Asynchronous Distributed Voltage Control in Active Distribution Networks

TL;DR

This paper proposes an asynchronous distributed voltage control strategy for active distribution networks using a primal-dual gradient approach, effectively handling communication delays and varying control rates.

Contribution

It introduces a novel asynchronous control algorithm based on operator splitting, with convergence proof and online adaptability for practical distribution systems.

Findings

Effective voltage regulation demonstrated on IEEE-123 network.

Algorithm converges under mild conditions despite asynchrony.

Online implementation adapts to time-varying environments.

Abstract

With the explosion of distributed energy resources (DERs), voltage regulation in distribution networks has been facing a great challenge. This paper derives an asynchronous distributed voltage control strategy based on the partial primal-dual gradient algorithm, where both active and reactive controllable power of DERs are considered. Different types of asynchrony due to imperfect communication or practical limits, such as random time delays and non-identical sampling/control rates, are fitted into a unified analytic framework. The asynchronous algorithm is then converted into a fixed-point problem by employing the operator splitting method, which leads to a convergence proof with mild conditions. Moreover, an online implementation method is provided to make the controller adjustable to time-varying environments. Finally, numerical experiments are carried out on a rudimentary 8-bus system and the IEEE-123 distribution network to verify the effectiveness of the proposed method.