为了提高有源电力滤波器的动态性能,基于切换系统理论研究其电流跟踪控制问题.首先,建立系统的切换动态模型,根据切换系统理论和空间电压矢量法证明二次稳定性,并设计相应的切换摔制序列.考虑到控制器的数字化实现,建立系统的离散切换系统模型,提出在采样周期内使系统性能最优的切换控制策略.仿真结果表明,该控制策略能实现对指令电流的精确跟踪,降低功率器件的开关频率,从而有效地提高系统的动态性能.
A current tracking control strategy for active power filters(APF) is proposed based on the switched system theory. Firstly, the switched affine dynamic model of APF is established. The quadratic stability of the system is proven based on the stability theory of the switched affine system and the voltage space vector method. A switching sequence is proposed consequently. In order to complete the digital realization of the controller, the discrete switched affine system model of APF is presented. An optimized switching rule is proposed to guarantee the optimal performance during each sampling period. Simulation results show that the proposed method can realize the accurate tracking of the reference current, decrease the switching frequency and improve the dynamic performance effectively.