摘要
对谏壁电厂7号机(18 kV,300 MW)更换线棒进行了多因子加速老化试验,在线棒的不同老化阶段进行了动态力学分析和超声波声速试验。动态力学分析发现,随着绝缘的不断老化,其玻璃化转变表观活化能增大,储存模量和动态黏度相应下降。超声波声速试验的结果显示出,随着线棒老化时间增长,其超声波声速明显降低,超声波声速可以表征发电机定子绝缘老化状态。动态力学分析和超声波法试验的结果较一致地证明绝缘性能的下降是由于界面黏结能力的下降。
Accelerated multifactor aging tests in laboratory have been conducted on stator insulation of large generator (18 kV, 300 MW) to identify useful diagnostic parameters for insulation aging characteristics. Dynamic mechanical parameters and ultrasonic wave velocity are measured for stator insulation of different aging time. The experimental results show that the apparent activation energy of glass transition (AAEGT) increases, while the storage modulus, dynamic viscosity of insulation decrease greatly with aging time, and the ultrasonic wave velocity propagated in stator also decreases obviously. Ultrasonic wave velocity can be used to describe the aging characteristics of stator insulation. The results also examined the adhesive properties decreasing of insulation interface results in the dielectric properties decreasing of insulation.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2002年第4期61-65,共5页
Proceedings of the CSEE
基金
国家科学自然科学基金重点资助项目(59837260)
