Comprehensive Dynamic Loss Model of Electrical Steel Applied to FE Simulation of Electrical Machines

This paper presents a dynamic loss model of electrical steel that can be used with the transient finite-element simulation of electrical machines. The model is used to compute the iron losses in a 37-kW induction machine fed from a sinusoidal and frequency converter voltage supply at different frequencies and loads. The computed losses are compared with results from conventional iron loss computation method based on harmonic analysis as well as with measured losses. The presented dynamic model is based on the investigation of different measurement results as well as on phenomenological backgrounds and analogies. The model is tuned to account for the rotational losses and thus can be used with arbitrary wave form or loci of the magnetic flux density vector (as is the case in the iron core of electrical machines). The parameters of the model are identified from measurements and can be stress dependent to account for the effect of mechanical stresses on the losses in magnetic materials. The presented model differs from previously presented ones in a way that the losses can be calculated at any time and not as an average over a period of the magnetic flux density.