Trajectory Tracking Wide-Area Control for Power Systems

Abstract

This dissertation reassesses traditional approaches to power system stabilization in the context of contemporary measurement and communication technology. Changes in bulk system dynamics driven by increases in power electronically-coupled generation and load pose challenges to existing control strategies. Rather than attempting to maintain a static equilibrium, we explore strategies that drive the system toward a desired trajectory. This approach emerges from a time-varying linearization of the equations of motion for a synchronous machine. First, we develop and demonstrate a generalized power system stabilizer architecture that incorporates local information with a real-time estimate of the speed of the center of inertia. This estimate is synthesized from data collected over wide-area measurement systems. We then turn our attention toward a new method for stabilizing transient disturbances by modulating the active power injected by inverter-based resources. The response of each inverter is calculated to drive the local bus voltage angle toward a trajectory that tracks the angle of the center of inertia. The results of this endeavor indicate that trajectory tracking control can improve both transient and small-signal stability, while also increasing tuning flexibility. In particular, we show that it is possible to decouple the effect of the control action on inter-area and local modes of oscillation from the effect on the frequency regulation mode.