New high-voltage power electronic converters and facilities for transmission grids tend to have multiple power switches at different floating potentials. Moreover, the trend goes towards the use of power switches with higher operating voltages (up to 10kV), in order to reduce the number of switches by system.
FastGrid is a project funding for an amount of 7.2 M€ by the European Union’s Horizon 2020. It started in January 2017 for a period of 42 months. Together 9 academic and 3 industrial partners participate to the development of a superconductive fault current limiter associated with a DC breaker will fulfil the requirement of one the protection strategies of the future HVDC networks. The project is divided in 4 technical main packages.
When a voltage is applied to a cable, electric charges are established in its electrodes, inducing an electric field in the dielectric. This electric field implies that the cable is submitted to an electrical stress which, under certain circumstances induces an accelerated ageing of its dielectric which may be followed by its breakdown.
Globally, the energy landscape is shifting; the generation of electricity is moving towards greener energies, to incorporate more and more renewable power. Transmitted over continents and oceans, transmission lines are spanning over longer distances when connecting power generation areas to consumers. How can we help making this international electrical network of the near-future into a reality?
The recent interest in renewable energies has encouraged the research on a new concept of electrical grid - the Supergrid based on HVDC meshed grids. To be implemented, this new system requires the development of new technologies. One key-enabling technology is the high power DC-DC converter, a topic that is increasingly gaining more attention from both academia and industry.
Numerous High Voltage Direct Current (HVDC) submarine cables have been installed in Europe and more are yet to come. Such transmission allows the trading of energy or the supply of isolated areas with almost no limitations on distance (typically 100-1000km). Interconnections such as NorNed and soon Nord Link and North Sea Link will provide a safe path for the large integration of renewable energies in northern Europe (Figure 1).
PROMOTioN is a 4 years project starting January 2016, with a 40 M€ EU funding, involving 35 Industrial and Academics Participants. It aims to develop meshed HVDC offshore grids on the basis of cost-effective and reliable technological innovation, in combination with a sound political, financial and legal regulatory framework.
Supergrid Institute is deploying real-time modelling and simulation facilities applied to the analysis of emerging HVDC electricity networks, in collaboration with OPAL-RT. The new platform is aimed at testing and assessing the grid architectures, the control and the protection strategies proposed by our research teams.
SuperGrid Institute has succeeded in the preliminary tests on their first DC-DC power converter in September 2015. The power converter nominal power is 100 kW with an input voltage of 1 kVdc and an output voltage of 500 Vdc. The converter topology is a Dual Active Bridge with silicon carbide transistors and a medium frequency transformer.