Single-phase Hybrid APF Background Harmonic Voltage Damping Control Method

The hybrid Active power filter (HAPF) is a low-cost solution for harmonic current compensation. However, the series capacitor of HAPF can lead to grid resonance issues, especially in the weak grid, such as low-voltage distributed gird and microgrid. The single-phase HAPF can be applied more flexibly than the three-phase products. This paper proposes a control method for single-phase HAPF to improve the local voltage quality of users based on the voltage feedback control method. The proposed method shows excellent harmonic current compensation performance and harmonic voltage immunity performance at the same time. According to the proposed method, with the added grid virtual impedance method, the harmonic grid current is suppressed under harmonic voltages. The parameter of added reactive can be user-defined to improve the power factor rather than fixed. The simulation results verify the comprehensive power quality improvement ability of the proposed control method.