双馈感应风力发电系统低电压穿越控制

传统的双馈感应发电机(DFIG)矢量控制方案忽略了定子暂态磁通,导致当电网出现故障时控制性能恶化.为了提高电网故障下DFIG的不间断运行能力,将矢量控制与自抗扰控制器结合起来,利用扩张状态观测器估计出定子暂态磁通和电机参数误差对系统的影响并加以补偿.仿真结果表明该文提出的控制方法削弱了电网故障时DFIG的转子暂态电流峰值和电磁转矩波动,有效地保护了转子变频器和风力机机械结构,而且对电机参数误差具有鲁棒性.

LOW VOLTAGE RIDE THROUGH CONTROL OF DFIG WIND ENERGY GENERATION SYSTEM

In order to improve the fault ride through capability of DFIG, auto disturbances rejection controller was introduced to combine with vector control. The influences of disturbances on the wind energy generation system, including stator transient flux and generator parameter errors, were estimated and compensated by the extended state observer. The simulation results showed that the control scheme presented can reduce DFIG rotor transient current peak value and electromagnetic torque fluctuation during grid fault, hence the rotor converter and mechanical structure of wind turbine is effectively protected. Further more, the control scheme ensure good robustness against generator parameter errors.