Ground fault accident prediction system and ground fault accident prediction method

摘要

PPROBLEM TO BE SOLVED: To provide a system and method for predicting a ground fault accident wherein the ground fault accident on an electric line due to contact with trees or the like can be predicted without calculating the effective values of a zero-phase voltage and a zero-phase current or a phase difference between the zero-phase voltage and the zero-phase current. PSOLUTION: In the system 1 for predicting the ground fault accident, a device 24 for predicting the ground fault accident is provided in which the continuation time of a slight ground fault on a distribution line 3 is calculated based on an instantaneous output signal SSB1/SBinput from a ground directional relay 4a of a ground fault protection relay 4, in which a voltage value of the zero-phase voltage on the occurrence of the slight ground fault is calculated based on a zero-phase voltage detection signal SSBV0/SBinput from a timing characteristic type ground overvoltage relay 6, and in which the ground fault accident on the distribution line 3 is predicted based on the calculated continuation time of the slight ground fault and the calculated voltage value of the zero-phase voltage. PCOPYRIGHT: (C)2009,JPO&INPIT