Evaluation of Iron Loss Models in Electrical Machines

Abstract

In this paper, more than ten different iron loss models are experimentally evaluated, which cover alternating and rotating fields, influence of temperature, DC bias flux density and distorted flux density due to PWM inverter. Iron loss models considering alternating fields are evaluated by the measured results of a lamination ring specimen. The iron loss model considering rotating field and non-sinusoidal field are evaluated by the measured results of an electrical machine under different conditions. The iron loss models considering temperature influence are also evaluated by thermal analyses and experimental tests. Based on these comprehensive investigations, the iron loss models having the best prediction accuracy for each case are identified.Index terms --Electrical machine, Iron loss, Thermal analysis.Z.Q. Zhu (M'90-SM'00-F'09) received the B.Eng. and M.Sc. degrees in electrical engineering from Zhejiang University, . His major research interests include design and application of electric machine and drive system.Jun Peng received the B.Eng. degree in mechanical design

Iron-Loss and Magnetization Dynamics in Non-Oriented Electrical Steel: 1-D Excitations Up to High Frequencies

“…Finally, the obtained distribution E s (x) satisfies the required BC at both boundaries of the model, as discussed in Subsection II-B. The value of E s (x) in the center of the sheet is always E s (x = 0) = 0, whereas the value at the sheet surface is obtained by evaluating (22)…”

“…In contrast to this, the macroscopic induced electric field E and, consequently, eddy current density j, cannot be calculated based on local rates of changes dB s dt individually. According to (22), E s is generated by dB s dt in the observed slice, as well as the rates of change inside all the inner slices. Furthermore, the induced electric field is oriented in different directions in the upper and lower halves of the sheet, as presented in Figs.…”

Thermal-Loss Coupling Analysis of an Electrical Machine Using the Improved Temperature-Dependent Iron Loss Model

“…The iron loss model developed in [9] is experimentally confirmed as the most accurate iron loss model when the temperature is constant with the help of variable coefficients [10]. This iron loss model can be expressed as: (1) where is the iron loss density.…”

“…The models developed in [6]- [9] are most commonly used iron loss models for electrical machines. With the help of variable loss coefficients, the iron loss model developed in [9] is experimentally confirmed as the most accurate iron loss model when the flux density alternates sinusoidally and the temperature is constant [10]. However, none of these iron loss models considers the temperature dependency of iron loss while the temperature can influence the iron loss significantly.…”

Evaluation of iron loss models in electrical machines

“…Different models have been developed in [17]- [18] to consider the influence of rotational field. Different iron loss models are evaluated and compared in [19]. However, no thermal evaluation is carried out, which is critical for electrical machine loss prediction.…”