Analytical approach and thermal signature of Switched reluctance motor iron losses

Abstract

This paper describes a fully analytical approach for iron losses estimation. This method allows us to quantify hysteresis and Eddy current losses in each part of a Switched Reluctance Motor (SRM), the validation of this method is obtained by comparing analytical and experimental phase inductance, the other validation method is based on comparison of static flux densities between this method and finite element method. Analytical air gap permeance model is used in association with analytical expression of magneto motive force (MMF) and current. It allows calculating the flux linked in each part of the SRM. The temporal and frequency characteristics of these fluxes, using static material iron losses under sinusoidal flux density excitation, FFT and correction factors leads to estimate iron losses and their location in the machine. The results show that the major part of the losses are located in the stator especially in the teeths, Hysteresis losses are higher than Eddy current losses in the SRM. As soon as the speed of the SRM increases the Eddy current losses become more important. 8/6 2 kW SRM is used in experimental test bench, Infrared camera placed in front of the lateral face removed just after operation give the thermal signature of these losses and confirm the previous results. Copper losses are located in the winding.