Classification of Faults in UPFC Compensated Transmission Line using MDL selected Wavelet based DWT Technique

Protective relaying is used to recognize the abnormal signals that indicate faults in a power transmission system. As a result, in a transmission line, precise fault classification is an important issue. Therefore, wavelet technique is applied to classify the short circuit asymmetrical transmission line faults such as single line to ground and line to line faults for a transmission line with UPFC compensation in MATLAB/SIMULINK environment. To increase the efficacy of discrete wavelet transform (DWT) based fault classification scheme in UPFC compensated transmission line and to avoid the arbitrary selection of wavelet so that the complexity and time of handling large data set can be reduced, this paper proposes minimum description length (MDL) method for an optimal mother wavelet selection. Here, two orthogonal wavelet series such as Symlet and Daubechies wavelet are taken and MDL algorithm is utilized to select the suitable wavelet among twenty wavelets. To compare the performance of selected wavelet, max norm method is used to calculate the norm value. This similar experiment is also done for the faulty line without UPFC case. The MDL selected wavelet provides higher max norm value for faulty phase compared to the healthy one which shows the potency of the method.