Sergentanis, Grigorios
(2024)
High-frequency power conversion for photovoltaic module applications.
PhD thesis, University of Nottingham.
Abstract
As world governments focus on transitioning to renewable energy production, power electronics are a mandatory tool in facilitating this transition. Power electronic converters are needed in all types of renewable energy production, whether that is wind, solar, geothermal, or wave energy.
This work focuses on solar energy generation in the residential market segment. In this segment, it is valuable to have individual control of each solar panel module, as environmental conditions can vary significantly at each neighbouring panel. This typically leads to the need to regulate the photovoltaic panel voltage across a wide voltage range, preferably with a favourable power conversion efficiency, to increase the annual energy yield from the installed panels.
Various actions were undertaken within this work to improve on the existing state of the art. First, a literature review of existing converters in this application area is presented. The benefits of wide-bandgap devices are also explored. Some of the Gallium Nitride devices typically used in this application area have been characterised for their performance, as this transistor technology has shown promising results in recent years and has led to the creation of breakthrough conversion systems in terms of size and efficiency.
In addition, a topology-morphing converter is proposed, achieving broad input voltage regulation with high efficiencies and constant operating frequency. The operation analysis and experimental verification are presented in the chapters of this thesis. Several design pitfalls are also presented, along with avenues to increase the performance of the designed solutions. The designed converter achieved a peak efficiency of 98.5% while also keeping the efficiency over 90% with a wide range of input voltages (8-35 V).
Finally, the proposed converter is redesigned to work in the MHz frequency range. The redesigned converter benefits from the use of planar magnetics, resulting in a slim converter profile. A low-profile conversion system can enable integration of the power conversion system with the photovoltaic panel, providing several benefits, such as easy and scalable installation. Most importantly, it allows an integrated solution for photovoltaic building materials, which have stringent dimension requirements. The size reduction is highlighted in the thesis, and experimental results are presented for this case. A peak efficiency of over 95% is seen in the redesigned conversion system, which also has a minimal height profile of 9.1 mm.
| Item Type: |
Thesis (University of Nottingham only)
(PhD)
|
| Supervisors: |
Johnson, Mark
Empringham, Lee
De Lillo, Liliana |
| Keywords: |
DC-DC converter, Resonant converter, Microconverter, GaN HEMT, GaN characterisation, Matrix transformer, Planar transformer |
| Subjects: |
T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK3001 Distribution or transmission of electric power |
| Faculties/Schools: |
UK Campuses > Faculty of Engineering > Department of Electrical and Electronic Engineering |
| Item ID: |
79418 |
| Depositing User: |
Sergentanis, Grigorios
|
| Date Deposited: |
10 Dec 2024 04:40 |
| Last Modified: |
10 Dec 2024 04:40 |
| URI: |
https://eprints.nottingham.ac.uk/id/eprint/79418 |
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