Discretization Study for 2D Axisymmetric Modeling of an Ultrafast Thomson Coil Actuator

DC circuit breakers (DC CBs ) play a crucial role in ensuring the safe and reliable operation of envisioned medium voltage and high voltage DC power grids. Existing AC circuit breaker technologies are not suitable for application in DC grids due to the lack of current zero-crossings. Additionally, the fault current interruption time is required to be at least an order of magnitude shorter compared to conventional AC circuit breakers. For DC grid applications, hybrid DCCBs are being developed, combining power electronic devices and an ultrafast mechanical switch actuated by a Thomson coil (TC) actuator. The design and optimization of these TC actuators requires accurate and efficient simulation models. In this study, a 2D axisymmetric multiphysics simulation model of a state-of-the-art TC actuator is presented. A numerical discretization study is performed regarding the meshing and time stepping of the simulation. The results indicate a computationally efficient discretization that maintains the required accuracy under the given boundary conditions.