DISTRIBUTION LINE ACCIDENT SECTION LOCATOR

PROBLEM TO BE SOLVED: To provide a distribution line accident section locator capable of detecting an accurate accident position and the direction without affected by a grid condition or a transient response due to the accident pattern. SOLUTION: Accident detectors distributed along the distribution line are inputted with a zero-phase voltage and a zero-phase current at an arrangement point from a zero-phase voltage sensor and a zero-phase current sensor. By judging the sign of an electric quantity (power product) of two vector products for a prescribed period, before and after occurrence of earth fault, the earth fault direction is accurately determined without affected by a grid condition, an accident pattern, etc. Thus, an accident direction is accurately detected without affected by the grid condition or a transient response due to an accident pattern. COPYRIGHT: (C)2004,JPO