| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a protection relay of a power transmission line and a re-loading method of a circuit breaker, capable of improving stability in a system by shortening a power transmission period under the condition of phase interruption. <P>SOLUTION: A protection relay of a power transmission line comprises; an arc disappearance detecting part 13 which calculates, for each defective phase, a correlation value representing relationship between the voltage of a defective phase (2A1) in defective lines (2A1-2C1) in which a failure is occurring and the voltage of a phase (2A2) corresponding to the defective phase (2A1) among sound lines (2A2-2C2) in which no failure is occurring, based on the voltage detected with transformers 5A1-5F1(5A2-5F2) connected to power transmission lines 2A1-2C1(2A2-2C2) respectively, and which also detects that, when a sign of deviation of the correlation value changes, the defective phase is released following the releasing of a circuit breaker 3A1, and that an arc has disappeared when a predetermined time has passed after that: and a command generation part 20 generates a loading command of the circuit breaker 3A1 based on an arc disappearance detection signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
