Benchmark for the eddy current problem in laminated iron cores

Abstract

A new benchmark for the eddy current problem in laminated iron cores is designed to evaluate homogenization methods based on the finite element method. To this end the variational form is derived to solve the nonlinear problem. In this work, in extension to excite the coil with a current source, a voltage source is used and in this case the current is treated as an unknown. The solution method needs to be extended accordingly. To facilitate the modeling of the laminated iron core hexahedral finite elements have been employed. The Biot-Savart field has been exploited to avoid the modeling of the cylindrical coils. In summary, a nonlinear problem with network coupling is solved utilizing the Biot-Savart field. To calculate the time-domain solution the resulting nonlinear equation system consisting of over 16 million degrees of freedom is solved in each time step. A Newton method is used with a line search technique. The design procedure of the benchmark is described, highlighting the key requirements. The simulation results show that the requirements are fulfilled. Measurements taken from a simple setup are also presented.