ABSTRACT: The three-dimensional finite element method is used to calculate the electric field of insulator strings for ±800 kV UHV DC transmission lines.
After the comparison of electric field distribution and voltage distribution with different ring diameter, tube diameter and shielding depth, the dimension and position of grading ring is recommended.
The ball-gap method is used to measure the voltage distribution of insulator strings for ±800 kV UHV DC transmission lines.
Test results are consistent with calculation results.
Findings of this professional paper are important for the grading ring configuration of ±800 kV UHV DC transmission lines.
KEY WORDS: electric field; finite element method; grading ring; insulator strings; optimization; UHV transmission lines.