A Low Cost, High Capacity, Smart Residential Distribution Network Enabled By SiC Power Electronics

One of the key challenges facing the UK electrical Distribution Network Operators (DNOs) today is the Increasing demand
for power being placed on residential networks e.g. general load growth, the proliferation of electrical vehicles (EVs) and
electrified heat. At the same time, there are problems associated with voltage limit violations caused by an increase in the
connection of distributed generation (DG) and energy storage devices. This project follows on from a TSB Feasibility Study
which showed that a cost effective solution to these problems can be achieved on the existing infrastructure by increasing
the local network phase voltage to 400 V (existing cable is rated at 600V). To step the voltage back down to 230 V at each
house, DNO-owned, low-cost, 99% efficient power electronic converters (PECs) will need to be installed in the meter-box.
Our previous study showed that the 99% efficiency was essential to avoid over-heating in the meter-box and hence new,
low-cost SiC devices were mandatory. However, the cost of existing commercially available SiC is very high, which
conflicts with the need for low-cost. Therefore this project will consider a new, highly innovative fabrication technique for
SiC power devices namely 3C SiC on Silicon. This system will not only increase network capacity, but also provide
optimised connections for emerging EV charging, DG and energy storage - the "smart-grid". The project will develop a PEC
prototype which will be deployed by Western Power Distribution in a small-scale demonstration of the project.

This project is serving to bridge the difficult gaps between the disparate elements of a complex supply chain running all the
way from a semiconductor device manufacturer to a power distribution company. If successful this new level of coordination
will have a substantial impact on the overall competitiveness of UK industry and go some way to the rebalancing
of the future UK economy towards manufacturing industry. The economic benefits of improving the efficiency,
capacity and flexibility of the local distribution network - the so-called smartgrid - have been recently documented in a
report by Ernst and Young (April 2012) for SmartGrid GB, a cross-industry stakeholder group, which informs both DECC
and Ofgem. In this report the forecast savings to the UK are around £19 billion if a smartgrid solution was employed over
conventional investment. In addition an average of 8000-9000 jobs will be generated up to 2030, and exports of £5 billion
are possible by deploying smartgrid technology. The combined value to secondary industries such as electric vehicles,
distributed generation, electro-heat and renewables is significant. For example the gross value added for electric vehicles
alone could be £17-52 billion between 2030-2050. This project directly feeds into this aim, by assessing the feasibility of
new SiC devices and converters for such a system to become a reality. At a Social and Environmental level as well as the
creation of jobs, this project is a key enabler towards the introduction of local, renewable power generation and the wide scale introduction of electric vehicles and plug-in hybrid electric vehicles, as well as increasing the efficiency of the local
residential power network. As such it could play a key role in future plans for the reduction of greenhouse emissions and
improving the security of energy supply.