The design and manufacture of high voltage stator windings for hydro-generators for onerous pumped storage service

The present paper is intended to highlight the approach taken by one major UK OEM in developing, designing and manufacturing high voltage hydrogenerator stator windings for use under the most arduous pumped storage operating conditions. The original concepts were developed in the early 1970s to meet a specific market requirement for some 16 kV hydrogenerators. During the next 10 years the performance and quality standards were further refined to meet the continuing search by discerning electric utilities for windings with ever greater reliability. The fully developed system, RESITHERM, was adopted for the 6-18 kV generator-motor units installed at the Dinorwig pumped storage power scheme in North Wales. The fundamental approach taken to system testing and the factors of importance for each one are outlined by the author.