Graph theoretic approach for preventive control of power systems

A new generation rescheduling approach for preventive control of power system is presented which can reallocate power generation for multiple unstable contingencies based on graph theory. The objective of preventive control is to prepare the system when it is still in normal operation, so that the system is able to face future uncertain events in a satisfactory way. The generator rescheduling is based on the outage of links from one generator area to the other without violating line overloads. The quantity of generation shifting from one generator area to other is calculated by the proportionality assumption. When rescheduling of generators fails to provide a feasible solution for secure operation, optimal load shedding/switching off disturbed area, called islanding formation, is resorted to. The suitability of the proposed method is demonstrated with the help of six bus three machine power system and IEEE 30-bus power system.