MVAr management on the pre-dispatch problem for improving voltage stability margin

Abstract

This paper presents a methodology that includes at the power system pre-dispatch problem the evaluation and improvement of voltage stability margin by optimizing generators and synchronous condensers reactive power injections. From modal participation. factors it is defined penalty indices for all generators, which are added to the optimal power flow objective function. The purpose is to obtain the most adequate reactive power injection for each generator or synchronous condenser, from a perspective of maximizing voltage stability margins. Preliminary results presented in this paper, obtained for the New England test system of 39 buses and 10 generators, show that the proposed methodology leads to significant voltage stability margin improvement for all the critical time intervals of the day. A clear advantage of the proposed methodology is that the optimal solution for generators active injection is kept unchanged. It means no impact on generators energetic targets, and no impact on the total generation cost. Hence, voltage stability margin is improved by just managing the reactive power dispatch.