基于功率变化和模糊控制的风力发电机组变速变桨距控制

Wind Turbine-generator Unit Variable-speed Pitch Control Based on Judgment of Power Changes and Fuzzy Control

由于风速测量的不准确性以及很难获得风力发电系统的精确模型,故采用传统的PID控制器难以在风速快速变化的情况下实现良好的控制效果。文中提出将风力发电机组输出功率变化情况作为变桨距执行机构工作的判断依据和控制策略,并根据该策略,进一步提出了基于模糊控制的变速变桨运行控制方法。通过构建仿真模型,按照基于功率变化判断的控制策略分别对变速变桨与工程上常规的匀速变桨进行了仿真比较研究。仿真结果表明,所提出的不依赖于风速测量和精确系统数学模型的控制策略,可以很好地稳定风电机组输出功率,且相对于匀速变桨控制,变速变桨控制方法一方面更好地将机组输出功率稳定在额定值,另一方面可以减轻变桨距执行机构的疲劳度,减少部件间的磨损,这对于延长变桨执行机构的工作寿命、降低其故障发生率以及维持整个风电机组安全稳定运行具有重要意义。

Because of the wind speed measurement and accurate system model are hard to obtain, so it＇s difficult to achieve good results by using the traditional PID controller in case of rapidly variable wind. The control strategy which was decided by the output power changes of wind turbine generation about the operation mode of pitch actuator was proposed and according this control strategy, the variable-speed pitch control which was based on the fuzzy control strategy was also proposed. The simulation model was designed and the comparison of variable-speed and fix-speed pitch control simulation results was analyzed according to the proposed control strategy. The results of the simulation indicate that the output power could be stable based on the proposed Control strategy, the output power could be more stable at the point of rated power in terms of variable-speed pitch control, 3the fatigue of pitch actuator could be alleviated, the loss between components could be reduced. So, it＇s very useful to extend the life of pitch actuator, reduce the failure rate and maintain the security and stability of wind power system.