直流电压下油中空间电场强度对油纸绝缘界面电荷特性的影响研究  

Influence of space electric field strength in oil on interface charge characteristics of oil-paper insulation under DC voltage

作　　者：张书琦[1,2] 高春嘉 赵晓林 孙建涛 苏飞洋 齐波 李成榕[1] ZHANG Shuqi;GAO Chunjia;ZHAO Xiaolin;SUN Jiantao;SU Feiyang;QI Bo;LI Chengrong(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 100026,China;China Electric Power Research Institute,Beijing 100192,China)

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京100026 [2]中国电力科学研究院有限公司,北京100192

出　　处：《绝缘材料》2023年第6期73-81,共9页Insulating Materials

基　　金：中国电力科学研究院有限公司科技项目资助(GYB51201902020)。

摘　　要：直流电压下油纸绝缘界面电荷特性是换流变压器绝缘结构设计的巨大挑战。传统电阻-电容(RC)模型仅考虑由于油、纸材料的介电常数、电导率不同而引起的界面极化电荷,忽略了其他形式来源的电荷及其对空间电场的影响。本文基于Kerr电光效应原理,搭建了油纸绝缘结构油中空间电场特性非接触式、实时测量平台,针对变压器油-电工绝缘纸、变压器油-变压器纸板组成的复合绝缘结构,获得了不同极性、不同幅值直流电压下油中空间电场特性,计算并分析了界面电荷密度与RC模型计算的极化电荷密度的差异。结果表明:当油中场强较低时,油纸界面电荷以极化电荷为主;随着油中场强的增加,油纸界面电荷密度与RC模型计算极化电荷密度差异逐渐增大,出现了其他形式电荷的积聚,且其在界面总电荷量中占比逐渐增加,对电场强度的影响逐渐增大。The interface charge characteristics of oil-paper insulation under DC voltage is a huge challenge in the design of the insulation structure of converter transformers.The traditional resistance-capacitance(RC)model only considers the interface polarization charges due to the different dielectric constants and electrical conductivity of oil and paper materials,ignoring other forms of charges and their effects on the space electric field.In this paper,based on Kerr electro-optic effect,a non-contact,real-time measurement platform for space electric field characteristics in oil of oil-paper insulation was built.Aimed at the composite insulation structure consist of transformer oil-electrical insulation paper and transformer oiltransformer paperboard,the space electric field characteristics in the oil under DC voltage with different polarity and different amlitude were obtained.The difference between the total interface charge density and the polarization charge density calculated by the RC model was analyzed.The results show that when the electric field intensity in the oil is low,the total interface charge is dominated by polarization charges.With the increase of the electri field intensity in the oil,the difference between the total interface charge density and the polarization charge density calsulated by RC model increases gradually,indicat other forms of charge accumulates and its proportion in total charge increases gradually,the effect of it on the electric field increases gradually.

关 键 词：换流变压器 油纸绝缘 直流电压 Kerr电光效应 界面电荷 空间电场 

分 类 号：TM403.3[电气工程—电器]