The integration of Dispersed Generation (DG) is by far the most important and challenging issue that modern power systems are facing nowadays, and is the only way of exploiting Renewable Energy Sources (RES) for electric production. This revolution is running particularly fast in Europe, where significant incentive schemes have been promoted by many Member States in order to match the targets decided by the European institutions. As a consequence of the important share of RES already connected (especially to low voltage and medium voltage networks), new technical challenges have to be faced both at a distribution network level and at a transmission system level. Some of these challenges are covered by Smart grids that represent a new framew...