Improvement of power systems security margins by using FACTS devices

This paper is treating the problem of identifying stability reserves and finding out the best solutions to improve available security margins in order to be at a safe “distance” from a blackout in the analyzed power system. The issue consists in the computation of the stability limits for a power system either with or without using FACTS devices in order to highlight the gain in power system stability and control by using these devices. The key aspects of the well known approaches related to the steady-state stability limits (SSSL) computation is reviewed and an algorithm for SSSL identification, developed by the authors in order to be fitted for power systems planning and operation is also described. A methodology to choose between different locations for a FACTS device in order to increase the security margins of the analyzed power system is going to be proposed. The paper is focusing on the aspects of preventing blackouts by finding out a methodology to establish the need of FACTS devices in a power system. The technical aspects treated here consist in assessing the stability reserves for a power system or for a specific constrained area in a power system (with and without using the FACTS devices) beyond which a blackout might appear.