A variable parameter model for precise analysis of iron losses in induction motors considering saturation and harmonic field

This paper proposes a piecewise variable parameter model of iron losses in induction motors. In this model, two additional flux density terms are used to reflect the non-linear characteristics of the magnetic materials, and the main loss parameters of the proposed model are piecewise varying with the peak value and frequency of the flux density. Meanwhile, the fine analysis of the iron losses caused by fundamental and harmonic fields can also be carried out. Experiments are performed on a 5.5kW motors with different supply voltages, and the calculated results by the proposed model and Bertotti model are compared. It is shown that the iron losses predicted by the proposed model agree well with the test ones over a wide range of supply voltages.