DTPSCIDM: Finite element modelling for medium frequency power electronics design and packaging

Dr Ahmed Elkhateb, EEECS Prof Gary Menary MAE Power Electronics medium and high-frequency power conversion systems have many desirable effects suitably oriented for modern power system architecture. Switching at high-frequency results in a smaller volume of magnetics but causes higher loss density. Thus, design and characterisation of a medium-frequency high-power transformer have a notable implication on its performance. Thermal management of a medium frequency isolated power converters is one of the key features for its characterisation. This project aims at proposing an equivalent thermal model of a multi-layer transformer winding in isolated power converters estimating and calculating copper and core losses, and thermal resistance and capacitance. Several cores for the converter will be explored. The outcome is envisaged to mitigate the drawbacks of low-efficiency converters and meet the requirements of miniaturisation, and high power density. This 3.5 year PhD studentship, potentially funded by the Department for Employment and Learning (DfE), commences on 1 October 2020. Eligibility for both fees and maintenance (approximately £15,000) depends on the applicants being either an ordinary UK resident or those EU residents who have lived permanently in the UK for the 3 years immediately preceding the start of the studentship. Non UK residents who hold EU residency may also apply but if successful may receive fees only. Applicants should apply electronically through the Queen’s online application portal at: https://dap.qub.ac.uk/portal/ Further information available at: https://www.qub.ac.uk/schools/eeecs/Research/PhDStudy/ Academic Requirements:- A minimum 2.1 honours degree or equivalent in Electrical and Electronic Engineering or relevant degree is required. - IELTS 6.0 with minimum of 5.5 in each element (International students)

This project studies the effects of temperature change on thermal properties of material and coolant. Time-domain analysis and response of the proposed thermal network will be validated using PLECS/MATLAB software. Furthermore, 5 to 10 kW, 20kHz transformer will be optimised and analysed through the finite element method. The research activities include modelling, analysis and design, with particular emphasis on addressing the limitations of existing technologies for low frequency isolated power converters for renewable energy networks. The measurable objectives of the proposed research are:

1- To design an isolated medium frequency converter that keeps components to a minimum with the view to maximising efficiency and reliability and miniaturising the system.

2- To investigate medium frequency power conversion systems with the employment of Finite Element Methods for the transformer.

3- To model and study the electric field distribution imposed by the medium voltage waveform using the multi-physics simulation package COMSOL.

4- To develop a model which optimises the operation of the proposed converter in terms of voltage stresses and losses, and which is tolerant of a wide range of operating conditions.

ELECTRICAL & ELECTRONIC ENGINEERING OVERVIEW

The School of Electronics, Electrical Engineering and Computer Science (EEECS) aims to enhance the way we use technology in communication, data science, computing systems, cyber security, power electronics, intelligent control, and many related areas.

You’ll be part of a dynamic doctoral research environment and will study alongside students from over 40 countries worldwide; we supervise students undertaking research in key areas of electronics and electrical engineering, including: power electronics,robotics, wireless communications, cybersecurity and sensor-based systems. As part of a lively community of over 100 full-time and part-time research students you’ll have the opportunity to develop your research potential in a vibrant research community that prioritises the cross-fertilisation of ideas and innovation in the advancement of knowledge.

Within the School we have a number of specialist research centres including a Global Research Institute, the Institute of Electronics, Communications and Information Technology (ECIT) specialising in Cyber Security, Wireless Innovation and Data Science and scalable computing.

Many PhD studentships attract scholarships and top-up supplements. PhD programmes provide our students with the opportunity to acquire an extensive training in research techniques.

Electrical & Electronic Engineering Highlights

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• ECIT brings together, in one building, internationally recognised research groups specialising in key areas of advanced digital and communications technology.

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• CSIT brings together research specialists in complementary fields such as data security, network security systems, wireless-enabled security systems, intelligent surveillance systems; and serves as the national point of reference for knowledge transfer in these areas.
• Electric Power and Energy Systems research is focused on problems related to distributed sources of energy and their integration into power networks. The cluster is a member of the IET Power Academy and is a major collaborator on all-island energy research.
• SoCaM is dedicated to the design of advanced, integrated, high-speed wireless and couples activities in High Frequency Electronics, System-on-Chip, Signals and Systems and Digital Signal Processing, and for Gigabit/sec wireless.

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• You will be working under the supervision of leading international academic experts.

Key Facts

Research students are encouraged to play a full and active role in relation to the wide range of research activities undertaken within the School and there are many resources available including:

• Access to the Queen's University Postgraduate Researcher Development Programme
• A wide range of personal development and specialist training courses offered through the Personal Development programme
• Office accommodation with access to computing facilities and support to attend conferences for full-time PhD students