Effects of torsional dynamics on nonlinear generator control. 1

The performance of a feedback-linearizing control for excitation control of a synchronous generator is investigated with respect to unmodeled dynamics of both the turbine-generator unit and the transmission network. It is found that certain types of dynamics that were not modeled during the design of the control enter in a manner that does affect the performance of the control, but that preserves the linearity of the closed-loop system. Moreover, the control acts to decouple the dynamics associated with the machine from the dynamics of the transmission grid, thus preventing subsynchronous resonance between the two subsystems when a series capacitor is used to compensate the transmission line.