Empowering the Grid: Decentralized Autonomous Control for Effective Utilization and Resilience

TL;DR

This paper introduces decentralized autonomous controllers (DACs) that enable inverter-based microgrids to maintain operational resilience and safety during disruptions by local, real-time adjustments, enhancing grid stability and resource utilization.

Contribution

The paper presents a novel decentralized control scheme that enforces resilience constraints in inverter-based microgrids using local measurements and minimal computation.

Findings

DACs effectively maintain frequency safety limits during disruptions

The control scheme is computationally efficient and suitable for real-time deployment

Simulation results demonstrate improved resilience and resource utilization

Abstract

With the emergence of low-inertia microgrids powered by inverter-based generation, there remains a concern about the operational resilience of these systems. Grid-forming inverters (GFMs), enabled by various device-level (primary) and system-level (secondary) control methods, are poised to play a significant role in achieving certain operational objectives, such as the effective utilization of clean energy resources while maintaining stability. However, despite the recent advances in GFMs, there is a lack of suitable controls that can ascertain resilience-constrained operations, like maintaining critical operational safety limits during transients under various cyber-physical disruptions. In this work, we develop decentralized autonomous controllers (DACs) that enforce resilience-constrained operation via local, minimally invasive adjustments (e.g., changes in set-points) while co-existing within the hierarchy of existing (primary and secondary) controls. The DACs work autonomously by sensing only local GFM measurements and act only when operational resilience constraints are violated. The proposed DAC scheme is computationally efficient (only algebraic computations), which enables fast, real-time execution and demonstrates the efficacy of the proposed control framework on GridLAB-D-HELICS-based control-grid co-simulations on the IEEE 123-node networked microgrid. Finally, we show how the developed DACs empower the grid by utilizing the available resources entirely to ensure resilience (maintain frequency safe limits).