15 - Hierarchical distributed voltage control for active distribution networks with DGCs based on GP and ADMM

Abstract

Chapter 15 proposes a hierarchical distributed voltage control (HDVC) scheme for active distribution networks (ADNs) with high penetration of distributed generation (DG) based on gradient projection (GP) method and alternating direction method of multipliers (ADMM). The reactive power outputs of several distributed generation clusters (DGCs) and DG units within each DGC are optimally coordinated to keep DG terminal voltages and the voltages of all critical buses of ADNs within the feasible range and mitigate voltage fluctuations. In the ADN layer, a decentralized reactive power control scheme based on GP is designed for the DGC, which regulates the voltages of all critical buses to be close to the rated value and mitigates the reactive power variations. In the DGC layer, the reactive power outputs of DG units are further optimized based on ADMM to minimize the voltage deviation of each DG terminal and track the reactive power reference from the DGC control. The proposed HDVC scheme regulates the voltages in a decentralized manner without communication between DGC controllers, while each DG controller only communicates with the corresponding DGC controller. This regulates the voltages in a completely decentralized manner and effectively reduces the computation burden of the DGC and DG controllers. A modified Finnish distribution network with eight DGCs was used to validate the control performance of the proposed HDVC scheme.