Fast ADMM-Based Hierarchical and Decentralized Volt/VAr Control in Distribution Networks

This paper aims to mitigate the voltage deviations and reduce the cost of supplying reactive power in distribution networks by optimally setting the reactive power of distributed energy resources. To solve this problem, we propose two types of Volt/VAr control (VVC) strategies, including hierarchical and decentralized VVC, based on a novel fast alternating direction method of multipliers (ADMM). For the fast ADMM-based hierarchical VVC strategy, it requires a central agent to iteratively communicate with local bus agents, but both the central agent and local bus agents can update variables in a closed-form without solving sub-optimization problems. In contrast, the fast ADMM-based decentralized VVC strategy only requires the minimal information exchange between neighboring buses, but solving sub-optimization problems are necessary for local bus agents. Finally, the numerical tests on the IEEE 123-bus test system validate the effectiveness of our proposed VVC strategies.