Power density of PCB-based power converters

Power electronics based on printed circuit boards (PCBs) has emerged as an attractive alternative to more established converter packaging technologies, providing close integration of electronic devices, reduced cost and flexibility in design. An important challenge relates to producing compact but high-power designs which achieve satisfactory efficiency and acceptable manufacturing cost. This project aims to investigate the limits of power density for PCB based power converters and quantify the improvements which can be achieved though emerging technologies. The project is in collaboration with YASA motors, a company which designs motors and drives for automotive applications and therefore a focus will be maintained on electric vehicle applications.

As part of the research, there are several questions to be addressed. The first relates to automation and optimisation of design procedures to produce high power, low volume converters. A suite of converter optimisation tools employing circuit simulation techniques would enable designers to select the best combinations of components for a PCB design. Furthermore, the impact of emerging technologies on achievable power density and efficiency can be quantified. Of particular interest is the range of new commercially available materials for electronic devices called wide band-gap semiconductors. Additionally, new circuit topologies suitable for power trains in electric vehicles will be explored as another means of achieving high efficiency conversion subject to the restrictive volume constraints found in automotive applications.

High quality, robust thermal management techniques are a crucial aspect of converter design required to prevent overheating of electronic devices or mechanical failure due to thermal stress. A further consideration of this project is the application of novel heat-sink technologies to achieve more compact solutions for the same power rating. Theoretical modelling and experimental characterisation will be performed for new, highly conductive heat-sink materials and innovative cooling mechanisms will be compared to well-established techniques like air-cooled heat-sinks.

The work proposed as part of this project falls within the EPSRC Energy research area. It has the potential to enable advancements within many different fields of energy and power and specifically for the electric vehicle industry, may contribute to improved motor drives as well as power converters for a fast charging infrastructure.