Voltage control stability and dynamic interaction phenomena of static VAr compensators

This paper describes the results of a comprehensive investigation on: (1) small-signal dynamic interactions of voltage control loops of multiple static VAR compensators (SVCs); (2) the phenomena of SVC-network interactions; and (3) torsional interactions with SVCs. This paper is concerned with small-signal dynamics in the high frequency (HF) range, i.e. above 4 Hz. The studies are conducted on various power system configurations, based on the use of a newly developed eigen analysis software tool. The eigen analysis tool provides a systematic approach to include the dynamic mathematical model of the transmission network in the overall system model, which is necessary for HF dynamic studies. The investigations identify undesirable small-signal oscillations associated with SVC-SVC and/or SVC-network interactions, and provide fundamental information for design/coordination of SVCs