Applications

Climate change, steadily growing demand for energy, increased self-awareness of the scarcity of natural resources, and concerns over the security of supply of traditional carbon based fuels, have led to a world-wide effort to find and exploit alternative and sustainable energy sources. This is coupled with a need to ensure the most efficient storage, distribution and use of the generated electrical energy. High-power semiconductors, forming the basis of power electronic technologies, are fundamental to the efficient control and use of all the energy-related technologies being developed, including the smart grid and wind power. The spectrum of applications covers from wind energy generation, through new transportation technologies (e.g., hybrid and electric cars, electric trains, aircraft and ships), to distribution via the Smart Grid.

The references to face these challenges are those of Silicon. For Si devices there is a solid knowledge base but for WBG devices the information is quite fragmentary yet, especially for HV devices. Furthermore, the much smaller dimensions and much higher electric fields lead to significantly increased stress compared to Si devices. Therefore, in order to reach the full potentiality of SiC, it is necessary to develop new approaches, rather from scratch, concerning the topics below. The introduction of SiC devices in these applications will allow for the evaluation of their contribution towards increasing efficiency, power density and reducing complexity of converters for wind power, power transmission systems, and solid state transformers.

Concerning the two applications addressed in this project: wind power converters and modular Solid State Transformers used in Power Transmission Systems, SiC devices offer advantages over existing solutions in terms of complexity, losses, power density, etc.  Also, offshore wind farms with DC collection grids are seen as a potential future application, where high power, high voltage DC-DC converters are needed. Based on the SiC devices properties, new cells will be designed, built, optimized and evaluated. Dynamic simulations will be used to verify thermal and electrical behaviour as well as load cycles of the selected designs. The SiC based cells will be further combined to build modular, medium voltage power converter systems. The results will be compared with those obtained with Si based solutions.

The real-life application conditions of power electronics in a node of the distribution grid have been barely explored. Demonstrators will be built for this purpose. Among other issues, short-circuit currents, steep-front overvoltage response, or overheating behaviour need to be investigated. A conventional transformer in the power grid responds towell-established, standardized requirements. The limits of power electronics under these requirements are unexplored. We will identify the weak points that have to be improved in order to design reliable devices that can be safely connected to the power grid.