Study on impacts of large-scale photovoltaic power station on power grid voltage profile

The large-scale photovoltaic (LSPV) power station in desert usually connects to local electric grid through long high- voltage transmission lines. However, it will impact the voltage profile along the transmission line due to the solar irradiance nature. In this paper, a simple and accurate method based on power system analysis principle is developed to analyze impacts of the grid-connected LSPV power station on voltage profile. Then, the method is verified through comparing to power flow analysis. From the results, the bus voltage presents a parabolic trend with the PV power output increasing; there is a maximum voltage point on each V-P curve, and the corresponding PV power output is determined by the impedances; the bus voltage sensitivity is also a nonlinear function of PV power output.