大型水氢氢汽轮发电机定子绝缘老化诊断

Assessment of Large-size Water-hydrogen-cooled Generator Winding Insulation Aging

将已经运行23年的300 M W水-氢-氢汽轮发电机和相同类型的新机组定子绕组老化状态进行对比。由于水氢氢汽轮发电机定子绕组运行温度远低于其绝缘系统的耐热等级,故与温度因子相比,电因子成为绝缘老化的主要影响因素。电老化过程中定子绕组绝缘的剩余击穿电压不随老化过程线性下降,而是呈幂函数下降。

Comparison between results of aging test on a new generator and those of an old one already running over 23 years was performed. Because the actual operation temperature was far lower than that of the insulation system thermal class, the electric element became the main factor to influence the insulation aging compared with the thermal factor. The residual breakdown voltage of the stator insula- tion fell as a power law rather than a linear function during electric aging.