考虑空间电荷效应的步进应力法获取XLPE绝缘直流电压耐受指数  

Obtaining DC Voltage Endurance Coefficient of XLPE Insulation by Step Stress Method Considering Space Charge Effect

作　　者：马志鹏 李宁一 陈新岗 谭世耀 范益杰 MA Zhipeng;LI Ningyi;CHEN Xingang;TAN Shiyao;FAN Yijie(School of Electrical and Electronic Engineering,Chongqing University of Technology,Chongqing 400054,China;Chongqing Engineering Research Center of Energy Internet,Chongqing 400054,China)

机构地区：[1]重庆理工大学电气与电子工程学院,重庆400054 [2]重庆市能源互联网工程技术研究中心,重庆400054

出　　处：《高电压技术》2025年第2期925-935,共11页High Voltage Engineering

基　　金：重庆市教育委员会科学技术研究项目(KJZD-K202101103,KJQN202201133);重庆理工大学科研启动基金(2021ZDZ016)。

摘　　要：直流电场下的场强畸变现象显著影响交联聚乙烯(XLPE)的长期耐压特性。现有的XLPE电压耐受指数n值的获取方法未考虑畸变电场对绝缘损伤的影响,导致同类样品在交、直流不同测试条件下获取n值相差较大。因此建模表征了畸变场强对累积损伤的影响,该模型考虑温度、空间电荷密度与外施场强等因素,通过将该模型应用于步进应力加速寿命试验,获取了不同类型畸变场强产生的累积损伤D_(sc)。提出一种步进应力试验数据分析方法,该方法通过求解m阶累积损伤方阵的特征值获取n值,分析了4组步进应力试验累积损伤数据,获取了未考虑与考虑D_(sc)时的n值范围,前者为14.42-15.36,后者为13.69-13.88,表明畸变场强使n值呈现减小的趋势。此外,提高升压步长ΔU使D_(sc)减小,最小D_(sc)=8.3×10^(21),对应的n值与未考虑D_(sc)时仅偏差3.7%,表明步进应力试验中选取更大的ΔU有助于削弱场强畸变的影响。The phenomenon of electric field distortion under DC electric field significantly affects the long-term voltage endurance characteristics of cross-linked polyethylene(XLPE).Existing methods for obtaining the n value of the voltage endurance coefficient of XLPE do not take into account the effect of the distortion field on insulation damage,resulting in large differences in the n value obtained for similar samples under different test conditions in AC and DC.Therefore,the effect of aberrant field strength on the cumulative damage is characterized by modeling,which takes into account factors such as temperature,space charge density,and externally applied field strength,etc.The cumulative damage D_(sc) produced by different types of aberrant field strengths is obtained by applying the model to the accelerated life test of stepping stress.A method is proposed to analyze the data from the stepping stress test,which obtains the n value by solving the ei-genvalue of the m-order cumulative damage square matrix.Four sets of cumulative damage data from the step stress tests are analyzed,and the n values are obtained with and without considering D_(sc),the former is in the range of 14.42~15.36 and the latter is in the range of 13.69~13.88,which indicates that the aberrant field strengths show a tendency to reducing the n value.In addition,increasing the step-up∆U decreases D_(sc) to a minimum of D_(sc)=8.3×10^(21),corresponding to an n value that deviates only by 3.7%from the one without taking D_(sc) into account,indicating that the selection of a larger∆U in the step-stress test helps to weaken the effect of the field-strength distortion.

关 键 词：交联聚乙烯 步进应力法 场强畸变 空间电荷 累积损伤 

分 类 号：TM24[一般工业技术—材料科学与工程]