Network Partition-Based Multi-Timescale Coordinated Voltage Regulation of Distribution Networks with High-Penetration Distributed PVs

Large scale integration of distributed photovoltaics (DPVs) into distribution networks is leading to issues of reverse power flow and voltage rise, which challenges the secure operation of distribution systems. This article focuses on the multi-timescale coordinated voltage regulation of distribution networks with large-scale DPVs and energy storage units. A comprehensive index that includes electrical distance, voltage autonomy, and comprehensive correlation index is established to partition the whole network into several independent regions, which can facilitate coordinated voltage regulation. On top of that, a multi-timescale coordinated distributed voltage control scheme is proposed by integrating the ADMM algorithm and global sensitivity-based fast voltage control approach. The ADMM is employed to coordinate different regions on a longer timescale in a distributed manner, while the global sensitivity-based fully distributed voltage control is used to achieve fast control of devices within a single region. Case studies on a modified IEEE 33-bus test system verify that the proposed voltage control scheme can coordinate multiple regions to achieve optimal voltage regulation and is able to mitigate voltage violations caused by fluctuations in DPV generation.