• Analyzes GFM wind farm stability under HVDC single-pole blocking faults. • Proposes a modified EAC method incorporating damping energy compensation. • Maps nonlinear damping-coupling dynamics into energy area boundaries. • Derives explicit analytical expressions for instantaneous CCA/CCT estimation. • Eliminates estimation conservatism and enables ultra-fast online screening. The voltage source converter-based high voltage direct current transmission (VSC-HVDC) system plays a critical role in large-scale renewable energy transmission systems. However, the traditional Equal Area Criterion (EAC) method exhibits low accuracy in power surplus scenarios. To address this limitation, this paper proposes an enhanced EAC approach incorporating damping terms. A simplified second-order model for the VSC-HVDC system under power surplus scenarios is established, and system stability is evaluated using the critical clearing angle (CCA) and the critical clearing time (CCT), providing theoretical support for the simulation results. Additionally, the validity of the proposed method was rigorously examined across multiple scenarios, and the effectiveness of the method is verified through Matlab/Simulink simulations.
Gong et al. (Thu,) studied this question.