Hybrid photovoltaic generation system with novel islanding detection method

This paper proposes an islanding detection method for a hybrid photovoltaic generation system (HPGS). This HPGS is controlled using an improved voltage-mode control method in both the grid-connected and the stand-alone conditions to unify and simplify the control circuit. The inverter of this HPGS is multi-functional, so it can perform the functions of active power filter, charging/discharging a battery set, uninterruptible power supply, and injecting power into the grid of distribution power system. The proposed islanding detection method is incorporated into the controller of the inverter. The advantage of islanding detection method is the time required to add a disturbance for detecting the islanding operation is very short. A prototype is developed and tested to verify the performance of the proposed HPGS. The experimental results verify that the proposed islanding detection method can effectively detect the islanding operation, so this HPGS achieves the expected performance.