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Project

Magnetically Controlled Transformers: Analysis and Implementation in a Dual Active Bridge Converter

Controllable magnetic devices, such as variable inductors, are gaining prominence in modern power electronics applications. These devices offer a new degree of freedom in the design and optimisation process, contributing to increased power density and efficiency. While conventional implementations using parallel premagnetisation are well understood, the same cannot be said for variable transformers and alternative biasing techniques. Therefore, this thesis focuses on modelling and analysis to establish trade-offs, addressing implementation challenges, and exploring potential applications for these devices. Specifically, a novel variable transformer implementation has been integrated into a dual active bridge converter, demonstrating the ability to reduce effective currents and enhance efficiency by regulating the primary-referred DC voltage gain under varying output conditions. This regulation is achieved by modulating the effective turn ratio of the transformer, a concept not explored in the literature thus far.
Furthermore, the use of orthogonal premagnetisation has been explored to increase the power density of the transformer, proposing modifications to commercial core shapes to ensure linear behaviour of the device during large signal operations while reducing the required control current, addressing a key challenge associated with this technique.
Although controllable transformers have the potential to be integrated into different topologies, a more comprehensive understanding of the fundamentals of this technology is necessary, and this thesis contributes to this endeavour.

Date:11 Sep 2018 →  16 Feb 2024
Keywords:Batteries, Electric Vehicles, Power Electronics, Semiconductors
Disciplines:Modelling, Multimedia processing
Project type:PhD project