Lightning studies are a critical part of any system involving overhead lines. As HVDC technologies develop, new problems and questions arise regarding the lightning performance of HVDC overhead lines. For instance, the installation of two separate HVDC circuits on the same transmission tower may become a popular alternative for the uprating of old AC lines to take advantage of the already existing Right-of-Ways. Double-pole flashovers may be particularly constraining in double circuit HVDC systems, since they could lead to the loss of both circuits at the same time due to the flashover of both poles of the same polarity having the same amplitude at all times (which is not the most likely case in AC systems). This corresponds to a 100% of loss of transmitted power, which could represent a threat for the system stability. This constitutes the main motivation for this work.

N. MANDULEY, S. Pack S. Touré B. Raison S. Poullain A. Xémard