Whole Process Simulation Of Wind Power And Solar Energy System Integrating To Power System

With the large scale construction and successional plunging into operation of wind power plants and solar power plants around the country, wind and solar energy have become the main source of power system, besides hydropower, thermal and nuclear power. However, since grid connected double-fed wind generation and solar power system include large quantity of various power electronic equipments, the states and performance of these equipments directly influence the safety and stability of generating unit during grid-connection, even the security and stability of the grid. Scientifically modeling of wind and solar power system has received much concern, as well as analysis and simulation of grid-connection. To focus on the deficits and difficulties of the modeling of the double-fed wind generation and solar power system and the whole process simulation of grid-connection, a thoroughly exploration and study have been done in this thesis and many satisfactory achievements are obtained. The main achievements and research contents are listed as followed.First, the mathematical models of each module of double-fed wind generation system are presented both in three-phase static coordinate and double-phase rotating frame. Then,the principle of dual-PWM converter and space vector pulse modulation is introduced. The control strategies of grid-side converter based on unity power factor and stable DC voltage, rotor-side converter based on grid voltage information and the decoupling control of active power and reactive power under grid-connection situation are investigated as well. On the basis of that, an integrated model of wind power system with PWM control is built, and the whole process from unload cut-in to grid-connection is simulated with the model constructed.The complete model of solar power system is further built. After analyzing the variation characteristic of the sunshine intensity and temperature, the mathematical model of solar power system is formed; then the complete model including inverter component for the solar power system is finished by combining the mathematical model of the solar part with the inverter and its control method.At last, the simulation samples demonstrate that mathematical model of double-fed wind generation and solar power system, and the control method of dual-PWM converter and inverter is valid.