FAULT DETECTOR FOR DETECTING FAULTS IN A DC CAPACITOR CIRCUIT

摘要

A fault detector for detecting faults in a DC capacitor circuit connected to the DC buses of an inventor circuit using semiconductor device for converting direct current into alternating current to suppress the voltage pulsation and comprising a plurality of parallel-connected capacitor circuits each having a plurality of seriesconnected DC capacitors. The fault detector comprises a comparison means connected to the junctions of the seriesconnected DC capacitors to compare the respective potentials of the parallel-connected capacitor circuits, and detects the short-circuit and time-aging of the DC capacitors of the parallel-connected capacitor circuits rapidly on the basis of the output signal of the comparison menas.