Enhanced cross-forming control for voltage source maintenance in current-limited GFM inverters

Extensive research has been conducted on grid-forming (GFM) inverters operating under current-limiting conditions. This paper further explores cross-forming (CFM) control, a current-limited GFM control concept that can maintain voltage source behavior during current-limiting periods. The applicability of CFM control is assessed across grids of varying strengths, demonstrating superior performance in weak grids. Furthermore, this research examines the fault recovery process of CFM control and establishes the necessary conditions for its effective implementation. Based on these insights, an enhanced control method is proposed to maintain the effectiveness of CFM control and enhance the transient stability. Finally, the theoretical findings and the proposed method are verified using control hardware-in-the-loop (CHIL) experiments.