Techniques for accommodating unscheduled flows in electricity networks and markets

Unscheduled power flows have played an important role in recent events like the 2003 North American blackout and cross border trading in European electricity markets. Such events have necessitated a need for efficient management of unscheduled flows in both the electric network as well as the market. In that perspective, some techniques for managing unscheduled flow are described in this paper. Contemporary practices relating to unscheduled flows are reexamined. The paper revisits the development of a formula for determining the contribution of participating generation companies toward unscheduled flows. Preliminary steps toward the application of a technique from game theory for equitable pricing of unscheduled flows are investigated. The reliance of the contribution factor method and the game theory method on the practice of E-tagging of electric power schedules is emphasized through an illustrative numerical example. The merits and shortcomings of various techniques for managing unscheduled flows are listed. Some avenues for research in the future are also mentioned.