Study on Electromagnetic Exciting Force Characteristics and Electromagnetic Noise of Permanent Magnet DC Motor

Abstract:

Electromagnetic exciting force is the key to generate electromagnetic noise. The characteristics of electromagnetic exciting force and the causing of electromagnetic noise were analyzed after the power was off for cooling fan Permanent Magnet DC (PMDC) motor. Time-stepping finite element method was selected to calculate its several parameters, such as air gap magnetic density harmonics generated by the stator and rotor, torque ripple and unbalanced magnetic pull at its different speed.Experiment on unloading vibration noise was carried out to confirm the validity of electromagnetic exciting force analysis. The results show: electromagnetic force amplitude keeps constant while the motor speed changing. Torque ripple decreases while the motor speed down. A kind of electromagnetic noise called howling noise produced by PMDC motor used in car cooling fan is mainly due to resonance. So the best way to eliminate this motor’s noise is to improve the order of electromagnetic waves and avoid the electromagnetic resonance.

• Periodical: Applied Mechanics and Materials (Volumes 128-129)
• Pages: 323-328
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.128-129.323
• Online since: October 2011
• Authors: Man Lan Liu, Tian Da Yu, Shu Mei Cui, David He
• Keywords: Air Gap Magnetic Flux Density Harmonic, Electromagnetic Exciting Force, Electromagnetic Noise, Permanent Magnet DC Motor, Torque Ripple, Unbalanced Magnetic Pull

References

[1] Chen Hanxun, Meng Lijun, Zhao Leigang. Analysis on Noise of Automobile. Micromotor [J] Micromotors. 2006, 39(3): 61~63.

[2] Ishimitsu, Shunsuke1 ; Takami, Kenji2 . Study on the contribution of intake noise using complex time-time analysis and subjective evaluation[J]. International Journal of Wavelets, Multiresolution and Information Processing. 2010, 8(07): 609~625.

DOI: 10.1142/s0219691310003675

[3] Jia Jide; Chen Jian; Wang Jun. Analysis and control of the interior noise in passenger car [J]. Transactions of the Chinese Society of Agricultural Machinery. 2009, 40(02): 204~208.

[4] LiuTao, GuYan. SEA Application in Vehicle Interior Noise Analysis[J]. Noise and Vibration Control. 2006, 25(02): 66~69.

[5] Kobayashi T, F Tajima, M Ito. Effects of Slot Combination on Acoustic Noise from Induction Motors[J]. IEEE Transactions on Magnetics. 1997, 33(2): 2101~2104.

DOI: 10.1109/20.582736

[6] Benbouzid M E H, G Reyne, S Derou. Finite Element Modeling of a Synchronous Machine. Electromagnetic forces and mode shapes[J]. IEEE Transactions on Magnetics. 1993, 29(2): 2016~(2018).

DOI: 10.1109/20.250805

[7] Han L, M Xin, H Xie. Numerical Method for Calculating Cogging Torque by Simulation of Actual Measurement[J]. Electric Machines and Control. 2007, 11(6): 589~593.

[8] Zou Jibin, Zhu HongLiu. Calculation of Cogging torque and Unbalanced Force in Brushless DC Motor with Eccentricity [J]. Small & Special Electrical Machines. 2008, 35(3): 5~8.