摘要
变压器油中纤维杂质颗粒在高压梯度场环境中易发生集聚,形成“贯通性”杂质颗粒小桥,诱发击穿放电的发生。受到强迫油循环风冷(OFAF)或导向风冷(ODAF)的影响,现场大型电力变压器中绝缘油处于流动状态,导致悬浮在绝缘油中的纤维杂质颗粒的运动特性发生改变。基于此,该文采用动力学分析方法构建了单颗粒纤维杂质在流动绝缘油中的固-液两相流多物理场模型,研究了在不同纤维杂质颗粒尺寸、电场强度幅值、油流速度、油温、初始速度和位置条件下单颗粒纤维杂质在高压直流场中的运动轨迹,获得了纤维杂质颗粒在流动绝缘油中的运动规律和影响因素。结果表明:纤维颗粒的初始速度仅对最大运动速度有影响,对颗粒与电极的碰撞次数无影响;在均匀电场中,纤维颗粒初始位置的改变,对其运动特性无影响;油流速增大将导致纤维杂质颗粒通过极板的速度变快,使得颗粒与电极板的碰撞次数减小,直径为50μm的纤维杂质颗粒在电场强度为10kV/cm、油流速度为0.4m/s的条件下几乎不会和电极发生碰撞,表明在该条件下很难形成杂质颗粒小桥,绝缘油流速是研究大型电力变压器绝缘油内纤维杂质颗粒集聚特性时要重点考虑的因素。
During the production,transportation,installation,insulating oil filling,operation and maintenance of large power transformers,impurities with different properties and sizes will be mixed.Through the analysis of on-site insulating oil,more than 90%of the impurities in the insulating oil are fiber impurity particles.Therefore,domestic and foreign scholars have mainly carried out research on the insulation ability of insulating oil containing fibrous impurities particles at rest.However,under the influence of forced-oil and forced-air cooling(OFAF)or forced-directed-oil and forced-air cooled(ODAF),the insulating oil actually used in large transformers is always in the flow state,which leads to the change of the movement characteristics of fiber impurity particles suspended in the insulating oil.Therefore,the influencing factors of the movement characteristics of fiber impurity particles in oil flow state are studied in this paper.First of all,through the force analysis of fiber impurity particles in flowing insulating oil,this paper uses the dynamic analysis method to build a solid-liquid two-phase flow multi physical field model of single particle fiber impurity moving in flowing insulating oil.Secondly,the corresponding formula is added to each physical field,and the geometric model is divided.Finally,the trajectory of fibrous impurity particles in oil flow is obtained by calculation.In this model,the solid-liquid two-phase flow multi physical field model is used to solve the problem of insulating oil flow.In order to study the movement characteristics and influence characteristics of single particle fiber impurities under high-voltage DC field under different particle size,electric field amplitude,oil flow velocity,oil temperature,initial velocity and position conditions.By changing the motion parameters in the physical field,each influencing factor is explored.The following conclusions can be drawn through simulation analysis:(1)The transverse motion of fiber particles is only related to the electric field forc
作者
张国治
闫伟阳
王堃
陈康
张晓星
Zhang Guozhi;Yan Weiyang;Wang Kun;Chen Kang;Zhang Xiaoxing(Hubei Engineering Research Center for Safety Monitoring of New Energy and Power Grid Equipment Hubei University of Technology,Wuhan,430000,China;Xiangyang Industrial Institute of Hubei University of Technology,Xiangyang,44102,2 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2023年第9期2500-2509,共10页
Transactions of China Electrotechnical Society
基金
国家自然科学基金项目(52107144)
湖北省教育厅科技项目(Q20211401)资助。
关键词
大型变压器
流动绝缘油
纤维杂质颗粒
运动
Large transformer
flowing insulating oil
fiber impurity particles
motion
