Distributed Optimal Voltage Control with Asynchronous and Delayed Communication
For power system operators, this work addresses the challenge of voltage regulation in distribution networks with high renewable penetration by enabling asynchronous and delayed communication, which is more practical than synchronous methods.
This paper proposes a distributed voltage control algorithm for distribution networks that allows asynchronous updates and bounded communication delays, proving convergence to the optimal feasible voltage profile under linear power flows and demonstrating effectiveness on nonlinear AC power flow models with static and fluctuating loads.
The increased penetration of volatile renewable energy into distribution networks necessities more efficient distributed voltage control. In this paper, we design distributed feedback control algorithms where each bus can inject \emph{both active and reactive} power into the grid to regulate the voltages. The control law on each bus is only based on local voltage measurements and communication to its physical neighbors. Moreover, the buses can perform their updates \emph{asynchronously} without receiving information from their neighbors for periods of time. The algorithm enforces \emph{hard upper and lower limits} on the active and reactive powers at every iteration. We prove that the algorithm converges to the optimal feasible voltage profile, assuming linear power flows. This provable convergence is maintained under bounded communication delays and asynchronous communications. We further numerically test the performance of the algorithm using the full \emph{nonlinear AC power flow} model. Our simulations show the effectiveness of our algorithm on realistic networks with both static and fluctuating loads, even in the presence of communication delays.