A 12/8 switched reluctance motor (SRM) has substantial benefits in many applications. However, noises and vibrations of the 12/8 SRM are large due to its large torque ripple. In order to solve this problem, a 12/10 SRM with a star connection has been proposed, which has less torque ripple. In this paper, we propose a 12/10 SRM with a hex connection. The hex connection does not need a neutral point, and the stator has a short coil end height. The effectiveness of the proposed hex connection is investigated through 2-D finite element analysis.

The performance of GPUs has improved dramatically in recent years. For example, the NVIDIA Tesla K20 released in 2012 had a single-precision computing performance of 3.52 Tflops, while the NVIDIA Quadro GV100 released in 2018 has a computing performance of 14.8 Tflops, more than four times higher.
By using them, JMAG-Designer has the ability to accelerate the analysis. However, before v19, there were requirements for analyses that could be performed using GPUs, and the analyses that could be accelerated were limited.
Therefore, this presentation will report the results of comparing the analysis time of JMAG-Designer v20.2 with that of JMAG-Designer v19 in the transient response analysis of IPM motors and induction machines using NVIDIA Quadro GV100.

Variable flux motors (VFM) receive much attention from a viewpoint of expanding operating torque-speed range and high efficiency area required for automotive traction drive application. As one of the types of VFM, this project focuses on the hybrid excitation flux switching motor (HEFSM) that can realize variable flux capability utilizing both field coil excitation and permanent magnets (PMs) arranged on a stator body. The first prototype using variably magnetizable PM (VM-PM) remarked high motor efficiency over the whole operating area thanks to the magnetization state change of VM-PMs. On the other hand, it resulted in an excess usage of PMs and poor variable flux and maximum torque capabilities. On the basis of these problems, the second prototype has been designed via FEA-based optimization, which employs a novel PM arrangement as well as a flat motor shape with an optimum L/D ratio. This presentation shows FEA-based shape optimization results using JMAG-Designer and the experimental drive characteristics validation using the second prototype.

Quantitative analysis of iron loss taking magnetic hysteresis behavior into account is essential to development of high-efficiency electric machines. In recent years, a play model has attracted attention since it needs no convergence calculation. Although a lot of measured dc hysteresis loops with different maximum flux densities are necessary in general to derive the play model, which is difficulty in practical use, we previously proposed an efficient method for deriving the play model by using the LLG equation, which requires only one or two measured dc hysteresis loops. In this presentation, we introduce examinations on calculation accuracy improvement in the LLG equation, and the play model derived from the LLG equation is incorporated into the magnetic circuit model to analyze a magnetic reactor.

Variable magnetic force IPM motors operate over a wide speed and power range at high efficiency. However, the variable magnetic force IPM motors need to reduce the de and re-magnetization current for a productization for EVs. In this poster, variable magnetic force IPM motors for the reduction of magnetization current are proposed. The analysis results indicated that the proposed motor can vary de and re-magnetization of the permanent magnet by the field due to the magnetization current of 2.0 times the rated current and operate almost constant maximum power over a wide speed range.

For practical realization of electric aircraft, we have proposed a novel ultralightweight motor using a magnetic resonance coupling. We describe the magnetic resonance coupling motor with a magnetic ring in order to enhance the torque and power. The analysis results indicated that the proposed motor with the magnetic ring can produce the torque and power 6.9 times the motor of previous study.