Application of High Temperature Superconductivity in Power Systems
This article reports on the results of a study on the application of high temperature superconductors (HTS) in power systems, with particular attention to the Swiss power network. The study has been financed and carried out by PSEL, BFE, RDP-CREE, ABB, ETHZ, and EPFL.
The goal of the study was to identify opportunities for HTS applications and to assess the technical potential and acceptable cost range of this new technology. A series of scenarios, ranging from near term options to more visionary scenarios, was considered in detail.
The application which is most probably closest to a product is the fault current limiter (FCL). The criteria for this application are met by presently available HTS material. The FCL has a number of interesting applications, such as meshing of “island” networks, lifetime prolongation of existing equipment, downsizing in new installations, etc.
The available HTS materials are in principle also suitable for cables. However, long distance cooling presents a considerable obstacle in this case. Among different HTS cables, the dc cable is clearly favoured over the ac cable. HTS cables are in principle very interesting. They allow for high power transmission on lower voltage levels, and therefore offer the possibility to eliminate one or several voltage levels.
For other applications the available HTS materials are not yet in a sufficient state of development. For transformers the ac losses need to be further reduced, and for superconducting magnetic energy storage (SMES) the robustness of HTS under magnetic field has to be improved.