Overload and voltage control of power systems by line switching and generation rescheduling

This paper presents a fast mathematical technique for solving security related problems in the steady-state operation of a power system. Both thermal overloads of transmission elements and nodal voltage violation problems are dealt with. In order to minimize the increase in operating costs, priority is given to the rescheduling of the network topology; however, the real and reactive power generation outputs and tap position of voltage transformers are also considered. A new network topology is determined by a set of distribution factors that relate the violating constraints to the transmission elements. The remaining control variables are determined by sensitivity analysis techniques. The violating constraints are reduced in steps so that, at any point during the computation, the most recent operating point is better than the previous one. The proposed algorithm has been implemented and tested on 24- and 118-bus power systems.