Intelligent voltage regulator to distributed voltage control in smart grids

Distribution networks have, in general, the electrical energy flow unidirectional from substation to customers. With high levels of distributed energy resources integration, the energy may flow backwards which creates challenges with legacy circuit designs and control techniques. The Distribution System Operator fixes a set-point and prepares scenarios and ranges based on seasonal load curves. However, the growing of distributed energy resources, distributed storage, flexible load and plug-in-electrical vehicles brings to the distribution systems substantial challenges. On one hand, the uncontrolled charging load may occur coincidentally with the peak hours. On the other hand the photovoltaic and wind generation may occur coincidentally with the off-peak hours and will affect or even deteriorate the operation performance of distribution systems dramatically. In both cases, the voltage regulators need to have their settings previously evaluated for these different operating conditions. From these considerations, this paper presents an innovative methodology to distributed voltage control developed to a Brazilian power utility (CEEE-D) from the project named Intelligent Dynamic Control for Voltage Regulators and Supervisory Systems in a Smart Grid Environment Code ANEEL PD-5707-4301/2015. The methodology is not restricted to voltage regulators settings. It acts also evaluating the hierarchy between the voltage regulators, adjusting the delay time, based on the network topology. The results are provided using a typical utility distribution circuit from Electrical Energy State Company-CEEE-D. Moreover, the authors discuss further opportunities and challenges in this field of research.