Generalized Sequence Impedance Modeling and Analysis of Grid-Forming Converters with Multi-Loop Control

Grid-forming converters are pivotal for stability support in modern power systems, where their interactive behavior is significantly determined by control parameters. However, prevalent impedance-based analysis is confined to individual control schemes, lacking a unified basis for comparative assessment and generalized parameter impact analysis. To bridge this gap, this paper develops a generalized sequence impedance model that consolidates major multi-loop GFM control strategies, structurally mapping each control loop to specific impedance components. Utilizing this generalized representation, the interactive effects of inner-loop parameters are analytically disentangled. Based on the found effects, a general parameter-tuning rule is proposed to improve the interactive stability of the GFM converter connected to different grids. Experimental validation confirms the model’s accuracy and demonstrates its utility for the systematic, stability-oriented design of GFM converters under diverse grid conditions.