基于四状态反馈的双馈风机转子侧变流器电流内环控制

Inner current loop of doubly fed induction generator based on four-state feedback

建立了双馈风机的四阶暂态电流模型,设计了四状态反馈的控制方法,用解析法分析了四状态线性反馈对双馈风机闭环极点的影响,确定了使系统稳定的定子电流反馈系数取值范围。为了消除稳态误差,在四状态线性反馈的基础上,再加入积分环节,给出了四状态反馈电流内环的PI控制方程。提出的电流内环能够快速跟踪参考电流,且在定子侧电压跌落时,相比于传统矢量控制具有更好的暂态性能。最后,通过PSCAD/EMTDC建立了0.9MW双馈风机仿真系统,验证了提出的电流内环的电流跟踪效果以及电压跌落时相比于传统矢量控制具有更强的鲁棒性。

The 4-order transient current model of DFIG was deduced, and then the dynamic behaviors of the stator and rotor currents and the effect of stator current linear feedback on closed loop poles of control system were analyzed. The stability region of stator current feedback coefficient was also analyzed. Finally, the PI control equation of the inner current loop based on four-state linear feedback was proposed. The proposed inner current loop could track the refer- ence current rapidly, and it had better transient performance compared to the traditional vector control when the stator voltage dropped. The simulation of a 0.9-MW DFIG in PSCAD/EMTDC well demonstrated the track performance and the strong robustness of the proposed inner current loop.