Dual-repetitive control algorithm for three-phase Shunt Active Power Filters

Shunt Active Power Filters (APFs) have been proved useful to correct distorted currents caused by nonlinear loads in power distribution systems. This paper presents a dual-repetitive control algorithm, which consists of one fundamental repetitive period to ensure the APFs' high tracking precision of both even and odd harmonics, and the other harmonic repetitive period to enhance the dynamic response of the controller. Compensation performance of APF with this dual-repetitive controller is compared with the ones of using PI and single repetitive and is tested for unbalance nonlinear load by simulation in Matlab/Simulink environment. The results verify the validity and superiority of dual-repetitive control algorithm in APF application.