Login | Register

Rectifier Transformers: Thermal Modeling and a Predictive Maintenance Application Using Estimated Hotspot Winding Temperatures

Title:

Rectifier Transformers: Thermal Modeling and a Predictive Maintenance Application Using Estimated Hotspot Winding Temperatures

Oranugo, Tochukwu Louis (2014) Rectifier Transformers: Thermal Modeling and a Predictive Maintenance Application Using Estimated Hotspot Winding Temperatures. Masters thesis, Concordia University.

[img]
Preview
Text (application/pdf)
Tochukwu_Final_Edited_Thesis.pdf - Accepted Version
2MB

Abstract

Predictive maintenance of rectifier transformers in the aluminum smelting industry has become a major area of interest in planning for a replacement or refurbishment of these assets before a failure event occurs. The end of life of a transformer is linked to the rate of degradation of the winding paper insulation which is mainly due to heating processes. Rectifier transformers are subject to high thermal stress due to harmonic currents flowing through them. The need of monitoring and regulation of the hotspot temperature on the rectifier transformer winding is of great importance to keep the temperatures within safe limits as to preserve its life span. In this thesis, existing thermal models; the IEC model, the improved IEEE model, the G. Swift model and the D. Susa model used for hotspot temperature estimation in regulating power transformers has been adapted to account for increased heating due to harmonic currents flowing in the rectifier transformers. Extrapolation techniques, nonlinear least square optimization and genetic algorithm optimization are used for obtaining the rectifier transformer thermal model parameters using online measurements. The thermal model parameters are obtained in two different cooling fan operation conditions; OFAF mode 1 (one fan operation) and OFAF mode 2 (three fans operation) as the transformers under case study are utilized in these cooling modes. A predictive maintenance technique is implemented using typical loading profiles of the transformers and forecasted ambient temperatures to estimate and regulate future hotspot temperatures within safe temperature limits as derived using an industry accepted end of life equation.

Divisions:Concordia University > Gina Cody School of Engineering and Computer Science > Electrical and Computer Engineering
Item Type:Thesis (Masters)
Authors:Oranugo, Tochukwu Louis
Institution:Concordia University
Degree Name:M.A. Sc.
Program:Electrical and Computer Engineering
Date:4 November 2014
Thesis Supervisor(s):Lopes, Luiz. A
ID Code:979170
Deposited By: TOCHUKWU LOUIS ORANUGO
Deposited On:09 Jul 2015 19:03
Last Modified:18 Jan 2018 17:48
All items in Spectrum are protected by copyright, with all rights reserved. The use of items is governed by Spectrum's terms of access.

Repository Staff Only: item control page

Downloads per month over past year

Back to top Back to top