S-transform based cumulative sum detector (CUSUM ) for islanding detection in Distributed Generations

The proposed technique uses time-frequency transform such as S-transform for islanding detection in Distributed Generations. The S-transform is an invertible time-frequency spectral localization technique that provides the time-frequency contours of the voltage and current signals retrieved at target DG location. A cumulative sum detector (CUSUM) is devised based on the spectral energy content of the negative sequence component of the current and voltage signals. The technique has been tested for islanding detection at different target DG location and provides accurate results. Thus the CUSUM based technique is found to be highly effective for islanding detection under wide range of operating conditions in the power distribution network including multiple DGs.