Security Improvement Using Facts Device Placement based on Modal Analysis

Abstract

Power system security is a major concern in the operation of today’s power system. Hence, security analysis becomes an inevitable task in the routine work of the power system operator. The operator has to ensure that the system does not proceed into insecure or extreme states of security, and practice various methods of improving the security of the power system. Security analysis begins with system monitoring and contingency screening. Later depending in the analysis of results, measures to improve security are opted. The Network composite overall severity index (NCOSI) is one of the methods of screening the contingencies to analyze the state of the system. The contingencies are ranked according to their severity based on this index value. NCOSI is computed from three fuzzy variables that depend on line overloading, bus voltage drop limit violation and the voltage stability index.