Dynamic Overload Operation System for 362kV GIS Circuit Breakers under Renewable Energy Expansion and Transmission Capacity Enhancement

This paper proposes a real-time dynamic operation system to ensure the equipment reliability of 362kV/6300A/63kA GIS circuit breakers under emergency overload conditions. These conditions result from the introduction of High Carbon Steel Core (HCSC) conductors, a measure taken to increase the capacity of 345kV transmission grids in response to the recent growth in renewable energy and power demand. The existing formula in IEC/TR 62271-306 recommend overload operation guidelines that take both temperature and current into account. This study presents a simplified formula that derives allowable duration based solely on current ratios by mathematically reducing complex temperature variable, alongside a three-stage serial priority determination logic that accounts for initial conditions. Furthermore, by benchmarking the practices of major international utilities, this study shifts away from fixed-table methods to establish a dynamic operation framework that tracks real-time ambient temperatures and load history, providing guidelines capable of responding effectively to both Short-Time Emergency (STE) and Long-Time Emergency (LTE) scenarios.