Design, build and testing of a 50 kVA SiC BJT inverter as a building block for high-power HVDC inverters

This project is a collaboration between Zagres Limited and Cambridge University Engineering Department (CUED) and
aims to study, prove and quantify the performance and economics of a newly developed Silicon Carbide Bipolar Junction
Transistor (SiC BJT) technology through building and testing a prototype 50 kVA SiC BJT inverter as a building block for
High Voltage Direct Current (HVDC) transmission applications. The SiC BJT power module technology has voltage,
frequency and thermal ratings substantially greater than existing Si-based modules, which can significantly reduce size and
enhance reliability and efficiency of power electronics inverters. These benefits will contribute to reducing the cost of
energy for offshore renewables.
The 50 kVA SiC BJT inverter will be the first of its kind and will act as a stepping-stone to develop and industrialise largescale
HVDC SiC-based inverters. The performance and benefits of the inverter will be assessed and compared to existing
commercial Si-based solutions. In addition, a thorough business plan and exploitation model will be developed to support
the follow-on commercialisation.
This project aims to prove and quantify the benefits and economics of the SiC BJT technology, on both device and
application levels, through the design and testing of a 50 kVA SiC BJT inverter as a building block for high-power HVDC
inverters and design assessment of an ultra-high voltage 10 kV SiC BJT power device.
According to TSB's Offshore Renewable Energy Catapult, the offshore renewable industry contributed circa £1bn to the UK
economy and supported 20,000 jobs in 2013. However, only 40% of the lifetime costs of currently operational UK offshore
wind farms will be spent domestically, since most large-scale components are imported. This project supports the
exploitation of a new HVDC technology, currently only supplied by non-UK suppliers, such as Siemens and ABB.
Successful commercialisation of project outcomes will not only reduce the LCOE from offshore renewables, but will also
increase the UK content of the supply chain, hence bring economic benefits and create new jobs across the supply chain.

A. Communications and Engagement
1. Meetings: The quarterly project meetings are principally for communication of the progress in the project between
Partners and all Partners are expected to attend. These briefings can be made with invited external representatives and
we would anticipate the attendance in turn of small numbers of invited guests. These would come from among members of
the TSB Offshore Catapult and EPSRC Underpinning Power Electronics 2012 program.
2. Collaboration: The project includes formal collaboration with Industrial Partners and University. The involvement of
University Investigators and Industrial Partners is across the tasks mostly by pairings and larger groups which involves
extra meetings during the tasks to dis-cuss the project.
3. Publication: The Industrial Partners understand the need to publish material and will take steps to protect IP such that
dissemination can proceed in leading professional journal publications such as IEEE Transactions and IET Proceedings as
appropriate and timely.
4. Start Up Company: Zagres is a start up company and is growing strongly and maintains a strong press engagement.
Therefore, we believe aspects of this research will form press releases, presentations and magazine articles to the wider
engineering community interested in power electronics applications in the renewable energy sector.
5. Skills Transfer: As part of the collaboration, PDRA will observe the industrial tests and have indirect access to some
manufacturing equipment and systems.
6. Business Awareness: The academics and PDRA involved will be exposed to Zagres and experience a significant period
in the life of an entrepreneurial start up company hoping to grow rapidly and establish sales. We believe this is an excellent
opportunity to learn about the life of a start up and how to act in an entrepreneurial and professional manner.
7. Intellectual Property Activities: Patents and License agreements are of primary importance to Zagres. Terms and
conditions of the collaboration agreement have been proposed and these will be finalised when funding is granted. The
ideas proposed here are probably not patentable as they stand, but we anticipate patentable ideas will flow for which the
companies together or separately can seek IP protection and they will agree to grant each other licenses to make use of
and exploit the inventions commercially.
B. Impact Activity (Deliverables and Milestones)
As a start up company is involved, we do not immediately anticipate a spin out company arising. Nonetheless, the direction
of Zagres may be considerably changed by the research findings on this project and the emphasis may change strongly
too. In which case there may be an opportunity for a spin off company to be formed to address the needs arising. In either
case the progress will be
1. Publications: A task in the quarterly group meetings with all Partners shall be an item to discuss dissemination of results
through publication, including choice of journal, conference or exhibition and an agreed plan will be in place (this also
assists in the protection of IP).
2. Patents: Patents will be applied for in a timely manner and a list of proposed patents, inventors and assignees will be
available at all times.
3. Participation in the offshore renewables and power electronics conferences, including Annual RenewableUK Offshore
conference, European Wind Energy Association Annual Off-shore Event and European Power Electronics Annual Event.