Analysis of nonlinear modal interaction in stressed power systems with SVCs

This paper discusses the application of normal form theory to study nonlinear modal interaction in stressed power systems that include static VAR compensators (SVCs). A second-order representation of the power system is developed wherein static compensation and synchronous machines interact through the linear representation of the transmission system. Then, a modified normal form method is used to study non-linear modal interaction between inertial modes and control modes. The proposed approach is general and may be extended to include other FACTS devices. A simplified 4-machine, 11-bus test system is used to study the effect of SVC voltage support on system damping