An Analytic Approach to Unit Commitment

Abstract

Unit commitment in electric power systems is a mixed integer programming problem which because of its high complexity has been approached primarily through numerical methods. Few general analytic results exist which shed light on the manner in which units are committed. In this paper the unit commitment problem is studied from an analytic point of view. A set of analytic conditions governing the switching mechanism of the system units is derived for the static case in terms of the load, reserve margins, load incremental cost, and reserve incremental cost. This analytic approach, termed the switching curve concept, provides new and unique insight into the unit switching mechanism not available from purely numerical approaches, as well as laying the groundwork for further related work on more general unit commitment formulations.