The Malta-Sicily EHV-AC interconnector

The Malta-Sicily 225 MW cable (20 km underground and 100 km submarine) line will be the longest 245 kV ac cable system in the world. The interconnector, which will synchronously connect Malta to the ENTSO-E system, is expected to be in service by the end of year 2013 and a duplicate link is foreseen in year 2016. The innovative connection scheme allows mutual reactive power support and steady-state voltage decoupling between Sicilian and Maltese network by use of joint operation of autotransformer (ATRs) with OLTCs and variable shunt reactors (VSRs). The paper presents main features of the link both from the technical and the environmental point of view; voltage stability and electro-magnetic transient studies are also dealt with in order to assess dynamic performances of the interconnected networks of Malta and Sicily. Losses estimates are also reported, showing that overall transmission losses are lower than 4% at full load, which makes the ac solution competitive with state-of-the-art HVDC-VSC systems.