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

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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Numerical Analysis on Short-Circuit Force Parameters of Windings for Power Transformer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.138-139.764 ◽

2011 ◽

Vol 138-139 ◽

pp. 764-769

Author(s):

Jian Jun Liu ◽

Jian Min Wang ◽

Chong You Jing ◽

Chang Zai Fan ◽

Yuan Zhai

Keyword(s):

Magnetic Field ◽

Numerical Analysis ◽

Power Transformer ◽

Short Circuit ◽

Strength Test ◽

Power Transformers ◽

Simplified Model ◽

Leakage Magnetic Field ◽

Set Up ◽

Short Circuit Condition

The Simplified model of both calculating leakage magnetic field and mechanical force of windings at short circuit condition for a 120MVA/220kV power transformer is set up. The leakage magnetic field ‚ short-circuit force and stress in transformer windings are analyzed and their distributing characteristics are acquired respectively by using FEM. The calculation method and results are validated by withstanding short circuit strength test of the product. A number of useful suggestions are given for design of power transformers.

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Fault Localization of Power-Ground Short via Signal Injection and Oscilloscope Technique

ISTFA 2010: Conference Proceedings from the 36th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2010p0202 ◽

2010 ◽

Author(s):

Binh Nguyen

Keyword(s):

Low Cost ◽

Short Circuit ◽

Fault Localization ◽

Fault Isolation ◽

Test Apparatus ◽

Good Working ◽

Signal Injection ◽

Set Up ◽

Non Destructive ◽

Short Circuit Condition

Abstract For those attempting fault isolation on computer motherboard power-ground short issues, the optimal technique should utilize existing test equipment available in the debug facility, requiring no specialty equipment as well as needing a minimum of training to use effectively. The test apparatus should be both easy to set up and easy to use. This article describes the signal injection and oscilloscope technique which meets the above requirements. The signal injection and oscilloscope technique is based on the application of Ohm's law in a short-circuit condition. Two experiments were conducted to prove the effectiveness of these techniques. Both experiments simulate a short-circuit condition on the VCC3 power rail of a good working PC motherboard and then apply the signal injection and oscilloscope technique to localize the short. The technique described is a simple, low cost and non-destructive method that helps to find the location of the power-ground short quickly and effectively.

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

IET Generation Transmission & Distribution ◽

10.1049/iet-gtd.2013.0268 ◽

2014 ◽

Vol 8 (2) ◽

pp. 250-260 ◽

Cited By ~ 16

Author(s):

Bashir Mahdi Ebrahimi ◽

Saeed Saffari ◽

Jawad Faiz ◽

Alireza Fereidunian

Keyword(s):

Short Circuit ◽

Power Transformers ◽

Analytical Estimation ◽

Radial Forces

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Short-Circuit Capability Exploration of Silicon Carbide Devices

Materials Science Forum ◽

10.4028/www.scientific.net/msf.821-823.810 ◽

2015 ◽

Vol 821-823 ◽

pp. 810-813 ◽

Cited By ~ 3

Author(s):

Maxime Berthou ◽

Dominique Planson ◽

Dominique Tournier

Keyword(s):

Silicon Carbide ◽

Short Circuit ◽

Electronic Systems ◽

Power Electronic ◽

Power Transistor ◽

Power Transistors ◽

Capacitive Load ◽

Short Circuit Condition

With the commercial availability of SiC power transistors, this decade will mark an important breakthrough in power transistor technology. However, in power electronic systems, disturbances may place them in short-circuit condition and little knowledge exist about their SC capability. This paper presents our study of SiC MOSFETs, JFETs and BJT under capacitive load short-circuit up to 600V.

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