Secondary Frequency and Voltage Control of Islanded Microgrids via Distributed Averaging

TLDR

The study introduces distributed controllers for secondary frequency and voltage regulation in islanded microgrids. The controllers employ localized information and nearest‑neighbour communication, enabling rapid frequency regulation with active‑power sharing and a voltage‑reactive‑power trade‑off without requiring knowledge of the microgrid topology. Experimental results confirm that the distributed architecture provides flexible, redundant control, eliminates a central controller, and maintains voltage stability even under communication failures and plug‑and‑play operations.

Abstract

In this work we present new distributed controllers for secondary frequency and voltage control in islanded microgrids. Inspired by techniques from cooperative control, the proposed controllers use localized information and nearest neighbour communication to collectively perform secondary control actions. The frequency controller rapidly regulates the microgrid frequency to its nominal value while maintaining active power sharing among the distributed generators. Tuning of the voltage controller provides a simple and intuitive trade-off between the conflicting goals of voltage regulation and reactive power sharing. Our designs require no knowledge of the microgrid topology, impedances or loads. The distributed architecture allows for flexibility and redundancy, and eliminates the need for a central microgrid controller. We provide a voltage stability analysis and present extensive experimental results validating our designs, verifying robust performance under communication failure and during plug-and-play operation.