| 摘要 |
PURPOSE:To activate a potential heat deterioration and make a thermic life of heat-proof rotating machine winding estimable with a high accuracy by obtaining a dielectric breakdown voltage through applying voltage simultaneously with or after adding a mechanical stress. CONSTITUTION:A sample 1 is caused to deteriorate under heat deterioration conditions of rating of a DC machine insulation system. In this case, 0.5-10mm bending strain is added at every cycle as a mechanical stress, while a voltage of 1/2 of an initial breakdown voltage value of sample 1 is applied to obtain a number of days of reduction by half of dielectric breakdown voltage value. A logarithm of said number of days of reduction by half is Arrhenius-plotted relative to a heat deterioration temperature to obtain thermic life characteristics of sample 1. A point of time for sample 1 to be subjected to dielecbreakdown at a voltage of 1/2 of the initial breakdown voltage is a life of said sample 1. |
