Economically Correct Secure Economic Dispatch embedding UPFC Investment Costin a Deregulated Power Market Scenario

Abstract

In a competitive power market scenario, the Independent System Operator (ISO) mainproblem is how to pursue its objectives taking into account generation costs, contractual clausesamong the different market agents and insecurity costs related to the possible power system operatingpoints. To face this problem, in previous papers, a model proposed by the authors, called Economicallycorrect Secure Economic Dispatch (EcSED), is adapted to the new deregulated market scenariotaking into account FACTS technology in order to reduce power system insecurity risk. AmongFACTS devices, the Unified Power Flow Controller (UPFC) is the most flexible and versatile and itsusage is under focus in this paper. But if, from one side, a UPFC installed in the transmissionnetwork can be exploited to minimize the insecurity risk, from the other side its use implies anexpense, function of the size of the device itself. Then, in the paper an enhanced formulation of theEcSED model embedding the UPFC investment cost is proposed to support the ISO in its decisionpertaining the choice of the UPFC size. Some numerical experiments on a 5-bus test system are alsoreported, to prove the effectiveness of the proposed enhanced EcSED formulation.