Analysis of photovoltaic power generation system low voltage ride through control during asymmetric fault

The electromagnetic transient model of photovoltaic power generation system is established based on PSCAD/EMTDC platform. The mechanism that 100Hz fluctuations appearing of PV output power and PV array operating point during asymmetric fault are simulated and theoretical analyzed. The paper proposes a positive and negative sequence separation control strategy, to filter the negative sequence current, making PV output current do not contain negative sequence component and outputting standard sinusoidal current waveform during asymmetric fault. The paper also proposes a DC voltage fluctuation suppression control strategy, to eliminate the DC voltage fluctuations and make the PV array operating point stable. Finally, simulation verification is made on PSCAD/EMTDC platform.