Definition of a zonal reactive power market based on the adoption of a hierarchical voltage control

The overall purpose of the paper is to suggest a suitable methodology of valuing the reactive power support in a deregulated electricity market from the point of view of Transmission System Operator (TSO). The valorization of the reactive resource available in a grid bus will be determined by means of an Optimal Reactive Power Flow (ORPF) procedure, which pursues both economic and security criteria. The methodology has been applied to a detailed model of the EHV Italian system with reference to a 2010 peak load condition and to a medium term forecast scenario (target year 2014). The results will show that an adequate Hierarchical Voltage Control (HVC) framework and above all a suitable definition of control areas may be a good way to implement a regional (zonal) reactive power market. The analysis will also investigate the possible consequences of delaying the network development planned by the Italian TSO.