晶型对等规聚丙烯电导电流和空间电荷特性的影响  

Influence of Crystalline Phase on Conduction Current and Space Charge in Isotactic Polypropylene

作　　者：滕陈源 张灵[1,3] 周远翔 张云霄[5] 莫雅俊 周仲柳[1] TENG Chenyuan;ZHANG Ling;ZHOU Yuanxiang;ZHANG Yunxiao;MO Yajun;ZHOU Zhongliu(State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments,Tsinghua University,Beij ing 100084,China;School of Electrical Engineering,Wuhan University,Wuhan 430072,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi＇an Jiaotong University,Xi＇an 710049,China;School of Electrical Engineering,Xinjiang University,Urumqi 830047,China;Electric Power Planning ＆ Engineering Institute,Beijing 100120,China;Hangzhou Power Supply Company,State Grid Zhejiang Electric Power Co.,Ltd.,Hangzhou 310052,China)

机构地区：[1]清华大学电力系统及发电设备安全控制和仿真国家重点实验室,北京100084 [2]武汉大学电气工程学院,武汉430072 [3]西安交通大学电力设备电气绝缘国家重点实验室,西安710049 [4]新疆大学电气工程学院,乌鲁木齐830047 [5]电力规划设计总院,北京100120 [6]国网浙江省电力有限公司杭州供电公司,杭州310052

出　　处：《高电压技术》2018年第8期2679-2686,共8页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2014CB239501);国家自然科学基金(51707100;51377089);中国博士后科学基金(2017T100079);电力设备电气绝缘国家重点实验室开放课题(EIPE16208)~~

摘　　要：聚丙烯材料性能改善过程中,材料内部会出现以α晶或β晶为主的2种晶型。为研究晶型对等规聚丙烯（iPP）电导电流和空间电荷特性的影响,选用α和β成核剂制备了具有不同晶型的iPP–pure（对照组）、iPP–α和iPP–β试样,开展了25℃下电导电流、空间电荷和直流击穿特性的研究。结果表明：iPP–β正负直流击穿强度最高,而iPP–α最低;3组iPP试样的电导电流大小为iPP–α〉iPP–pure〉iPP–β,空间电荷限制电流的转折电压大小为iPP–α〉iPP–β〉iPP–pure;-20 MV/m电场强度极化30 min后,3组iPP试样在极化过程中均出现正负空间电荷积聚;去极化过程中iPP–pure中空间电荷积聚量最大,而iPP–α中最少。分析认为：α晶和β晶的晶胞形态使得iPP–α中存在大量浅陷阱、iPP–β中平均陷阱深度较深;载流子在iPP–α中容易迁移并产生俄歇效应,而在iPP–β中容易在试样表面附近被捕获。An α or β crystalline phase will appear primarily during the improvement of polypropylene materials. To study the influences of crystalline phase on conduction current and space charge in isotactic polypropylene（iPP）, α and β nucleating agents are adopted separately to prepare iPP samples with different crystalline phases, denoted as iPP–pure, iPP–α, and iPP–β, for the study of conduction current, space charge, and DC breakdown characteristics at 25 ℃. The results show that iPP–β possesses the maximum breakdown strength under both positive and negative DC voltages, while iPP–α is the minimum. The magnitude of conduction current is： iPP–α〉 iPP–pure 〉iPP–β, and the transition voltage of space charge limited current is： iPP–α〉 iPP–β〉 iPP–pure. Both positive and negative space charges can be accumulated in three groups of iPP samples after 30 minutes polarization under-20 MV/m at 25 ℃. During the depolarization process, the amount of space charge accumulated in iPP–pure is the largest, while iPP–α is the smallest. Analyses reveal that the crystalline morphologies of α crystalline phase and β crystalline phase can result in the formation of shallow traps in iPP–α and deep traps in iPP–β, respectively, which will lead to a larger carrier mobility in iPP–α accompanying the Anger effect and capture space charge near the surface of iPP–β sample.

关 键 词：等规聚丙烯 晶型 电导电流 空间电荷 直流击穿 

分 类 号：TM21[一般工业技术—材料科学与工程]