基于EMPC的无刷双馈发电机直接功率控制

Direct Power Control of Brushless Doubly-fed Generators Based on EMPC

针对无刷双馈发电机模型复杂、耦合性强的问题,提出一种基于扩张状态观测器显式模型预测的直接功率控制策略。通过研究定子控制绕组侧电压与功率绕组侧有功功率和无功功率的关系,推导基于d-q旋转坐标系的直接功率控制状态方程,对功率实现解耦控制。针对模型预测控制在线计算的局限性和系统中存在的扰动因素,提出一种基于扩张状态观测器的显式模型预测控制。该控制策略通过扩张状态观测器对扰动项进行补偿,结合显式模型预测控制将模型预测控制中的优化问题移到“线下解决”,该控制策略提高了在线计算速度和精度,同时扩大了模型预测控制的应用范围。详细介绍了该控制策略的设计原理,并对30 kW低功率无刷双馈风力发电机的控制策略进行了仿真验证。结果表明,该控制方案性能良好,能够提高无刷双馈电机的抗扰动能力,特别是提高了转速和功率变化时的稳定性和鲁棒性。

A direct power control strategy based on explicit model prediction of extended state observer was presented to overcome the drawbacks of complex model and strong coupling brushless doubly-fed generators.By studying the relationship between the stator control winding side voltage and the power winding side active power and reactive power,the state equation of direct power control based on d-q coordinate system was derived to realize the decoupling control of power.An explicit model predictive control based on extended state observer was proposed for the limitation of online calculation of model predictive control and the disturbance factors in the system.The control strategy compensated the disturbance term by expanding the state observer,and combined the explicit model predictive control to move the optimization problem in the model predictive control to the"offline solution".The control strategy improved the online calculation speed and accuracy,and at the same time expanded the application range of model predictive control.The design principle of the control strategy was introduced in detail,and the control strategy of the 30 kW low-power brushless doubly-fed wind turbine was simulated and verified.The results show that the proposed control scheme has good performance and can improve the anti-disturbance capability of the brushless doubly-fed motor,especially the stability and robustness when the speed and power change.