Wavelet based transmission line fault identification and classification

Fault identification and classification is necessary to ensure stable and reliable operation of the power system. During the fault condition, tripping action mainly depends on current and voltage waveforms which are obtained at relay location. In order to identify and classify the power transmission line faults, fast and accurate analysis is required. Many signal processing algorithms are used to study the voltage and current waveforms of fault signals. This paper focuses on discrete wavelet based signal analysis to identify and classify the type of transmission line faults. Discrete wavelet transform uses the current waveform of fault signals to identify and classify the fault. The coefficients of discrete approximation of the db8 wavelet are used as an index for fault identification and classification. MATLAB/SIMULINK is used to test the model system and to generate the various types of fault signals. The proposed system performance is illustrated from the simulation results obtained by applying the algorithm and it is easy to implement for computer relaying applications.