Optimal design of generator circuit breakers up to a capacity of 2000 MVA using thermal models

Generator circuit breakers must be able to carry operating currents of several 10 kA and short time currents of several 100 kA. It is shown how a generator circuit breaker to be developed can be optimized by calculation using the thermal network method and finite element models for high operating currents. The essential parameters are found out which mainly determine the temperatures of the conductor path and the contact systems. The parameters, which are needed for the calculation of the thermal network models and the optimization of the circuit breakers, were determined experimentally or by calculation (FEM).