交流电场下变压器油中气泡动力学特性仿真

Bubble Dynamics Simulation in Transformer Oil under AC Electric Field

对交流电压下变压器油中柱板电极间气泡动力学特性进行了数值仿真研究。建立了交流电压下变压器油中气泡运动二维数值模型,通过麦克斯韦应力张量在气泡界面上的面积分求得气泡受到的电动力,通过气泡受力分析获得交流电场中不同位置释放后气泡的运动轨迹。计算结果显示在工频交流电场作用下,气泡在柱板电极间场强集中区域存在振荡平衡位置,不同大小的气泡对应的振动平衡位置比较接近,且处于柱板电极间场强集中区域。这意味着气泡有可能在该位置出现聚集,导致油间隙击穿电压的降低。

The dynamics of gas bubbles in transformer oil was theoretically explored. A numerical model was introduced for the bubble dynamics in the transformer oil under AC electric field. The electrodynamic force was calculated by integrating the Maxwell stress tensor on the surface of the bubble, and then the bubble trajectory was obtained through the force calculation of the bubble under the AC electric field. Notably, trajectories calculated indicate the bubble aggregation in concentrated area of the electric field between the needle-plane electrode, and different bubble radius will affect the trajectory of the bubble. Also, different bubble radiuses cause a small change in the equilibrium position of bubble between the electrodes. It is concluded that the bubble can play a catalytic role in the breakdown of the oil gap.