中国电力 ›› 2021, Vol. 54 ›› Issue (4): 63-71.DOI: 10.11930/j.issn.1004-9649.202006208

• 高压电缆及附件关键技术专栏 • 上一篇    下一篇

挤包绝缘高压直流电缆制造与应用中的径向梯度效应

李飞1, 钟力生1, 李文鹏1,2, 高景晖1, 任海洋1, 张翀2   

  1. 1. 西安交通大学 电力设备电气绝缘国家重点实验室, 陕西 西安 710049;
    2. 全球能源互联网研究院有限公司 先进输电技术国家重点实验室, 北京 102211
  • 收稿日期:2020-06-23 修回日期:2020-08-14 发布日期:2021-04-23
  • 作者简介:李飞(1992-),男,博士研究生,从事高压直流电缆方面的研究工作,E-mail:lifei.01@stu.xjtu.edu.cn;钟力生(1961-),男,通信作者,博士,教授,博导,从事电介质与电气绝缘方面的研究工作,E-mail:lszhong@mail.xjtu.edu.cn
  • 基金资助:
    国家重点研发计划资助项目(2016YFB0900702);国家电网有限公司科技项目(SGZJ0000KXJ1900243)

The Radial Gradient Effect of HVDC Extruded Cables in Manufacturing and Application

LI Fei1, ZHONG Lisheng1, LI Wenpeng1,2, GAO Jinghui1, REN Haiyang1, ZHANG Chong2   

  1. 1. State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China;
    2. State Key Laboratory of Advanced Power Transmission Technology, Global Energy Interconnection Research Institute Co., Ltd., Beijing 102211, China
  • Received:2020-06-23 Revised:2020-08-14 Published:2021-04-23
  • Supported by:
    This work is supported by National Key Research and Development Program of China (No.2016YFB0900702), Science and Technology Project of SGCC (No.SGZJ0000KXJ1900243)

摘要: 挤包绝缘高压直流电缆在直流输电工程中应用广泛,但制造与应用中的梯度效应显著影响其直流电气性能。以500 kV交联聚乙烯直流电缆为研究对象,首先,通过仿真计算理想均匀绝缘电缆中的场强分布;然后,计算交联和脱气过程中绝缘层的温度分布,并对电缆绝缘切片取样,测量不同径向位置绝缘的相态结构和直流电气性能;最后,根据实测电导率对电缆绝缘中场强分布进行仿真。结果显示:电缆绝缘在交联和脱气过程中存在温度梯度,绝缘的相态结构和直流电气性能在径向上分布不均匀,绝缘电导率在径向上的梯度分布导致电缆绝缘中场强均呈现出内低外高的分布规律,且最外侧绝缘的场强大于均匀绝缘中的最高场强。

关键词: 高压直流电缆, 挤包绝缘, 梯度效应, 直流电气性能, 场强分布

Abstract: Extruded cables are widely used in HVDC projects, but the gradient effect in manufacturing and application affects their DC electrical performance significantly. The 500 kV XLPE DC cable was studied in this paper. Firstly, the field strength distribution in the uniformly insulated cable was simulated. Secondly, the temperature distribution of the insulation in the process of cross-linking and degassing was calculated, and the phase structure, by-product content and DC electrical performance of the insulation of cable at different radial positions were also measured. Finally, the field strength distribution of the insulation was simulated. The results show that there is a temperature gradient of cable insulation in the process of cross-linking and degassing, and the phase structure, and DC electrical properties of the insulation are non-uniformly distributed in the radial direction. The gradient distribution of the insulation conductivity in the radial direction results in the distortion of the field strength, in which the field strength of outer layer of insulation is greater than that of inner layer, and the field strength of the outer layer of insulation is greater than that the maximum electric strength in the uniform insulation.

Key words: HVDC cable, extruded insulation, gradient effect, DC electrical properties, field strength distribution