Large rotating electrical machines¿stator insulation condition appraisal

Although there has been a downturn in the demand for energy in the past year, the past decade has seen an unprecedented increase in electrical load growth. This has been reflected in the rapid development of large turbine generators and strategic auxiliary high-voltage motors. One important factor of the successful operation of these large units is the condition of the stator insulation; and this article deals briefly with the complete stator-insulation system from initial construction to final on-site testing and subsequent appraisal on a routine basis during overhaul periods