Performance improvement of V/f induction -motor control in the low-frequency range

2009 ◽  
Author(s):  
Wu Di ◽  
C.S. Chang ◽  
Y. Fang ◽  
H. Bai
Keyword(s):  
Motor Control ◽  
Induction Motor ◽  
Performance Improvement ◽  
Low Frequency ◽  
Frequency Range

scholarly journals Implementation of Close Loop Speed Control with VVVF Control and Slip Regulation on LIM

2014 ◽  
Vol 4 (2) ◽  
pp. 596-599
Author(s):  
K. Aditya ◽  
A. Newwel
Keyword(s):  
Induction Motor ◽  
Low Frequency ◽  
Speed Control ◽  
Conveyor Belt ◽  
Open Loop ◽  
Frequency Range ◽  
Test Rig ◽  
Output Torque

Open loop VVVF control has the disadvantage of low output torque when working at low frequency and poor speed precision at different load conditions.Various performance-improving schemes have been proposed for the basic VVVF control by compensating slips occurring in the low frequency range and slips caused by changing loads. Numerous papers have been published on the close loop speed control of rotary induction motor. In this paper a close loop speed control with VVVF control and slip regulation has been implemented for LIM based conveyor belt test Rig which compensates the disadvantages of traditional Volts/Hz control. SIMULINK results are presented to validate the effectiveness of proposed scheme.

scholarly journals Influence of Sugar Palm Ash Fraction and Resonator Configuration on Acoustic Absorption Performance of Expose Brick

2016 ◽  
Vol 4 (01) ◽  
pp. 19
Author(s):  
Zulfa Kamila R ◽  
Iwan Yahya ◽  
Utari U
Keyword(s):  
Performance Improvement ◽  
Performance Optimization ◽  
Sound Absorption ◽  
Low Frequency ◽  
Helmholtz Resonator ◽  
Raw Material ◽  
Frequency Range ◽  
Helmholtz Resonators ◽  
Resonator Structure ◽  
Absorption Performance

<span>Sound absorption performance optimization of expose brick has been conducted in associated with <span>the fraction of sugar palm ash in its raw material and configuration of Helmholtz resonators inside <span>the brick structure. The testing was conducted experimentally refer to ASTM E-1050-98 standard <span>procedure. In this case there are three variations sugar palm ash fractions of 0%, 5%, and 10%, as <span>well as two array resonator configurations. The results showed that the brick with fraction of 10% <span>sugar palm ash has the best sound absorption performance. As for the configuration of array <span>identical Helmholtz resonator giving better performance improvement at low frequency span than <span>complex resonator structure with coupled cavity where the best performance occur on(376-488) <span>Hz frequency range with the absorption coefficient α of 0.54.</span></span></span></span></span></span></span></span><br /></span>

Evaluation of Special Hearing Aids for Deaf Children

1971 ◽  
Vol 36 (4) ◽  
pp. 527-537 ◽  
Author(s):  
Norman P. Erber
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Hearing Aid ◽  
Low Frequency ◽  
Acoustic Stimulation ◽  
Deaf Children ◽  
Frequency Range ◽  
Frequency Limit ◽  
Unpublished Studies ◽  
Published Research

Two types of special hearing aid have been developed recently to improve the reception of speech by profoundly deaf children. In a different way, each special system provides greater low-frequency acoustic stimulation to deaf ears than does a conventional hearing aid. One of the devices extends the low-frequency limit of amplification; the other shifts high-frequency energy to a lower frequency range. In general, previous evaluations of these special hearing aids have obtained inconsistent or inconclusive results. This paper reviews most of the published research on the use of special hearing aids by deaf children, summarizes several unpublished studies, and suggests a set of guidelines for future evaluations of special and conventional amplification systems.

Dynamic Damping and Stiffness Characteristics of the Rolling Tire

2001 ◽  
Vol 29 (4) ◽  
pp. 258-268 ◽  
Author(s):  
G. Jianmin ◽  
R. Gall ◽  
W. Zuomin
Keyword(s):  
Dynamic Behavior ◽  
Variable Parameter ◽  
Low Frequency ◽  
Vertical Load ◽  
Frequency Range ◽  
Inflation Pressure ◽  
Vehicle Simulation ◽  
Dynamic Damping ◽  
Speed Range ◽  
Stiffness Characteristics

Abstract A variable parameter model to study dynamic tire responses is presented. A modified device to measure terrain roughness is used to measure dynamic damping and stiffness characteristics of rolling tires. The device was used to examine the dynamic behavior of a tire in the speed range from 0 to 10 km/h. The inflation pressure during the tests was adjusted to 160, 240, and 320 kPa. The vertical load was 5.2 kN. The results indicate that the damping and stiffness decrease with velocity. Regression formulas for the non-linear experimental damping and stiffness are obtained. These results can be used as input parameters for vehicle simulation to evaluate the vehicle's driving and comfort performance in the medium-low frequency range (0–100 Hz). This way it can be important for tire design and the forecasting of the dynamic behavior of tires.

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