This paper presents the mechanical design of a 70 kW Switched Reluctance Motor prototype with a nominal airgap length of 0.4 mm with a relatively large stator outer diameter of 280 mm. It presents the mechanical design considerations and manufacturing tolerances that are vital for an electric motor to maintain component integrity and meet performance requirements. Multi-stage design of the mechanical components and fittings for the complete mechanical system are presented and justified with finite element analysis results. The radial and axial stack-up analysis are presented which account for the dimensional variations during the manufacturing of motor components. The assembly of the motor prototype is described, which demonstrates that the axial and radial alignment of the motor components are achieved while maintaining the small airgap length required. The motor assembly is then verified with static end-of-line tests, such as winding insulation and housing leakage tests. Additionally, experimental modal analysis of the housing assembly is performed to examine the influence of the winding, housing, and potting on its modal frequencies and damping characteristics.

Accurate core loss measurement considering manufacturing effects is essential for improving motor efficiency and reliability. This paper explores pre-assembly core loss measurement techniques in electric motors, focusing on the influence of manufacturing processes and the efficacy of core loss measurement methods. Traditional methods such as the Epstein frame, Single Sheet Tester (SST), and toroidal core measurement are discussed, along with recent advancements in measurement techniques. Experimental methods with an excitation yoke placed inside a stacked stator for core loss measurement, mainly under an alternating magnetic field, are presented. The application of advanced core loss measurement in industrial settings highlights that automation plays a vital role in enhancing measurement efficiency. The gaps in the existing literature and specific areas where further research is needed are discussed.

A higher machine speed is an enabling factor in achieving a higher power density. However, higher speed poses a challenge to the structural integrity of the rotor, as the centrifugal force acting on the rotor increases quadratically with speed. This high stress may lead to failure in the rotor ribs and bridges of an Interior Permanent Magnet Synchronous Machine (IPMSM). This paper presents a high-speed rotor strain measurement experimental setup that uses strain gauges and a telemetry system to measure strain at critical locations of the IPMSM rotor up to 18,000 rpm. Strain measurements are conducted at both room and high temperature to emulate the operating conditions of a high-speed machine. The measured strain is then correlated with the results of the finite element analysis strain to evaluate the fidelity of the rotor stress model. Also, the effect of anisotropic mechanical properties of electric steel on rotor strain is investigated.

Core loss significantly impacts the efficiency of a switched reluctance motor (SRM), especially under high-frequency operation. Conventional measurement methods are often inadequate for capturing losses in assembled stator cores, where flux paths are complex, and excitation waveforms are non-sinusoidal. In this paper, a core loss measurement method is introduced for SRM based on transformer induction theory, enabling time-domain reconstruction of magnetic field quantities from voltage and current waveforms. The method is validated using a ring core and SRM stator geometry with finite element analysis (FEA), replicating practical excitation conditions. An experimental setup is built with a fractional SRM stator core and custom-designed magnetizing yokes. The experimental setup captures induced voltage and current waveforms from the stator. The proposed method is experimentally validated over a wide frequency range from 100 Hz to 10,000 Hz and under varying flux density levels, confirming the applicability for practical core loss characterization of SRM stators.