A Dispersing Proportional Resonance Controller for Selective Harmonic Current Compensation in a Shunt Active Power Filter

The shunt active power filter (SAPF) is widely utilized for harmonic and reactive power control in modern power grid systems. Current SAPF control systems typically consist of two parts: harmonic detection and harmonic control. The output of the harmonic detection serves as the control target for the harmonic control, resulting in a relatively complex system. This study introduces a novel SAPF control algorithm that integrates harmonic detection and control into the current closed-loop using quasi-proportional resonance (QPR) controllers with leading phases. The proposed control algorithm consists of two control loops: an inner loop providing inverter-side current proportional feedback active damping, and an outer loop managing harmonic and reactive current control. Simulation and experimental results confirm the feasibility and effectiveness of the proposed control algorithm. The novel control algorithm presented in this study offers significant flexibility, eliminates the need for complex harmonic detection, and ensures higher steady-state accuracy and faster dynamic response compared to existing techniques.