Adaptive latency compensator considering packet drop and packet disorder for wide area damping control design

Abstract

Network based wide-area controls will form an important part of smart grid implementation to improve power system stability. The performance of such control systems can seriously deteriorate under various network uncertainties such as time-varying delays, packet loss, and packet disorder. To address these issues, an Adaptive Time Delay Compensation (ATDC) scheme has been suggested to design wide area damping controller for a Flexible AC Transmission System (FACTS). The proposed TDC scheme is based on a direct phase advancement methodology that requires the signal modal information such as amplitude, frequency, and damping. This information has been utilized to compensate the latency by predicting the future trajectories of oscillatory response. An Adaptive Extended Kalman Filter (AEKF) is employed to estimate the low-frequency oscillatory modes with missing measurement data. To compensate the error due to packet disorder, a new methodology of packet-reordering, has been proposed. Further, the Wide-Area Damping Controller (WADC) is designed addressing the issue of sampled data control. The performance of the proposed scheme has been validated on the 16-machine, 68-bus power system.