Islanding Detection based on Fast Discrete S-Transform and Support Vector Machine

This paper presents a new approach for islanding detection based on fast STransform, in distribution networks with distributed generators. In this method, at first, S-Transform of voltage and current at point of common coupling are calculated; then, features of normal and islanding operation are extracted using S matrix and frequency contours. The features are extracted using several simulations; considering load switching, motor load switching, transient faults, and islanding conditions with different power mismatches for local load. Finally, support vector machine has been proposed for classifying the extracted features to detect the islanding. For more studies, a distribution system is simulated using PSCAD/EMTDC and feature vectors corresponding to different situations of islanding and normal operation are extracted and used for training and test of support vector machine classifier. To evaluate the performance of proposed scheme, the obtained results are compared with results of other methods. Comparison of the results shows that the proposed method has higher accuracy and speed in islanding detection. Also, the proposed approach is effective, fast and would not be affected by noise during classifying of conditions.