Decentralized control of interconnected electric power systems in competitive markets

This paper investigates the prospects of decentralized control in the emerging competitive electricity markets. The weaknesses of current control performance criteria for dealing with such markets are discussed and it is hypothesized that decentralized control, providing full control over economically independent electrically interconnected areas, is necessary in such markets. To study the feasibility of such a decentralization rigorously, a state space decomposition method is introduced and applied to the model of an interconnected system. As a result it is shown that, in electric power systems, regardless of the number and location of the tie lines and implemented control schemes, the frequency and phase of each area are in the controllable subspaces of all areas in the interconnection. This shows that, if decentralization is to be achieved, flexible links which decouple the phases of areas must be utilized. The side effects of such implementations are also discussed.