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In this project in the form of a study, the advantages and disadvantages of large electrical ma-chines with superconducting winding are investigated. The main target is synchronous generators, particularily turbogenerators in the range 50...>1000MW, having a field winding of the high-temperature superconductor (HTSC) technology. The one-year study is divided in the three phases "State", "Benchmark" and "Action Plan". The Phase "State" was used for the survey of current other projects and for the contacting of Swiss and international partners. Two current development projects with fast rotating rotors are of inter-est, the 100MVA replacement rotor of General Electric and the 8MVAr rotating var-compensator of American Superconductor. These projects make use of the first generation HTSC of the type Bi-2223 in a mechanically reinforced special version. The phase "Benchmark" involved intense discussions of the generator manufacturer with clients and HTSC wire suppliers. The resulting analysis revealed no clear market incentives of a HTSC-rotor. In view of the high operational risk the savings in operational costs are too moderate. The advantages going beyond standards (short circuit ratio, power factor) are currently not reckognized by the market. The wire material is still too expensive, however for the year 2010 a reduction to 1/4 of today's price is predicted. Generators combining HTSC rotors with a stator air gap winding will achieve higher utilization, however this novel stator brings along new, own risks. The phase "Action Plan" shows possibilities for a continuation of the project. Regarding market in-troduction for large generators it seems the replacement rotor (pursued by General Electric) is a suited approach with acceptable risk. A partnership with a split into machine-wire or stator-rotor is nearly compulsory. Various optimized elements of the (more neglected) stator are in investigation and might be brought in such a partnership. A concurrent approach "improved conventional gen-erators" might relegate advantages of the HTSC-generator (efficiency, stability). However a quanti-tative rating against the superconducting machine remains to be done.
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