228 / 2024-05-28 11:09:59

Study on the High-Current Arcing Characteristics of Large Contacts for Generator Circuit Breakers

Large size contacts; High current arc characteristics; Vacuum arc; Generator circuit breaker;

High-capacity generator circuit breakers (GCB) are crucial equipment for ensuring the safe operation of generator sets. GCBs require a strong ability to interrupt large currents. Compared to vacuum circuit breakers, traditional SF6 circuit breakers are harmful to the environment and have a slower interruption speed. Currently, commonly used vacuum interrupter don’t meet the interruption needs of high-capacity GCBs. This paper investigates the arc voltage characteristics and morphological evolution of large-size longitudinal magnetic contacts. First, arcing experiments were conducted on large-size axial magnetic field contacts in a detachable vacuum interrupter. A high-speed camera was used to capture the shape of the vacuum arc. It was found that large-size contacts develop multiple stable arc columns based on multiple arcing points. Subsequently, the effects of short-circuit current magnitude and arcing time on the arc were comparatively analyzed.It was found that as the current increases, the vacuum arc becomes brighter, the arc evolution speed slows down, and the arc voltage increases. As the arcing time increases, the multi-arc column stage lasts longer and the arc becomes more concentrated. Finally, comparing the arcing results of large-size longitudinal magnetic contacts with ordinary longitudinal magnetic contacts, it was found that ordinary contacts do not have a multi-arc column stage, the arc light intensity is stronger, the voltage is higher, and the arc is more unstable. The findings of this study can provide a reference for the design of GCB vacuum interrupters.