistances Rp, Rn. COPYRIGHT: (C)2007,JPO&INPIT