Application and Optimization of Fast Fault Current Limiters in Regional Grid Expansion

Recent advancements, including the deployment of additional 500 kV and 150 kV interconnection substations and the integration of numerous generation units, have resulted in a significant escalation of short-circuit currents locally. This phenomenon induces thermal effects, insulation degradation, and mechanical stress, thereby posing substantial risks to equipment safety and system stability.

To mitigate these challenges, this study explores the application of a mechanically switched high-speed fault current limiter(FCL) within transmission network as an effective method for short-circuit current suppression. The paper discusses various solutions to short-circuit current issues, presenting a comprehensive simulation-based analysis of the technical principles and operational efficacy of FCLs, focusing on enhancements in system impedance and fault current limitation. Results indicate that, under fault conditions, the FCL significantly reducing fault current amplitudes to safe operational levels.

Feasibility assessments are conducted considering system layout, interface integration, and impacts on protection schemes. Compared to conventional approaches, the FCL-based solution demonstrates favorable technical viability and practical applicability for fault current control. This research provides both theoretical insights and practical guidance for the implementation of short-circuit current limiting technologies in high-voltage power networks and proposes innovative pathways for the intelligent upgrading of regional power systems.