铝护套结构对XLPE电缆绝缘屏蔽层悬浮电位影响  

Influence of aluminum sheath structure on floating potential of XLPE insulation shielding layer

作　　者：陈杰 李文杰 刘顺满 周韫捷 杨天宇 刘刚[3] CHEN Jie;LI Wenjie;LIU Shunman;ZHOU Yunjie;YANG Tianyu;LIU Gang(State Grid Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,China;China Electric Power Research Institute,Wuhan 430074,China;School of Electric Power,South China University of Technology,Guangzhou 510641,China;State Grid Shanghai Municipal Electric Power Company,Shanghai 200122,China)

机构地区：[1]国网江苏省电力有限公司电力科学研究院,江苏南京211103 [2]中国电力科学研究院有限公司武汉分院,湖北武汉430074 [3]华南理工大学电力学院,广东广州510641 [4]国网上海市电力公司,上海200122

出　　处：《电力工程技术》2022年第6期147-153,162,共8页Electric Power Engineering Technology

基　　金：国家电网有限公司科技项目“高压XLPE电缆缓冲层故障机理与检测关键技术研究”。

摘　　要：近年来,高压交联聚乙烯(XLPE)电缆缓冲层烧蚀缺陷频繁发生,对电缆安全运行造成严重影响,研究如何降低缓冲层缺陷造成的影响迫在眉睫,文中通过改进铝护套结构以降低缓冲层烧蚀缺陷的严重程度。首先,理论分析形成缓冲层烧蚀缺陷的原因;然后,建立缓冲层分压模型;最后,以某缺陷电缆为仿真对象,计算在含有缓冲层白斑缺陷时,分别降低铝护套最小内径以及铝护套波谷处曲率后的绝缘屏蔽层悬浮电位以及缓冲层电场强度值变化。以文中缺陷电缆为例,由仿真定量分析得出,当铝护套最小内径减小后,绝缘屏蔽层悬浮电位下降30%,缓冲层间电场强度值下降30.9%;当铝护套波谷处曲率降低后,绝缘屏蔽层悬浮电位下降13.7%,缓冲层间电场强度值下降13.3%。当出现缓冲层白斑后,铝护套最小内径和铝护套波谷处曲率的减小可降低绝缘屏蔽层悬浮电位以及缓冲层间电场强度值,从而抑制缓冲层间局部放电的发生,降低缓冲层缺陷造成的影响。In recent years,high voltage cross linked polyethylen(XLPE)cable buffer layer ablation defects occur frequently,which has a serious impact on the safe operation of the cable.It is extremely urgent to study how to reduce the impact of the buffer layer defects.Therefore,how to reduce the severity of the buffer layer ablation defects by improving the aluminum sheath structure is studied in this paper.Firstly,the reason of ablative defect of buffer layer is analyzed theoretically.Secondly,the buffer layer voltage calculation model is established.Finally,a defect cable is taken as the simulation object to calculate the suspension potential and the electric field intensity of the buffer layer after reducing the minimum inner diameter and the curvature at the trough of the aluminum sheath respectively with the white spot defect of the buffer layer.Taking the defective cable as an example,the simulation quantitative analysis shows that when the minimum inner diameter decreases,the suspension potential of insulation shielding decreases by 30%,and the electric field intensity between buffer layers decreases by 30.9%.When the curvature at the trough of the aluminum sheath decreases,the suspension potential of insulating shield decreases by 13.7%,and the electric field intensity between buffer layers decreases by 13.3%.When the buffer layer white spot appears,the decrease of the minimum inner diameter and the curvature at the trough of the aluminum sheath lead to the suspension potential of the insulating shield layer and the electric field intensity between the buffer layer decrease,thus reducing the possibility of partial discharge and the impact caused by the buffer layer defect.

关 键 词：交联聚乙烯(XLPE)电缆 电缆缓冲层 电场分布 分压模型 电缆铝护套 电缆烧蚀 

分 类 号：TM205[一般工业技术—材料科学与工程]