文档介绍：摘要
近些年来,随着经济、社会的发展与城市化的进程,电力工业进入高速发展
期,电力电缆越来越多的应用到电力系统之中,尤其是交联聚乙烯电力电缆,凭
借着其优异的电气、机械以及耐热特性,获得了非常广泛的应用,大有一枝独秀
之意。
随着交联聚乙烯电力电缆在电力系统中应用数量的增多,其绝缘材料的安全
性与可靠性对整个电力系统安全与稳定的运行具有至关重要的影响。交联聚乙烯
电力电缆在运行过程中会产生电树枝老化、水树枝老化以及热电老化现象,它们
都会导致空间电荷在电缆绝缘层中的聚集,致使绝缘层中局部电场发生畸变,场
强大为增强,进一步导致绝缘层的老化,形成恶性循环。因此研究交联聚乙烯电
缆生产过程中某些因素会否对空间电荷的特性造成影响,对从源头上防治电缆老
化延长电缆使用寿命有着极其重要的现实意义。
本文从交联聚乙烯电力电缆生产工艺中的两个重要因素(交联温度和交联时
间)着手,采用 LDPE 作为基料,以 DCP 作为交联剂,制作出了不同交联温度
和交联时间下的薄片状样品,搭建了老化试验平台与空间电荷检测试验平台,通
过加速老化试验,模拟了不同交联工艺下生产的交联聚乙烯绝缘材料在长期运行
后的情况,采用温差法测量了老化样品中的空间电荷的分布与电场畸变情况。为
生产企业和电力公司运行管理部门提供了可供参考的科学数据。
温差法数据结果显示,绝缘层中空间电荷的分布与电场的畸变都会受到交联
温度与交联时间的影响利用温差法测量空间电荷,最后给出了不同交联温度和交
联时间对交联聚乙烯电缆绝缘层中空间电荷特性的影响。
关键词: 交联聚乙烯,电力电缆,空间电荷,交联温度,交联工艺
ABSTRACT
In recent years, electrical industry experienced a huge advance with social
development and the progress of urbanization. Power cables, especially XLPE cables,
were universally employed in the power system thanks to their excellent performance
in electrical, mechanical strength and heat resistance.
With the growing amount of XLPE cables in power system, their quality and
reliability count a lot for the security and stability of the system. In service, some
aging phenomena will be observed in insulation layer, such as water tree and
electrical tree. All of them will lead to the accumulation of space charge in insulation
layer, which will strengthen local electric field, accelerating the aging process.
Accroding to the reasons above, researching the behavior of space charge in XLPE
cables is meaningful for preventing the preaging of XLPE cables.
In this paper, we focus on two important factors in the manufacturing process of
XLPE cables, crossling temperature and crosslinking time. LDPE is taken as base
material to make testing sample, with DCP working as crosslinking agent. Testing
samples are divided by crosslinking temperature and time. We establish a system for
accelerating aging experiment and space charge diag