A centralized proportional resonance controller for harmonic current compensation in the SAPF

To enhance power quality by mitigating harmonic currents injected into power grids, active power filter has been developed, with shunt active power filter (SAPF) being widely adopted due to their relatively simple structure and scalability. However, the broadband control requirement of SAPF presents a significant challenge in controller design. To address this challenge, this paper proposes a centralized proportional-resonant (CPR) controller with phase compensation. This controller is designed to suppress harmonic currents by compensating for increasing phase angles with increasing harmonic order. Simulations and experimental results demonstrate that the proposed CPR controller effectively fulfils the broadband control requirements of SAPFs, achieving zero steady-state error tracking of individual harmonic currents and thereby significantly suppressing power grid harmonics.