Centralized Control Scheme for Energy Management in Smart Microgrids

Abstract

The development in smart grid technologies will authorize consumers to participate in the decision making of their electricity consumption. This participation in decision making is the called demand side management (DSM). DSM allows the customers to optimally manage their loads and hence reduce their energy bills and overall consumption. This work proposes a new real-time energy management system (EMS) for smart microgrids (MGs) including DSM with several distributed energy resources (DER) technologies, such as photovoltaic panels, dispatchable distributed generation (DG), capacitor banks, and battery energy storage systems (BESS). The developed EMS consists of three main units that are controlled by the centralized MG controller (MGC). The aim of the MGC is to optimally schedule the grid and customers' assets to benefit both the grid operators and the customers. The MGC utilizes the rolling horizon concept to manage real-time information and to provide the plug-and-play option for all controllable devices such as controllable loads and DER. The three units managed by the MGC are the data collection and storage unit, the forecasting unit and the optimization unit. The optimization unit receives the current and forecasted information from the other units; then, it develops the optimal scheduling decisions for all controllable devices with the target of reducing the overall operating costs while meeting the customers' requirements. The MG can either operate in grid-connected mode or in islanded mode of operation. In this work, both modes are considered. Simulation results on a typical MG system of the proposed approach are compared to the results of the traditional day-ahead approach. The proposed approach results show same savings as the day-ahead approach. However, unlike the day-ahead approach, the proposed approach is more robust to disturbances and fast changes of PV panels' output. Moreover, the proposed approach can accommodate changes in customers' preferences and new connected equipment in a timely manner.