核电厂安全壳中压电气贯穿件绝缘支撑盘绝缘耐潮性能试验分析

Test Analysis of Insulation and Moisture Resistance of Insulation Support Plate of Electrical Penetration in Containment of Nuclear Power Plant

针对中国核动力研究设计院(NPIC)设计生产的中压电气贯穿件的绝缘支撑盘注塑材料聚砜,测试其吸水率、介质损耗、相对介电常数,绝缘电阻、体积电阻率、表面电阻率、介电强度等随环境温度和相对湿度的变化趋势。测试结果表明,环境相对湿度对聚砜材料的吸水率影响显著,23℃时湿度由30%增至98%,对应吸水率由0.012%增至0.106%,增幅高达783.3%;绝缘电阻随环境温度和相对湿度的增大而逐渐减小,降幅最高达99.82%,但绝缘支撑盘相间绝缘电阻始终大于200 TΩ;绝缘电阻受表面电阻率影响较大,绝缘电阻和表面电阻率随环境温度和相对湿度的变化趋势非常接近;相对介电常数和介电强度受环境温湿度影响很小。因此,NPIC设计生产的中压电气贯穿件绝缘支撑盘耐潮性能和电气绝缘性能优良,能够在高电压和高温高湿环境中稳定可靠工作。

The variation trend with temperature and relative humidity of water absorption,dielectric loss,relative permittivity,insulation resistance,volume resistivity,surface resistivity,and dielectric strength of polysulfone are measured.Polysulfone used as the insulating support plate on the medium voltage electrical penetration is designed and produced by Nuclear Power Institute of China(NPIC).The result shows that the relative humidity of environment has a significant effect on the water absorption of polysulfone.When the ambient temperature is 23℃and the relative humidity increases from 30%to 98%,the corresponding water absorption increases from 0.012%to 0.106%,with a growth rate of 783.3%.The insulation resistance decreases gradually with the increasing of ambient temperature and relative humidity,with a maximum decreasing of 99.82%.However,the interphase insulation resistance of the insulation support plate of the electrical penetration is always greater than 200 TΩ.At the same time,the insulation resistance is greatly affected by its surface resistivity.The variation trend of insulation resistance and surface resistivity with ambient temperature and relative humidity is very close.The relative permittivity and dielectric strength are little affected by the ambient temperature and humidity.The insulation support plate of the medium voltage electrical penetration designed and produced by NPIC is with excellent moisture resistance and electrical insulation performance,and can work stably and reliably in high voltage,high temperature and high humidity environment.