A Novel L_2-Gain Repetitive Control Algorithm for Single-Phase Active Power Filter

A novel L2-gain repetitive control algorithm for single-phase active power filter (APF) based on the port controlled Hamiltonian (PCH) averaged model of single-phase APF with disturbances and parametric perturbations was proposed. Firstly, equivalent transform of error system averaged equations was adopted so that the influence of parametric perturbations could be converted into part of the periodic disturbances. Then, L2-gain repetitive control algorithm was designed. Specifically speaking, repetitive control was used to compensate periodic disturbances, while the convergence of learning process was guaranteed by L2-gain control. L2-gain control could also ensure asymptotically tracking control objectives of single-phase APF and suppress other aperiodic disturbances. In addition, in order to deal with the difficulty in estimating the ripple component on dc-side capacitor reference voltage, the modified control algorithm was proposed by ignoring the ripple component. Simulation results verify the validity of the proposed algorithm. The simulation responses of the traditional PI control strategy and the L2-gain control method are also presented for comparative study.