Classification Of Faults In Series Compensated Transmission Line Using Wavelet

Fault detection is very tedious task in transmission lines with a fixed series capacitor because of the nonlinear behavior of protection devices and seriesparallel resonance. This paper proposes a new method based on DWT for fault classification in this series capacitor is fixed at the middle of the line. The DWT is used here for extracting the unseen factors from the fault current signal and here harr is used as a mother wavelet. The average values of the wavelet coefficients of the lower frequency band for the currents of three phases and ground are computed and as there are higher frequency components in the faulted phases than that of the unfaulted phases, the fault classification can be done easily. The performance of the proposed scheme is checked for the all possible faults at various locations, different compensation levels and different power angles. This transient fault study is carried out using the PSCAD software and the wavelet transform and protection algorithm is implemented in a MATLAB environment.