Power Transformer Online Differential Protection Using Wavelet Transform and Correlation Factor Analysis

This paper present a new online approach for power transformer differential protection. This method is concluded by sampling from differential current product of three phases primary and secondary currents. Recognition of fault type in protection area is based on wavelet transform and correlation factor appointment and eventually correlation factor matrix analysis and determines the size of each dip. Simulations of power system, online relay, and fault applying for relay analysis have been performed by MATLAB/Simulink. Unlike other current proposal methods, the most important advantage of our approach is being online of the performance of its designed relay in each time period that provide to make the industrial sample of that. Simulation results show that the performance of designed relay is remarkable and the performance of this relay is compared to that of other existing offline methods, obtaining considerably better and very promising results.

Keywords:

Power Transformer , Differential Protection , Wavelet Transform , Correlation Factor , Online Performance