Magnetostriction Effect in Motor Vibration and Acoustic Noise
-Finite Element Analysis and Experimental Investigation-

Yifei Cai･Naoki Saikawa･Akira Chiba (Tokyo Institute of Technology)･Souichiro Yoshizaki (JFE Steel)

The reduction of acoustic noise is one of main concerns in recent traction electric motors for automotive applications. Magnetostriction generates expansion of stator yoke. In this research, toroidal windings are added to stator cores made of three different irons, these are high silicon steel, conventional silicon steel and amorphous iron. Acoustic noise is measured and compared.

Experimental Considerations on Circulating Current Losses of Armature Windings in Permanent Magnet Synchronous Motors

Hiroaki Makino･Daisuke Mori･Makoto Matsushita (Toshiba Infrastructure Systems & Solutions)

Parallel strands, which are often used in permanent magnet motors for automobiles, are composed of bundles of electrically parallel-connected small wire, resulting in circulating current losses due to unbalanced inductances caused by the arrangement of wires in the slot. In this paper, the effects of circulating current losses are discussed by experimentally comparing the motor winding losses for a motor with the same wire arrangement in all slots and a motor with the wire arrangement in the slots swapped.

Research on Halbach Array Automotive Permanent Magnet Motor using Laminated Neodymium Magnets

Ryujiro Gombi･Taketsune Nakamura･Emiko Tsuru (Kyoto University)･Tetsuhiko Mizoguchi･Masato Sagawa (NDFEB)･Alberto Castellazzi･Shinichi Domae (Kyoto University of Advanced Science)

We are conducting research on permanent magnet motors for small EVs. The performance required for this motor is high power density at starting and high efficiency during steady running, and we aim to achieve the ultimate in performance by adopting a Halbach array rotor structure using neodymium magnets. In this presentation, we will report on the results of our study using electromagnetic field analysis to further improve the characteristics of the laminated magnets developed by NDFEB Co., Ltd. using the hot press method.

Development of a Vibration and Acoustic Analysis Methodology for Electric Drive System using Wave Based Technique

Hong Ryul Kim (Hyundai Motor)

A new analysis method of vibration and vibro-acoustic for electric power system including motor, gear deceleration unit was developed in this paper. The methodology for electromagnetic analysis of traction motor, dynamic analysis for electric drive system and vibro-acoustic analysis was proposed and it shows satisfactory results to understand the dynamic properties of this system. The new method for vibro-acoustic method was examined to calculate the radiated acoustic level in mid frequency range, which is the main area of interest in electric drive system. The analysis results also show the main resonance mode, vibration order tracking, and the weakest part of acoustic radiation.