| 摘要 |
PROBLEM TO BE SOLVED: To provide an insulation level monitoring device capable of accurately performing ground insulation resistance determination at the level based on an electrical facility technical reference requirement in an electrical facility operation state. SOLUTION: A simulation circuit 72 having a known value between a measuring object circuit 1 and the ground is selectively connected, and insulation resistance is determined by calculation using variation in ground leakage current before and after simulation circuit connection and admittance of the simulation circuit connected to the current flowing on the ground through the simulation circuit. Thus, precise insulation resistance measurement that is not affected by phase error between voltage and current of a current transformer. By correcting the current detection deviation of a zero phase current transformer, goodness/badness is determined accurately performed based on the ground insulation resistance value (1mA in resistance part leakage current conversion, for example 0.2 MΩin 200V circuit) defined to the electrical facility technical reference. Therefore, a sign of insulation degradation of each electrical facility can be obtained early and correctly. COPYRIGHT: (C)2008,JPO&INPIT
|
