| 摘要 |
An insulation detecting method, an insulation detecting system, and a leakage current compensation device for an electric power supply system are provided not to influence other insulation detectors by not additionally generating zero phase leakage current between the system and the ground in a leakage current compensator for attenuating reactive leakage current, thereby preventing erroneous operation of the other insulating detectors. A zero phase current transformer(10) detects a leakage current component flowing between a 3-phase electric power supply system and the ground. A leakage current detection device amplifies and filters the leakage current component detected by the zero phase current transformer. A leakage current display device displays an output value of the leakage current detection device. Voltage detection lines(12,13,14) detect AC voltage of the 3-phase electric power supply system. A voltage component detection device converts a voltage component of each of 3 phases inputted by the voltage detection lines into a uniform size and selects a voltage component of one of 3 phases or detects voltage components of all the 3 phases. A phase difference detection device detects a phase difference between the voltage component detected by the voltage component detection device and a leakage current component outputted from the leakage current detection device. A leakage current compensator(30) makes compensating leakage current capable of allowing leakage current not to additionally flow in the substantial electric power supply system and compensating leakage current due to capacitance of the substantial electric power supply system, thereby allowing the compensating leakage current to flow to the zero phase current transformer or ground earth. |
