| 摘要 |
PROBLEM TO BE SOLVED: To provide a bus protecting system for high-resistance grounded high- voltage spot network power receiving equipment, which detects early a fault point for preventing the all power failure, and ensures higher degree of reliability in power supply. SOLUTION: This bus protecting system comprises protector breakers 41, 42, 43 connected with the secondary side of network transformers 31, 32, 33 connected with power receiving lines 14, 15, 16, bus interlinked breakers 44, 45 46 connected with network buses 17, 18, 19, grounding transformers 51, 52, 53 and ground current detectors 81, 82, 83 connected between the network buses, and controllers 91, 92, 93 which detect bus ground fault through the ground current detectors and open the protector breakers. A first specified time after the detection of a bus ground fault by the ground current detectors 81, 82, 83, the controllers 91, 92, 93 open the bus interlinked breakers 44, 45, 46. When the ground fault is not longer detected, the controllers 91, 92, 93 reset the bus interlinked breakers, and, after a second specified time longer than the first specified time, open the protector breakers 41, 42, 43. |
