长期运行的110kV XLPE电缆的绝缘状态评估

发布时间：2018-04-23 17:55

  本文选题：XLPE电缆 + 老化状态　； 参考：《华南理工大学》2016年硕士论文

【摘要】：在探讨XLPE电缆老化机理的基础上,从理、化、电3个角度对运行电缆样品的寿命进行评估。对110kV XLPE电力电缆的老化状态及剩余寿命的研究分为两个阶段。第一阶段为电力电缆的理、化、电特性老化试验,第二阶段为电力电缆绝缘层的理、化特性老化试验。第一阶段的试验包括局部放电试验、逐级耐压试验、等温松弛电流试验、热老化试验、热失重分析实验、差示扫描量热法试验。局部放电试验结果表明,这6个电缆样品状态仍然符合国家标准可以进行后续的理、化、电特性试验。逐级耐压试验结果表明,运行电缆的剩余寿命为10~30年,备用电缆的剩余寿命为30~50年。等温松弛电流试验结果表明,由老化因子得到的结果只是一种趋势性的判断。经电热老化处理后,电缆的老化因子增大。热老化试验结果表明,电缆线芯温度介于80~90℃之间时,这些电缆的剩余寿命在10~25年之间。热失重试验结果表明,热老化后,4个样品活化能下降,2个样品活化能上升;材料体系的相互配合、抗氧化剂的使用及工艺会影响电缆的质量。电热老化试验老化后,5个样品的氧化诱导期明显降低,1个样品升高。说明老化后,氧化诱导期趋于明显降低。第二阶段绝缘层的理、化试验包括PEA、TGA、FTIR、X-ray试验。PEA、TG、FTIR微观试验结果表明,与中层相比,内层空间电荷积累量增多14.86%,活化能下降3.68%,羰基指数增大5.57%,亚甲基指数下降66.78%,内、外层老化更严重。X-ray实验结果表明电缆绝缘层中存在发生形变的球晶。运行初期,在无氧条件下以聚乙烯分子交联反应占主导,促进分子结构完善;运行后期,在有氧条件下以氧化降解反应占主导,加速绝缘材料老化。通过空间电荷积累量、活化能以及羰基指数的变化能合理解释内、中、外层的老化规律。
[Abstract]:On the basis of discussing the aging mechanism of XLPE cables, the life of running cable samples was evaluated from three aspects: mechanism, chemistry and electricity. The study on the aging state and residual life of 110kV XLPE power cable is divided into two stages. The first stage is the aging test of power cable insulation layer, the second stage is the aging test of power cable insulation layer. The first stage of the test includes partial discharge test, step by step voltage test, isothermal relaxation current test, thermal aging test, thermogravimetric analysis test, differential scanning calorimetry test. The results of partial discharge test show that the state of the six cable samples is still in accordance with the national standard. The results show that the residual life of the running cable is 10 ~ 30 years and the remaining life of the spare cable is 30 ~ 50 years. The results of isothermal relaxation current test show that the results obtained from aging factor are only a trend judgment. After electrothermal aging, the ageing factor of cable increases. The results of thermal aging test show that when the cable core temperature is between 80 鈩，

本文编号：1792999