Locus of apparent impedance the zone (zone) penetrated on

摘要

PROBLEM TO BE SOLVED: To provide a method for detecting the failure of a transmission line using a harmonic wave and a state transition diagram.;SOLUTION: When a failure occurs on a transmission line, a harmonic wave and a state transition diagram are used to detect the failure, and the total of the magnitude of the apparent impedance of normal state characteristics and the harmonic wave component of excessive state characteristics is used to output two logic signals. When the two logic signals are used as an input for the state transition diagram, a system state can be estimated during the state transition process by a change in the system. Malfunction of a distance relay is protected in a state such as an increase in load or unstable voltage or the like. In addition, the system state can be estimated by using the harmonic wave and the state transition diagram, thereby enabling detection of the failure of the transition line precisely.;COPYRIGHT: (C)2005,JPO&NCIPI