Cross-Forming Control and Fault Current Limiting for Grid-Forming Inverters
<|reference_start|>Cross-Forming Control and Fault Current Limiting for Grid-Forming Inverters: This article proposes a "cross-forming" control concept for grid-forming inverters operating against grid faults. Cross-forming refers to voltage angle forming and current magnitude forming. It differs from classical grid-forming and grid-following paradigms that feature voltage magnitude-and-angle forming and voltage magnitude-and-angle following (or current magnitude-and-angle forming), respectively. The cross-forming concept addresses the need for inverters to remain grid-forming (particularly voltage angle forming, as required by grid codes) while managing fault current limitation. Simple and feasible cross-forming control implementations are proposed, enabling inverters to quickly limit fault currents to a prescribed level while preserving voltage angle forming for grid-forming synchronization and providing dynamic ancillary services, during symmetrical or asymmetrical fault ride-through. Moreover, the cross-forming control yields an equivalent system featuring a constant virtual impedance and a "normal form" representation, allowing for the extension of previously established transient stability results to include scenarios involving current saturation. Simulations and experiments validate the efficacy of the proposed cross-forming control implementations.<|reference_end|>
@article{he2024cross-forming,
    title={Cross-Forming Control and Fault Current Limiting for Grid-Forming
  Inverters},
    author={Xiuqiang He, Maitraya Avadhut Desai, Linbin Huang, Florian D"orfler},
    journal={arXiv preprint arXiv:2404.13376},
    year={2024},
    archivePrefix={arXiv},
    eprint={2404.13376},
    primaryClass={eess.SY cs.SY}
}