A smart local voltage regulator methodology for dynamic integration between volt-var control and distributed energy resources

This paper studies the changes which has been occurring by the connection of distributed energy resources (DER) in the electrical distribution system. The big number of houses acquiring the photovoltaic generation system connected on-grid, increases the challenge of the distribution system company in maintain the service entrance voltage within service range. One problem of the on-grid system is that the network presents a big voltage fluctuation by the unpredictable resultant load profile in each residence that depends the instantaneous house power generation and consumption. While the big injection increases, the low injection of energy decreases the nominal house voltage, and without some kind of control, this voltage fluctuation is able to impact not only the own voltage profile, but also the neighbors’ voltage profile. For this reason, this paper proposes a smart local voltage control that uses an energy storage system (ESS) and Volt-VAr control in each house, triggering them when it is more conventional, maintain the nominal house voltage within the service range. Different from others studies, this local control is developed looking for small changes that when added, can impact in a positive way the entire system, improving the voltage profile and not overloading the voltage regulators and capacitor banks along the network. All control was developed, tested and analyzed on Matlab/Simulink, where was used a modified version of the IEEE 34-bus test feeder as case study.