A new approach to islanding detection in distributed generations

This paper presents new techniques for islanding detection in distributed generations. In the proposed approach, the negative sequence component of the voltage and current at the target DG location are extracted and processed using Wavelet Transform. The detailed coefficient at the level-1 (d1) clearly localizes the event and thus detects the islanding condition. Also the change in energy and standard deviations of the detailed coefficients for one cycle current and voltage signals distinguishes islanding conditions from non-islanding ones. Also the negative sequence impedance is calculated at the target DG location and effectively detects the islanding conditions. The proposed techniques are tested on islanding and possible non-islanding conditions such as normal operation, sudden load change and tripping of other DG etc. and found to be highly effective in islanding detection at different target DG locations in the power distribution network including multiple DGs.