A novel islanding detection technique based on wavelet packet transform

In this manuscript, wavelet packet transforms (WPT) based method is proposed for detection of the islanding condition in the distribution system with distributed generation (DG). The system consist of DG sources like hydro turbine generator with synchronous machine and wind turbine generator with asynchronous machine. Negative sequence component based assessment of fault condition is considered here. A new feature index named Change of energy at different node are calculated using WPT for various islanding and non-islanding fault cases which are very often occurred practically like capacitor switching, load rejection, line to line fault, three phase fault, voltage sag and swell etc. The obtained simulated results show the proposed technique is found to be highly effective for discriminate islanding events under a wide range of operating conditions from other type of disturbances in the power distribution network. The proposed scheme are fully analyzed by extensive MATLAB simulation study.