Utilizing reduced build concepts in the development of insulation systems for large motors

In the last decade, significant technology advancements have dramatically altered approaches to electrical insulation development. This revolution came about with the discovery and patenting in the 1980s, of the use of inorganic fillers to enhance the electrical properties of insulating materials. The first commercial introduction was to increase the corona resistance of enamelled wire, a product used for many years as strand and turn insulation in the manufacture of electrical motors and generators. More recently, the concepts surrounding the advantages of corona resistance have migrated to insulating composites. This paper reviews the developments of one manufacturer, in introducing corona resistant insulation systems to vertical generators, the benefits accrued, and the preliminary introduction of these concepts into the large motor arena.