电工技术学报2025，Vol.40Issue(5)：1540-1558,19.DOI:10.19595/j.cnki.1000-6753.tces.240345
高压XLPE电缆缓冲层烧蚀机理及检测方法综述
Review on Ablative Mechanism of the Buffer Layer in High Voltage XLPE Cable and Associated Detection Methods
摘要
Abstract
The water-blocking buffer layer,as an essential component of high-voltage cross-linked polyethylene(XLPE)cables in China,plays roles in electrical connection,moisture absorption and water blocking,and mechanical buffering.However,in recent years,the problem of buffer layer erosion in corrugated aluminum sheath cables has become more prevalent,affecting the safety of equipment and systems.This article provides a comprehensive review of cable structure,buffer layer failure mechanisms,and buffer layer failure detection methods,aiming to provide references for research on buffer layer erosion issues in high-voltage cables,development of detection technologies,and formulation of efficient operation and maintenance strategies. Based on the analysis of the three-dimensional structure,development history,equivalent circuit principles,and key electrical parameters of cable buffer layers,this paper systematically analyzes three types of erosion mechanisms:chemical/electrochemical corrosion,suspended potential,and radial current concentration.It summarizes the reaction or action mechanisms of chemical/electrochemical corrosion,and the white powder formed after corrosion mainly consists of sodium polyacrylate,sodium carbonate,sodium bicarbonate,aluminum hydroxide,and aluminum oxide.The white powder on the surface of the insulation shielding layer mainly includes sodium polyacrylate precipitated by moisture and sodium carbonate and sodium bicarbonate precipitated by chemical reactions inside the buffer layer;the white powder on the surface between the buffer layer and the corrugated aluminum sheath includes sodium carbonate and sodium bicarbonate precipitated by chemical reactions inside the buffer layer,sodium carbonate,sodium bicarbonate,aluminum hydroxide,and aluminum oxide generated by chemical corrosion of the aluminum sheath,and aluminum hydroxide and aluminum oxide generated by electrochemical corrosion.Meanwhile,circuit models or multi-physics field simulation models are established to summarize the forms of suspended potential and radial current concentration faults and key influencing factors.It is found that increasing the thickness of the buffer layer can reduce the maximum surface electric field strength at the defect to a certain extent,but the difference is not by an order of magnitude,so the improvement effect is limited.However,the gap distance between the aluminum sheath and the buffer layer has a significant impact on the maximum surface electric field strength at the defect.When the gap distance increases from 0 to 1 mm,the maximum electric field strength decreases by 62%,indicating that adjusting the physical coordination between the aluminum sheath and the buffer layer is the key to improving the distribution of the electric field between the buffer layers.In addition,compared with the condition of radial current concentration erosion of the buffer layer combined with moisture and radial current concentration,the temperature rise of the buffer layer and the peak intensity of the heat source increase significantly,and the length of poor axial contact of the cable is shortened by nearly 58%.Finally,the feasibility and existing problems of three types of methods,namely X-ray detection,partial discharge detection,and characteristic gas detection,in buffer layer failure detection are discussed.It is found that the defect detection technology based on characteristic gas recognition has advantages such as high accuracy,non-destructive testing,and short detection time.It has great potential in diagnosing buffer layer erosion defects in cables,but it still needs to develop technologies suitable for on-site applications. The following conclusions can be drawn from simulation analysis and systematic review:(1)Water is the premise for the formation of white powder in the buffer layer,so preventing cables from getting wet is the key to avoiding chemical/electrochemical corrosion of the buffer layer.(2)Reasonable adjustment of the physical coordination between the aluminum sheath and the buffer layer is the key to improving the distribution of the electric field between the buffer layers.(3)The combination of buffer layer white powder and radial current concentration erosion conditions is more in line with actual engineering applications.Subsequent research on thermal erosion theory related to buffer layers should focus on the influence of white powder on the electrical characteristic parameters of the buffer layer.(4)The buffer layer defect detection technology based on characteristic gas recognition has broad development prospects.Subsequent research should focus on developing new types of inflatable cables with strong gas detection capabilities and accelerating the exploration and development of on-site portable devices for buffer layer erosion gas generation mechanisms,gas sampling,and gas detection.关键词
高压电缆/XLPE电缆/阻水缓冲层/波纹铝护套/烧蚀机理/故障检测Key words
HV cables/XLPE cables/buffer layer/corrugated aluminum sheath/ablation mechanism/fault detection分类
信息技术与安全科学引用本文复制引用
段肖力,刘雨丰,刘三伟,刘慧聪,钟理鹏..高压XLPE电缆缓冲层烧蚀机理及检测方法综述[J].电工技术学报,2025,40(5):1540-1558,19.基金项目
国家自然科学基金(52107147)和国网湖南省电力有限公司科技项目(5216A5220026)资助. （52107147）
