UPFC sizing by means of an economically correct secure economic dispatch in a deregulated power market scenario

In a deregulated power market scenario, the Independent System Operator (ISO) main problem is how to minimize the power system insecurity risk. To face this problem, in previous papers, assuming the insecurity risk as a part of the global cost, a model named Economically correct Secure Economic Dispatch (EcSED) has been proposed by the authors. Further, the EcSED has been improved considering the presence of an Unified Power Flow Controller (UPFC) device in the transmission network. In this paper, by means of an enhanced formulation of the improved EcSED, the size of an UPFC is determined, by including the UPFC investment cost within the objective function. Indeed, an UPFC installed in the transmission network may minimize the insecurity risk, hence the global cost, although its usage implies an expense, function of the size of the device itself. Some numerical experiments on a 5-bus test system are also reported, to prove the effectiveness of the enhanced EcSED model formulation. Copyright © 2007 John Wiley & Sons, Ltd.