Cálculo de distancias de seguridad en la repotenciación de líneas de corriente alterna con tecnología HVDC

Abstract

During the last decades, the combination of several factors  (rapid growth of electricity consumption, deregulation of the  electricity market and increase of distributed generation)  has led to important changes in power flows in the Spanish  Electricity System, overloading power lines that were  not initially designed to withstand those levels of energy  transmission. Considering the inherent difficulties related  to building new power lines, repowering the existing lines  emerges as a necessary solution. At the same time, the  important development of power electronics based on  new semiconductors has boosted the appearance of new  technologies applicable to transmission and distribution  systems, such as HVDC (High Voltage Direct Current). The  technical and economic benefits associated to this technology  represent an attractive alternative to AC power line repowering.  However, AC-to-DC power line conversion requires converter  stations at its ends, as well as adapting the insulation system  to the new working conditions. In this regard, the lack of a  specific regulation for DC lines and the last change of the  existing regulation for AC lines have caused a regulatory  gap, whose consequences are analyzed in this paper. Special  emphasis is laid on the different criteria to calculate safety  clearances, when converting AC power lines into DC lines