Detecting system of ground fault of transmission line

Abstract

Abstract PURPOSE:To detect the presence of a ground fault easily, by providing a pair of zero-phase current detectors with time-count display units measuring and displaying a time from a time point of the amplitude of a zero-phase current exceeding a set value to a time point of the zero-phase current changing from negative to positive or from positive to negative, respectively, and by measuring a difference between the times measured and displayed by these units. CONSTITUTION:At the opposite end points A and B of a prescribed section (AB) of a transmission line 1, current transformers 2 and 2a measuring a current of each phase and zero-phase current detectors 3 and 3a finding a zero-phase current from said current of each phase are located. These zero-phase current detectors 3 and 3a in a pair are provided with time-count display units 8 and 8a measuring and displaying a time from a time point of the amplitude of the zero-phase current exceeding a prescribed set value when a ground fault of the transmission line 1 occurs, to a zero-cross point of the zero-phase current changing from negative to positive or from positive to negative, respectively. The presence of the ground fault in the prescribed section (AB) of the transmission line 1 can be detected easily from a different between the times measured and displayed by these paired time-count display units 8 and 8a.

Inventors

• 👤 Hiroshi Kawakami

Bibliographic Details