Step-by-step analysis and design procedure for repetitive controller in active power filter system

Active power filter (APF) has been demonstrated to be an effective way to eliminate power system harmonics. Repetitive controller, which could realize zero steady-state error tracking for all harmonics, is widely used in the controlling of grid-connected converters. This paper proposes a novel repetitive controller in APF system, and introduces the regeneration spectrum and sensitivity function for controller analysis and design. The detailed discussions about stability, steady-state error, convergence are carried out and a step-by step design procedure for parameters design is presented. Simulation and experiments demonstrate the practicability of analysis and design method and the validity of step-by-step design procedure.