Study on Photovoltaic Generation System and Its Islanding Effect

The operational principles of photovoltaic generation system and the islanding of grid-connected generation system were analyzed, and the active identification method of islanding: active frequency disturbance method was proposed. The simulation model of system was established, and the experiment was reached. The results prove: experiment is almost the same as the simulation, and the output wave of grid-connected current is better, and has the same frequency and phase as utility grid, and the islanding can be detected effectively within 100 milliseconds basically.