Integration over discontinuities in field-circuit coupled simulations with switching elements

Three-dimensional magnetic vector potential formulation discretized by the Finite Integration Technique is coupled to an electrical circuit containing switching elements. As a consequence, the corresponding mathematical model exhibits hybrid (continuous/discrete) behavior. The discontinuity handling algorithm presented here consists of three steps: event detection, event location and determination of consistent initial conditions. The last step of the algorithm is challenging, because the field part causes the major computational cost, and, as a consequence, a lot of computational time. Therefore, a special technique is proposed here by which highly transient phenomena at the circuit side are only resolved by the circuit model avoiding unnecessary evaluations of the field problem. The presented algorithm is illustrated by a three-phase transformer model coupled to a diode rectifier.