Design Of Controller And Experiment System For Variable Pitch Wind Turbine

Wind power has been widely concerned because it is a kind of clean and inexhaustible energy. Effective way of absorption and transformation of wind energy is wind power generation. Because the wind is unstable, wind turbine must be controlled in order to output steady electricity which can be fed from wind turbine into the electricity grid system. Variable pitch wind turbine has become a popular research topic, it can stabilize the output power, improve electric energy quality and increase the wind turbine life. Researchs on variable pitch wind turbine controller is very difficult, because it is a nonlinear system of multi-disciplinary and the accurate model of wind turbine is always unavailable.Based on a large 1.5MW wind turbine, wind turbine pitch control principle is analyzed. The wind generator is divided into four parts to build a mathematical model. The wind speed changes are studied to establish a wind speed model. In this paper, a variable pitch wind turbine test system is established by the configuration software and MATLAB simulation platform, so researchs on variable pitch wind turbine controller become one of practiced contents for the automation professional.Based on the analysis of mathematical model, wind turbine pitch controller and experiment system are designed, the specific work are as followed:(1) Variable pitch wind turbine system is a nonlinear controlled object. When it is above rated wind speed, variation of the pitch angle with the wind speed is analyzed based on the aerodynamic characteristics, a piecewise PID controller with forward feedback is designed while its parameters are optimized by genetic algorithm. In order to switch without disturbance, schmidt switching strategy is designed; To improve the control accuracy and improved dynamic performance of system, BP-PID control algorithm is put forward. Finally, performances of the controllers designed by different methods are analyzed using MATLAB software. The simulation results show that the BP-PID controller is better in robustness and anti-interference feature.(2) Experimental system is established, to which controller structure and parameters can be adjusted. The human-computer interaction interface software is established with the KingView configuration software, and the communication function with the external controller is achieved. The mathematical model of variable pitch wind turbine is built by MATLAB software using background datas processing. Foreground and background datas communication are via OPC technology, and simulating wind turbine is built on computer.