High Frequency Power Conversion Using Wide Band-Gap Semiconductors

Wide band-gap (WBG) semiconductors offer many potential benefits to designers of power electronic systems. Lower switching losses allow operation at higher switching frequencies, which in principle allows a reduction in passive component values in many converter applications. However, efficient operation at higher switching frequencies requires increased voltage and current transition rates. With conventional packaging and circuit construction, parasitic inductance and capacitance can deteriorate converter performance, reducing efficiency and adding to the electromagnetic interference (EMI) emitted from the system. Outside the commutation cell, fast voltage transitions may lead to unacceptably high levels of conducted and radiated EMI.
To mitigate these effects in conventional modules, switching speeds are often deliberately limited and the potential benefits of using WBG technologies cannot be fully realized. New approaches are thus required, moving from assemblies of discrete components, each of which is designed and packaged separately, to fully integrated assemblies comprising power devices, gate drives, filters, sensing, and control functions.
The research project will examine the design and realization of Converter-in-Package (CiP) modular blocks for system power levels from 100s W to 100s kW, incorporating individual commutation cells with close-coupled gate drives, input/output filtering and reduced EMI. Potential areas with scope for detailed investigation include:
1. Converter topology and control design for high frequency operation
2. Passive component design and realization
3. Assembly and manufacturing methods for high frequency compact converters
4. Circuit layout and EMI mitigation strategies

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