Research and simulation analysis of control strategies for the large-scale grid-connected photovoltaic system

With the continuous development of new energy technologies, solar photovoltaic(PV) plays an increasingly important role in modern society. There is still no workable technology research and project implementation plan for PV power grid control about the problem of large-scale PV grid. First of all, the paper analyzed the basic principle of the solar cell power generation and introduced the equivalent circuit model of solar cell. The solar cell is a nonlinear power supply. Environmental temperature and light intensity have an important effect on its output power. To make the solar cell convert solar energy into electrical energy most efficiently, it needs to be maximum power point tracked(MPPT). Secondly, the paper studied on the control strategy for photovoltaic grid power generation system and established grid model with photovoltaic power plants, including a system circuit model and the active control model. Then in turn it analyzed automatic generation control(AGC) response of the system under the power fluctuations of new energy and under off-grid PV power plant emergency situations, the effect of photovoltaic active control mode on the grid frequency modulation(FM), the coordination control simulation of realtime scheduling and AGC. Finally it gave some research conclusions of active control strategy on the side of main station with large-scale photovoltaic grid.