Distributed power control for DERs based on networked multiagent systems with communication delays

This paper develops a distributed secondary cooperative scheme for the current-controlled PWM inverters (CC-PWMIs) based on networked multiagent systems that can guarantee the accurate power sharing among the distributed energy resource (DER) units in microgrids. With the assumption that the communication networks are local, time-varying, and with low bandwidth, two distributed secondary controllers are designed such that all DERs in the microgrid can share their active and reactive powers accurately on the conditions of both fixed and switching topologies with time-varying communication delays. Moreover, delay-dependent sufficient conditions are obtained by using the Lyapunov-Krasovskii stable analysis method. The proposed controllers, allowing each DER unit to receive the current and active/reactive load information intermittently from its neighboring DERs, are then fully distributed. The effectiveness of the proposed control methodology is verified by the simulation of a low-voltage microgrid test system in the MATLAB/SimPowerSystems Toolbox.