Coordinated single-phase control scheme for voltage unbalance reduction in low voltage network

Abstract

Low voltage (LV) distribution systems are typically unbalanced in nature due to unbalanced loading and unsymmetrical line configuration. This situation is further aggravated by single-phase power injections. A coordinated control scheme is proposed for single-phase sources, to reduce voltage unbalance. A consensus-based coordination is achieved using a multi-agent system, where each agent estimates the averaged global voltage and current magnitudes of individual phases in the LV network. These estimated values are used to modify the reference power of individual single-phase sources, to ensure system-wide balanced voltages and proper power sharing among sources connected to the same phase. Further, the high / ratio of the filter, used in the inverter of the single-phase source, enables control of reactive power, to minimize voltage unbalance locally. The proposed scheme is validated by simulating a LV distribution network with multiple single-phase sources subjected to various perturbations.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'.

Energy management: flexibility, risk and optimization

“…In particular, there are two 'framework' contributions that cover important general applications of stochastic and probabilistic modelling, namely smart grid and low-carbon power system planning [1], and system stability analysis [13]. Then, a number of papers deal with more specific and technical topics such as optimal location of advanced measurement devices in transmission networks [14], distribution network voltage control through multi-agent systems [15] and identification of analytical conditions for synchronous generators' stability [16].…”

“…Pullaguram et al [15] introduce a coordinated control scheme aimed at reducing voltage unbalances in low-voltage distribution networks. The control approach considers single phases, as typical unsymmetrical line configurations as well as the rise of both new relatively large loads (e.g.…”