Superconducting generators have many advantages such as increasing generation efficiency and improving power system stability etc. In Japan, 70MW class superconducting generators have been developed through the national project“Electric Power Application of Superconducting Technologies (1988-1999)”.
In this paper, performance evaluation of the rotor damper structure for the 70MW class model generator is discussed. Double-layered damper structure, which consists of a squirrel-cage warm damper and a single-layered cold damper was set as the target. As the first step, basic electromagnetic and thermal performances were obtained through the experimental model. In the following step, the 70MW model rotor damper structure was designed based on the experimental results and the rotor was manufactured. Evaluation of the damper structure of the 70MW rotor was carried out in the verification test from the technical view point of ‘unbalance current capability’, ‘flux shielding’ and ‘generator reactance’ etc. and satisfactory results were obtained. Consequently, it was proven that the damper structure had the performances to satisfy the requirements of the superconducting generators. Performances obtained from the experimental model, design of the 70MW model rotor and evaluation by the verification tests are described in this paper.