CHANNEL SELECTION PROTECTION RELAY DEVICE AND PARALLEL TWO-LINE POWER TRANSMISSION LINE PROTECTION SYSTEM

摘要

To reduce unnecessary operation delay of a circuit breaker when a power transmission line protection relay provided at a terminal of a parallel two-line power transmission line is operated.SOLUTION: A relay function operation unit 11d generates, on the basis of a reactance component value X from among impedance in proportion to a distance to a fault point on a B line and a C line that are a branch power transmission line from an A terminal or a B terminal, a main protection 150S, a transmission line 1L backup protection range 144SX1 signal, a transmission line 1L backup protection range 144SX2 signal, a transmission line 2L backup protection range 244SX1 signal, and a transmission line 2L backup protection range 244SX2 signal. When the transmission line 1L backup protection range 144SX1 signal is ineffective and the backup protection range 144SX2 signal and the backup protection range 244SX2 signal are effective, an accident detection sequence unit 11e delays the main protection 150S signal for a prescribed time to generate a trip control signal. When the backup protection range 144SX2 or the backup protection range 244SX2 signal becomes ineffective within a prescribed time, generation of the main protection 150S trip control signal is stopped.SELECTED DRAWING: Figure 4