XLPE电缆状态监测与绝缘诊断研究进展

Research Progress in Condition Monitoring and Insulation Diagnosis of XLPE Cable

交联聚乙烯电缆的绝缘状态关系到输配电系统的安全可靠运行,因此,研究电缆状态监测和绝缘诊断方法工程意义重大。依据电缆不同服役阶段的缺陷特征、故障原因以及绝缘检测方法的特点,总结了适合电缆不同老化阶段的状态监测和绝缘检测方法的研究现状。介绍了针对电缆服役早期由于制造及安装原因引起的缺陷(气泡、划痕)从而导致电缆故障的局部放电检测方法,包括局部放电测试所用各种传感器的原理、特点,并指出放电图谱与缺陷类型的关系是局部放电方法后续研究的重点。总结了适用于电缆运行期间的护套电流及温度的在线状态监测研究现状。综述了适合电缆运行中后期整体老化的基于陷阱参数的绝缘检测方法,包括Qt、空间电荷、极化/去极化电流法,同时指出了基于陷阱特性评估绝缘性能方法存在的不足,认为后续的研究需要进一步制定陷阱参数测试相关标准,积累数据,建立普适的陷阱参数与聚合物老化程度之间的关联,并给出每种方法评估绝缘状态的判据。

The insulation condition of XLPE cable is related with the security operation of power transmission and distribution system, thus it is of great significance to research the methods of condition monitoring and insulation diagnosis of cable. In this study, we summarized the condition monitoring and insulation diagnosis methods for different aging stages of XLPE cable during the service period according to the defect characteristics, fault causes, and testing methods features. Meanwhile we introduced that partial discharge testing that is fit for cable faults mainly coming from defects caused by manufacturing and installation in the early service stage, such as bubbles and scratches, including the principles and features of every kinds of sensors, and pointed out that the further research should mainly focus on the relationship between partial discharge pattern and defect type. Moreover, we summarized the research status of temperature and sheath current testing for the whole cable operation stage. For the overall aging of cable material in the middle and later service stage, it is considered that the testing methods based on trap parameters are suitable, such as Qt, space charge and polarization/depolarization current. And it is also pointed out that some testing standards about trap testing should be set, the universal relationship between trap parameters and insulation condition should be established, and the criterion for the above methods should be given in further studies.