| 摘要 |
PURPOSE: To improve the reliability of power supply by, if any failure occurs in a bus, separating the failing bus from others to prevent overall power interruption, and, if any failure occurs on the load side, separating only the load side without separating the buses to continue the parallel operation of transformers. CONSTITUTION: When fault current flows to the point of failure, a first and a second protective relay 61 , 62 detect fault current on the secondary side of each transformer 11 , 12 . Further, a first or a second direction relay 211 , 212 detects the fault current according to the direction of the fault current. A breaking control means disconnects a first breaker from an interlinked breaker if a fault current is detected by the first protective relay and the first direction relay; it disconnects a second breaker from the interlinked breaker if a fault current is detected by the second protective relay and the second direction relay. The point of failure is thus removed. |
