冲击电压下变压器油中空间电场测量方法及装置  

Measuring Method and Device for Space Electric Field in Transformer Oil under Impulse Voltage

作　　者：齐波 赵晓林 张书琦[2] 蔡承均 田坤 李成榕 

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206 [2]中国电力科学研究院,北京市海淀区100192

出　　处：《中国电机工程学报》2017年第6期1843-1849,共7页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51477052);国家电网公司科技项目(GYB17201500159)~~

摘　　要：冲击电压下油纸绝缘结构的电场分布特性是变压器绝缘设计的关键环节,目前主要利用仿真软件基于容性场等效进行变压器电场的计算,并在容性场计算结果的基础上乘以一定的裕度系数,作为冲击电压下变压器绝缘涉及的参考依据,但仿真结果缺乏实测手段的支撑和验证。该文提出了冲击电压下油纸绝缘空间电场分布的非接触式实时测量方法,构建了由光路系统、光电转换器件、密封腔体、冲击电源构成的油纸绝缘空间电场测量装置,并利用平板电极对装置性能进行了标定和检验。在17~47k V雷电冲击电压下获得了电场测量值曲线和电场实际值曲线,并用相关系数描述二者之间的吻合程度。结果表明本装置最小可测峰值为3.49k V/mm的雷电冲击电场,最大误差小于3.56%,满足冲击电场测量的试验需求。The electric field distribution characteristic of the oil-pressboard structure under impulse voltage is the vital part of the design of the transformer insulation. The electric field distribution in the transformers under impulse voltage is usually equivalent to capacitive field and calculated by the simulation software. An appropriate margin is selected according to the calculation result, considering the allowable field strength as well. However, the simulation results are lack of the support and verification of the actual measurement. In this paper, a non-contact real-time measuring method of the space electric field of the oil-pressboard structure under impulse voltage was proposed; and the measuring apparatus was constructed, which was composed of optical system, photoelectric converter device, sealing cavity, impulse voltage generator. The characteristic of measuring apparatus was calibrated and verified by a pair of plate electrodes. Under the lightning impulse voltage of 17~47kV, the curves of the measured electric field and the applied electric field were acquired, and the correlation coefficient was used to describe the degree of agreement between the two. The calibration result under uniform electric field shows that the lightning impulse electric field as low as 3.49kV/mm （peak value） can be measured, with the maximum error of 3.56%, which satisfies the requirement of the impulse electric field measurement.

关 键 词：变压器油 KERR效应 冲击电压 灵敏度 误差 

分 类 号：TM[电气工程]