DISTRIBUTION LINE FAILURE DIAGNOSIS METHOD AND SYSTEM WHICH USES A PROTECTIVE RELAY FOR REPETITIVELY COMPARING DIAGNOSIS FAILURE CURRENT AND ESTIMATION FAILURE CURRENT

摘要

PURPOSE: A distribution line failure diagnosis method and system are provided to calculate a failure point of a distribution line which breaks down.;CONSTITUTION: A distribution line failure diagnosis system comprises a delay time calculating part(100), a diagnosis failure current calculating part(200), and a failure point determining part(300). The delay time calculating part calculates an interval between pick up time of failure occurrence and motion start time of a protective relay due to the failure as delay time. The diagnosis failure current calculating part calculates pickup multiple based on the relay time and a lever value of the protective value. The diagnosis failure current calculating part calculates failure current using the pickup multiple, a tab value of the protective relay, and current ration. The failure point determining part determines a failure point by comparing a current value of a plurality of estimation failure currents with a current value of failure current.;COPYRIGHT KIPO 2013;[Reference numerals] (100) Delay time calculating part; (200) Diagnosis failure current calculating part; (300) Failure point determining part; (400) Database part; (AA) Failure current; (BB) Protective relay; (CC) Operating time and pick up time; (DD) Pick up multiple; (EE) Diagnosis failure current; (FF) Failure spot; (GG) Lever value, tab value, current ratio; (HH) Bus line impedance, line impedance