METHOD AND APPARATUS FOR DETECTING A FAULT SECTION USING COMPARISON OF PHASE DIFFERENCE AND MAGNITUDE DIFFERENCE BEWTEEN ZERO PHASE CURRENTS IN UNGROUNDED DISTRIBUTION POWER SYSTEMS

摘要

PPROBLEM TO BE SOLVED: To separate a fault section from a distribution system without causing power interruption by detecting the fault section, while comparing inter-line voltages, phase differences between zero-phase currents, and the magnitude of each of the zero-phase currents measured by each terminal machine of lines. PSOLUTION: Line terminal devices 21, 22, which are installed to each section of the lines so as to measure inter-line short circuit voltages and the zero-phase currents to transmit the phase differences and magnitude of the zero-phase currents to a central controller 30 after calculating them, and to execute the opening/closing command of a switch corresponding to instructions of the central controller 30, are provided in fault section detection in a non-grounded distribution system. The central controller 30 controls overall operations of a fault section detection system and a fault line detector 10 which transmits the presence or the absence of faults in self lines to the central controller 30, after detecting it when line faults occur, determines the fault section in the line, by requesting the transmission of phase difference information to each line terminal device when fault information is transmitted from the fault line detector 10, separates the fault section from the system by turning on a linked switch, and continues power supply to a load by switching a sound section to a linked line. PCOPYRIGHT: (C)2007,JPO&INPIT