DC Microgrid Energy Management System Containing Photovoltaic Sources Considering Supercapacitor and Battery Storages Mohammad Amin Jarrahi 1 , Farzad Roozitalab 2 , Mohammad Mehdi Arefi 1 , Mohammad Sadegh Javadi 3 , and Jo˜ ao P.S. Catal˜ ao 3, 4 1 School of Electrical and Computer Engineering, Shiraz University, Shiraz, Iran 2 School of Industrial and Information Engineering, Politecnico di Milano Univesity, Milan, Italy 3 Insitute for Systems and Computer Engineering, Technology and Science (INESC TEC), 4200-465 Porto, Portugal 4 Faculty of Engineering of the University of Porto (FEUP), Porto 4200-465, Portugal Abstract—The tendency to use renewable energies in DC microgrids (MGs) has been increased in the past decades. Due to the unpredictable behavior of renewable resources, it is vital to utilize energy storage resources in the MG structure. The generation sources and storages in DC MGs should be chosen in order to meet the maximum demand in both grid-connected and islanded mode. Also, penetration of power electronic based devices is essential to connect these resources to the network. The control of these devices are another challenge in this regard. So, a proper configuration along with an efficient control approach is needed for development of DC MGs. In this paper, a new structure for DC MG is presented which includes solar photovoltaic (PV) as generation sources and supercapacitor and battery as storages. Furthermore, an innovative control method based on voltage variations is introduced for the proposed structure. It is shown that simultaneous usage of battery and supercapacitor improves the performance of the MG in han- dling the abrupt load changes in the both grid-connected and islanded mode operations. To evaluate the performance of the proposed structure and control algorithm, different conditions are simulated in MATLAB/Simulink software and the results are presented. The results confirm a high degree of performance for proposed structure and control method. Index Terms—DC Microgrid, Energy Management, Dis- tributed Control Method, Battery Storage, Supercapacitor NOMENCLATURE Abbreviations PV Photovoltaic MG Microgrid DG Distributed Generation DBS Distributed Bus Signal MPP Maximum Power Point P andO Perturb and Observe CC Constant Current SOC State of Charge Parameters and Variables A Ampere V Volt W Watt F Farad H Henry G(s) Function s Input of function C f Capacitance of low pass filter L f Inductance of low pass filter f s Switching frequency C grid Capacitance in bidirectional converter output P out Maximum load power V grid DC link voltage V ripple Maximum acceptable DC link voltage L batt Inductance in input of battery C batt Capacitance in input of battery D Incremental converter switching cycle r ESR Internal battery resistance Δi battery Maximum acceptable charge/discharge current L pv Inductance in input of PV Δi pv PV current variation L SC Inductance in input of supercapacitor I. I NTRODUCTION A. Motivation and Background Nowadays, use of renewable energies as a suitable choice for clean energy is expanding. Recent advances in increasing the efficiency and reliability in MGs have made renewable energies good choices for decentralizing electric power gen- eration. Since most renewable sources, such as PV systems, fuel cells and variable speed wind power plants produce DC voltages with variable voltage and frequencies, use of power electronic converters is necessary to connect these resources to the network [1]. In addition, new loads such as electric vehicles, as well as common loads require DC power. So, the wide applications of DC networks over the AC ones are reasonable. DC MGs have advantages in terms of cost and efficiency; in addition, they can convert DC to AC or AC to DC power in AC MGs to aggregate the mentioned loads and renewable energy sources [2]–[5]. Power systems in commercial centers containing sensitive loads [6], industrial [7] and aerospace industries [8] are examples of typical DC MG applications. 978-1-7281-7455-6/20/$31.00 ©2020 IEEE 1 Authorized licensed use limited to: b-on: UNIVERSIDADE DO PORTO. Downloaded on September 23,2020 at 08:38:53 UTC from IEEE Xplore. Restrictions apply.