Sensitivity Analysis for the Space-Charge-Free Electric Field on ±1100kV UHVDC Transmission Lines

In this paper, four methods of calculating the surface electric field of the bipolar HVDC transmission lines were compared. To study the influence factors on the space-charge-free electric field of the bundle surface quantitatively, which include conductor radius, bundle spacing, polar distance and the height of conductors, sensitivity analysis method was introduced. Two sensitivity indexes were calculated to describe the influence of the transmission line parameters, namely the local sensitivity and the global sensitivity based on partial derivative. The work done in this paper can provide a useful preference for further ±1100kV UHVDC transmission lines design.