Nonlinear VAr control for damping multivariable swing equations

Idealized swing equations are used in the development of local control strategies for VAr (reactive volt-ampere) units, with the objective of providing damping to all oscillatory modes of multimachine power systems. A one-machine infinite-bus system is used to introduce and motivate the method. The control strategy provides damping even during severe transients involving reverse power swings. For systems containing n machines, simulation results indicate that n -1 locally controlled VAr units, using only local output feedback, can be placed to dampen all oscillatory modes of the system, provided that a stable equilibrium point exists and that the initial disturbance is limited in severity