Research And Application Design Of MPPT For Off Grid Wind Solar Complementary Power Generation System

With the development of the energy-saving society and the sustainable development strategy,wind and solar energy,as widely distributed and inexhaustible green renewable energy,have been applied on wide-range applications.In view of the complementary characteristics of these two energy sources in resource distribution,this thesis designs a small off-grid wind-solar complementary power generation system for distributed generation environment,and analyzes the overall structure and control strategy of the system to meet the demand of dc load and ac load.First,this thesis reviews the research status of wind-light complementary system and working principle,and construct mathematical models of the photovoltaic cells and wind turbines on the Matlab/Simulink platform.Moreover,the characteristics of the power of wind turbine simulation curves and shade photovoltaic cells under the condition of sufficient lighting and shadows are analyzed.The influence of the topological structure of control,inverter and the energy storage on the operating efficiency of the system is studied,and the control strategy is comprehensively analyzed.The power output curve of photovoltaic cells presents multiple peaks under shadow.Taking advantages of such character,this thesis proposes an adaptive inertia weight particle swarm optimization algorithm for Maximum Power Point Tracking(MPPT)based on Buck circuits.Compared with the traditional particle swarm optimization(PSO)algorithm,this new algorithm can effectively improve the accuracy and speed of maximum optimization under multi-peak conditions.To improve the efficiency of traditional algorithms in the MPPT process of wind power generation,an adaptive step size disturbance-observation algorithm that suitable for MPPT of wind power generation system is selected based on Boost circuit.Compared with traditional mountain climbing search method,this algorithm can effectively improve the converging efficiency.Then,a hardware circuit and a software program are designed based on a TMS320F28335 chip.The hardware circuit consists of a main circuit for realizing the maximum power tracking of the system,a battery charging and discharging circuit,a quasi-z source inverter circuit,the MOS tube drive circuit and a peripheral detection circuit.The system software program consists of main program,MPPT subroutine,signal acquisition program,PWM driver subroutine and battery charge and discharge management subroutine.Finally,to verify the effectiveness of their respective MPPT control algorithm,simulation models of photovoltaic power generation system and wind power generation system based on the given theoretical studies are realized using Matlab/Simulink.A simulation model of the overall structure of the system is also constructed to analyze the working state of battery charging and inverter.To test the operation effect of the system,a small off-grid wind-solar complementary power generation experimental device is built on the experimental platform.The results show that the wind-solar complementary controller designed in this thesis can meet the needs of ac and dc loads.