数字化变电站电子式互感器渐变性故障诊断方法研究_王洪彬.pdf

40 24 Vol.40 No.24 2012 12 16 Power System Protection and Control Dec. 16, 2012 Diagnosis of soft fault of electronic transformer in digital substation 1,2 1 2 2 3 WANG Hong-bin , TANG Kun-ming , XU Rui-lin , ZHU Xiao-jun , LI Xiao-jing (1. State Key Laboratory of Power Transmission Equipment System Security and New Technology (Chongqing University), Chongqing 400044, China; 2. Chongqing Electric Power Research Institute, Chongqing 401123, China; 3. Super High Voltage Operation and Maintenance Company of Sichuan Province, Nanchong Center, Nanchong 637100, China) Abstract: At present, the research on on-line monitoring and fault diagnosis of electronic current transformer (ECT) is in the initial stage, especially for the soft fault diagnosis. Based on the physical electrical characteristics of system components, the current observer models of transmission line and transformer are established. The observer outputs and ECT outputs are compared to constitute the residual for the diagnosis of soft fault, meanwhile the network graph theory is used to locate fault source. The simulation results have verified the correctness of the proposed observer models and the validity of the proposed fault diagnosis method. The method is not affected by the mode change of network operation, and could realize the