High Temperature Superconducting Partial Core Transformers (2012)

Type of Content
Theses / DissertationsThesis Discipline
Electrical EngineeringDegree Name
Doctor of PhilosophyPublisher
University of Canterbury. Electrical and Computer EngineeringCollections
Abstract
The thesis begins by providing an introduction to transformer theory. An ideal transformer is examined first, followed by full core transformer theory. The partial core transformer is then introduced and compared to the full core design. An introduction to superconductors is then presented where a simplified theory of superconductivity is given. High temperature superconductors are then examined including their physical structure, superconducting properties and the design of the superconducting wire.
The early development of high temperature superconducting partial core transformers at the University of Canterbury is then examined. Early partial core development is discussed followed by some material testing at cryogenic temperatures. This work lead into the development of the first high temperature superconducting partial core transformer. This transformer failed during testing and an examination of the failure mechanisms is presented. The results of the failure investigation prompted an alternative winding insulation design which was implemented in a full core superconducting transformer.
The modelling used to design a high temperature superconducting partial core transformer is then presented. Based upon the reverse design method, the modelling is used to determine the components of the Steinmetz equivalent transformer circuit. The modelling includes a combination of circuit theory and finite element analysis. An ac loss model for high temperature superconductors is also presented.
A new 15 kVA, 230-230V high temperature superconducting partial core transformer was designed, built and tested. The windings are layer wound with first generation Bi2223 high temperature superconductor. The modelling was used to predict the performance of the transformer as well as the ac losses of the high temperature superconductor. A series of electrical tests were performed on the transformer including open circuit, short circuit, resistive load, overload, ac withstand voltage and fault ride through tests. The test results are compared with the model. The transformer was found to be 98.2% efficient at rated power with 2.86% voltage regulation.
Keywords
Transformers; High Temperature Superconductors; Partial Core; Transformer Modelling; Transformer TestingRights
Copyright Andrew Craig LapthornRelated items
Showing items related by title, author, creator and subject.
-
An Experimental High Temperature Superconducting Transformer: Design, Construction and Testing
Lapthorn, A.; Chew, I.; Bodger, P.; Enright, W. (University of Canterbury. Electrical and Computer Engineering, 2010)In 2005, the development of a 50Hz, 15kVA, 30V:115V partial core high temperature superconductor (HTS) transformer was completed. The transformer was designed purely as a proof of concept, rather than as a unit that would ... -
High Temperature Superconducting Partial Core Transformer and Fault Current Limiter
Sham,Jit Kumar (University of Canterbury. ELECTRICAL AND COMPUTER ENGINEERING, 2015)The thesis begins with an introduction to transformer theory. The partial core transformer is then introduced and compared with a full core design. A brief introduction to superconductors and high temperature superconductors ... -
A low-voltage, mains frequency, partial core, high temperature, superconducting transformer
Bodger, P.S.; Enright, W.; Ho, V. (University of Canterbury. Electrical and Computer Engineering., 2005)A high temperature super-conducting transformer (HTST) has been built. It has been designed to operate in liquid nitrogen, an environmentally benign element that represents little fire and personnel safety risk. The ...