Line switching for alleviating overloads under line outage condition taking bus voltage limits into account

This paper presents an interactive line switching algorithm for overload alleviation under line outage condition. Line outage distribution factors are used to determine line flows. It has the advantage that a contingency from a base case can be computed for an actual flow on a line in a real time situation. A relation has been derived for calculating load bus voltages under post-contingency condition and after line switching. In the event of bus voltage limit violation the algorithm explores the possibility of the other line to be switched. The algorithm also investigates the possibility of overload rotation amongst two disjoint sets of overloaded lines obtained after line switching, if overload elimination is not possible. The algorithm has been tested on the IEEE 25 bus system.