Transformer Protection Based On Fault Recorder Data Analysis System

The digital fault recorder is the important equipment in power system for fault and transient data recording. When faults or oscillations occur, the recorder data plays an important role in analyzing the fault cause and testing the operation.Through the recorder data acquisition system, we can get detailed and actual waveform and data with large numbers of information. These waveforms and data have large analytic potential. Designing fault analysis software, which can be used to analyze fault information and fix fault cause, is of much consequence for excluding fault and improving protection principle.Electrical transformer is one of the most important electrical equipments of power system, and its normal operation has respect to the security of the power system. Transformer fault analysis based on the fault recorder data, can not only re-create the fault process, but also reckon the fault reaction competence of various kinds of principles and algorithm.On the basis of introducing the development and actuality of transformer protection, in the first place, the paper illustrates the important role played by Fault Recorder data in transformer fault analysis. Then, it analyzes the transformer main protection and back-up transformer protection. At last, the detailed function analysis, main design, data processing and implementation algorithm of each function module is proposed.Based on the recorder data, the paper finished the development of protection analysis software for transformer protection. As the basic analysis tool for transformer fault analysis, the software provides several analysis modules, including ratio differential analysis, second harmonic restraint analysis and back-up protection analysis. It can be used to display the data process and the results, and also can replay the fault waveform and event data. When incorrect operation occurs, the software can analyze the cause, and analyze the sensitivity when correct operation. It overcomes the flaws of the existing fault analysis software in operating analysis of protection, and satisfies the analysis needs for the fault operating.The software is compiled in C++ language, using Microsoft Visual C++ as development tools, and passed debug in Windows XP.