Observer-based Event-Triggered Control of Load Frequency Control System

Abstract

The aim of the work is to develop an observer-based H∞ controller for traditional load frequency control (LFC) system with time-varying communication delay and by using output-based event-triggered communication scheme. In traditional LFC system with remote control center, the state estimation and secondary frequency control is performed remotely in the control center based on the available frequency measurements. When the observer is remotely located, the general assumption regarding the state estimation capability of sensor become overruled and state estimate-based event-triggering (ET) condition cannot be applied. Hence, in this work an output-based ET condition is utilized and based on the event-generated or transmitted system frequency samples, state estimate and control input is produced by the observer-based controller at the control center. Further, the controller and observer gains ensuring prescribed H∞ performance of the system are obtained using asymptotic stability criterion derived from Lyapunov Functional (LK) stability analysis considering time-varying communication delay.