A Novel Islanding Detection Method for Microgrid Using Complex Voltage Unbalance Factor

Accurate islanding detection is vital for grid stability, power system reliability and for sustainable energy practices. To address this, the paper introduces a novel technique, the Complex Voltage Unbalance Factor which is the ratio of negative and positive sequence voltage at the rate of angle. The magnitude of this ratio and the associated angle, are both used to detect the islanding separately and emphasizes the significance of the angle for islanding and to enhance the accurate operation of real-time relay systems. The performance of the technique is illustrated utilizing a test system of four Distributed Generation units with three wind farm and one emergency diesel generator connected into a radial distribution network and the obtained results are compared to the existing methods like Rate of Change of Phase Angle Difference and Rate of Change of Frequency. The suggested technique has also been examined under various scenarios notably short circuit faults and load shedding, encouraging reliable integration of renewable energy.