Research and development of slow response type 70 MW class superconducting generator with high-current density superconductors Original Research Article

Some 70 MW class superconducting generators have been developed in Japan to verify the basic technologies for a 200 MW class superconducting pilot generator. The manufacture of a 70 MW rotor with a slow response excitation began from 1992, and factory tests were conducted in 1996. Succeeding the factory tests, the rotor was combined to the stator with air gap windings at the verification test facility in Osaka power station, and verification tests were conducted in 1998. The advantages and reliability of superconducting generators had been clarified by these tests. In this paper, verification test results including stability of superconducting field windings and helium cooling characteristics are described. The main results are summarized as follows: (1) the advantages of the superconducting generators, such as increasing generation efficiency and improving power system stability were verified, and the operational reliability was confirmed by the long-term operation, (2) the superconducting stability against constant current and rapid current variations corresponding to the load conditions of the 200 MW class slow response pilot generator were confirmed to be satisfactory and (3) helium cooling characteristics such as cooling down and heat loss were confirmed to be also satisfactory.