Validation of a Comprehensive Analytic Noise Computation Method for Induction Machines

Acoustic Noise Characterization of Space Vector Modulated Induction Motor Drives – An Experimental Approach

“…There are instances where the analytical results agree well with the experimental results in predicting the resonant frequencies, but not so much in terms of the magnitudes of noise at and around resonant frequencies [7]; also, the troughs are some times not clearly visible in the measured frequency response [27]. Such errors have been attributed to errors in the assumed modal damping factor [10].…”

“…The major causes for the harmonics in the air-gap flux are [6]- [9]: 1) Spatial mmf harmonics due to non-sinusoidal distribution of stator and rotor windings [6] 2) Harmonics in the air-gap permeance, which depend on: a) Numbers of the stator and rotor slots [7], [8] b) Geometry of slots and teeth in stator as well as rotor [8], [9] c) Saturation in the iron core [10] 3) Harmonic currents in the stator winding [6] Long and extensive research in the area of acoustic noise [1]- [5] has led to valuable design guidelines with regard to number of stator slots, number of rotor slots, and the design of stator and rotor windings to reduce (and keep at a minimum) the adverse effects of the spatial mmf harmonics and permeance harmonics [3]. Recent research works have focused on reduction in acoustic noise through improved rotor design [11] and skewing [12].…”

“…In inverter-fed induction motor drives, the time harmonics in the stator currents cause high-frequency audible noise [7], [13]. In case of constant-frequency PWM, these noise components are concentrated in narrow bands around integral multiples of the carrier frequency, which is irritating to the human ear [14].…”

Research on vibro-acoustic characteristics of the aluminum motor shell based on GA-BP neural network and boundary element method

“…Modern motors have started the development towards high current, high flux density and light structure. Therefore, problems with vibrations and noises of motors become especially prominent [1,2].…”

Influence of constructive parameters and power signals on sound quality and airborne noise radiated by inverter-fed induction motors

“…On the other hand, certain constructive parameters of the machine such as pole number also condition the level of noise that it generates [9][10][11][12][13]. These do so; not only in terms of speed, but the distribution of windings in slots, input current waveform distortion, air gap permeance fluctuations, rotor eccentricity, and phase unbalance give rise to mechanical deformations, vibrations and changing electromagnetic acoustical noise [14].…”