| 摘要 |
PURPOSE:To make it possible to perform accurate, quick load selective breaking by comparing the lengths of the tolerance time of overload operation and the time required for computing selective breaking, and selecting a breaking signal of either a selective breaking computing part or a preset part. CONSTITUTION:In a breaking-allowance-time judging part 4, the amount of shortage in the state of a system after a fault and the possible time of the overload operation of a remaining feeding power supply are computed with an operating means. The lengths of the tolerance time of the overload operation and the time required for the computation of the selective breaking are compared. When operation tolerance time > required computation time, a switch part 3 is changed to the side of a selective-breaking computing part 1, and the selective-breaking signal is outputted into an object breaker. Or when operation tolerance time < required computation time, the switch part 3 is changed to the side of a preset part 2, and the selective breaking signal is outputted into the object breaker. Therefore, the selective breaking having the advantages of both methods can be performed, and the load undergoes the selective breaking accurately and quickly. |
