Research on state estimation of power system with large-scale photovoltaic plant

With the emergence large-scale centralized high-voltage photovoltaic plants integrated into power grid, the fluctuation power of the photovoltaic plants impacts the security and stability of the power grid. This paper proposes a state estimation method of the transmission network which includes the photovoltaic plants, and fully considers the mutual influence between photovoltaic plants and the power grid. Firstly, the grid-connected model of photovoltaic plant is presented and analyzed such that state estimation calculation will consider the network connected to the converter as the transmission network parameters. Secondly, the weighted least square method is employed to estimate the presented state estimation model for the grid-connected photovoltaic plant. Finally, the improved example based on the classical IEEE30 node system is used to verify the feasibility of the proposed the scheme.