Secondary Frequency and Voltage Control of Islanded Microgrids via Distributed Averaging

TL;DR

This paper introduces distributed controllers for secondary frequency and voltage regulation in islanded microgrids, using local communication to enhance robustness and eliminate the need for centralized control.

Contribution

The work presents novel distributed control strategies that operate without requiring knowledge of microgrid topology or loads, improving flexibility and robustness.

Findings

Controllers achieve rapid frequency regulation and active power sharing.

Voltage control balances regulation and reactive power sharing.

Experimental results confirm robustness under communication failures.

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-neighbor 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.