Robust Hybrid Wide-Area Damping Control for Power Systems with Communication Errors

The broad deployment of phasor measurement units has enabled effective wide-area damping control for enhancing small-signal stability of large and interconnected power systems. However, this requires networked communication between systems that may be subjected to intermittent, noisy, and delayed feedback measurements. In this paper, we present a distributed wide-area damping controller that applies local power injections via a sample-and-hold mechanism to synchronize the states of the interconnected power systems, thereby damping inter-area oscillations. We model the nominal closed-loop system as a hybrid system. Then, leveraging analytical hybrid systems tools, we apply sufficient conditions that guarantee that the set characterizing synchronization is globally exponentially stable. Moreover, due to the hybrid system construction, we show that this set is robust to certain classes of perturbations, which include both perturbations and delays on the communication between the power systems. We demonstrate the damping controller's performance in a numerical example that considers interconnected heterogeneous nonlinear systems with intermittent communication that is subjected to significant noise and time-delays.