220 kV金属氧化物避雷器电位分布研究

Research on the potential distribution of 220 kV metal oxide surge arresters

由于交流无间隙金属氧化物避雷器(MOA)对地杂散电容的存在,在持续运行电压下MOA沿电阻片轴向的荷电率分布不均匀,靠近高压端的电阻片一般比远离高压端的电阻片承担更大的电压负荷,并且这一情况随着MOA高度的增加和元件数的增多以及安装底座高度的减小而愈加严重。MOA的电位分布严重影响电阻片的工作荷电率,电阻片的局部荷电率过高会引起MOA的加速老化和热崩溃。改善MOA的电位分布,可以降低电阻片的局部荷电率,提高MOA运行的可靠性和安全性。采用ANSYS14.5分析软件,以220 kV电压等级所选用的Y10W-216/562W型MOA为例进行了电位分布仿真计算,对几种改善MOA电位分布的措施进行了分析。

Due to the existence of stray capacitance of the AC gapless metal oxide surge arrester(MOA)to the ground,the electric load rate of the MOA along the axial direction of the resistor sheet is not uniform under continuous operating voltage.The resistor sheet bears a greater voltage load,and this becomes more and more serious as the height of the MOA increases and the number of components increases and the height of the mounting base decreases.The potential distribution of the MOA seriously affects the working load rate of the resistance sheet.If the local load rate of the resistance sheet is too high,it will cause accelerated aging and thermal collapse of the MOA.Improving the potential distribution of MOA can reduce the local load rate of the resistance sheet and improve the reliability and safety of MOA.Using analysis software of ANSYS14.5,taking the Y10W-216/562W MOA selected for 220 kV voltage level as an example,the potential distribution simulation calculation was performed,and several measures to improve the MOA potential distribution were analyzed.