Research On Power Optimization And Control Method Of Variable Speed Variable Pitch Wind Power Generation System

In modern society,energy crisis has become more serious and ecologic environmental destructions have occured frequently.The development and utilization of renewable energy play an important role in improving the ecological environment and building a sustainable society.It has become one of the most promising renewable energy sources and the wind energy technology has become one of the fastest growing technologies.The efficiency and safety of wind power generation system have received immense attention.The power optimization and control methods of the system have also become the focus of research.The double-fed wind power generation system is selected as the research object.By analyzing the basic structure and operation status of the wind power generation system.The mathematical model of variable speed variable pitch wind power generation system and the simulation model of wind speed are established to provide simulation environment for verifying the effectiveness of the control strategy.For the maximum wind energy capture problem below the rated wind speed,the mountain climbing search method and the improved extreme value search method are employed to control the maximum wind energy capture of the system.The control target that tracking the stable operation by variable step sizes is realized by improving the integrator.The simulation results show that the improved extreme value search control can make the wind speed change tracked rapidly and maintain the optimal tip speed ratio,which improves the wind energy coefficient and wind energy utilization efficiency.For how to maintain constant power above the rated wind speed,conventional PID and fuzzy adaptive PID pitch control are employed respectively.The fuzzy controller is used to adjust the three parameters of the PID controller in real time,which improves the dynamic response characteristics of the pitch control system,stabilizes the output power,reduces the mechanical load and ensures a smooth and safe running.As for the method of power optimization and control of wind power generation system,a control strategy of operating in two control modes under full wind speed has been proposed.The low wind speed section implements the MPPT control based on the improved mechanism search method;the high wind speed section adopts the fuzzy-PID pitch control.The power optimization and control of the system are realized for different conditions,which can make the system respond quickly and effectively improve the wind energy utilization efficiency and constant power.It not only improves the economic efficiency of the system but also ensures safety and stability.Figure36;Table8;Reference 44...