Calculation of Ion-Flow Field Near the Crossing of HVdc Transmission Lines Using Equivalent Corona Conductors

The crossing of two-circuit high-voltage direct current (HVdc) overhead lines will happen with the increasing number of HVdc transmission projects. The 3-D calculation is needed to predict the ion-flow field near the crossed HVdc lines. In order to decrease the difficulty of meshing near the bundle conductors, the equivalent single conductors are applied in the modeling. A roughness coefficient converting approach for equivalent conductor in Peek's formula is presented. Thus, the corona degree of bundle conductors can be reflected by the equivalent single conductor. Afterward, the effectiveness of equivalent corona conductors in ion-flow field calculation is checked by a series of experiments and simulation. Finally, the 3-D ion-flow field distribution near the crossing of ±800 and ±500 kV HVdc overhead lines is calculated using equivalent corona conductors.