Optimized Field/Circuit Coupling for the Simulation of Quenches in Superconducting Magnets

In this paper, we propose an optimized field/circuit coupling approach for the simulation of magnetothermal transients in superconducting magnets. The approach improves the convergence of the iterative coupling scheme between a magnetothermal partial differential model and an electrical lumped-element circuit. Such a multiphysics, multirate, and multiscale problem requires a consistent formulation and a dedicated framework to tackle the challenging transient effects occurring at both the circuit and magnet level during normal operation and in case of faults. We derive an equivalent magnet model at the circuit side for the linear and the nonlinear settings and discuss the convergence of the overall scheme in the framework of optimized Schwarz methods. The efficiency of the developed approach is illustrated by a numerical example of an accelerator dipole magnet with accompanying protection system.