有载分接开关级间气泡形变规律及对电场分布的影响  

Bubble Deformation Law Between the Interstage of on Load Tap Changer and Its Influence on Electric Field Distribution

作　　者：李鹏[1] 李嘉熙 汪可[1] 张书琦[1] 李刚[1] 李戈琦 杨帆[1] LI Peng;LI Jiaxi;WANG Ke;ZHANG Shuqi;LI Gang;LI Geqi;YANG Fan(China Electrical Power Research Institute,Haidian District,Beijing 100192,China)

机构地区：[1]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》2023年第6期2460-2471,共12页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2021YFB2402100)。

摘　　要：有载分接开关(on-load tap changer,OLTC)机构快速动作不可避免地会产生气泡,容易在OLTC级间部位诱发局部放电。该文针对气泡在OLTC主触头级间形变及电场畸变特性开展研究。首先,构建包含气泡及变压器油的OLTC主触头气液两相流模型,对主触头级间电场进行仿真,通过Kerr效应的光电试验平台验证了仿真结果。然后,以OLTC实际工况作为边界条件,研究油温、气泡体积、变压器油流量对气泡形变及电场分布的影响。结果显示,毫米级气泡在经过OLTC级间时经历多次拉伸及形状恢复,其长短轴比大于1.5,气泡引起OLTC级间场强增大10%左右。当OLTC油室内变压器油流的流量达到7L/min时,经过级间的气泡开始出现破裂,形成内部场强相近的两枚子气泡。级间场强达到气泡击穿场强时,两枚气泡均可能发生放电,从而增大了油隙放电的概率。该文的研究内容与结论可为后续OLTC设计及运行提供有益参考。The rapid action of the on-load tap-changer(OLTC)mechanism will inevitably generate air bubbles,which are easy to induce partial discharges in the interstage part of OLTC.The deformation of bubbles and the characteristics of electric field distortion between the main contact interstage of OLTC are investigated in this paper.First,a gas-liquid two-phase flow model of OLTC main contact is constructed,which contains air bubbles and transformer oil.Then,the electric field between the main contacts is simulated and simulation results are verified by the photoelectric test platform of the Kerr effect.Subsequently,taking the actual working condition of OLTC as the boundary condition,the effects of oil temperature,bubble volume,and the rate of transformer oil flow on the bubble deformation and electric field distribution are investigated.The results show that millimeter-level bubbles undergo multiple stretching and shape recovery when passing through the OLTC interstage.The ratio of the long and short axis of the bubble is more than 1.5,and the induced field strength increases by about 10%.When the oil flow rate of the transformer in the OLTC oil chamber reaches 7L/min,the bubbles passing through the interstage begin to burst,forming two sub-bubbles with similar internal field strengths.If the field strength between the interstage reaches the bubble breakdown field strength,both bubbles may discharge,and thereby the probability of oil gap discharge is increased.The research work in this paper provides a beneficial reference for the subsequent design and operation of OLTC.

关 键 词：有载分接开关 电场仿真 气泡形变 气泡体积 变压器油流流量 

分 类 号：TM403[电气工程—电器]