A Hybrid Islanding Detection Method Considering Voltage Unbalance Factor

Islanding Detection in the distributed generation (DG) system is a major function that needs to be addressed. Traditional Islanding Detection methods such as the passive ones have drawbacks in the form of existence of large nondetection zones whereas Active Detection Methods have devastating effects on power quality. To overcome these drawbacks an inventive islanding detection approach has been proposed that is built on the basis of Islanding Detection Signal (IDS) and Voltage Unbalance Factor(VUF). Detection of VUF at the Point of Common Coupling (PCC) helps in accurate determination of an islanding condition. False islanding under faulty operation can be prevented by setting the threshold voltage unbalance factor and the minimum judgment time of three cycles for which IDS may be absent. The simulation results suggest that the method that has been proposed is able enough to perform effective and rapid detection of islanding in all the circumstances for the chosen system model.