AUTHOR : Young-Jin Shin, Joon-Woo Gi, Myung-Hwan Yoon, Seung-Hee Chai, Jung-Pyo Hong
ORGANIZATION : KSAE
JOURNAL :
YEAR : 2015
VOL :
ISSUE : EVS 28
PAGE : 1 ~ 4
This paper proposes a method to improve the waveform of the back-EMF to obtain sinusoidal waveform. The improvement of back-EMF waveform has many advantages such as reduction of torque ripple and noise and vibration. A dent is discovered from the middle of the back-EMF waveform of the Surface-Mounted Permanent Magnet Synchronous Machine (SPM) type vehicle-generator. This phenomenon occurred due to the flux leakage and causes higher total harmonic distortion (THD). The flux leakage variation occurs due to the relative position between permanent magnet and teeth. A method of widening intervals of the permanent magnets is suggested for the solution of this problem. The flux leakage can be constant as permanent magnet interval is wider than slot opening. This solution is applied to the target generator and THD reduction of back-EMF is confirmed. Not only THD reduced from 19.5% to 5.8% but also the torque ripple reduced by more than 30%. The proposed method is verified by the results of finite element analysis.