Design of a robust UPFC controller for enhancing the small signal stability in the multi-machine power systems

This paper presents the design of a robust unified power flow controller (UPFC) for enhancing the small signal stability in the multi-machine power systems. Using the structured singular value (/spl mu/) analysis, the parameters of the UPFC controller are selected to have robust stability against the model uncertainties. To simulate the dynamic responses of the UPFC installed in power systems, new simulation software named PowerDyn has been developed. Comprehensive time-domain simulation studies using PowerDyn show that the proposed robust UPFC controller can enhance the small signal stability efficiently in spite of the variations of power system operating conditions.