Increasing the loadability of power systems through optimal-local-control actions

This paper deals with the problem of increasing the loadability of power systems which, in turn, can be linked to voltage collapse occurrences. As voltage collapses may be caused by insufficiency of reactive power support, and considering that reactive power can be locally supplied, for instance, by shunt capacitors, this paper addresses the impacts of local control actions on the system loadability. The study is carried out in two steps. First, by using the tangent vector technique, two important areas of the power system are identified: the critical area under the point of view of voltage collapse, and the area most sensitive to active power losses reduction. Second, once these two areas are identified, an optimization technique takes place to optimize the amount of shunt reactive power compensation that should be available in each bus. Numerical results are obtained using the IEEE 14- and 118-bus systems. Index Terms--Interior-point method, load margin, optimal power flow, voltage stability.