Harmonic Suppression of Voltage‐Controlled DG–Grid Interface Converters Based on a Two‐Step Virtual Impedance Strategy

ABSTRACT With the progressive power‐electrification of conventional power systems, the penetration level of distributed generation (DG) systems has been steadily increasing. However, if improperly designed, DG systems may introduce power quality issues. In particular, when severe harmonic distortion is caused by nonlinear loads, the effectiveness of conventional harmonic mitigation approaches becomes limited. To address this issue, this paper investigates a harmonic suppression strategy implemented through the DG‐grid interface inverter. Specifically, a two‐step virtual impedance control method is proposed for voltage‐controlled DG systems to suppress harmonic components. This strategy can be seamlessly integrated into voltage‐controlled DG units, thereby improving the harmonic performance of the DG‐side current. Finally, the effectiveness of the proposed method is validated through MATLAB‐based simulations and hardware‐in‐the‐loop (HIL) experimental results.