An Improved Voltage Control Method for Distribution Networks Incorporating Adaptive Partitioning and Two-Layer Coordinated Control

The wide integration of volatile renewable energy has intensified voltage regulation challenges in distribution networks. Conventional centralized control approaches are inherently limited by slow response times, heavy reliance on communication, and poor coordination. To address this issue, this paper proposes a voltage optimization method that integrates adaptive partitioning and hierarchical coordination. First, node electrical coupling characteristics are extracted based on the voltage-reactive power sensitivity matrix analysis. The elbow method and K-means clustering are jointly applied to achieve network partitioning, where the optimal number of partitions is automatically determined. On this basis, a hierarchical coordination control architecture is established. The upper level employs scenario-based worst-case dispatch to minimize comprehensive operating costs and voltage deviations, generating reactive power regulation references for distributed generators in each partition. The lower level uses an improved droop control based on the voltage-squared relationship, enabling distributed generators to adjust reactive power in real time according to local voltage deviations, thereby achieving coordination between global optimization and local response. Lastly, simulation results on a modified IEEE 33-bus system demonstrate the effectiveness of the proposed method in eliminating voltage violations, particularly under heavy-load conditions.