Thermographic method for measuring insulation fault and loss density on laminated cores

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Sähkötekniikan korkeakoulu | Master's thesis
Ask about the availability of the thesis by sending email to the Aalto University Learning Centre oppimiskeskus@aalto.fi

Authors

Date

2017-03-13

Department

Major/Subject

Electrical Power and Energy Engineering

Mcode

ELEC3024

Degree programme

AEE - Master’s Programme in Automation and Electrical Engineering (TS2013)

Language

en

Pages

42 + 7

Series

Abstract

In this thesis work, a measurement system was developed for detecting insulation fault and loss density estimation in laminated electrical steel sheet, based on the principles of thermography. Comsol simulation of the measurement process was carried out to show the effect of temperature plot region on the accuracy of loss density estimation. The application of the measuring system was demonstrated in two cases; firstly, insulation fault caused by burr contacts created on the cutting edges of laminated steel sheet was measured. DC current was supplied to 10 stacked pieces of laminated steel sheets compressed with a force of 2500 N for 5 seconds. IR camera was used to capture the surface of the sample and the images obtined was visibly analyzed. The temperature rise curves were compared with the simulation results. In the second experiment, a 24/12 V 50 Hz transformer was supplied at 300 Hz under no-load condition for 30 seconds. IR camera was use to obtain the images of the core at the instant of supply for three different flux densities. The core losses where estimated from the gradient of temperature rise and compared with the no-load power loss obtained directly from the power analyser. The results show that the developed system can accurately detect insulation fault and estimate loss density over a wide range, with error margin of less than 6%. However, the accuracy of the results obtained is affected by measurement condition.

Description

Supervisor

Arkkio, Antero

Thesis advisor

Shah, Sahas Bikram

Keywords

fault detection, insulation, IR camera, loss density, thermography

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Citation

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https://urn.fi/URN:NBN:fi:aalto-201704133573

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[dipl] Sähkötekniikan korkeakoulu / ELEC