Superconducting generator technology-an overview

Application of superconducting technology to the field windings of large ac generators provides virtually unlimited field capability without incurring resistive losses in the winding. Several small-scale superconducting generators have been built and tested demonstrating the feasibility of such concepts. For machines of much larger capacity, conceptual designs for both 300 MVA and 1200 MVA have been completed. The results of those studies lend credence to the viability of such technology on the larger scale. The development of large, superconducting generators will require a substantial, sustained effort to produce a machine with performance and reliability equal to, or greater than that of conventional generators. However, the potential benefits include increased efficiency, improved steady-state and transient stability, potential for higher voltage machines, improved I2²t capability, potential for growth to higher ratings and voltages, reduced size and weight, as well as reduction or elimination of onsite generator fabrication. The Electric Power Research Institute (EPRI) will fund a 300 MVA generator. Designed, engineered and fabricated as a turbo generator, the superconducting machine is to be installed in a powerplant, tested and operated in concert with a prime mover, the steam generator and the auxiliary support systems of the powerplant. This method of demonstration will eliminate the more conventional method of evaluating new generator technology and will provide answers to the viability of operating a superconducting machine and its cryogenic handling systems in a fulltime, demanding environment.