500kV超高压电缆设计.doc

摘要 随着社会经济的发展和用电需求的不断增长，城市输电系统正在逐步从架空线路向电力电缆方向发展，电力电缆正逐步向更高电压等级、更大传输容量发展，500kV超高压电力电缆的应用将逐渐扩大。但目前国内对超高压电缆及附件的开发能力、长距离500kV电缆的设计、施工和运行等问题的研究还比较薄弱，相应的技术很难跟上发展的速度，500kV超高压电力电缆的设计、选材和生产也面临着重重问题，超高压电力电缆的设计研发经迫在眉睫。 本文简述了500kV电缆的研究背景及意义，介绍了国内外的发展现状并着重了解了日本的发展过程。给出了500kV单芯电力电缆的典型结构，对充油电缆和XLPE电缆进行了对比，给出了生产XLPE聚乙烯料应满足的性能需求及挤包的相关问题。概述了超高压电缆的屏蔽层缓冲层的意义，对金属护套的选择和生产工艺进行了详细介绍，叙述了超高压电缆外护层的性能要求和阻水的意义等相关问题，简要介绍了载流量的计算。 最后，通过对XLPE电缆和充油电缆的对比可以知道XLPE电缆优势明显，必然成为EHV发展的主要趋势。本文对500kV XLPE的选材结构等进行了较为全面的介绍，希望可以为500kV XLPE电缆的设计和生产提供一些帮助。 关键词 500kV；XLPE绝缘；超高压；电力电缆 Abstract With the development of social economy and the growing demand for electricity, city transmission system develops gradually from overhead line to the power cable, power cable gradually come to have the higher voltage, larger transmission capacity, the application of 500kV ultra-high voltage power cables gradually expand. But at present the design of domestic EHV cables and accessories capacity, construction and operation of research is still relatively weak, the corresponding technical is difficult to keep up with the speed of development. The design of ultra-high voltage power cable material and production is faced with many problems, The design and research of ultra-high voltage power cable are at the imminent. This paper describes the research background and significance of 500kV cable, introducing the development status at home and abroad and focusing on the understanding level of the process in Japan. We also compare the typical structure of the 500kV single core cables, the oil-filled cable and XLPE cables, the performance demand for the production of XLPE polyethylene material and describe the needs which meet the related problems. We overview the significance of the shielding layer of buffer layer of EHV cable and the selection and production process of metal sheath in detail, as well as the problems related to performance requirements of protective layer of EHV cable and the significance of water resistance, we also br