Modeling and simulation of energy-removal system for superconducting magnets

The Large Coil Test Facility at the Oak Ridge National Laboratory employs six D shaped superconducting coils. The coil current ranges from 10 to 20 kA. The protection scheme of these coils requires the coil current to be interrupted. This interruption will generate high-voltage transients in the coil. To prevent destruction of the coil isolation, these transients have to be reduced. Two types of suppressor networks, one a varistor and the other an R-C network, were reviewed. Then each suppressor circuit was simulated to determine the effectiveness of each suppressor. The modelling used the Super Sceptre computer program to simulate these transients