Experimental Evaluation of Voltage Positive Feedback Based Anti-Islanding Algorithm: Multi-Inverter Case

The novel scenario of power systems with massive utilization of distributed generation (DG) imposes that islanding detection methods for voltage source inverter (VSI)-interfaced DGs must be evaluated taking into account multi-inverter configurations. This paper presents the experimental validation of an active islanding detection algorithm for multi-inverter systems proposed by the authors in previous work. Field programmable gate array implementation of power control and islanding detection algorithms has been used to test this proposition in a multi-inverter system based on grid-connected insulated gate bipolar transistor VSIs. The proposed islanding detection algorithm offers a very low impact on power quality and rapid and efficient islanding confirmation which is demonstrated by simulation and experimentation. The performance of the algorithm was tested under critical conditions as resonant load with high quality factor and unity power factor and also for cases where load and VSI powers are matched.