研究了变速恒频双馈感应风力发电系统的鲁棒控制问题.利用基于定子磁场定向的矢量变换技术,建立了同步旋转坐标系下双馈感应发电机的状态空间模型,为了降低控制器的阶数以利于工程实现,对该动态数学模型进行了合理简化.针对最大功率点跟踪控制中建模误差、外部干扰等不确定性的影响,应用H∞鲁棒控制理论,设计了具有鲁棒干扰抑制作用的电机转子电压控制器.仿真结果表明,即使在参数变化、未建模动态等不确定因素以及风速突变干扰下,所设计的控制器仍可保证电机转速很好地跟踪指令值,使风力发电系统最大效率地吸收风能.
The robust control problem was studied for variable speed-constant frequency(VSCF) wind energy conversion systems based on doubly fed induction generators(DFIG).Using vector transformation a state space model of DFIG was established when the synchronous frame was linked to the stator flux.The dynamic model was simplified reasonably to reduce the order of the controller to be actualized easily in fact.Aiming at the influence of modeling error and gust in maximum power points tracing(MPPT) control,a robust rotor voltage controller was designed by using H∞ robust control method,which makes the system have the robust performance of restraining external disturbances.Simulation results validate that the conversion system with the controller proposed above can trace the reference command exactly and achieve the maximum energy from wind even if with the uncertainty of parameter variety and unmodeled dynamic and external disturbances.