为研究单相有源电力滤波器(APF)的高性能控制器设计问题,基于脉宽调制技术提出了一种考虑开关切换混杂特性和外界干扰的单相APF等效离散切换非线性鲁棒控制系统,并在平衡流形邻域近似线性化得到了线性等效离散切换鲁棒控制系统模型,最后为该模型设计了能实时跟踪补偿指令电流并满足一定干扰抑制指标的H∞鲁棒控制器。该控制器避免了以往周期平均模型中的等效占空比环节,物理意义清晰,设计思路合理,易于在工程中实现。仿真结果验证了上述系统模型和控制器设计方法的正确性和有效性。
In order to research the high performance control of single phase active power filter, a new equivalent discrete-time switched nonlinear robust system (EDSNRS) of the single phase APF is put forward on the basis of pulse width modulation (PWM). Then the equivalent discrete-time switched nonlinear robust system is further transformed to a linear equivalent discrete-time switched linear robust system (LEDSLRS) by linearization at some neighborhood of the equilibrium manifold with respect to the pulse width function. Finally, a H∞ robust controller is designed with on-time tracking property based on the linear equivalent discrete-time switched linear robust system model, where the duty cycle is adopted as the control variable. The proposed control scheme has clearer and more rational physical significance, and it can be easily adopted in practice. The control model for single phase APF with H∞ robust controller is simulated using Matlab/simulink based on waveform and the FFT analysis. The results show that the proposed single phase APF model and the control strategy are correct and effective.