A passive islanding detection approach for distributed generation using rate of change of negative sequence voltage and current

In this paper a new passive islanding detection technique is proposed for distributed generation using rate of change of negative sequence voltage and current. The proposed technique is based on the voltage and current measurement at targeted distributed generation (DG). The retrieved voltage and current are converted into symmetrical component through sequence analyzer then rate of change of negative sequence voltage (ROCONSV) and rate of change of negative sequence current (ROCONSC) are calculated for islanding detection. ROCONSV and ROCONSC are tested for different active power mismatching and work effectively even power imbalance is less than 15%. The proposed technique detects islanding very fast less than one cycle. This technique is efficient and free from non detection zone (NDZ).