Development of Power Transformer Remaining Life Model Using Multi-Parameters

Disk failures can be caused by a number of mechanisms under the turbine operating conditions of high rotational speed at elevated temperatures. It is not uncommon for highly stressed turbine blades and disks to operate at temperatures in excess of 1,000°F, where increased exposure can affect their life. In the past, it has been adequate to analyze the life of these high temperature components using methods which calculate creep life and low cycle fatigue life independently in predicting service hours. More often than not, the parameters included in the creep life model are based on empirical data. Here, a practical methodology is presented to predict the remaining life of a turbine disk that utilizes a combination of Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA) and a creep model. A full three-dimensional CFD analysis is performed on the turbine disks at design and off-design conditions, in order to accurately capture the thermal loads. A detailed FEA is performed on the turbine disk. The stress inputs for the creep life model are based on the stresses obtained from the FEA. A case study is presented that utilizes the proposed methodology. It is found that the methodology is beneficial for the remaining life analysis on highly loaded turbine disks. The accuracy of the methodology is somewhat dictated by the amount of historical operating data that is available.

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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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