Yasuaki Aoyama

Simple modeling and prototype experiments for a new high-thrust, low-speed permanent magnet disk motor

Fully integrated electric propulsion systems are gaining popularity in both commercial and military sectors. Propulsion motor manufacturers are investigating new direct drive solutions for use in electric ships. These applications require motors with high torque output at low speeds. Such requirements were the motivation for the design of a new PMSM with a novel topology. This paper describes the efficient mathematical model used to optimize our PMSM design. Based on a simplified theoretical model for the motors behavior, we were able to quickly and accurately predict torque output. The minimalist design of this TFM is shown to be advantageous for computer simulation and machine manufacturing. Initial results from a prototype are included and discussed. Future plans for the prototype are outlined.

Basic experiments for high-torque, low-speed permanent magnet synchronous motor and a technique for reducing cogging torque

Fully integrated electric propulsion systems are gaining popularity in both commercial and military sectors. Propulsion motor manufacturers are investigating new direct drive solutions for use in electric ships. These applications require motors with high torque output at low speeds. Such requirements were the motivation for the design of a new PMSM with a novel topology. Firstly, this paper describes an efficient model of a motor used for high thrust at low speed. Secondly, the authors analyze the theory for motors behavior. To compare the theoretical result, characteristics of the proposed motor have been tested. The cogging torque has been a serious problem. Therefore, an analytical model of the cogging torque has been derived for calculating and reducing it. An appropriate skew angle can be designed based on the model.

Simple Modeling and Prototype Experiments for a New High-Thrust Low-Speed Permanent-Magnet Disk Motor

Fully integrated electric propulsion systems are gaining popularity in both commercial and military sectors. Propulsion motor manufacturers are investigating new direct-drive solutions for use in electric ships. These applications require motors with high torque output at low speeds. Such requirements were the motivation for the design of a new permanent-magnet synchronous motor (PMSM) with a novel topology. This paper describes the efficient mathematical model used to optimize our PMSM design. Based on a simplified theoretical model for the motors behavior, we were able to quickly and accurately predict torque output. The minimalist design of this transverse flux machine is shown to be advantageous for computer simulation and machine manufacturing. Initial results from a prototype are included and discussed. Future plans for the prototype are outlined.

Design using simple modeling and experimental study on direct-drive disk-type motor with dense stator configuration

Electric propulsion system in marine application has been given high attention due to energy saving and low maintenance requirements. A transverse flux-type machine (TFM) with permanent magnets (PMs) has been developed as a direct-drive propulsion motor without gearbox called for high torque at low speed and high reliability simultaneously. This manuscript describes design procedure of the TFM using simple modeling focused on magnetic-circuit structure of the motor. The electrical design of the motor is based on electrical and magnetic theory. The minimalist design is shown to be advantageous for effective use in three-dimensional numerical analysis. The validity of the proposed method and the fulfillment of design requirements, torque density defined as torque to total volume ratio of more than 10kNm/m3 and power factor (PF) of more than 0.80, are verified through the numerical computation and experimental result on a prototype machine. High torque density and high PF contributes to compactness of whole motor-drive system including motor and power converter system.

A novel magnetic gear for high speed motor system

In the industrial field, the drive system integrated the high speed motor and the gear is required to effectively utilize the limited space. However, mechanical gears often require their lubrication and cooling, they generate whilst noise and vibration. To overcome these problems, the magnetic gears have been expected. Magnetic gears achieve the system with maintenance-free, low noise and low vibration characteristics by contact-less power transformation. However, conventional magnetic gears are not suitable system for high speed motors because the mechanical strength is weak due to permanent magnets of the high speed rotor. This paper presents a novel reluctance magnetic gear and flux switching magnetic gear for the super high speed motor. The high speed rotor of the proposed magnetic gears is constructed by only iron core. Therefore, the structure is very simple and robust and it is possible to rotate in the high speed region. Moreover, the reluctance magnetic gear realizes high efficiency compared with the conventional surface permanent magnet (SPM) magnetic gear because the magnet eddy current loss on high speed rotor is not generated. While, the flux switching magnetic gear realizes the high torque density by utilizing the magnetomotive force of stationary field magnets. In this paper, the performances of these proposed magnetic gears including torque density, the system size, loss and efficiency are evaluated.

Reluctance magnetic gear and flux switching magnetic gear for high speed motor system

In the industrial field, the drive system integrated the high speed motor and the gear is required to effectively utilize the limited space. However, mechanical gears often require their lubrication and cooling, they generate whilst noise and vibration. To overcome these problems, the magnetic gears have been expected. Magnetic gears achieve the system with maintenance-free, low noise and low vibration characteristics by contact-less power transformation. However, conventional magnetic gears are not suitable system for high speed motors because the mechanical strength is weak due to permanent magnets of the high speed rotor. This paper presents a novel reluctance magnetic gear and flux switching magnetic gear for the super high speed motor. The high speed rotor of the proposed magnetic gears is constructed by only iron core. Therefore, the structure is very simple and robust and it is possible to rotate in the high speed region. Moreover, the reluctance magnetic gear realizes high efficiency compared with the conventional surface permanent magnet (SPM) magnetic gear because the magnet eddy current loss on high speed rotor is not generated. While, the flux switching magnetic gear realizes the high torque density by utilizing the magnetomotive force of stationary field magnets. In this paper, the performances of these proposed magnetic gears including torque density, the system size, loss and efficiency are evaluated.

Development of high-acceleration linear motor system using the transient loss evaluation

For the purpose of the range expansion of the product which applied a linear motor, the examination of the linear motor realizing high acceleration drive progresses. In this situation, the importance of the evaluation of the linear motor for the acceleration region increases. This report describes the investigation that can evaluate performance of a linear motor at the transient state. The performance at the transient state is calculated by using control simulator and the FEM model. As a result of quantification, it was proved that the copper loss and the metal loss are dominant in all losses. Moreover we also described about the calculation results of comparison of different material plate on this method.