3种绝缘薄膜在液氮中拉伸状态下的冲击绝缘强度

Impulse dielectric trengths of three films under tension status in liquid nitrogen environment

用于超导设备的薄膜型绝缘材料绕包于导体时往往承受一定的绕包张力,需要研究薄膜型绝缘材料在液氮环境中拉伸状态下的冲击绝缘强度。通过设计的波拉拉伸击穿测试系统,对聚酰亚胺、聚丙烯层压纸和聚四氟乙烯三种薄膜在液氮中拉伸状态下的冲击绝缘强度进行了测量,并通过Weibull概率分布的方法对测试结果进行了处理。结果发现随拉伸应力的增加,3种材料的冲击绝缘强度均在一定幅度内随之下降。所得结果可为超导电力装置的绝缘设计提供基础数据。

The dielectric sheets used for superconducting devices usually endure several lapping tension when lapped on the conductor. So the impulse dielectric strengths of dielectric sheets under tension status in liquid nitrogen was be studied. A special electrode system was designed,the impulse dielectric strengths of polyimide,polypropylene laminated paper（ PPLP） and polytetrafluoroethylene（ PTFE） films under tension status in liquid nitrogen are tested,then the tested data are processed by the method of Weibull probability plot. As a result,the impulse dielectric strengths of three materials all decreased in a small range as the tensile stresses increased. The results could provide data base for the insulation design of superconducting devices.