工频电场下全尺寸电缆的空间电荷检测系统研制  

Development of Space Charge Measurement System Used for Full-size Cable Under Power Frequency Electric Stress

作　　者：刘德远 张昱 邓云坤 吴建东[1] 尹毅[1] LIU Deyuan;ZHANG Yu;DENG Yunkun;WU Jiandong;YIN Yi(Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;Postdoctoral Workstation of Yunnan Power Grid Corporation, Kunming 650217, China)

机构地区：[1]上海交通大学电气工程系,上海200240 [2]云南电网有限责任公司博士后工作站,昆明650217

出　　处：《高电压技术》2019年第10期3327-3334,共8页High Voltage Engineering

基　　金：国家自然科学基金(51737009);中国南方电网科技项目(K-YNKJXM20160149)~~

摘　　要：由于交联聚乙烯电力电缆长期运行在交流电压下,对于其内部空间电荷在交流电场下的分布规律研究十分必要。为研究电缆绝缘中的空间电荷在交流电场下的动态特性,基于电声脉冲法研制了工频电场下全尺寸电缆空间电荷检测装置。利用自动均分移相原理,在不设置相位检测和同步模块的条件下,通过调整周期电场和检测脉冲的频率关系完成周期电场下的高相位分辨率空间电荷检测。通过Multisim仿真确定检测系统的硬件参数,保证了系统的可行性。最后在工频电场下,以电压等级8.7/10 kV的交联聚乙烯电缆为研究对象进行了全尺寸空间电荷的检测。为了克服电场频率的波动,提出2种不同的数据分析模式。根据交流相位误差与平均次数的关系确定正确的分析模式,确保空间电荷信息的准确性。结果表明:该空间电荷检测装置可获得1.79°的高相位分辨率,通过不同电场下的空间电荷检测验证了检测系统的准确性,并获得了准确的空间电荷信息。It is necessary to study the distribution of space charge after the long-term operation of the cross-linked poly- ethylene(XLPE) power cable under AC stress. In order to study the dynamic characteristic of space charge in the insulation of cable, we developed a space charge measurement system used for full-size cable under AC electric stress based on the pulsed electro-acoustic (PEA) method. Using automatic equal phase shift principle(AEPS), we could obtain a high phase-resolution space charge signal by setting the frequency of the periodic electric field and detecting pulse properly, without any phase detection and synchronization module. The hardware parameters were determined by the Multisim simulation, which ensures the feasibility of the system. The space charge measurement and analysis were carried out on a 8.7/10 kV XLPE cable under 50 Hz AC stress. In order to overcome the frequency fluctuation, two data analysis modes were pointed out. The accuracy of the space charge profile could be determined by the relationship of the AC fre- quency error and average time. The results show that a relatively high phase resolution of 1.79°, as well as accurate space charge profiles, can be obtained. The high accuracy of the measurement system is also proved through the space charge detection under different electric fields.

关 键 词：交流电场 交联聚乙烯电缆 空间电荷 电声脉冲法 自动均分相移检测原理 

分 类 号：TM75[电气工程—电力系统及自动化]