3D SIMULATION OF GENERATOR CIRCUIT BREAKERS

In this contribution we present a transient 3D simulation of a generator circuit breaker that is based on the pincher arc principle. For this purpose we developed a novel MHD simulation tool. We combined appropriate numerical methods for fluid dynamics, for radiation transport and in particular for electromagnetism. We relied on fmite elements as they are predominantly used for discretization of low frequency 3D electromagnetism. For fluid dynamics we used finite volumes and for radiation transport we used the discrete ordinate method. Our simulation shows that the arc is unsteadily oscillating in the arc-zone, therefore axial symmetry cannot be assumed for this simulation. These 3D arc fluctuations are deemed to be one reason for the transient oscillations of the arc voltage.