Resultant Electric Field Reduction With Shielding Wires Under Bipolar HVDC Transmission Lines

A time-domain method is presented to solve the dc ion flow field in bipolar transmission lines under which shielding wires are built to reduce the resultant electric field. In this method, the charge simulation method, the finite element method, and the finite volume method are used to solve the space-charge-free electric field, ion flow field, and current continuity equation, respectively. The method is validated by measurement results. Meanwhile, the shielding effect is explained theoretically from three aspects: the nominal electric field distribution, space charge injection, and space charge distribution. The ion filed formation can be illustrated clearly with this method. Relationships between configurations of transmission line and shielding wires are evaluated on the basis of calculation results.