Time-Frequency Analysis based Approach to Islanding Detection in Micro-grid System

摘要

This paper presents a novel technique based on time-frequency analysis to detect the islanding conditions in distribution network with the presence of multiple distributed generations (DGs). Various islanding and non-islanding fault conditions such as capacitor switching, load rejection and line to line fault etc., are analyzed through negative sequence decomposition technique. Feature extraction has been carried out by two time-frequency analysis techniques based on wavelet transform (WT) and S-Transform (ST). For the detection of various disturbances the energy and standard deviation (SD) features of signals are estimated by wavelet transform coefficient and S-transform matrix. Furthermore, based on the estimated features the artificial neural network (ANN) and support vector machine (SVM) are used as a classifier to classify the islanding and non-islanding events. For showing the effectiveness of the proposed technique to delect islanding conditions under a wide range of operating environment, some simulated results are presented.