考虑末端电压的长距离海缆耐压试验中新频率约束  

A new frequency constraint for the long distance cable withstand voltage test considering terminal voltage

作　　者：孙凯 潘文霞[1] 朱正鼎 赵坤 陈洁[3] SUN Kai;PAN Wenxia;ZHU Zhengding;ZHAO Kun;CHEN Jie(College of Energy and Electrical Engineering,Hohai University,Nanjing 210098,China;Huai′an Hongze District Power Supply Branch,State Grid Jiangsu Electric Power Co.,Led.,Huai′an 223100,China;Guodian Nanjing Automation Co.,Ltd.,Nanjing 210032,China)

机构地区：[1]河海大学能源与电气学院,江苏南京210098 [2]国网江苏省电力有限公司淮安市洪泽区供电公司,江苏淮安223100 [3]国电南京自动化股份有限公司,江苏南京210032

出　　处：《电力科学与技术学报》2020年第5期96-102,共7页Journal of Electric Power Science And Technology

基　　金：国家自然科学基金(51377047);高等学校学科创新引智计划(B14022)。

摘　　要：长距离海底电缆在进行交流耐压试验时由于容升现象,沿线电压升高,其升高的数值与电缆长度和试验电源频率有关。极端条件下,该数值会威胁到电缆的耐压水平从而阻碍了电缆耐压试验的进行。在此背景下,以研究电缆末端电压为目的,建立一种计及电缆护层的分布参数等值电路模型。基于该模型,推导单芯电缆沿线电压计算公式,并通过仿真验证其计算公式的正确性,继而探究沿线电压与电缆长度以及试验电源频率的关系,从而得知电缆长度越长,其沿线电压受试验频率变化越明显。最后为限制末端电压幅值,以220 kV XLPE电缆为例,对于不同长度的电缆耐压试验的电源频率提出新的约束范围,给现场耐压试验设计人员提供指导性意见。During the AC voltage withstand test,the voltage along the long distance submarine cable would be increased due to the capacitance effect.The elevated voltage value is related to the cable length and the test power supply frequency.Under extreme conditions,this value might threaten the withstand voltage level of cable and hinder voltage withstand test.In this paper,a distributed parameter equivalent circuit model considering cable sheath is established to study the cable terminal voltage.Based on this model,the calculation formula of the voltage along a single core cable is obtained.Then the obtained formula is verified by a simulation.Furthermore,the relationship among the voltage along the cable,the cable length and the power frequency is explored.Research results indicate that,the influence degree of test voltage frequency on the voltage along cable increases with the increasing cable length.Finally,a new frequency scope limitation of withstand test source is proposed for the 220 kV crosslinking polyethylene cable with different lengths to restrict the terminal voltage amplitude.It provides some guidance to field test designers.

关 键 词：耐压试验 长电缆容升 试验电源频率 末端电压 

分 类 号：TM831[电气工程—高电压与绝缘技术]