EVALUATION OF AN EFFICIENCENT TRANSFORMER CORE DESIGN HEXATRANSFORMER

EVALUATION OF AN EFFICIENCENT TRANSFORMER
CORE DESIGN
Poonam Lutchman
A Dissertation submitted to the Faculty of Engineering and the Built
Environment, University of the Witwatersrand, in fulfilment of the requirements
of the degree of Master of Science in Engineering.

The hexa-transformer is a three-phase transformer with a symmetrical core. The
transformer core consists of nine rolls of laminated steel bands, with the core legs
having a cross sectional shape of a hexagon.
 Abstract

Distribution transformers have inherently high efficiencies of up to 99%, however they are in continuous operation and have a long lifespan, hence their power loss cost is still significant. A small efficiency improvement can lead to a considerable amount of energy savings over the lifetime of the transformer. Symmetric core design has the potential to improve transformer efficiency. The aim of this dissertation is to evaluate a relatively new symmetrical triangular core transformer for use in the Eskom Distribution network in South Africa. The transformer is called the hexa-transformer. A three phase 100 kVA hexa-transformer unit has been purchased from Hexaformer AB in Sweden. The unit has been routinely tested. A 50% no-load loss reduction has been achieved. The transformer was also opened and examined. The results indicated sound manufacturing quality. The economic analysis indicated a life cycle saving of R 2 727.41 per transformer over a 25 year period when compared to a conventional E-core transformer of the same rating. It is recommended that Eskom consider these units for future implementation in their Distribution network. LINKS THESIS
LINK1
http://wiredspace.wits.ac.za/handle/10539/12390
LINK2
http://www.mediafire.com/view/xw4x00cs9qyot73/Evaluation_of_an_efficient_transformer_core_design.pdf

Projecto e construção de um transformador de potência supercondutor

Paulo Rogério Santos Figueira Licenciado em Ciências da Engenharia Electrotécnica e de Computadores
Projecto e construção de um transformador de potência supercondutor
 Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores
 Paulo Rogério Santos Figueira, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa.

Resumo
 Os transformadores de potência baseados em supercondutores de alta temperatura têm revelado potencial para diversas aplicações práticas, proporcionando benefícios aos níveis económico, ambiental e operacional. Na presente dissertação, dois protótipos de transformadores monofásicos de 650 VA foram dimensionados, desenvolvidos, ensaiados e caracterizados: um convencional, com enrolamentos de cobre, e outro com o mesmo enrolamento de cobre no primário mas com o secundário composto por fita supercondutora de alta temperatura. Os dois protótipos foram comparados em relação às propriedades magnéticas, perdas, parâmetros eléctricos e rendimento, apresentando e interpretando os resultados obtidos. Foram ainda efectuadas medições para determinar a corrente crítica em AC da fita supercondutora. Os resultados foram comparados com os da corrente crítica obtida em DC para a mesma fita.
LINK
http://run.unl.pt/bitstream/10362/10258/1/Figueira_2013.pdf

Efficient Integration of Distributed Generation in Electricity Distribution Networks Voltage Control and Network Design

Efficient Integration of Distributed Generation in Electricity Distribution Networks Voltage Control and Network Design
 Ingmar Leiße
Doctoral Dissertation Department of Measurement Technology and Industrial Electrical Engineering Department of Measurement Technology and Industrial Electrical Engineering Faculty of Engineering Lund University
LINK1
https://www.iea.lth.se/publications/Theses/LTH-IEA-1071.pdf
LINK2
https://www.mediafire.com/?olt2jw4icwbdu68

A study of life time management of Power Transformers at E. ON’s Öresundsverket, Malmö Chaitanya Upadhyay

A study of life time management of Power Transformers at
E. ON’s Öresundsverket, Malmö
Chaitanya Upadhyay
June 2011
Supervisors:
Jonas Stenlund, E.ON Värmekraft
Olof Samuelsson, LTH
Examiner:
Gunnar Lindstedt, LTH

Division of Industrial Engineering and Automation at Faculty of Engineering at Lund University,Sweden.
FULL THESIS
https://www.mediafire.com/?c0ryimc8fn8zymc

ALL NEWS DELLS OptiPlex™ desktops and Precision™ workstations REQUIRE PURE SINE WAVE UPS's?

DELL™ OPTIPLEX™ 390 TECHNICAL GUIDEBOOK —FINAL
POWER
NOTE: These form factors utilize a more efficient Active Power Factor Correction (APFC) power supply. Dell recommends only Universal Power
Supplies (UPS) based on Sine Wave output for APFC PSUs, not an approximation of a Sine Wave, Square Wave, or quasi-Square Wave. If you
have questions, please contact the manufacture to confirm the output type.
Power Protection & Back-up

 In the case of a power outage, be prepared with an Uninterruptible Power Supply (UPS) that can provide business continuity to prevent critical data loss. For Dell OptiPlex™ desktops and Precision™ workstations that utilize Active Power Factor Correction (APFC) power supply units, Dell recommends Universal Power Supplies (UPS) based on Sine Wave output, not an approximation of a Sine Wave, Square wave, or quasi-square wave (see UPS technical specifications).
http://www.manualslib.com/manual/471510/Dell-Optiplex-390.html?page=8#manual