Analysis and realization of a novel repetitive controller in active power filter system

The repetitive control has been widely used in grid connected voltage source converters, such as uninterruptible power supplies (UPS), photovoltaic inverter (PV) and active power filter (APF). This paper introduces a new repetitive control strategy in the APF system; the proposed control strategy has a forgetting factor (FF), which could improve control system robustness. Control system stability and convergence analysis points out that control system characteristics depend on characteristic expression, which is essential for controller design. Appropriate design of this characteristic expression could make control system have good stability and fast convergence rate. Combination of industrial application, this paper presents a controller analysis and design methods, at last, simulations and experiment results demonstrate the validity of proposed repetitive control strategy.