Abstract

Switched Reluctance Machines (SRM) have recently received increasing interest from the research community, insomuch as this converter has several advantages compared to other types of AC or DC machines such as its greater efficiency, robustness, and mechanical simplicity. The magnetic design of the SRM includes salient poles at stator and rotor cores while the operation principle is based on the alienation of the rotor poles with the stator poles. This work presents a comparison of the magnetization characteristic and the inductances modeling for an SRM obtained with 2-D planar magnetostatic simulation and experimental results. A commercial 4-phase, 9.8 kW, 8/6 poles SRM was simulated using the Finite Element Method (FEM) with the FEMM4.2® software, considering the core nonlinearity and approximate geometry. The experimental test rig includes the 9.8 kW SRM, a three-phase rectifier, and a filter circuit. Self and mutual inductances were measured with DC step voltages applied to the stator for several rotor angle positions and voltage and current were digitally registered at the machine terminals. Additionally, to determine the magnetization characteristic, the current was increased up to 140% of its rated value for each rotor position. The inductance waveforms obtained from FEM and experimental analysis match between them and a seventh-order Fourier Series expansion is proposed to model the inductances. Meanwhile, the magnetizing outcomes allow representing the saturation effect in position or speed control of SRM.