Electric Field Calculation and Optimization of Shielding Device for Filter Capacitor Tower in ± 1100kV Indoor DC Yard

As the key equipment in the DC yard, filter capacitor tower is a tower-type assembly consisting of capacitor racks, supporting insulators, connection line and so on. Due to the complex structure of filter capacitor tower, serious potential and electric field distortion occurs more frequently. It is necessary to analyze the characteristic of potential and electric field distribution in depth. In this paper, the finite element method is used to simulate the indoor DC yard of the ± 1100 kV converter station, and the distribution of the potential and electric field of the DC yard is obtained. On the basis of this, the sub-model technique is used to calculate the surface electric field distribution on the surface of filter capacitor tower. The electric field distribution of DC filter capacitor tower with the shielding devices designed for typical outdoor solution was calculated. According to the calculation results, for the indoor DC yard, the structure parameters of filter capacitor tower was adjusted in the some aspects. After the optimization, the maximum surface field strength of the key positions is reduced from 1439 V/mm to 1197 V/mm (lower by 16.82%) and appears at the edge chamfer of the top shielding cover. the shielding effect is obvious. The calculation results could provide valuable references for the design of UHVDC filter capacitor tower.