A rapid voltage detection method for low voltage ride through under distorted voltage conditions

This paper deals with a novel voltage detection method for low voltage ride through under distorted voltage conditions. According to the new Grid Codes, the photovoltaic (PV) system should keep connected with the grid and inject the acquired reactive power as soon as possible when the grid voltage sags. So the voltage detection is important to the PV system. The principle of voltage detection is analyzed in detail. Then, by comparing with T/4 delay detection method and single vector detection method, the double vectors detection method is designed to suppress the harmonic voltage. Finally, the simulation results are carried out to validate the proposed voltage detection method.