Eddy currents in medium power switched reluctance machines

Automated copper loss calculation for switched reluctance machines

“…Both of them are of great importance in SRM due to high current gradients and high flux densities, especially at the pole tips. This behavior has been observed in previous studies, e.g., [1], [2], [3], [4]. Analytical calculations [4], [5], [6], [7], [8] of the current displacement represent easy methods with limited accuracy.…”

Temperatures Evaluation in an Integrated Motor Drive for Traction Applications

“…SRMs have concentrated windings, and the coils are mounted on the stator teeth; this solution leaves an empty triangular area between two adjacent coils, thus reducing the surface available for the thermal contact between copper and iron. Furthermore, to reduce the additional copper losses (eddy currents, skin effect) [22], [23], the conductors are disposed parallel to the slot base, that leads to a higher thermal resistance along the radial direction. Since the copper-iron thermal resistance is the largest one in the thermal equivalent circuit of the machine, the reduction of the temperature gradient between copper and iron significantly reduces the total temperature gradient between the copper and the cooling fluid.…”

Loss prediction in switched reluctance motors using finite element method

“…Another possible source for additional losses in SRM is the eddy current loss in the stator windings due to the leakage flux [16]. This component of the losses can be estimated with an acceptable accuracy as follows [17]: 745 where B i is the leakage flux density in conductor number i, d c the conductor thickness, r c the resistivity, l ax the axial length of the motor, and n is the number of conductor in coil.…”