A DIRECT METHOD FOR SECURITY-CONSTRAINED UNIT COMMITMENT

Secure operation is an enduring concern to electric utilities. Several factors oblige utilities to operate their systems-particularly transm ission systems-at or close to their capacities. Few methods for schedu ling electric generating units, however, take security into account. U tilities, therefore, may inadvertently risk overloading critical trans mission lines if units are not rescheduled. Without advance planning a utility may incur significant costs if it must reschedule generation retroactively. This paper presents a practical method to account for s ecurity constraints when scheduling electric generating units. Our res ults indicate that this method obtains lower-cost solutions faster tha n if the security constraints are considered retroactively.