Optimal Power Flow Pursuit

TL;DR

This paper introduces distributed feedback controllers for inverter-interfaced energy resources in distribution networks, enabling real-time AC optimal power flow solutions through low-cost microcontroller operations.

Contribution

It develops a novel control framework based on linear approximations and Lagrangian methods that allows continuous, real-time OPF targeting without hierarchical separation.

Findings

Controllers converge to OPF solutions

Effective voltage regulation achieved

Real-time optimization demonstrated

Abstract

This paper considers distribution networks featuring inverter-interfaced distributed energy resources, and develops distributed feedback controllers that continuously drive the inverter output powers to solutions of AC optimal power flow (OPF) problems. Particularly, the controllers update the power setpoints based on voltage measurements as well as given (time-varying) OPF targets, and entail elementary operations implementable onto low-cost microcontrollers that accompany power-electronics interfaces of gateways and inverters. The design of the control framework is based on suitable linear approximations of the AC power-flow equations as well as Lagrangian regularization methods. Convergence and OPF-target tracking capabilities of the controllers are analytically established. Overall, the proposed method allows to bypass traditional hierarchical setups where feedback control and optimization operate at distinct time scales, and to enable real-time optimization of distribution systems.