A Multilayer Hierarchical Adaptive Volt-Var Control for Voltage Regulation and Reactive Power Coordination in Distributed PV Inverters

Abstract

The rapid proliferation of Distributed Energy Resources (DERs), particularly grid-connected photovoltaic (PV) systems, has significantly altered the operational characteristics of modern distribution networks. While DERs contribute to reducing greenhouse gas emissions and enhancing energy resilience, they simultaneously introduce challenges such as voltage rise, reactive power imbalance, and bidirectional power flow and Conventional voltage regulation relies on passive or slowacting devices such as On-Load Tap Changers (OLTCs), shunt capacitors, and voltage regulators. This paper proposes aAdaptive Volt–VAR Control with Hierarchical Coordination (AVVC–HCS) framework that combines local autonomy with supervisory optimization and it employs voltage–VAR sensitivities, dynamic trust-region updates, and learning-based adaptation to ensure fast response, fairness, and global voltage regulation. The proposed approach is simulated on IEEE 33-bus and IEEE 69-bus radial distribution systems using a MATLAB–OpenDSS co-simulation platform in achieving voltage regulation, reactive power coordination, loss reduction, fast dynamic recovery, and fair inverter participation under varying PV penetration levels.