An Investigation Into the Trade-Off Between Full Machine and Single-Slot FEM Simulations for Electrical Machine Modeling at High Frequencies With Respect to Inter-Wire Couplings

High frequency machine models are commonly employed due to the rising number of defects resulting from bearing currents. The model parameters are identified by finite element method (FEM) simulations, taking current and field displacement due to inter-wire couplings into account. Usually, this identification is performed with a single-slot model. Unfortunately, a single-slot cannot achieve the accuracy of a full model, which in turn is computationally expensive. Thus, this paper deals with the trade-off between time and cost efficiency of a single-slot and the accuracy of a full machine simulation. The coupling coefficients of all wires within a machine’s cross-section will be examined to identify the number of relevant slots. The single-slot model will be extended to the number of relevant slots. The extended model will be validated using comparisons with the full machine model. The result shows that the extended model provides a attractive compromise between accuracy and running time.