Study on multi-factor aging characteristics of stator insulation for wind turbine generator

The stator insulation of wind turbine generator (WTG) would be subject to the repeated pulse voltage, thermal, mechanical and other environmental stresses. In this paper, the methods of the accelerated multi-factor aging test and evaluation for WTG were established. Specimens for modeling stator insulation system were prepared. The multi-factor stresses containing the repeated pulse voltage, change of temperature and steady damp heat were applied, in turn, to the specimens for periodically aging test. At each interval of aging periods, some non-destructive measurements or diagnoses have been carried out. The residual breakdown voltages after the aging tests were measured also. The micro-structures of aged and un-aged specimens were analyzed by means of microscope and infrared spectroscopy.