Study Of Power Generation Control System For Small-Scale PV

With the continuous deterioration of the global environment,many countries in the world pay more attention to environmental protection issues.The research and the exploitation of new energy sources have become hot spot of environmental protection.As an important issue of new energy projects,photovoltaic power generation has received more and more attention and very rapid development.In addition,the applications of it range from large-scale centralized photovoltaic power generation gradually extended to small-scale photovoltaic power generation system.Therefore,the small-scale photovoltaic power generation control system is studied in the thesis.From the mathematical model of the photovoltaic matrix,the simulation model is built in this thesis,and the output characteristics of the photovoltaic matrix in different environment are analyzed.Based on the output characteristics of photovoltaic matrix,the mainstream maximum power point tracking control strategy is simulated and analyzed.A more efficient maximum power point tracking control method is proposed,and the simulation experiment is carried out.In the inverter grid connected part,the voltage and current double closed loop control mode is adopted,and voltage feedforward control is added to the current loop to achieve better inverter current control effect.In the current loop control,the quasi proportional resonance controller is adopted to solve the problem that the PI controller can not track the sinusoidal signal accurately and the small bandwidth of proportional resonance controller.On the basis of simulation experiment,the hardware circuit and software program of inverter grid connection are designed.The hardware circuits include the grid-connected inverter main circuit,frequency and phase detection circuit,isolate and drive circuit,etc.The software programs include the initialization program design,the interrupt service program design,the main program design.Through the inverter control experiment,the output voltage of the inverter has reached the basic grid connection requirements of the same frequency as the voltage of the power grid.