Wavelet based transmission line differential protection scheme

Abstract

For protection of transmission line we require the most reliable system with reduce restoration capability. This paper deals with wavelet transform based transmission line fault classification and utilizes differential protection scheme for to locate the fault as well as to overcome the performance limit of differential protection transmission lines. The tripping action mainly depends on the current and flux waveforms obtained under fault conditions at two ends of relay location. Wavelet analysis is added as mathematical tool for pattern recognition and feature extraction and to classify the type of fault occurring on the transmission line. The continuous approximation of the Mexican hat as a mother wavelet and coefficients like 32nd and 64th are used to extract frequency information and detect the faulted phase selection. In current differential protective relay system CT saturation problem affect the faithful performance. So with the problem of mal-operation it causes differential protection system. The three phase transmission line currents of two ends are used as input signals at relay location using communication links. Simulation is carried out in Matlab/Simulink which confirms the security and sensitivity of the proposed scheme.