General Electric has reported that its demonstration model for a new high-temperature superconducting generator has been successfully tested. This is a significant step for a research programme funded by the US DOE and with a development team that includes American Electric Power and the national laboratories at Oak Ridge and Los Alamos.
In late 2001, GE received a $12.3 million contract from the DOE to support a 3.5-year programme to move HTS generator technology toward full commercialisation. The programme formally got under way at GE’s Global Research Center in October 2002.
A 1.8 MVA proof-of-concept model for the rotor, cryo-refrigeration and HTS subsystems has now been designed, manufactured and tested. Results of the tests will be scaled to a 100-MVA prototype generator that will be fully tested under load. The refrigeration system and transfer coupling in the model are full-size prototypes directly applicable to the 100 MVA generator, while a high-strength HTS coil of first-generation wire (BSCCO) and a coil support structure are scaled-down versions.
According to GE the prototype features a new rotor design and winding of unprecedented simplicity. Recent progress in HTS wire manufacturing has helped pave the way for this development, with the potential for competitive cost, high reliability, rapid market introduction and a high probability of acceptance by the power industry. Extensive cryogenic, mechanical, electrical component and systems tests were conducted.
Special attention was focused on the performance of the HTS coil, which maintained its capability throughout all tests, including sudden short circuit tests and rotor overspeed tests. “The successful tests validated all key HTS components and physics-based design analysis models. Valuable design enhancements were identified for the 100 MVA generator,” said Dr. Meng-Ling Hsiao, general manager of generator technology for GE Power Systems.
The next stage will be to continue economic evaluation of HTS generators. The design phase for the 100 MVA prototype machine is expected to be completed in 2004. “We expect to meet the goal of initially testing the full-size (100) MVA prototype by 2005,” said the DOE’s James Daley, lead physicist for the DOE’s superconductivity programme.