earticle

영어

The negative-sequence eddy current field of the first AP1000 third-generation 1,250 MVA nuclear half-speed (4-pole) turbo-generator is deeply researched in this paper. In order to find out the influence rules of using different rotor slot wedge materials, the eddy current loss densities, which are generated by negative-sequence current, are compared and analyzed. It is well known that aluminium and aluminum-bronze are widespread materials in electric machine industry. Hence, the two materials are adopted respectively as the slot wedge material, the eddy current loss calculations of slot wedges, rotor teeth and damping bars are given, and the loss characteristic analysis results are also obtained in this work. The calculation and analysis results indicate that different materials have different effects on eddy current loss, especially for the loss density of slot wedges, eddy current loss density of the big tooth area is bigger than the small tooth, and damping bars have the biggest loss density on the rotor surface, which all should be attached importance to in actual large capacity generator design.