ELECTRICAL WEAR IN HIGH-VOLTAGE CIRCUIT BREAKERS USING SF_6 ALTERNATIVE GASES

摘要

Every current interruption involves an arc burning between the contacts of a circuit breaker (CB). The produced arc energy and associated pressure increase is used in gas circuit breakers to cool the arc region leading to current interruption. The same arc energy causes wear that can be separated into two main phenomena: 1. Nozzle ablation, which affects pressure build up, flow characteristics, and interrupting efficiency. 2. Contact erosion, which reduces the time interval available for the current commutation and changes the contact surface, affecting the dielectric characteristic of the interrupter.