Assessing DP value of a power transformer considering thermal ageing and paper moisture

2018 ◽  
pp. 125-142
Author(s):  
Ricardo David Medina Velecela ◽  
Andres Arturo Romero Quete ◽  
Enrique Esteban Mombello ◽  
Giuseppe Ratta ◽  
Diego Xavier Morales Jadan
Keyword(s):  
Power Transformer ◽  
Thermal Ageing

Analysis on the Micro Surface Morphology of Aged Oil-Paper Used in Power Transformer

2013 ◽  
Vol 860-863 ◽  
pp. 894-898
Author(s):  
Chao Tang ◽  
Sheng Li Dai ◽  
Jiao Li
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Power Transformer ◽  
Roughness Parameter ◽  
Fiber Surface ◽  
Thermal Ageing ◽  
Molecular Arrangement ◽  
Atomic Force ◽  
Roughness Analysis ◽  
Mesh Structures

In order to analyze the ageing mechanism of oil-paper, the Atomic Force Microscope (AFM), which is one of the important instruments in nanometer area, was used in this paper for the analysis of the micro surface morphology, and a 3-D surface roughness analysis on the AFM image was presented. The AFM figures indicates that the molecular arrangement of the initial cellulose paper is close and ordered, some of the hexagonal mesh structures of the D-glucopyranose units were broken down after 100 days accelerated thermal ageing. The roughness analysis indicates that he fiber surface roughness parameter Sa increases with the deepening of ageing degree. Special attention should be paid on the increase in the surface roughness of insulation paper, as it will aggravate the oil streaming electrification when the paper is applied to the power transformers.

Influence of electrical and thermal ageing on the mineral insulating oil performance for power transformer applications

2020 ◽  
Vol 62 (4) ◽  
pp. 222-231
Author(s):  
C Ranga ◽  
A Kumar ◽  
R Chandel
Keyword(s):  
Power Transformer ◽  
Stress Test ◽  
Oxidation Stability ◽  
Chemical Properties ◽  
Mineral Oil ◽  
Thermal Ageing ◽  
Test Cell ◽  
Transformer Oil ◽  
Power Transformers ◽  
Solid Dielectrics

In the present work, a new electrothermal combined stress test cell has been designed and fabricated to conduct accelerated electrothermal ageing. The fabricated test cell includes all possible real working conditions of the transformers. The effects of accelerated electrothermal ageing on the performance of power transformers with thermally upgraded Kraft (TUK), Nomex-910 and Nomex-410 solid dielectrics in conjunction with mineral oil have been investigated. The accelerated electrothermal ageing has been performed for a temperature range of 100°C to 220°C, along with 10 kV electrical stress. Subsequently, several electrical, thermal, mechanical and chemical properties of transformer oil and different paper dielectrics have been determined. It has been observed from the diagnostic test results that Nomex impregnated mineral oil samples have better electrothermal performance as well as oxidation stability when compared to the thermally upgraded Kraft oil samples. Therefore, Nomex insulating materials in conjunction with mineral oil are suggested as alternative solid dielectrics for power transformers in order to achieve better oxidation stability, improved thermal performance for long service runs and reduced operating and maintenance costs. It is envisioned that the present experimental study will be very beneficial to utility managers and end-users of power transformers.

scholarly journals Experimental Investigation on Vegetative Oils under Accelerated Thermal Ageing against Their Dielectric Strength

2017 ◽  
Vol 7 (3) ◽  
pp. 1588
Author(s):  
Siti Sufiah Abd Wahid ◽  
Mohd Fikri Hilmi Mohd Taib ◽  
Yanuar Z. Arief ◽  
Mohd Hafizi Ahmad ◽  
Noor Azlinda Ahmad ◽  
...  
Keyword(s):  
Power Transformer ◽  
Research Work ◽  
Dielectric Strength ◽  
Mineral Oil ◽  
Thermal Ageing ◽  
Transformer Oil ◽  
Accelerated Ageing ◽  
Insulation Material ◽  
Low Dielectric ◽  
High Dielectric

Insulation is one of the most important parts in high voltage apparatus such as power transformer. Most power transformer use liquid insulation material, known as power transformer oil. Petroleum-based oil so called mineral oil has been used for many years as power transformer oil. This is due to its high dielectric field strength, low dielectric loses and good long-term performance. This research work has been carried out to investigate the effect of thermal accelerated ageing on electrical properties for several vegetative-based oils. The oil samples that have been used in this research work are soy bean-based oil (FR3) and commercial palm-based oil (PFAE). As comparison, Hyrax mineral oil has also been investigated. The results revealed that vegetative-based oils have as well as dielectric strength compared with mineral oil.  It was found that the dielectric strength for all oil samples decreased when undergo the thermal accelerated ageing process.

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.

Determination of parameters of short circuit of power transformer by means of mathematical modeling

2017 ◽  
Vol 26 (102) ◽  
pp. 110-119
Author(s):  
D. S. Yarymbash, ◽  
◽  
S. T. Yarymbash, ◽  
T. E. Divchuk, ◽  
D. A. Litvinov
Keyword(s):  
Mathematical Modeling ◽  
Power Transformer ◽  
Short Circuit ◽  
Determination Of Parameters
Sign in / Sign up

Export Citation Format

Share Document