Strand-level finite element model of stator AC copper losses in the high speed machines

In high speed machines, the skin and proximity effects cause significant increase of the total copper losses in stator windings at the high frequency. The cause and behavior of the eddy currents are studied at two extreme time moments. The AC copper losses are divided into 3 components with different sources. The dimensions of the conductors must be carefully selected to minimize the stator AC copper losses. The optimal strand thicknesses at 4 different frequencies are investigated. The ratio between AC and DC resistances calculated in finite element (FE) model is compared with the results from the analytical method.