Research on a new voltage control strategy for photovoltaic grid-connected system

In this paper, an improved voltage control strategy for photovoltaic grid-connected system (PVGS) is proposed, which can effectively mitigate the grid-side voltage fluctuations affected by environmental disturbances with high penetration of PVGS. Firstly, the mathematical model of PVGS is established. Then an improved voltage automatic coordination control strategy (VACCS) based on double-layer coordination control is proposed to mitigate the voltage fluctuations. VACCS coordinates the automatic voltage control (AVC) and battery energy storage control (BESC), which can significantly increase the control range and sensitivity to voltage fluctuations and extend the life expectancy of batteries. The correctness and effectiveness of VACCS is verified by some simulations based on the commercial software DIg SILENT.