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An executive master's programme thesis from Aalborg University
Book cover


Multiwinding Medium Frequency Transformer for Application in Proposed EV Fast Charging Architecture Incorporating a 400 Hz Microgrid

Term

4. term

Publication year

2025

Submitted on

Pages

94

Abstract

Electric vehicles (EVs) have witnessed a tremendous growth in the recent years, driven by technological advancements and a global push towards sustainability. DC fast charging alongside has emerged as a promising charging architecture, reducing the charging times and making long distance travel more feasible, but faces issues of reliable protection and metering standards. Another prevalent problem is the different bus voltages of the EVs. This thesis focuses on solving these problems by proposing a DC fast charging architecture based on 400 Hz AC microgrid and multiwinding transformer. The main focus is the design of a 10 kVA multiwinding transformer tested on a dual output SAB converter. Various aspects of the design of the transformer like core material selection, conductor sizing, optimum operating flux density, and manufacturing of the transformer are discussed. The transformer is then tested with open circuit and short circuit tests and on the dual output SAB converter within certain limitations. The results, shortcomings, and possible solutions are highlighted. The thesis concludes as a starting platform for the implementation of the proposed architecture by discussing the faced challenges and extracted learnings.

Electric vehicles (EVs) have witnessed a tremendous growth in the recent years, driven by technological advancements and a global push towards sustainability. DC fast charging alongside has emerged as a promising charging architecture, reducing the charging times and making long distance travel more feasible, but faces issues of reliable protection and metering standards. Another prevalent problem is the different bus voltages of the EVs. This thesis focuses on solving these problems by proposing a DC fast charging architecture based on 400 Hz AC microgrid and multiwinding transformer. The main focus is the design of a 10 kVA multiwinding transformer tested on a dual output SAB converter. Various aspects of the design of the transformer like core material selection, conductor sizing, optimum operating flux density, and manufacturing of the transformer are discussed. The transformer is then tested with open circuit and short circuit tests and on the dual output SAB converter within certain limitations. The results, shortcomings, and possible solutions are highlighted. The thesis concludes as a starting platform for the implementation of the proposed architecture by discussing the faced challenges and extracted learnings.