基于模糊理论的多判据信息融合小电流接地系统单相接地故障选线方法

Fault Line Selection Method for Single Phase-to-ground Faults of Multi-criteria Information Integrated with Lower Current Grounding Power System Based on Fuzzy Theory

小电流接地系统的单相接地故障选线问题是长期以来一直存在的技术难题,为提高故障选线的可靠性,提出基于模糊理论的多判据信息融合的单相接地故障选线方法。电网一次故障数据经电压互感器、电流互感器变换后,将故障特征量送入不同的选线判据,然后根据模糊变换得到母线及各条出线的故障测度及各种判据的权系数,最后进行融合决策,并输出最终决策结果。指出该故障选线方法的关键技术是合理定义故障测度隶属函数和判据权函数。

Line selection for single phase-to-ground fault for low current grounding power system has been a technical problem since long before. Fault line selection for single phase-to-ground fault of multi-criteria information integrated with low current grounding power system is proposed for reliability improvement. After conversion of primary data through VT and CT, fault features will be sent to various criteria for line selection; afterwards, fault measures of each busbar and outgoing line according to fuzzy transformation and weight coefficients of various criteria will be concluded; ultimately, fusion deci- sion will be made and final decision result will be output. The paper points out that the key technology of this fault line selection is to reasonably definition of membership function of fault measures and weight function of criteria.