Stability Analysis Based on Hybrid αβ-impedance Model of Grid-Connected Inverters under Weak Grid
DOI:
https://doi.org/10.52152/4092Keywords:
Grid-connected Inverter (GCI), Hybrid Impedance Model, Weak Grid, Stability MarginAbstract
The robustness of the grid-connected inverter (GCI) system in weak grids is deteriorated due to consider discrete characteristics of the GCI control system. Under the same main circuit parameters and control loop parameters, the small signal models of the GCI controlled with continuous-impedance model and hybrid-impedance model are constructed, respectively. Compared with the small-signal hybrid impedance model of the GCI controlled indomain, the number of control loops of GCI controlled indomain is one less. Moreover, the rationale behind the enhanced stability of the GCI system governed by a hybrid-impedance control scheme, as compared to one based on hybrid-impedance control, is examined and elucidated. This lays a theoretical underpinning for the analysis and development of a discretized control loop to enhance the stability of the GCI under weak grid. Finally, the theoretical analysis is confirmed through simulation and experimental validations.
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Copyright (c) 2025 Jun Gu, Tianle Li, Jing Shen, Hao Ma, Meiying Yang (Author)
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