Study On Control Strategy Of Small Intelligent Wind Turbines

Faced with deteriorating environment, the phenomenon of serious haze throughout the country, wind power as a clean energy has an indispensable energy supplement in the proportion of energy. Although China has made certain achievements in the development of wind power generators, at present, the working conditions is unstable and the power generation has low efficiency because of the simple wind turbine and the single control mode. Thus it can not be applied in the micro grid well. Therefore, it has sufficient practical significance to improve the efficiency and reliability of the wind turbine through the advanced and reliable control technology application.Firstly, this paper introduces the basic theory of wind turbine and the characteristics of wind turbine, it establishes mathematical model according to all parts of wind turbine and completes the establishment of the linear mathematical model of 20 kW wind turbine.This paper studies on power control strategy of wind turbine and analyzes maximum power tracking control strategy and certains overall plan of torque control. It completes a model and calculation of 20 kW wind turbine and gets the optimal modal and maximum power tracking range according to traditional maximum power point tracking control method of torque curve method. Based on traditional torque curve method, the improved maximum power tracking control strategy is studied. Finally, the feasibility of the maximum power tracking control strategy is verified by simulation and experiment.In order to improve the reliability and applicability of main control system, this paper designs the main control system of 20 kW permanent magnet direct drive wind turbine. Based on the programmable logic controller PLC, which is produced by SIEMENS company, the main controller completes the design and manufacture of the main control logic system, HMI, variable pitch controller, yaw controller and other parts. In order to achieve the normal operation of the unit, we test the hardware in laboratory. And the reliability of the unit has been verified through the experiment of wind turbine. Meanwhile, this paper proves the output energy is in conformity with the theory under the control strategy, and it can track the maximum power output of the wind turbine and improve the operating efficiency and stability of wind unit.