Analysing the power transformer temperature limitation for avoidance of bubble formation

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

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Power Transformer Condition Monitoring and Diagnosis

10.1049/pbpo104e ◽

2018 ◽

Keyword(s):

Condition Monitoring ◽

Power Transformer ◽

Monitoring And Diagnosis

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Effect of No-load and Load Condition on Transformer Sound

International Journal of Scientific Research in Science Engineering and Technology ◽

10.32628/ijsrset184113 ◽

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.

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