No. 1048
	Analysis Technology for Electromagnetic Vibration and Acoustic Noise of Induction Machines
	Investigating R&D Committee on analysis technology for electromagnetic vibration and acoustic noise of induction machines
	Recently increasing of awareness of environmental noise and improvement of living amenity have led to increasing demand for reduction of vibration and noise. Development of electric motorization and power electronics has increased the use of induction motors around people. Improvements need to be made in the quality as well as level of vibration and noise from motors. Induction machines, induction motors, produce electromagnetic noise, fan noise and mechanical noise. In these days, the machine yields electronic vibration and electronic sound due to non-sinusoidal power sources of semiconductors drive. This report describes equation and FEM analysis on the procedure for electromagnetic forces and magnetostriction to vibration and acoustic noise through a structure. Mechanical characteristics, that is, natural frequency, as well as electromagnetic forces and magnetostriction stress greatly affect production of electromagnetic vibration and noise. Mechanical characteristics and natural frequency of the structure is also studied and experimented. Vibration and noise of a single phase motor and an inverter-fed motor are also studied. Eccentricity due to manufacturing processes are was also checked. In the latter part of the study, vibration and noise reduction measures, active noise control, a measuring method and standards are surveyed with regard to the state of the arts. This report summarizes the study results.
	©2006. The Institute of Electrical Engineers of Japan