Retro-Design of TurboGenerators Part 2: Determination of the stator geometry

Abstract

Increasing the power delivery requires to optimize high power generators thanks to numerical tools as finite element applications. In this way, this paper presents a new concept called retro-design. It has been naturally introduced by the difficulties to determine the inner dimensions of high power machines, installed from many years, and for which plans are not always available. It concerns especially turbo-generators of thermal nuclear power stations. Consequently, in order to make easy the improvement of the generator performances with reliability without dismounting them for a long time, this paper presents an original procedure to find - a posteriori - the inner dimensions of the stator armature starting from a restricted initial data set as the rating plate. Such a determination do not use only a classical design method ; it requires to be coupled with a data base, even if this latter is restricted. The paper presents the procedure and the choices to make in order to find the best design parameters according to the power or the installation date of the generator. A retro-design example is given with a 1485 MW turbogenerator.