构网型变流器多目标约束下的故障穿越策略

Transient synchronization stability (TSS), current limitation and reactive power support (RPS) are the key objectives for fault ride-through (FRT) that grid-forming converters (GFMCs) must satisfy. However, the complex coupling restraints among these objectives, along with the fact that GFMC cannot directly control current due to its voltage-source nature, present significant challenges for FRT. To address these issues, this paper first analyzes the coupling relationships among the three objectives, and reveals the formations and control mechanisms of phase current, reactive current, and fault inrush current in GFMC. Inspired these insights, an adaptive FRT strategy is designed by cooperatively adjusting the active power and voltage references, as well as the adaptive virtual resistance, which satisfies FRT multi-objective constraints even if the voltage sags to 0. And it is straightforward to implement. Furthermore, the proposed FRT strategy is shown to exhibit superior TSS and RPS performance, as demonstrated through region of attraction and voltage phase portraits. Finally, simulation and experiment results validate the effectiveness and superiority of the proposed FRT strategy.