Research on the Griding Ring Configuration of ±800kV Ultra-High Voltage DC Switchyard Post Insulators

The griding ring configuration of post insulators is one of the key technologies in the design of ±800 kV Ultra-high Voltage (UHV) DC switchyard. The configuration will influence the safety and reliability of insulators directly, and then influence the safe and stable operation of the HVDC system. For this purpose, the three-dimensional simulation model of high voltage bus loop in the DC switchyard was established by a secondary development of the finite element software in the paper. By means of finite element method (FEM), the electric field and potential distribution about equipments and fittings in the loop were calculated, and the effect of electric field and potential distribution about post insulators with different griding ring configuration schemes was discussed. Based on the calculation and discussion, an optimal scheme of the griding ring configuration of post insulators was put forward. Verified by simulation and engineering practice, the optimal scheme could meet the external insulation requirements of post insulators in ±800kV UHV DC switchyard.