Assembly of generators with rated voltage higher than 100 kV

Abstract

Powerformer/sup TM/ is a newly developed synchronous machine that generates electric power directly at transmission voltage levels. This is achieved by replacing the rectangular conductors in the traditional stator winding with circular conductors based on proven high voltage cable technology with solid extruded dielectric. The new machine is designed for both hydro and thermal applications. The concept with cables, as stator winding, requires new techniques in the design and assembly process. This paper discusses the concept of Powerformer and the assembling process that has been developed for the following two cases: Eskilstuna rated 42 MVA at 136 kV, which will be used in a thermal application and was assembled in the workshop, and Porsi rated 75 MVA at 155 kV for a hydropower application and assembled at site. Finally, some future outlooks regarding applications for Powerformer are presented.