Calculation of Radio Interference for Unconventional High Surge Impedance Loading Transmission Lines

It is crucial to study the effects of corona discharge during the design of an overhead transmission line. These effects include power losses, radio interference (RI), television interference (TVI), and audible noise (AN). Extra high voltage conventional transmission lines above 300 kV are designed to have more than one conductor per phase to form conductor bundles which causes the electric field stress on the subconductors to be reduced, which in turn reduces the corona effects. Conventional high surge impedance loading (HSIL) lines consist of a higher number of subconductors with a larger bundle radius which effectively increases its transmission capacity. On the other hand, unconventional HSIL lines have demonstrated the potential to deliver higher natural power which surpasses that of both conventional and conventional HSIL lines. The term unconventional refers to the asymmetrical arrangement of the subconductors in bundles. With the increased number of subconductors per bundle, HSIL lines may have higher electric field stress on the conductors' surface leading to greater corona effects. In this paper, the RI from unconventional lines are evaluated and analyzed.