Protection of Distribution Feeder Using Stockwell Transform Supported Voltage Features

This paper presents a research work focussed on the identification of faults on the distribution feeder supported by Stockwell transform based summing of absolute values and median features using the voltage signals. A fault index is proposed which is obtained by the multiplication of H-index (obtained summation of absolute values S-matrix evaluated by ST supported decomposition of voltage) and VS-index (obtained median of absolute values S-matrix evaluated by ST supported decomposition of voltage). Classification of faults is achieved using decision rules. Investigated faults include phase to ground, fault between two phases, two phases to ground fault and fault involving all three phases and ground. Performance of algorithm is tested on high fault impedance and fault incidence angle. Proposed study is performed using MATLAB software in Simulink environment.