Analytical estimation of short circuit axial and radial forces on power transformers windings

The main equipment responsible for connection and transmission of electric power from generating centers to consumers are power transformers. This type of equipment is subject to various types of faults that can affect its components, in some cases also compromising its operation and, consequently, the electric power supply. Thus, in this paper, electromagnetic, thermal, and structural analysis of power transformers was carried out with the objective of providing the operator with information on the ideal moment for performing predictive maintenance, avoiding unplanned shutdowns. For this, computational simulations were performed using the finite element method (FEM) and, from that, the different transformer operation ways, nominal currents, inrush current, and short-circuit current were analyzed. In this perspective, analyses of the effects that thermal expansion, axial forces, and radial forces exerted were carried out, contributing to possible defects in this type of equipment. As a study object, simulations were carried out on a 50 MVA single-phase transformer. It is important to emphasize that the simulations were validated with real data of measurements and with results presented in the current literature.

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Analytical Estimation of MMC Short-Circuit Currents in the AC In-feed Steady-State Stage

IEEE Transactions on Power Delivery ◽

10.1109/tpwrd.2021.3061739 ◽

2021 ◽

pp. 1-1

Author(s):

Meng Li ◽

Yiping Luo ◽

Jinghan He ◽

Yongjie Zhang ◽

A. P. Sakis Meliopoulos

Keyword(s):

Steady State ◽

Short Circuit ◽

Analytical Estimation ◽

Short Circuit Currents

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Magneto-Thermo-Structural Analysis of Power Transformers under Short Circuit Condition

10.1109/induscon51756.2021.9529721 ◽

2021 ◽

Author(s):

Antonio R. M. Sousa ◽

Wellington Da S. Fonseca ◽

Marcus V. A. Nunes ◽

Ramon C. F. Araujo ◽

Diorge de S. Lima

Keyword(s):

Structural Analysis ◽

Short Circuit ◽

Power Transformers ◽

Short Circuit Condition

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Impact of short-circuit impedance and tap changing method selection on the key-design parameters of core-form power transformers

Electrical Engineering ◽

10.1007/s00202-017-0642-z ◽

2017 ◽

Vol 100 (3) ◽

pp. 1631-1637 ◽

Cited By ~ 2

Author(s):

Tamás Orosz ◽

Zoltán Ádám Tamus

Keyword(s):

Short Circuit ◽

Power Transformers ◽

Design Parameters ◽

Method Selection ◽

Circuit Impedance

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Localising low‐level short‐circuit faults on the windings of power transformers based on low‐frequency response measurement of the transformer windings

IET Electric Power Applications ◽

10.1049/iet-epa.2014.0182 ◽

2015 ◽

Vol 9 (8) ◽

pp. 533-539 ◽

Cited By ~ 9

Author(s):

Mojtaba Mahvi ◽

Vahid Behjat

Keyword(s):

Frequency Response ◽

Short Circuit ◽

Low Frequency ◽

Power Transformers ◽

Response Measurement ◽

Low Level ◽

Frequency Response Measurement

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Advanced On-line Condition Monitoring of, and Inter-turn Short Circuit Detection in, Power Transformers

2018 53rd International Universities Power Engineering Conference (UPEC) ◽

10.1109/upec.2018.8542095 ◽

2018 ◽

Author(s):

Ehnaish Aburaghiega ◽

Mohamed Emad Farrag ◽

D.M. Hepburn ◽

Belen Garcia

Keyword(s):

Condition Monitoring ◽

Short Circuit ◽

Power Transformers ◽

On Line ◽

Line Condition

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On Simplified Calculations of Leakage Inductances of Power Transformers

Energies ◽

10.3390/en13184952 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4952 ◽

Cited By ~ 1

Author(s):

Tadeusz Sobczyk ◽

Marcin Jaraczewski

Keyword(s):

Power Transformer ◽

Short Circuit ◽

Power Transformers ◽

Stray Field ◽

Good Representation ◽

The Finite Element Method ◽

Leakage Inductance ◽

Leakage Flux ◽

Calculation Results ◽

Discrete Differential Operator

This paper deals with the problem of the leakage inductance calculations in power transformers. Commonly, the leakage flux in the air zone is represented by short-circuit inductance, which determines the short-circuit voltage, which is a very important factor for power transformers. That inductance is a good representation of the typical power transformer windings, but it is insufficient for multi-winding ones. This paper presents simple formulae for self- and mutual leakage inductance calculations for an arbitrary pair of windings. It follows from a simple 1D approach to analyzing the stray field using a discrete differential operator, and it was verified by the finite element method (FEM) calculation results.

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Leakage Inductances of Transformers at Arbitrarily Located Windings

Energies ◽

10.3390/en13236464 ◽

2020 ◽

Vol 13 (23) ◽

pp. 6464

Author(s):

Marcin Jaraczewski ◽

Tadeusz Sobczyk

Keyword(s):

Differential Operators ◽

Short Circuit ◽

The Self ◽

Power Transformers ◽

Stray Field ◽

The Finite Element Method ◽

Leakage Inductance ◽

Leakage Flux ◽

Partial Differential Operators ◽

Internal Asymmetry

The article presents the calculation of the leakage inductance in power transformers. As a rule, the leakage flux in the transformer window is represented by the short-circuit inductance, which affects the short-circuit voltage, and this is a very important factor for power transformers. This inductance reflects the typical windings of power transformers well, but is insufficient for special transformers or in any case of the internal asymmetry of windings. This paper presents a methodology for calculations of the self- and mutual-leakage inductances for windings arbitrarily located in the air window. It is based on the 2D approach for analyzing the stray field in the air zone only, using discrete partial differential operators. That methodology is verified with the finite element method tested on real transformer data.

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