Abstract
Although the performance of an Induction Motor (IM) can be maximized for any speed by use of an inverter, there is still room to contribute by optimizing the rotor slot shape while decreasing the mechanical disturbing effects and acoustic noise. This paper focuses on the effect of different individual rotor slot shapes on the performance of an IM including overall space harmonic, vibration and acoustic effects. A number of rotor slot shapes were implemented to the rotor of a commercial IM and efficiency of all designs were maximized for constant torque region by optimization. Afterwards, operational performance including starting, breakdown and rated operations; moreover, harmonic content and torque ripple were analyzed numerically in association with the mentioned rotor slot shapes. Best performing 4 rotor slot shapes in terms of chosen operational quantities were designated. Furthermore, the determined motors were carried out to vibration and acoustic noise analysis. Superposed acoustic disturbances in terms of sound power level for different harmonic frequencies were obtained and results are given in comparison. All-in-all, this paper contributes to associating the end-to-end disturbing effects to certain rotor slot shapes. This study determines disturbance and performance criterions for choosing an appropriate motor for an IM to be used in an electric vehicle. It was shown that rotor slot shape still deserves considerable attention to increase the performance of an IM while decreasing the adverse effects of space harmonics, mechanical vibration and acoustic disturbance.
Highlights
Environmental pollution, global warming, depletion of fossil fuels and energy efficiency have increased interest in electric vehicles because of their low fuel consumption and low cost, quiet operation and low maintenance costs
The main types of electrical machines used in electric vehicles are direct current motor (DC), caged rotor induction motor (CRIM), permanent magnet synchronous motor (PMSM), switched reluctance motor (SRM) and synchronous reluctance (SynRM) motor
Cons and pros of these motors according to some operational criteria are shown in the Table 1 and it can be seen that CRIM serves low cost, simplicity and robustness, high efficiency, low vibration/noise with high performance compared to other motors [2], [3]
Summary
Environmental pollution, global warming, depletion of fossil fuels and energy efficiency have increased interest in electric vehicles because of their low fuel consumption and low cost, quiet operation and low maintenance costs. Electromagnetic noise is associated with space and time harmonics, magnetic saturation, phase unbalance and reluctance change according to stator and rotor slot openings and geometry [21]. The vibrating stator contacts the air and causes noise to spread from the stator surface which can be calculated analytically [22]–[25], [38] These studies include optimisation of main dimensions, presentation of designs for different numbers of rotor types, evaluation of operational quantities for determining the electromagnetic noise without classification. Different CRIMs were analyzed in terms of both electromagnetic and mechanical operational performance, space harmonic and adverse magnetic noise effects to serve a better performance to an electric vehicle. Results including torque-speed curves, air-gap flux density distribution, harmonic spectrum, torque ripple, mechanical stress and acoustic noise are given in comparison
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call