Digital Control of Electric Power Flows in Unbalanced Distribution Networks as Part of The Automated Metering and Control System
Keywords:distribution network, unbalanced mode, control of electricity flows, digital controller, control algorithm
This paper aims to address the problem of controlling the electricity flows in power distribution networks (PDN) operating under current and voltage unbalance. As is known, the unbalance factor is responsible for significant losses of active power and, therefore, is detrimental to the PDN efficiency and technical and economic performance. The purpose of control is to minimize technical power losses in the distribution network. This is to be achieved by building an information control system (ICS) for balancing a three-phase network as part of the automated metering and control system (AMCS). The latter is currently being widely adopted to automate information processes in PDNs. However, the AMCS does not include technologies for solving the problem in question. We propose an algorithm of the digital controller operation for the ICS. Its primary function is to maintain phase power at a given level in real-time. The algorithm concept is based on the idea of required redistribution of electricity flows between the phases of the distribution network by appropriately switching single-phase loads of consumers (users) to ensure a minimum spread of phase powers relative to their required level. To achieve the goal of control, we construct criterion functions that determine qualitative indices of the ICS operation and develop computational schemes for their minimization. Control actions to be generated by the digital controller and performed on the facility represent a digital code that contains data on the coordinates of three-phase network loads to be switched to another phase.