Research Progress and Prospects of High-Capacity Generator Circuit Breakers

Generator circuit breakers (GCB), serving as critical protection equipment for million- kilowatt generating units, are of significant importance for ensuring the safety of power systems. However, their interruption technology still faces severe challenges, including extremely high short-circuit currents and slowly decaying DC components. This paper systematically reviews the research progress of high-capacity GCB. Firstly, the technological evolution path of GCB is outlined. Compressed-air GCB rely on strong gas blast but suffer from disadvantages such as large system size and limited breaking speed, SF GCB with puffer or self-blast designs have become mainstream due to their excellent arc-extinguishing performance, yet they are under pressure for environmentally friendly alternatives because of greenhouse gas concerns. Vacuum GCB, with advantages such as environmental friendliness, fast dielectric recovery, and long service life, have emerged as a major development direction. Secondly, regarding the current status of key technologies, relevant research on SF, circuit breakers including are characteristic simulation, dielectric recovery enhancement, and gas flow field optimization is reviewed. Focus is placed on the are characteristics under high currents, the interaction between ares and electrodes, and the current-sharing mechanism in multi-break configurations. Furthermore, the cutting-edge technological advancements in vacuum circuit breakers for overcoming high-current interruption challenges, primarily through magnetic field control and multi-break parallel techniques, are systematically summarized. Finally, future development directions in the field of high-capacity GCB are pointed out, which include enhancing the interruption limit of single breaks, optimizing the coordinated control of multi-break systems, and developing intelligent operation and maintenance technologies. This work aims to provide theoretical reference and engineering guidance for developing a full series of green products and supporting the construction of new power systems.