On possibility of power transformer operational reliability increase

During the operation of transformers, the insulating oil is aging, therefore, there is the deterioration of its insulating properties, which is determined by multiple physico-chemical processes. The most dangerous factor, from the point of view of preserving the operational reliability and resource of a power transformer, is the moisture content of the insulation. Most methods for determining moisture content have measurement errors. These errors are largely dependent on impurities that are contained in the oil. The modified Fisher method proposed in the article allows determining the amount of impurities in the oil and the absolute moisture content. Conducted research allows also to determine the composition of impurities, to reveal the relationship between impurities and some parameters of transformer oil.

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CREATION OF A STRUCTURAL MODEL OF AN POWER TRANSFORMERS IN THE FORM OF AC TRANSFORMING COMPLEXES

Integration of traditional and innovative scientific researches: global trends and regional aspect ◽

10.30525/978-9934-26-001-8-2-13 ◽

2020 ◽

Author(s):

Dmytro Yarymbash ◽

◽

Mykhailo Kotsur ◽

Keyword(s):

Structural Model ◽

Power Transformer ◽

Geometric Model ◽

Operational Reliability ◽

Power Transformers ◽

Thermal Processes ◽

Design Data ◽

Production Program ◽

Specialized Software

Due to the multiple transformation of electrical energy, the rated capacity of power transformers can be 8 or more times the rated generation capacity. Therefore, the state of reliability of power transformers, their parameters and characteristics affecting on the reliability and efficiency of power networks, electrical production facilities, and electrical equipment of consumers. High indicators of operational reliability should be provided by the corresponding level of quality of design of power transformers both at a stage of development of tender offers, and during preparation of production of new or modernized types of power transformers. Im-proving approaches to design and increasing the accuracy of design data requires the use of modern specialized software for spatial modeling of electromagnetic and elec-tro-thermal processes in testing and rated modes of operation based on 3D geometric models of parts, assemblies, systems in the active parts of power transformers. To improve the design quality of power transformers, a unitary structure is proposed, which combines tuples of design data of certain types of power transformers. Crea-tion of a unitary structure of power transformer projects for the production program of the enterprise provides a significant time reduction to develop projects of new types of power transformers by importing the generated design data of the same parts, components, systems from previously developed power transformer projects. Application of unitary structure of power transformers projects allows to reduce time for creation and import of detailed 3D geometric model of power transformer in structure of specialized software of field modeling of electromagnetic and electro-thermal processes. This allows to significantly reduce the cost of design preparation of production, increase the accuracy of design data and implement design solutions to increase the level of reliability and efficiency of operation of power transformers. Therefore, the design data for the unavailable parts, components, elements of individual systems in a transformer are displayed in the corresponding design tuple "zero" elements. For development of projects of new types of power transformers, import of the structured design data of identical details, knots, systems of earlier developed projects of power transformers is carried out. Updating the unitary structure of power transformers is provided by supplementing the existing unitary structure with a tuple of design data of a new type of power transformer. This provides a significant reduction in design time and increase the accuracy of determining new design data.

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Study on the Online Detecting Technology for Partial Discharge of Power Equipment with Mechanical Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.644.51 ◽

2013 ◽

Vol 644 ◽

pp. 51-55 ◽

Cited By ~ 1

Author(s):

Guo Jin Chen ◽

Ming Xu ◽

Tin Tin Liu ◽

Jing Ni ◽

Dong Xie ◽

...

Keyword(s):

Optimization Design ◽

Power Transmission ◽

Power Transformer ◽

Partial Discharge ◽

Operational Reliability ◽

Case Based Reasoning ◽

Power Equipment ◽

Accurate Judgment ◽

Transmission Equipment ◽

Online Detecting

From the physical characteristics of the partial discharge, this paper analyzed the UHF signal’s characteristic parameters for the partial discharge of the power transmission equipment, used synthetically the detecting technology which combines the ultra high frequency (UHF) and the acoustic emission (AE), and established the online monitoring system for the partial discharge of the power equipment. On the premise ensuring the integrity of the partial discharge signal, the acquisition, amplification, analysis and storage of the partial discharge signal are implemented. The case-based reasoning technology determines the fault type and fault degree of the partial discharge to make the accurate judgment for the operational state of the equipment and improve the intelligence level and the operational reliability for the state diagnosis of the power equipment. The structural optimization design of the power transformer makes the no-load loss down by 50%, and the load loss down by 15%. That improves greatly the mechanical and electrical properties of the transformer.

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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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Influence of unbalanced magnetic force on shaft deflection in permanent magnet synchronous motor with fractional slot concentrated windings

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209466 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 1461-1468

Author(s):

Ting Dong ◽

Juyan Huang ◽

Bing Peng ◽

Ling Jian

Keyword(s):

Permanent Magnet ◽

Magnetic Force ◽

Permanent Magnet Synchronous Motor ◽

Operational Reliability ◽

Topology Structure ◽

Permanent Magnet Synchronous Motors ◽

Synchronous Motors ◽

Shaft Deflection ◽

Large Length ◽

Fractional Slot

The calculation accuracy of unbalanced magnetic forces (UMF) is very important to the design of rotor length, because it will effect the shaft deflection. But in some permanent magnet synchronous motors (PMSMs) with fractional slot concentrated windings (FSCW), the UMF caused by asymmetrical stator topology structure is not considered in the existing deflection calculation, which is very fatal for the operational reliability, especially for the PMSMs with the large length-diameter ratio, such as submersible PMSMs. Therefore, the part of UMF in the asymmetrical stator topology structure PMSMs caused by the choice of pole-slot combinations is analysized in this paper, and a more accurate rotor deflection calculation method is also proposed.

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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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