Ring Network Switchgear Intelligent Protection Devices Developed

The thesis discusses the research and development on the Ring Main Unit intelligentized and its measure and protect function-implemented project, which is a sub-project of national technique creative project.At first, the thesis introduces the framework and actuality in power distribution automation, and the function of Ring Main Unit for distribution network system. Based on the analysis, the thesis proposes some key techniques. A novel fault judgment matrix, with the information from each Ring Main Unit, can judge the fault area on distribution network quickly, so the system can isolate the fault area and restructure the distribution network; switchgear cubicle status diagnosis adopt a condition-based diagnosis expert system, which knowledge representation combines the advantage of fault tree, frame and rule representation. At the same time, some research and practices are made for several newly components of electric system and the difficult problem of measure on high-voltage circumstance. To solve the problem of how to transmit small signal from new type voltage and current combined sensor, ensure on-line vacuum and joint temperature tester work safely, some effective anti-interference and isolation technique are presented.The test results come from national authoritative organization shows that the R&D on the apparatus achieves its expectation.