Discussion on “Effects of rotor eccentricity on acoustic noise from induction machines” and “Natural frequencies of stators of small electric machines”

1971 ◽  
Vol 118 (7) ◽  
pp. 899
Keyword(s):  
Natural Frequencies ◽  
Acoustic Noise ◽  
Induction Machines ◽  
Electric Machines ◽  
Rotor Eccentricity

Dependency of Machine Efficiency on the Thermal Behavior of Induction Machines

Machines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Svenja Kalt ◽  
Karl Ludwig Stolle ◽  
Philipp Neuhaus ◽  
Thomas Herrmann ◽  
Alexander Koch ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Electric Vehicles ◽  
Thermal Load ◽  
Load Capacity ◽  
Maximum Load ◽  
Induction Machines ◽  
Electric Machines ◽  
Model Parameters ◽  
Dynamic Operating ◽  
The Impact

The consideration of the thermal behavior of electric machines is becoming increasingly important in the machine design for electric vehicles due to the adaptation to more dynamic operating points compared to stationary applications. Whereas, the dependency of machine efficiency on thermal behavior is caused due to the impact of temperature on the resulting loss types. This leads to a shift of efficiency areas in the efficiency diagram of electric machines and has a significant impact on the maximum load capability and an impact on the cycle efficiency during operation, resulting in a reduction in the overall range of the electric vehicle. Therefore, this article aims at analyzing the thermal load limits of induction machines in regard to actual operation using measured driving data of battery electric vehicles. For this, a thermal model is implemented using MATLAB® and investigations to the sensitivity of model parameters as well as analysis of the continuous load capacity, thermal load and efficiency in driving cycles under changing boundary conditions are conducted.

Effects of Actuators and Sensors Position on Independent Modal Control Performance

2012 ◽  
Author(s):  
Simone Cinquemani ◽  
Ferruccio Resta
Keyword(s):  
Natural Frequencies ◽  
Acoustic Noise ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Spillover Effects ◽  
Point Of View ◽  
Control Technique ◽  
Modal Control ◽  
Sensors And Actuators ◽  
Active Vibration

Independent modal control technique allows to change the eigenvalues of a system, without changing its eigenvectors. From a mechanical point of view, it means it is possible to modify the natural frequencies and the damping of a n-DoF system, letting modal shapes unchanged. Independent modal control can be profitably used in active vibration control increasing the damping of the system without changing its natural frequencies and vibration modes. A control of this type can improve the dynamic performance, reduce the vibratory phenomenon (and the resulting acoustic noise) and increase the fatigue strength of the system. This work demonstrates how the performance of the control depends on the number and position of sensors and actuators used besides, obviously, on the reduced model used to synthesize the control itself. Finally the paper suggests a simple optimum function to minimize the spillover effects due to unmodeled modes. Theoretical aspects are supported by numerical simulations.

scholarly journals Electric Machine Design Tool for Permanent Magnet Synchronous Machines and Induction Machines

Machines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 15 ◽  
Author(s):  
Svenja Kalt ◽  
Jonathan Erhard ◽  
Markus Lienkamp
Keyword(s):  
Fossil Fuels ◽  
Induction Machines ◽  
Electric Machines ◽  
Electric Machine ◽  
Design Tool ◽  
Pollutant Emissions ◽  
Machine Design ◽  
Permanent Magnet Synchronous Machines ◽  
Promising Solution ◽  
Electric Machine Design

The rising mobility demand of today’s society leads to an increasing strain of noise and pollutant emissions on people and the environment. An increasing environmental awareness and the scarcity of fossil fuels are increasingly placing alternative-powered vehicles in the focus of politics, research and development. Electric vehicles represent a promising solution to this problem. The electric machine represents a design control lever for the optimization of the electric powertrain with regard to efficiency, power, weight and size. Therefore, accurate and realistic machine design tools for the design of electric machines are becoming increasingly important. In this paper, the authors present an electric machine design tool for electric machines using MATLAB® in order to enable an automated machine design. The electric machine design tool is published under an LGPL open source license.

Noise reduction of an induction motor for a forklift

2009 ◽  
Vol 223 (6) ◽  
pp. 1311-1317
Author(s):  
W Kim ◽  
H Im ◽  
J Chung
Keyword(s):  
Induction Motor ◽  
Electromagnetic Force ◽  
Natural Frequencies ◽  
Acoustic Noise ◽  
Excitation Frequency ◽  
Design Guidelines ◽  
Electromagnetic Excitation ◽  
Noise Sources ◽  
Magnetomotive Force ◽  
Noise And Vibration

This article presents the reduction of acoustic noise generated by electromagnetic forces in an induction motor. After summarizing the electromagnetic excitation forces due to the interaction between the stator—rotor slot permeance and the stator winding magnetomotive force, the effects of electromagnetic force on the noise and vibration of an induction motor are analysed. To identify experimentally the noise sources of the motor, the signal analyses for noise and vibration are performed by using waterfall plots of noise and vibration spectra. It is found that severe noise and vibration are caused by the electromagnetic force when the mode number of the excitation shape for a stator is low. Furthermore, it is verified that the motor noise is amplified if the excitation frequency of the electromagnetic force coincides with one of the natural frequencies of the stator. It is experimentally demonstrated that this severe noise can be considerably reduced by structure modifications. Finally, some design guidelines are suggested to develop an induction motor with a low level of noise.

Vibration and Modal Analysis of Induction Motor

2012 ◽  
Vol 226-228 ◽  
pp. 92-97 ◽  
Author(s):  
Rui Li ◽  
Qi Fen Jia ◽  
Shun Zhong
Keyword(s):  
Induction Motor ◽  
Natural Frequencies ◽  
Vibration Mode ◽  
Acoustic Noise ◽  
Mode Shapes ◽  
Electrical Machine ◽  
3D Finite Element ◽  
Motor Mode ◽  
Element Technique ◽  
Motor Vibration

Calculation of the induction motor machine modal frequencies of an electrical machine accurately is the base of reducing acoustic noise and vibration. This paper presents a detailed research on the induction motor mode shapes and natural frequencies of induction motor by using 3D finite element technique, based on simplified modal, The influence of and mounting feet and rotor on mode shapes and natural frequencies are investigated systematically. Mounting feet and rotor have a great effect on natural frequencies, the mounting feet and rotor will result in the number of the motor low-vibration mode increases\the frequencies rise obviously, the mounting feet result in motor vibration mode becomes more complicated, rotor modals become an important part of motor mode shapes, the number of the motor low-vibration mode increases. Predictions are validated against experimental results.

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