800 kV MOA电位分布数值分析和测量

Numerical Analysis and Measuring for the Potential Distribution of 800 kV MOA

针对800 kV氧化锌避雷器(MOA)的电位分布,笔者从数值仿真和试验两个方面进行分析。首先,采用有限元法及ANSYS分析了无并联电容时800 kV MOA的电位分布,得到了所有氧化锌组件(MOR)的电压偏差和每单元内MOR所占电压的百分比,并同时求出各法兰之间的部分电容和对地电容。并联电容后将MOA的"静电场"问题转化为"电路"问题,用节点电压法求出并联电容后的电位分布和MOR的电压偏差。接下来,采用自行研制的光纤测量系统对800 kV MOA的电位分布进行了实测,得出了流过MOR的电流分布曲线,从而求得实测电位分布曲线。二者的结果表明,测量结果能较准确的反映MOA的电位分布趋势,而计算方法则能准确的得出各MOR的电压偏差。二者在反映电位分布趋势上取得了一致性。

Numerical analysis and measuring for The potential distribution of 800 kV MOA are introduced in the paper. Firstly, the potential distribution of 800 kV MOA with no parallel connection of capacitors, is studied with the finite element method （FEM）and ANSYS software. All of MOR voltage deviation and MOR voltage share ratios in each unit are obtained. The partial capacitance between every flange and the capacitance to the earth of each flange are also calculated at the same time. After connecting parallel capacitor, MOA ＂electrostatic field＂ issue will be transformed into ＂circuit＂ problem. We can get the partial capacitance by ANSYS, and then calculate the potential distribution of MOA and the voltage deviations of MOR using node potential method （NPM）, when there is parallel connection of capacitors. Then, the potential distribution test of 800 kV MOA has been done by using the designed optic-electric measuring system. The current distribution curve of MOR is gotten, and then the potential distribution is obtained. The results show that the measuring results relative accurately reflect the potential distribution of MOA＇, and the calculating results accurately obtain the voltage deviations of MOR. Both trends reflect the potential distribution achieve consistency.