Inclusion of inter-bar currents in multi-slice FE modelling of induction motors -: influence of inter-bar resistance and skew discretisation

Purpose - To study the inclusion of inter-bar (IB) currents in a multi-slice finite element (FE) model of induction motors and in particular the effect of the associated skew discretisation. To validate the model experimentally. Design/methodology/approach - Both a classical uniform distribution and a gauss distribution of the slices and the lumped IB resistances are considered. Measurements on a 3kW induction motor allows one to estimate its IB resistance and to validate the FE model. Findings - A gauss distribution of the slices allows one to use fewer slices and thus reduces the computational cost. The simulation results show that, at full load, skew changes the different loss components significantly, while the IB currents have a minor effect. Research limitations/implications - The direct measurement of the IB resistance is by no means trivial. In the frame of this paper, it was indirectly determined, namely by means of a short-circuit test. Originality/value - The gauss distribution of the slices and the IB resistance; the systematic study of the skew discretisation; the experimental determination of the IB resistance.