Interactions and co-ordination of multiple-function FACTS controllers

This paper presents two study cases of interaction analysis of multiple-fun ction FACTS (flexible AC transmission systems) controllers: - the contradic tion between the voltage and the damping control of a SVC (static VAr compe nsator); - the interaction between the voltage control of the DC link capac itor and the damping control of a UPFC (unified power-flow controller). In the paper, an algorithm is proposed for the co-ordinated design of these tw o multiple-function FACTS controllers. Examples are presented to confirm th e analytical conclusions obtained and to demonstrate the effectiveness of t he algorithm of the co-ordination proposed.