大型永磁直驱风力发电机变桨距控制的研究

THE DYNAMIC RESEARCH OF VARIABLE PITCH CONTROL ON LARGE PERMANENT MAGNET DIRECT DRIVE WIND TURBINES

随着风力机单机容量的不断增加,变桨矩控制起动、制动和输出均具有明显优势。特别在高于额定风速时,变桨距控制方式是一种行之有效的控制方法,能够使发电机的输出功率保持在额定功率附近。其控制原理是通过改变桨叶的角度而改变攻角,从而叶片的气动性能、发电机的电气性能及二者的协调特性均发生改变,限制了风力机在额定风速以上对风能的吸收。本文通过在Matlab/Simulink环境下仿真实验研究,当风速上下波动时,通过设计的滞环比较器使风机的变桨距系统性能得以平稳。并且就风速分布差异导致的风轮输出转矩脉动产生的桨距角脉动而影响电能质量做了详尽分析。结果表明,变桨距控制对风机的动态性能具有良好的改善效果。

As the unit capacity of wind turbine increases,using the variable pitch to control starting,braking and output has an obvious advantage.Variable Pitch Control is an effective control method especially when the wind speed is higher than rated wind speed.It can keep the output power of the turbine near the rated power.The control theory is to change the angle of attack via changing the angle of the blade.So the aerodynamic performance of the blade,electrical performance of the turbine and the coordination of both properties will all change.This will limit the wind energy absorption of wind turbine when above rated wind speed.In this paper we have done simulation experiment researches using Matlab/Simulink.And we found that hysteresis comparator by design could smooth performance of fan variable pitch system when the wind speed fluctuated up and down.And we made a detailed analysis about how the turbine output torque ripple of pitch angle pulsation caused by wind speed distribution difference affect the power quality.The result shows that Variable Pitch Control on dynamic performance of the fan has a good improvement effect.