Supervisory Controller for Power Management of AC/DC Microgrid Mohamed El-Hendawi, G.El-Saady, El-Nobi A. Ibrahim Electrical Engineering Department, Faculty of Engineering Assiut University Assiut, Egypt e-mail: Mohamed.Ahmed@uoit.ca; gaber1@yahoo.com; nouby60@yahoo.com Abstract—This paper proposes a hybrid AC/DC micro grid to reduce the processes of multiple conversions in an individual AC or DC micro-grid. The hybrid grid consists of both AC and DC networks connected together by a bidirectional AC/DC converter. Wind generator, AC loads, and utility are connected to the AC bus whereas PV system and DC loads are tied to the DC bus. The coordination control algorithms of supervisor controller are proposed for smooth power transfer between AC and DC links and for stable system operation under various generation and load conditions. In this paper, a flexible supervisor controller is developed for a hybrid AC/DC micro- grid, where the power flow in the micro-grid is supervised based on demanded power with maximum utilization of renewable resources. A small hybrid micro-grid has been modeled and simulated using the Simulink in the MATLAB. The simulation results show that the system can maintain stable under load variations. Keywords-Hybrid AC/DC micro-grid; supervisor controller; BIC; MPPT; PV system; wind generation I. INTRODUCTION THREE PHASE AC power systems have existed for over 100 years due to their efficient transformation of AC power at different voltage levels and over long distance as well as the inherent characteristic from fossil energy driven rotating machines. Recently more renewable power conversion systems are connected in low voltage AC distribution systems as distributed generators or AC microgrids due to environmental issues caused by conventional fossil fueled power plants [1]. Previous research topics mainly focus on AC micro-grid applications [2]–[5]. Recently, The penetration of DC loads including LED, communication and computation devices, motors with DC drives, etc. is increasing dramatically nowadays [6]. So DC microgrids have recently emerged for their benefits in terms of efficiency, cost, and system that can eliminate the DC-AC or AC-DC power conversion stages and their accompanied energy losses. However, since the majority of the power grids are presently AC type, AC micro-grids are still dominant and purely DC microgrids are not expected to emerge exclusively in power grids [7]. Therefore, The concept of hybrid AC/DC systems is, therefore, emerging to combine the benefits of both AC and DC micro-grid [8].The main advantages of the hybrid AC/DC micro-grid are as follows: 1) the elimination of unnecessary multi-conversion processes, which results in conversion loss reduction and 2) the elimination of embedded rectifiers for DC loads in the current AC grids, which results in simplified equipment and cost reduction in electronic products [9]. The idea is to merge the AC and DC microgrids through a bidirectional AC/DC converter (BIC)and establishing a hybrid AC/DC micro-grid in which AC or DC type energy sources and loads can flexibly integrate into the micro-grids and power can smoothly flow between the two micro-grids. In this paper, a proposed microgridconsists of two renewable energy sources, Photovoltaic and wind energy systems. There are many papers that propose different topologies to connect these renewable energy systems to the AC and DC buses [10]–[13]. Nevertheless, forcing the micro-grids to work independently, may lead to not utilizing maximum available wind or solar power and may hamper the efficiency of the system [14]. The idea is that if there is a building have a DC and AC loads and these loads connected to the proposed microgrid. It is accepted that for the excellent operation of the microgrid, a supervisory controller to manage the power split between different energy sources is essential, which is called power management system. This paper is organized as follows; Section II gives a brief overview of the renewable power source models and their corresponding converters, where the model of wind turbine as power source of the AC microgrid is given in Section II.A, and a model of PV panel as a source of the DC micro-grid is given in Section II.B. In Section III, a supervisory controller to coordinating between the AC and DC microgrids is proposed, in which different operating modes are programmed in order to manage the power split between the AC and DC microgrids. Coordinated control strategies and MPPT for the converters for all the circuit in the grid- connected mode are presented in Section IV. Simulation results obtained with the proposed supervisory controller are reported in Section V. Finally, conclusion section summarizes the main outcome of this paper. II. SYSTEM MODELING The grid-connectedmicrogrid is connected as shown in Fig. 1 where the PV source connected to DC bus and wind source with utility connected to AC bus. 147 2016 the 4th IEEE International Conference on Smart Energy Grid Engineering Hossam A. Gabbar Faculty of Energy Systems and Nuclear Science University of Ontario Institute of Technology (UOIT) Ontario, Canada e-mail: hossam.gabbar@uoit.ca 978-1-5090-5111-3/16/$31.00 ©2016 IEEE