An important issue for a generator circuit breaker is its current carrying capability.The rated currents of generators range typically between 3000 A (for 50 MVA units) and 50000 A (for 2000 MVA units).As a consequence of these currents, heat is generated in the circuit-breaker.An increase of the rated current of a given circuit-breaker can only be achieved by improving the heat transfer to the environment ensuring that the temperatures of all components stay within admissible limits.
The ensuing challenge is therefore to remove this heat from the conductor.Heat pipes are highly efficient heat transport elements and consist of a hermetically sealed enclosure containing a small amount of working fluid.In principle a heat pipe is operational for all temperatures between the melting point and the critical temperature of the working fluid.They make use of the evaporation of a suitable working fluid, transport of the latent
This technology at now used by ABB generator circuit breaker (GCB) in high current value.
