| 摘要 |
PROBLEM TO BE SOLVED: To perform a normal interception instruction to a protector breaker when an accident occurs in a network power distribution line while preventing unnecessary interception of the protector breaker caused by generation of rush current.SOLUTION: A network protector according to an embodiment comprises a control circuit which is installed in order to protect the load side of a network power distribution system where power is supplied from a plurality of high voltage power distribution lines to a network bus line through a network transformer and is further supplied from the network bus line to the load side through a protector breaker; does not intercept the protector breaker when a phase angle of current flowing into the load side shows delay within a predetermined angle range exceeding 0 to 90° to secondary side voltage of a network transformer; and intercepts the protector breaker when the phase angle shows delay in other than the predetermined angle range or advance within a predetermined angle range exceeding 90°. |
