Siemens and GEC Alsthom are to cooperate to develop a compact transformer using high-temperature superconducting materials. A single phase prototype with a rating of 1 MVA is scheduled to be completed in the middle of next year.
The project will involve the German company’s Power Transmission and Distribution Group. Its initial aim is to develop a transformer for the traction market, for use in high speed trains. Later development is likely to be aimed at power transmission and the goal after the 1 MVA transformer is to develop units with a rating of around 10 MVA.
Conventional traction transformers have transmission losses of around ten per cent, whereas the losses in transformers used for power transmission networks are around one per cent. High temperature superconducting materials should enable transformers to be made that are lighter, can handle more power and have lower losses.
High temperature superconducting materials need to be cooled to the temperature of liquid nitrogen, rather than to the liquid helium temperatures that low temperature materials require.
However, materials available today are brittle and difficult to make into filaments. Future development work is likely to focus on improvement in material properties.
In the USA meanwhile, The US Department of Energy has announced that two superconducting projects involving the company American Super- conductor have been short listed for financial support. One project aims to build and install a 120 m high temperature superconducting cable system while the second involves construction of a 10 MVA superconducting transformer for deployment on a US utility grid by June 2001.
