Residual technological stresses in stator bar insulation of large machines

The author outlines various stresses in stator bar insulation of large machines. The nature and level of temperature-related stresses which are inherent in modern thermoreactive insulation systems are examined in detail. An approach to calculating and regulating their level through optimum design of the system and its processing parameters is outlined. Strain gauge measurements to determine residual stress in insulation of 200- and 500-MW turbogenerator bars are presented. The data are analyzed in the context of ultimate stress of insulation, and it is concluded that the two insulation systems are quite safe.<>