Reconciling hierarchical control and open access in the changing electric power industry

In this paper we briefly review the basic concepts and assumptions underlying hierarchical control of large-scale electric power systems. In the second part we pose the problem of open access electricity service. As the electric power industry restructures, and various disruptive technologies evolve, it becomes necessary to introduce new models for representing and managing the evolving systems. The emphasis in this paper is on basic information needs for implementing flexible and efficient open access electricity service according to well-defined objectives. In today´s literature two extreme information structures are most often considered, i.e. either a fully integrated, or a fully decentralized information structures. Integrated structures do not allow for decentralized decision making, and the decentralized structures have a hard-to-predict performance. To overcome these fundamental problems, we consider in this paper a hybrid information framework which facilitates decentralized decision making by various industry layers; these decisions are then coordinated in minimal ways capable of guaranteeing performance of the system as a whole according to the desired criteria. Multilayered protocols for implementing such hybrid information framework are described. Some recent results are put in the context of the problem of interest, and further open questions are identified. The concepts presented in this paper are potentially generalizable to other network-type infrastructures.