Research Of The Fault Detection And Recovery System Of Puyang Power Distribution Network

Non-effectively earthed neutral system in 6~35kV distribution networks is widely adopted in China and it is also called small current grounded system. The single line ground fault happens most frequently in the system, almost 80% of all faults in the system. During occurrence of the fault, the voltage of the grounded phase is down to zero and the voltage of the ungrounded phase up to the line voltage. Since the line voltage is still symmetrical under fault conditions, the systems can keep operating for two hours. However the fault line must be detected quickly to avoid more seriously fault and destroying devices. The fault line detection is a difficult problem, especially in the resonance-grounded power system, because of the small fault current and arcing effect etc.This article describes the small current grounding system single-phase earth fault line selection state of development, analyzing a variety of alignment patterns successes and failures, and through fault features in-depth analysis, research has developed a small current grounding system single-phase ground fault The intelligent integration of diagnostic systems, has formed a variety of criteria as one of the full criteria, and use a valid domain technology, continuous judgments technology, resulting in a real sense of the intelligent fault diagnosis system accurately. Newly developed fault diagnosis system for precision laboratory, substation simulation test, the correct rate reached 100%, in May 2009 in Henan Puyang Zhongyuan points have been installed so far put into operation and accurately determine the 10kV power system single-phase ground fault occurred . System works so far, and achieved satisfactory results, to achieve the desired goals.