An experimental study of winding vibration of a single-phase power transformer using a laser Doppler vibrometer

2015 ◽  
Vol 87 ◽  
pp. 30-37 ◽  
Author(s):  
Jing Zheng ◽  
Jie Pan ◽  
Hai Huang
Keyword(s):  
Experimental Study ◽  
Single Phase ◽  
Power Transformer ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler

Harmonics Performances of Single Phase Transformer due to DC Bias

2015 ◽  
Vol 793 ◽  
pp. 202-205 ◽  
Author(s):  
Syafruddin Hasan ◽  
Muzammir Isa ◽  
M.A. Roslan ◽  
M. Hafizi ◽  
D. Musdar ◽  
...  
Keyword(s):  
Experimental Study ◽  
Single Phase ◽  
Power Transformer ◽  
Bias Current ◽  
Half Cycle ◽  
Bias Effect ◽  
Ac Power ◽  
Dc Bias ◽  
Magnetizing Current ◽  
Even Harmonics

The investigation of the direct current (dc) bias effect on single phase power transformer through their harmonics performance is present in this paper. The experimental study is done by the dc bias current injected simultaneously with alternating current (ac) source to primary winding of transformer. The input ac voltage to primary winding is maintained constant during investigation and the dc currents increased gradually. Compare to pure ac power applied, the results show that the waveforms distorted when the dc bias exist. The pulsated waveforms are pushed to half cycle in which the bias current is in the same direction as magnetizing current (unsymmetrical pulsated) and even harmonics are significant.

Effect of No-load and Load Condition on Transformer Sound

2018 ◽  
pp. 11-15
Author(s):  
Dr. Hitesh Paghadar
Keyword(s):  
Experimental Study ◽  
Power Transformer ◽  
Load Condition ◽  
Noise Pollution ◽  
Sound Level ◽  
Measurement Scale ◽  
Dominant Factor ◽  
Public Attention ◽  
Level Measurement ◽  
Human Ear

Increasing environment noise pollution is a matter of great concern and of late has been attracting public attention. Sound produces the minute oscillatory changes in air pressure and is audible to the human ear when in the frequency range of 20Hz to 20 kHz. The chief sources of audible sound are the magnetic circuit of transformer which produces sound due to magnetostriction phenomenon, vibration of windings, tank and other structural parts, and the noise produced by cooling equipments. This paper presents the validation for sound level measurement scale, why A-weighted scale is accepted for sound level measurement, experimental study carried out on 10MVA Power Transformer. Also presents the outcomes of comparison between No-Load sound & Load sound level measurement, experimental study carried out on different transformer like - 10MVA, 50MVA, 100MVA Power Transformer, to define the dominant factor of transformer sound generation.

Experimental and Numerical Study of Methanol-Water Mixture Single-Phase Heat Transfer in a Micro-Channel Heat Sink

2012 ◽  
Author(s):  
Chun K. Kwok ◽  
Matthew M. Asada ◽  
Jonathan R. Mita ◽  
Weilin Qu
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Sink ◽  
Single Phase ◽  
Numerical Study ◽  
Pure Water ◽  
Molar Fraction ◽  
Water Mixture ◽  
Micro Channel ◽  
Numerical Predictions

This paper presents an experimental study of single-phase heat transfer characteristics of binary methanol-water mixtures in a micro-channel heat sink containing an array of 22 microchannels with 240μm × 630μm cross-section. Pure water, pure methanol, and five methanol-water mixtures with methanol molar fraction of 16%, 36%, 50%, 63% and 82% were tested. Key parametric trends were identified and discussed. The experimental study was complemented by a three-dimensional numerical simulation. Numerical predictions and experimental data are in good agreement with a mean absolute error (MAE) of 0.87%.

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