基于扰动观测器的微网逆变器鲁棒H∞控制策略

H∞robust control strategy based on disturbance observer for microgrid inverter

为抑制微网逆变器在孤岛模式下运行存在的内部参数摄动和负载扰动,文章提出了一种基于扰动观测器的鲁棒H∞控制策略。基于所建立的逆变器多参数摄动模型,利用内模原理和小增益定理设计电压环鲁棒H∞控制器;采用扰动观测器对负载投切时所产生的负载电流扰动进行观测和补偿,以提高系统的动态特性。采用2 kW实验样机对所提出的控制策略进行验证。实验结果表明,该控制策略不仅能有效抑制逆变器工作时的内部参数摄动和负载扰动,提高微网逆变器的鲁棒性能,而且在负载切换时具有快速的动态响应。

In order to suppress the internal parameter perturbation and load fluctuation of microgrid inverter under islanding mode,this paper proposes a novel robust H∞robust control strategy based on disturbance observer.The robust H∞controller of voltage loop is designed by adopting the internal model principle and the small gain theorem,which is based on the established inverter model with multi-parameter perturbation.The dynamic characteristics of the system is improved by adopting the disturbance observer which is used to observe and compensate the load current disturbance caused by load switching.Finally,the proposed control strategy is verified by a 2 kW prototype.The experimental results show that the robust control strategy can effectively suppress internal parameter perturbation and load fluctuation of inverter,and improve the robust performance.Moreover,the system can achieve fast dynamic characteristic during load switching.