A Decentralized Multiagent-Based Robust Backstepping Control for Restoring Secondary Voltage and Frequency of Autonomous Microgrids

The droop characteristics of primary control of autonomous microgrids cause voltages and frequencies of the distribution generations (DGs) to deviate from their reference values. Various secondary control approaches have been proposed to tackle this problem. This paper proposes a decentralized synchronization control to restore the voltages and frequencies to their initial states. The control problem is formulated using the robust backstepping strategy and takes into account the impacts of dynamic uncertainties and external disturbances. The network of the interconnected DGs is modeled with a decentralized multi-agent system (MAS) such that each generator is monitored by its own local controller and then takes proper action to maintain the voltage and frequency synchronizations. By employing the Lyapunov stability theory, it is shown that the closed-loop tracking errors are asymptotically stable. Finally, simulation results demonstrated that the presented secondary control technique is effective in synchronizing the voltages and frequencies of the microgrids.