Distributed secondary frequency control scheme with A-symmetric time varying communication delays and switching topology

Abstract

A distributed control of a Microgrid (MG) depends on the communication network for the exchange of information among the Distributed Generators (DGs). Most of the control schemes consider ideal communication among the DGs; however, in practical systems, delays are inherited in a system that can affect the dynamic performance and even destabilize an MG. Therefore, in this research work, delay independent distributed secondary frequency control for MGs is presented. Sufficient delay independent conditions for robust stability of the buffer-free Distributed Averaging Integral (DAI) control scheme is proposed while considering A-symmetric time varying communication delays and switching network topology. Moreover, in this work, slow as well as fast varying delays are analyzed using Lyapunov Krasovskii and Lyapunov Razumikhin's approach. Furthermore, a Lyapunov function based adaptive control approach is employed that updates the constant gain parameters to compensate for the uncertain or varying parameters. Finally, the efficacy of the controller is demonstrated through simulation studies that validate its performance in different scenarios.

Keywords

• Adaptive control
• Communication delays
• Distributed secondary control
• Islanded mode
• Microgrid
• Switching topology