变压器油中阴极放电起始过程的气泡模型
发布时间：2018-10-22 09:04
【摘要】：为研究冲击电压下变压器油中阴极放电起始过程的物理模型,统计分析了不同冲击电压下稍不均匀场中变压器油的放电时延,利用Laue图获得了不同脉冲下的平均放电统计时延和放电形成时延,建立了稍不均匀场中阴极流注起始的"气泡"模型:阴极表面微凸起处的场致发射电流加热电极附近的液体;当液体达到一定过热度之后,过热液体内会产生气泡核心,气泡核心在场致发射电流的持续加热作用下会膨胀生长,直至气泡内放电产生。利用过热液体的汽化成核理论获得了成核时间的数学表达式,并结合F-N理论获得了放电统计时延和外施电场的关系式。结果表明,放电统计时延主要由电极附近过热液体的成核时间和气泡的膨胀形变时间组成,且成核时间占有主要部分;放电统计时延ts与间隙内电场E满足t_sE~3=ae~b/E。
[Abstract]:In order to study the physical model of cathode discharge initiation process in transformer oil under impulse voltage, the discharge delay of transformer oil in slightly uneven field under different impulse voltage is analyzed statistically. By using Laue diagram, the statistical delay of average discharge and the time delay of formation of discharge are obtained, and the bubble model of cathode flow initiation in slightly inhomogeneous field is established: the liquid near the electrode is heated by the field emission current at the micro-protruding point on the surface of the cathode; When the liquid reaches a certain degree of superheat, the bubble core will be produced in the superheated liquid, and the bubble core will expand and grow under the continuous heating of the field emission current until the discharge in the bubble is produced. The mathematical expression of nucleation time is obtained by using the vaporization nucleation theory of superheated liquids, and the relationship between the statistical time delay of discharge and the external electric field is obtained by combining the F-N theory. The results show that the statistical delay is mainly composed of the nucleation time of the superheated liquid near the electrode and the expansion deformation time of the bubble, and the nucleation time is the main part of the nucleation time, and the discharge statistical delay ts and the electric field E in the gap satisfy the t _ S _ E _ 3ae _ (b / E).
【作者单位】： 西安交通大学电气工程学院;
【分类号】：TM41
[Abstract]:In order to study the physical model of cathode discharge initiation process in transformer oil under impulse voltage, the discharge delay of transformer oil in slightly uneven field under different impulse voltage is analyzed statistically. By using Laue diagram, the statistical delay of average discharge and the time delay of formation of discharge are obtained, and the bubble model of cathode flow initiation in slightly inhomogeneous field is established: the liquid near the electrode is heated by the field emission current at the micro-protruding point on the surface of the cathode; When the liquid reaches a certain degree of superheat, the bubble core will be produced in the superheated liquid, and the bubble core will expand and grow under the continuous heating of the field emission current until the discharge in the bubble is produced. The mathematical expression of nucleation time is obtained by using the vaporization nucleation theory of superheated liquids, and the relationship between the statistical time delay of discharge and the external electric field is obtained by combining the F-N theory. The results show that the statistical delay is mainly composed of the nucleation time of the superheated liquid near the electrode and the expansion deformation time of the bubble, and the nucleation time is the main part of the nucleation time, and the discharge statistical delay ts and the electric field E in the gap satisfy the t _ S _ E _ 3ae _ (b / E).
【作者单位】： 西安交通大学电气工程学院;
【分类号】：TM41
【参考文献】
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