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Mutually coupled switched reluctance motors (MCSRMs) are alternatives in the family of reluctance machines that can overcome switched reluctance motor's (SRM's) system-level integration and control challenges by utilizing standard three-phase voltage source inverters. In this article, a novel segmented-rotor, fractional-slot, tooth-wound MCSRM with notched rotor design is presented, which has very low torque ripple compared to other machine types in the SRM family. The torque ripple is reduced to 3.6% without utilizing any current profiling techniques or torque sharing functions. The ripple minimization is achieved primarily through rotor segment shaping, which has a strong influence on stator flux densities, flux linkages, and torque harmonics. The design strategy, along with the optimization details, is presented for a 120 W, 12 slot-8 pole MCSRM. The designed MCSRM is prototyped for experimental verification and validation of the finite element analysis results and design methodology. [ABSTRACT FROM AUTHOR]

Outer-rotor switched reluctance machines (SRMs) have drawn much attention as promising candidates for in-wheel direct-drive motors of future electric vehicles. This article presents a systematic performance comparison of three outer-rotor SRM topologies for in-wheel traction applications in terms of the specific torque, electromagnetic efficiency, torque ripple, radial force, and mechanical aspects. A generalized design optimization framework for SRMs is proposed to enable the fast evaluation of large numbers of designs generated from the differential evolution by incorporating an analytical current profile estimation into the transient finite element analysis. The relationship between the saliency ratio and converter volt-ampere rating is also discussed. The calculations are then benchmarked with the experimental results from an existing prototype. The effectiveness of the performance prediction method and the proposed optimization approach is validated. [ABSTRACT FROM AUTHOR]

The inherent structure of double-stator switched reluctance motor (DSSRM) provides a significant improvement in energy conversion efficiency by eliminating the radial component of the forces. Reduction of the radial force (RF) in rotational motion increases efficiency and performance of the machine. This paper proposes and implements a new flat-type double-stator segmented cup-rotor SRM (DSSCR-SRM). In this structure, the shaft is placed on one bearing, which reduces the system cost and friction. The rotor structure is designed to be connected directly to the load (direct-drive system) without the shaft requirement. Moreover, the rotor can be balanced between two stators such that the resultant RFs is reduced to zero. Due to the difference between the number of turns in inner and outer stator-coils, the forces exerted on the segmented rotor will cause it to stay partially suspended. In order to improve the results and determine appropriate performance of the motor, the magnetic analysis has been done on a 3-D model. The results of analytical calculations and the finite-element method analyses are validated by testing a prototype model of the DSSCR-SRM. [ABSTRACT FROM PUBLISHER]

Abstract: Hysteresis motors being capable of producing a steady torque at low speeds and providing good starting properties at loaded condition became popular among different fractional horse power electrical motors. High temperature superconducting materials being intrinsically hysteretic are suitable for this type of motor. In the present work, performance study of a 2-pole, 50 Hz HTS hysteresis motor with conventional stator and HTS rotor has been carried out numerically using finite element method. The simulation results confirm the ability of the segmented HTS rotor with glued circular sectors to trap the magnetic field as high as possible compared to the ferromagnetic rotor. Also the magnetization loops in the HTS hysteresis motor are obtained and the corresponding torque and AC losses are calculated. The motor torque thus obtained is linearly proportional to the current which is the common feature of any hysteresis motor. Calculations of torques, current densities etc are done using MATLAB program developed in-house and validated using COMSOL Multiphysics software. The simulation result shows reasonable agreement with the published results. [Copyright &y& Elsevier]