Voltage Control Strategy for Distribution Networks Based on Distributed Photovoltaic Cluster Partition

To address voltage over-limit and instability issues caused by high penetration of distributed photovoltaic in distribution grids, this paper proposes a voltage regulation strategy based on distributed photovoltaic cluster partition. Firstly, a dual-criterion modularity function considering net load and equivalent electrical distance is constructed. A community detection algorithm based on modularity (i.e. fast-unfolding) is applied to dynamically partition photovoltaic clusters. Secondly, differentiated voltage regulation is designed according to the severity of cluster over-limit conditions: intra-cluster reactive power adjustment for mild over-limits, and multi-device hierarchical collaborative control for severe over-limits, with task allocation based on response speed and economic priority. Finally, an optimization model targeting minimization of network losses and voltage deviation is established. The improved multi-organization particle swarm optimization (MPSO) algorithm, combined with niche-based techniques, is employed to determine the optimal regulation sequence and device action levels. Simulation results demonstrate that this method effectively controls voltage fluctuations, reduces network losses, and enhances system stability in both the modified IEEE 33-node system and the IEEE 123-node system.