Design of Distributed Controllers Seeking Optimal Power Flow Solutions Under Communication Constraints

TL;DR

This paper presents a distributed control framework for power distribution networks with DERs, enabling real-time optimal power flow solutions despite communication constraints and asynchronous updates.

Contribution

It introduces a primal-dual-based control design that handles communication losses and partial updates, allowing asynchronous operation and real-time OPF tracking.

Findings

Achieves fast voltage regulation in high PV penetration systems

Demonstrates robustness to communication packet losses

Enables near real-time AC OPF solution pursuit

Abstract

This paper focuses on power distribution networks featuring distributed energy resources (DERs), and develops controllers that drive the DER output powers to solutions of time-varying AC optimal power flow (OPF) problems. The design of the controllers is grounded on primal-dual-type methods for regularized Lagrangian functions, as well as linear approximations of the AC power-flow equations. Convergence and OPF-solution-tracking capabilities are established while acknowledging: i) communication-packet losses, and ii) partial updates of control signals. The latter case is particularly relevant since it enables an asynchronous operation of the controllers where the DER setpoints are updated at a fast time scale based on local voltage measurements, and information on the network state is utilized if and when available, based on communication constraints. As an application, the paper considers distribution systems with a high penetration level of photovoltaic systems, and demonstrates that the proposed framework provides fast voltage-regulation capabilities, while enabling the near real-time pursuit of AC OPF solutions.