SUMMARYSuperconducting generators have many advantages such as increasing generator efficiency and improving power system stability. In Japan, a national project has been conducted since 2000 which is aimed at the development of fundamental technologies required for high-output-density and large-capacity superconducting generators. This paper describes the results of this project, focusing on 6000-A-class field winding development.A superconducting generator with a high output density and a large capacity has inherent factors that decrease superconducting stability. These are: (1) increase in the magnetic field in the winding which is caused by the increase in winding current density and (2) difficulty in fabricating windings which increases as a conductor diameter becomes larger. To secure the stability, we adopted a higher-copper-content conductor and a design that increases winding fixing pressure, along with devising a winding method that accommodates larger conductor diameter. These improvements were applied to a partial model of a 600-MW field winding. Test results of the model showed good stability, indicating that design and fabrication technique for a 6000-A-class superconducting field winding has been successfully evaluated. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(2): 7-18, 2007; Published online in Wiley InterScience (www.interscience. wiley.com).