Converter Architectures

Power Electronics plays a very important role in the electrical power conversion and is widely used in transportation, renewable energy and utility applications. By 2020, 80% of electrical power will go through power electronics converters somewhere between generation, transmission, distribution and consumption. So high-efficiency, high-power-density and high-reliability are very important for power electronics converters. The conventional power electronics devices are based on silicon materials and have reached the limit of their potential. The emergence of wide-bandgap (WBG) material such as silicon-carbide (SiC) and Gallium-Nitride (GaN) based devices has brought in clear opportunities enabling compact, more efficient power converters, operating at higher voltages, frequencies and powers to meet the increasing demand by a range of existing and emerging applications. For example, more/full electric aircrafts with hybrid propulsion requires 10s of MW efficient power conversion with high frequency drives, higher voltage levels as well as higher power density. Wireless power charging is pushing the frequency from 100s of kHz to MHz at kW power level to minimise passive elements such as inductors and capacitors. Transformerless, compact, high-efficiency medium-voltage (1kV~10kV) power conversion enabled by high voltage SiC devices is critical for the realisation of power electronics based distribution networks (including energy storage interfacing) for smart grid as well as future transportation systems.

Whilst WBG devices offer the possibility to operate at higher voltages with lower on-state losses, and faster switching speeds than Si devices, maximising the performance benefits at a converter level creates a range of interrelated challenges. For example, high voltage and current changing rates of WBG devices will generate significant electro-magnetic-interference (EMI) and affect the running of other equipment. Identifying the most effective circuit topologies, passive component technologies and control methods, and managing the very high switching rates to extend the frequency/voltage/power envelope present great challenges to power electronic engineers, but are vital if the true potential of WBG circuits is to be achieved. They therefore form the main motivation for this project.

This Converter Architecture (CA) project brings together the UK's best academic and industrial expertise to investigate optimal converter architectures, advanced passive components design methods, fast speed control techniques and holistic optimisation to realise the full potential of WBG devices in achieving higher efficiency, high power density with extended voltage, frequency and power handling capability.

The Converter Architectures (CA) topic, along with the four other Topics, will directly contribute to the delivery of the underpinning research undertaken within the UK EPSRC Centre for Power Electronics, and to the dissemination and exploitation of the resultant research innovations. The proposed technologies of high-efficiency, high-density wide-bandgap (WBG) power converters with extended frequency, voltage and power capability will benefit a range of electrical power conversion applications and will also enable new applications such as aircraft hybrid electric propulsion, wireless EV charging, power-electronics based distribution network, etc, which are enablers for low-energy/low-carbon economy with the UK taking an international lead in this field. The technologies and know-how developed during this project will be available to UK industry for exploitation, principally through companies involved in power electronic converter development, passive component manufacture and power conversion system integrators.

The project will benefit UK companies and manufacturers with improved knowledge and opportunities with new WBG devices and clearer pathways for implementing research outcomes with increased IP residing in the UK. The electronics industry, where UK remains competitive, contributes around £16bn to UK GDP and provides direct employment to over 300,000 people in 12,000 companies. The contribution and economic impact to these figures is not only direct component sales, but also the infrastructure of indirect equipment manufacturers, with a high percentage of exports. Taken overall, if the UK could become the world leader in providing new WBG-device-based high-performance power electronics equipment with the technologies developed through this project, the economic impact for the UK could be considerable.

The project will benefit the society by reducing greenhouse emissions and enhanced opportunity for meeting future targets (e.g. 2020 and 2050 goals for CO2 reduction) through more efficient power conversion, cleaner urban environment due to enhanced impact of clean transportation (electric/hybrid vehicles, rail, 'more electric' aircraft systems, ship propulsion) and better electrical grid infrastructure with greater adoption of renewable energy sources

The project will benefit the academia by having new scientific breakthroughs on WBG converter architectures, control and design optimisation through the research, with follow-on funding from external bodies (Innovate UK, EPSRC, EC, Industry). The research results will be widely disseminated through leading international conferences and journals.

The project will provide greater supply of and more coordinated approach to train young researchers, PhD students, engineers from industrial partners to address skill shortage in power electronics, e.g. by embedding the generated knowledge and skills into undergraduate and postgraduate teaching, technical workshops, industrial lectures, etc.

The project partners have a strong track record in generating high impact from their work, including engagement with a wide range of industrial collaborators. Impact will be managed as an activity of the Hub of the Centre, through the Executive Management Team and the affiliated Industry Advisory Group as well as through the five topics via four routes:

1. Establish the Centre brand as a natural point of contact for power electronics expertise through active dissemination; build the public image of power electronics/engineering and its importance to society.
2. Promote the transfer of knowledge and IP gained from the research to the UK industrial community and stimulate new business activity.
3. Contribute to the development of relevant policy through engagement with national government, national and international funding bodies and professional societies.
4. Build collaborative links with leading academic groups and other relevant industrial organisations around the world.