Progress of the Mediterranean ring and the interconnection with Europe

The paper will firstly address the status of the Mediterranean interconnections and the evolution of demand and power exchanges in the area. Thereafter, the main driving forces prompting full integration of the power systems will be discussed. These refer mainly to different load patterns in the various countries (see shifted weekly cycle in some Arab countries), imbalance in generation availability and the introduction of market rules that are going to eliminate custom barriers for energy trading. From the technical point of view, the closure of the MedRing sets challenging problems that shall be investigated and suitably solved before starting the system operation. These are essentially related to the capability of reacting to small and large disturbances keeping the system stability. To this end, the paper will highlight the potentially critical dynamic phenomena that might occur and the most appropriate counter-measures to be undertaken. As will be shown, due to the very stretched structure undertaken. As will be shown, due to the very stretched structure of the grid in the South-Eastern area, even a single contingency of kilometres away from the disturbance\´s location. Other phenomena of concern are related to steady-state stability. As a matter of fact, interconnecting systems by adding HVAC tie-lines creates new natural oscillation modes that, if not properly damped, can cause instability even in highly meshed systems such as the European one. Some of the results presented in the paper have been obtained by the "MedRing Feasibility Project", a study project completed in June 2003, supported by the European Commission and with the objective of defining a framework for coherent development of interconnections between the power systems of the Mediterranean Basin. Finally, the perspectives for a further extension of interconnections towards South, the Gulf Countries and North- East of the MedRing will be presented.