Delay margin computation of load frequency control system with demand response and constant communication delays

Abstract

The paper aims to present a comprehensive delay-dependent stability analysis technique of a networked single area Load Frequency Control (LFC) systems integrated with demand response. Demand Response (DR) has been an integral part of power system control and operation. The time-delays in LFC schemes are due to the utilization of communication channels for signal transmission among the various sub-systems and control center. The deterioration of the dynamic performance of the system is the most feasible effect of time-delays and at the worst these delays lead to instability. Therefore, the computation of delay margins for a stable operation of the single-area LFC system with DR control is crucial. A less conservative stability criterion using Lyapunov approach is derived in linear matrix inequality framework for determining the stability of closed loop LFC system under study. The stability criterion is tested for different subsets of the controller parameters and participation factors using standard benchmark system. Through extensive simulation results, the analytical results are validated. The time domain simulation results indicate the effectiveness of the analytical results.