POWER CABLE GROUND FAULT DETECTING APPARATUS AND POWER CABLE GROUND FAULT PROTECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a power cable ground fault detecting apparatus for ground fault protection in a power cable line without installing an expensive grounded measurement device transformer and a neutral point resistor.;SOLUTION: The power cable ground fault detecting apparatus 10 is provided with a ground fault accident determination circuit 12, a sheath current comparison circuit 13, and an AND circuit 14. The ground fault determination circuit functions as ground fault accident occurrence detection means for detecting occurrence of a ground fault accident in a power cable line based on a zero phase current I₀ input from zero phase converters 5 installed in R-phase/S-phase/T-phase power cables 2_R, 2_S and 2_T, which constitute a power cable line, and a sheath current I_S input from a sheath current detecting transformer 6 arranged in each sheath ground fault line 4 for grounding a metal sheath of the R-phase/S-phase/T-phase power cables 2_R, 2_S and 2_T.;COPYRIGHT: (C)2010,JPO&INPIT