摘要
本文以110kV XLPE电力电缆为研究对象,比较了直埋、排管、电缆沟敷设方式下电缆服役13年的情况。为了对XLPE绝缘材料的劣化规律进行表征,本文采用了傅里叶红外光谱(FTIR)、差式扫描量热(DSC)、扫描电子显微镜(SEM)、热重分析(TG)、宽频介电谱和工频击穿试验等多种研究手段。结果表明:服役13年的XLPE电缆绝缘相比未服役电缆在微观结构和宏观性能上均出现明显劣化,具体表现为XLPE分子链发生断裂,C=O、C=C、—OH等极性基团增多,直埋、排管敷设时熔融温度、结晶度较低,电缆沟道敷设时熔融温度、结晶度较高,球晶形态均遭到破坏;3种不同敷设方式下的XLPE电力电缆介电常数及介电损耗均上升,工频击穿场强下降。其中,排管敷设的电缆绝缘在结构和性能上具有更快的劣化速率,直埋敷设次之,电缆沟道敷设劣化速率最慢。产生上述差异的原因在于沟道敷设电缆的散热条件最好,在施加电流相同的情况下,电缆运行温度最低,排管敷设电缆散热条件最差,电缆运行温度最高。
In this paper,the 110 kV XLPE power cable is taken as the research object,and the service of the cable for 13 years under different laying methods is compared.In order to characterize the deterioration of XLPE insulating materials,this paper used a variety of research methods,such as Fourier transform infrared spectroscopy(FTIR),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),thermogravimetric analysis(TG),broadband dielectric spectroscopy and power frequency breakdown test.The results show that the microstructure and macroscopic properties of XLPE cable insulation in service for 13 years are significantly degraded compared with those in non-service cables,as follows:XLPE molecular chains are broken,polar groups such as C=O,C=C and—OH are increased, the melting temperature and crystallinity are lower in direct burial and drain laying, andthe melting temperature and crystallinity are higher in cable trench laying. The dielectric constant anddielectric loss have increased, and the frequency breakdown field strength has decreased. Among them,the structure and performance of the cable insulation laid in the row pipe has a faster rate of deterioration,the direct burial laying is the second, and the cable trench laying has the slowest rate of deterioration.The reason for this difference is that the trench laid cable has the best heat dissipation conditions and thelowest cable operating temperature with the same applied current, while the duct laid cable has the worstheat dissipation conditions and the highest cable operating temperature.
作者
张瑞祥
马耿
权胜利
ZHANG Ruixiang;MA Geng;QUAN Shengli(China Railway Xi'an Bureau Group Co.,Ltd.,Xi'an High speed Rail Infrastructure Section,Xi'an 710000,China)
出处
《有色设备》
2024年第4期55-64,共10页
Nonferrous Metallurgical Equipment
关键词
XLPE
热老化
敷设方式
微观结构
直埋
排管
电缆沟道
XLPE
thermal aging
laying method
microstructure
direct burial laying
duct laying
cable trench laying
