Vol.10 (2020) No. 3 ISSN: 2088-5334 Modeling and Simulation of a DC Micro-Grid with a Model Predictive Controller Vladimir Prada a,1 , Oscar I. Caldas a,2 , Edilberto Mejía-Ruda a,3 , Mauricio Mauledoux a,4 , Oscar F. Avilés a,5 a Davinci Research Group, Universidad Militar Nueva Granada, Bogotá, Colombia E-mail: 1 vladmont@gmail.com; 2 oscar.caldas@unimilitar.edu.co; 3 edilberto.mejia@unimilitar.edu.co; 4 mauricio.mauledoux@unimilitar.edu.co; 5 oscar.aviles@unimilitar.edu.co Abstract— This paper presents the modeling strategies of a micro-grid to control the power supply of a battery bank by adopting a Model Predictive Controller (MPC). The grid was sized to light two tennis courts at a university sports complex, which is not connected to the national power grid and thus must be a stand-alone setup. The paper starts with an introduction that defines the statement of purpose and the state of the art. Then continue with the power generators and storage modeling: photovoltaic (PV) modules, wind turbine, buck converter (takes power from the rectified national grid) and the battery bank. The MPC was designed to effectively manage the energy supplied to the batteries, depending on the state of charge, hence the controller output is the signal used to regulate the charging current. The data used for prediction is the meteorological measures taken during three years using an in- situ weather station that collected irradiance, wind speed and direction, temperature, and pressure. Finally, as the entire control system was simulated step by step using MATLAB/Simulink, the components and systems behavior graphs are shown to lead to analysis and conclusion remarks. Keywords— buck converter; micro-grid; model predictive controller; photovoltaic; wind turbine. I. INTRODUCTION The current methods for energy production are not sustainable, mainly due to environmental reasons and the lack of responsible use of resources [1]. Therefore, the demand for renewable energy, smart electrification, and rational use of electricity are important factors that will provide answers to the global energy challenge. Also, the scheme currently used for the generation of energy is made from fossil fuels, hydroelectric, or nuclear reactors, which are centralized, and the distribution includes losses of up to 69%. In Colombia, 66% of the territory is not connected to the National Grid. The areas are called Off-Grid Zones (OGZ), and their energy requirements are obtained from traditional fuels such as diesel or biomass, or few Renewable Energy Sources projects (RES), mainly small hydro projects. However, social and economic constraints still cause the lack of available energy or its low-quality services for these regions. On the other hand, the energy sector in Colombia is based on free-market policies since 1994, which have caused that current RES initiatives are without potential size and scope because of the lack of economic incentives and the absence of private stakeholders. Furthermore, the Institute of Planning and Promotion of Energy Solutions for Off-Grid Zones (IPSE, by the Spanish acronym) is in charge of creating such projects. It has a Financial Office (FANZI) which have allocated more than USD 85 million since 2003. It is also a victim of a weak legal framework that has been reformed several times and have directed a lot of efforts and resources to administrative and legal processes [2]. In contrast, renewable energy generation does not pollute, is decentralized, and has innovated with concepts such as "smart grid." Smart grids constitute the framework of future sustainable energy systems, allowing the integration of large amounts of renewable energy, improving reliability, quality of supply, and ensuring safety. Therefore, and due to the significant advantages and developments on renewable energy, it is necessary to analyze how energy should be used in a micro-grid with RES, considering that usually the power is supplied without regard if it comes from the network or renewable supply [3]. In this context, it is vital to perform research and development projects related to emerging technologies in such a manner that they achieve greater electrical energy efficiency and lower emissions. Hence, this work model and simulates a DC grid that can get power from different centralized and renewable sources, optimizing generation, and consumption. Therefore, this paper focuses on the value of energy storage devices when operating in combination with intermittent supply from renewable energy sources. Since forecasts never are perfect, a Model Predictive Control (MPC) strategy is used for keeping the 1091