Congestion management in a deregulated environment using corrective measures

This paper presents a congestion management system (CMS) based on corrective measures. In an unbundled power system, the schedules of the generation units and of the demands are given to the transmission system operator who has to realize them. This may cause multiple congested conditions, which can be eliminated by the following corrective measures: adjustment of the network elements like transformer taps or shunt elements, corrective switching, corrective redispatch of generation. The aim of the CMS is to specify a state of the transmission system, which represents an undisturbed state and enables all schedules. The search for a state of the transmission system, which fulfills these requirements, represents a mixed-integer-nonlinear-problem, which cannot be described in an analytical way. Particularly the topology changes generate a problem of large dimension. The paper presents the mathematical model representing a CMS to formulate an optimization problem and gives exemplary study results. The described problem is solved by an evolution strategy.