电力系统保护与控制
電力繫統保護與控製
전력계통보호여공제
POWER SYSTM PROTECTION AND CONTROL
2014年
18期
9-13
,共5页
励磁涌流%差动保护%差分预处理%双正交多分辨率分析%小波熵
勵磁湧流%差動保護%差分預處理%雙正交多分辨率分析%小波熵
려자용류%차동보호%차분예처리%쌍정교다분변솔분석%소파적
inrush current%differential protection%difference pretreatment%biorthogonal multi-resolution%wavelet entropy
励磁涌流仍然是制约差动保护正确动作的最主要问题之一。分析了励磁涌流和内部故障电流的波形特征,根据励磁涌流突变点分布特性,提出了一种小波熵识别励磁涌流的新判据。用双正交多分辨率分析取代常规的正交多分辨率分析,以解决下坡突变点难以辩识问题。采用差分预处理策略放大突变点的奇异性特征,并利用三相小波熵的分布特征识别励磁涌流。在此基础上,制定了励磁涌流识别的具体实现方案。仿真及实验表明,所提出的励磁涌流识别方法有效。
勵磁湧流仍然是製約差動保護正確動作的最主要問題之一。分析瞭勵磁湧流和內部故障電流的波形特徵,根據勵磁湧流突變點分佈特性,提齣瞭一種小波熵識彆勵磁湧流的新判據。用雙正交多分辨率分析取代常規的正交多分辨率分析,以解決下坡突變點難以辯識問題。採用差分預處理策略放大突變點的奇異性特徵,併利用三相小波熵的分佈特徵識彆勵磁湧流。在此基礎上,製定瞭勵磁湧流識彆的具體實現方案。倣真及實驗錶明,所提齣的勵磁湧流識彆方法有效。
려자용류잉연시제약차동보호정학동작적최주요문제지일。분석료려자용류화내부고장전류적파형특정,근거려자용류돌변점분포특성,제출료일충소파적식별려자용류적신판거。용쌍정교다분변솔분석취대상규적정교다분변솔분석,이해결하파돌변점난이변식문제。채용차분예처리책략방대돌변점적기이성특정,병이용삼상소파적적분포특정식별려자용류。재차기출상,제정료려자용류식별적구체실현방안。방진급실험표명,소제출적려자용류식별방법유효。
Inrush current is still one of the most important issues which restricts the accuracy movements of differential protection. The characteristics of the differential current under the conditions of inrush and internal fault are analyzed. According to the feature of the inrush mutations, a new judgment to identify the inrush current based on wavelet entropy is proposed. In order to solve the problem that the downhill mutations are difficult to identify, biorthogonal multi-resolution analysis is used instead of the conventional orthogonal multi-resolution analysis. The difference pretreatment is used to amplify the characteristics of the singularity of mutations, and the inrush current is identified by the use of the distribution of the three-phase wavelet entropy. Based on the above analysis, the specific implementation scheme is made. Simulation and experiments show that the proposed method is effective.