A Method of Improving Grid Impedance Adaptability for Grid-Connected Inverters Considering Asymmetry Effect of PQ Power Loop

doi:10.3969/j.issn.1008-0198.2025.02.007

Abstract

Abstract: Aiming at the difficulty of grid-connected inverters under PQ power control to adapt to large grid impedance, a method to enhance the grid impedance adaptability of grid-connected inverters considering the asymmetric effect of PQ power loops is proposed. First, by constructing the small-signal control block diagram of the PQ power-controlled grid-connected inverter, the asymmetric effects of the active and reactive power control loops are revealed. On this basis, considering the characteristic that the parameters of the reactive power loop controller are more sensitive to the stability of the grid-connected inverter, an asymmetric design method for the active and reactive power loop controller parameters based on phase compensation is proposed, which significantly expands the adaptability range of the grid-connected inverter to grid impedance and aids in the high penetration rate access of new energy. Finally, the correctness and effectiveness of the proposed control method are verified through simulation and experimentation.

Key words: grid-connected inverter, grid impedance, PQ control, asymmetry, phase compensation, stability

CLC Number:

TM464

WANG Xiaoyuan, NING Zhihao, QING Mengqi, GAO Jiayuan, TANG Xingzhu, WANG Huijuan. A Method of Improving Grid Impedance Adaptability for Grid-Connected Inverters Considering Asymmetry Effect of PQ Power Loop[J]. Hunan Electric Power, 2025, 45(2): 54-62.

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