电容屏破损缺陷局部放电过程规律特征及仿真分析  

Characteristics and Simulation Analysis of Partial Discharge Process of Condenser Foil Layer Defect

作　　者：杨帆[1] 张玉琛 王鹏博[1] 吴兴旺 吴杰 Yang Fan;Zhang Yuchen;Wang Pengbo;Wu Xingwang;Wu Jie(State Key Laboratory of Power Transmission Equipment Technology Chongqing University,Chongqing 400044 China;State Grid Anhui Power Supply Company,Hefei 230061 China)

机构地区：[1]输变电装备技术全国重点实验室(重庆大学),重庆400044 [2]国网安徽省电力有限公司,合肥230061

出　　处：《电工技术学报》2024年第9期2860-2872,共13页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划项目(2021YFB2401700);国家电网总部科技项目(5500-202220136A-1-1-ZN)资助。

摘　　要：油纸电容式变压器套管因性能好、成本低而被广泛采用。当电容屏存在边缘破损工艺缺陷时易发生局部放电,进而会改变油纸绝缘性能,缩短套管使用寿命,严重时危及电网设备安全运行。为研究电容屏破损局部放电过程变化规律,明确放电发展阶段,该文搭建了缺陷套管放电实验模型分析局放过程中相位谱图、放电量等参数发展规律,并基于实验规律及流体漂移扩散理论、固体双极电荷传输理论,建立了末屏缺陷针板沿面放电过程仿真模型,结合仿真中电荷形态变化、放电时间及油纸界面电荷密度分布对电容屏破损放电过程进行阶段划分:放电初始阶段,铝箔尖端电荷聚集发生电晕放电;放电发展阶段,尖端处带电粒子在电场作用下向油纸发展,小部分达到油纸界面产生沿面放电;放电破坏阶段,经过长时间沿面放电进入油纸发生预击穿,电场强度更大使带电粒子能量更高,冲击油纸表面造成油纸表面纤维素断裂炭化形成通道。仿真结果与实验结论相对应,证明了仿真的有效性。该文的研究成果进一步阐明了油纸套管电容屏工艺缺陷局部放电的过程及机理。Oil-paper capacitive transformer bushings are widely used.However,partial discharge(PD)is a serious threat to safe and stable operation of power system.In order to study the variation law of PD process with condenser foil layer damage and clarify the PD development stage,this paper establishes a defect bushing PD model to analyze the development law of parameters.Based on fluid drift diffusion theory and solid bipolar charge transfer theory,a simulation model for the surface PD process of the end screen defect needle plate is established,which combines the changes in voltage,charge morphology,PD duration and the charge density distribution at the oil-paper interface.Firstly,build a test sample bushing with process defect.According to a set of 220 kV test apparatus to test the relationship between the voltage level and PD parameters,capacitance,and discharge carbonization trace.Then based on the hydrodynamic drift-diffusion model and the bipolar charge transport model,a needle-plane surface PD simulation model was built to simulate the process and space charge distribution of PD.Finally,with the experimental phenomenon and simulation results,the 3 stages PD process and space charge distribution at different applied voltage are provided.Simulation and experiment results show that the bushing in the AC electric field causes the capacitor core plate to generate static electricity and causes electric field distortion,which results in charge migration and forming streamer.Tip defective foil layer is at extremely inhomogeneous electric field,the needle tip part of the high voltage positive pole,collision ionization will occur first at the tip,collision formation of positive ion density increases to form streamer,negative ions at the tip of the compound.Through experimental verification in needle-plane surface discharge simulation,it can be assumed that the process of PD is as follows:(1)At the initial stage,corona discharge at the tip of the foil layer can be observed.At this time the electric field strength near the ti

关 键 词：油纸套管 电容屏工艺缺陷 针-板沿面放电 电荷分布仿真 放电过程阶段 

分 类 号：TM216[一般工业技术—材料科学与工程]