| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a protection system of generator equipment, which can stop a failed generator using only ground overcurrent relays. SOLUTION: An AND gate GATE1 decides whether a generator G1 whose neutral is grounded is in operation from a breaker 52G1 and a neutral switch 42G1 of the generator G1. AND gates GATE2-GATE4 output the trip commands of other generators G2-G4, when a ground overcurrent relay 51GG1 of the generator G1 with the grounded neutral, ground overcurrent relays 51GG2-51GG4 of the respective other generators G2-G4 and the ground overcurrent relay 51GG0 are in operation. A timer T1 outputs the trip command of the generator G1 with the grounded neutral, when the ground overcurrent relay 51GG0 operates continuously for a period longer than a predetermined time.</p> |
