Reactive power compensator null for systematic run type conservation

摘要

PROBLEM TO BE SOLVED: To make it possible to surely defect an islanding state without selecting a variation frequency for the reactive power unit or using an expensive transmission breaking device and realize reliable protective function without a decrease in detective sensitivity caused by mutual interference of a reactive power unit. ;SOLUTION: When an islanding state takes place, a change in frequency at linkage points is detected by control units 45 to 49, and a reactive power reference value is adjusted under control in such a way as to increase the frequency change. A reactive power compensating unit 40 generates reactive power to cause a hunting state, in which frequency at the linkage point fluctuates in a given frequency cycle near to a rated frequency. Under these conditions, protective operation can be carried out by opening breakers 6 and 63 between the linkage point and a non-utility generator.;COPYRIGHT: (C)1997,JPO