Pham Van Doan

Compressed air, the solution for generator breakers problems

A high arc voltage being essential to interrupt currents without a zero pause, it has become compulsory to use compressed air as an interrupting medium in generator breakers. The use of compressed air for cooling purposes has resulted in simpler, hence more reliable breakers. The circuit breakers PKG have been subjected to short-circuit current interruptions up to 340 kA. For configurations where the generator delivers through two transformers, a new arrangement of interrupting equipment has been proposed in order to meet the resulting increase of short-circuit currents.

Technico-Economical Response of the Generator Circuit Breaker to Future Generation Ratings

The increase of power units of generators and main transformers, and of short- circuit-carrying capability of transmission networks, compel the interrupting switchgear manufacturers to improve continuously the performances of the equipment in order to make best use of the new techniques through properly adapted testing facilities and methods. The problem raised by high nominal currents has been examined and solutLons proposed for extra- high short-circuit currents beyond 300 kA.