Optimisation of WBG power converters to reduce EMI

The project is structured in literature review, simulation, practical research activities and writing the thesis research.

Literature review
The project will compare different WBG devices and identify which WBG device is suitable for which application. The project will investigate the cause of oscillations and techniques to minimise them. The project will investigate EMI standards and compare different EMI minimisation techniques this may involve looking at gate drivers and/or filtering strategies.

Simulation
A power converter topology will be selected for this project and implemented in simulation. Different scenarios will be simulated to gain a better understanding of the cause of oscillations and how to minimise them. Results will be compared with EMI standards. Gate driver and or filtering circuits may also be designed, simulated and compared if required.

Practical work
Based on the two main activities rules and design criteria will be developed. New designs will be first tested in simulation for optimisation and in a second step a new layout will be designed and built. The optimised WBG converter will be tested, and its performance will be compared to EMI standards. If required, an optimised gate driver circuit and/or a filter will also be designed and tested. This gate driver and/or filter will be embedded in the power converter to achieve optimal performance.

Thesis writing
A thesis will be written that summarises all the findings with in-depths discussions, analyses and recommendation.

Power electronics experiences a transition from silicon (SI)-based power switches to Wide-Band-Gap (WBG) devices. There are many benefits in using WBG devices in power converters such as reduced size, reduced cooling requirement and reduced current oscillations. However, some of these benefits cannot be fully exploited due to electro-magnetic-interference (EMI) that is caused by the fast-switching transients. The project will study the impact that EMI has on components and controllers and will produce design rules and optimisation strategies to minimise oscillations and overshoots without limiting the speed turn-on and turn-off speeds. The project will also be optimising gate driver and/or filter circuits and identify optimised passive components. Passive components such as capacitors and inductors are made from different materials. Some of the materials do not withstand high frequency currents and voltages. Thus, the project is identifying the best materials for passive components.

This CDT will produce power electronics specialists with industrial experience, and will equip them with key skills that are essential to meet the future power electronics challenges. They will be highly employable due to their training being embedded in industrial challenges with the potential to become future leaders through parallel entrepreneurial and business acumen training. As such, they will drive the UK forward in electric propulsion development and manufacturing. They will become ambassadors for cross-disciplinary thinking in electric propulsion and mentors to their colleagues. With its strong industrial partnership, this CDT is ideally placed to produce high impact research papers, patents and spin-outs, with support from the University's dedicated business development teams. All of this will contribute to the 10% year upon year growth of the power electronics sector in the UK, creating more jobs and added value to the UK economy.

Alongside the clear benefits to the economy this CDT will sustain and enhance the UK as a hub of expertise in this rapidly increasing area. UK R&D is set to shift dramatically to electrical technologies due to, amongst other reasons, the target to ban petrol/ diesel propulsion by 2040. Whilst the increase in R&D is welcome this target will be unsustainable without the right people to support the development of alternative technologies. This CDT will directly answer this skills shortage enabling the UK to not only meet these targets but lead the way internationally in the propulsion revolution.

Industry and policy stakeholders will benefit through-
a) Providing challenges for the students to work through

b) Knowledge exchange with the students and the academics

c) New lines of investigation/ revenue/ process improvement

d) Two way access to skills/ equipment and training

e) A skilled, challenge focused workforce


Society will benefit through-
a) Propulsion systems that are more efficient and require therefore less energy reducing cost of travel

b) Engineers with new skillsets working more cost-effective and more productive

c) Skilled workforce who are mindful considering the environmental and ethical impact

d) Graduates that understand equality, diversity and inclusion


Environment will benefit through-
a) Emission free cars powered by clean renewable energy increasing air quality and reducing global warming

b) Highly efficient planes reducing the amount of oil and therefore oil explorations in ecological sensitive areas such as the arctic can be slowed down, allowing sufficient time for the development of new alternative environmental friendly fuels.

c) Significant noise reduction leading to quiet cities and airports