Power Control among Photovoltaics and Electric Energy Storages in DC Microgrid

Photovoltaic (PV) is one of the most popular renewable energy sources today. Outputs of PVs are fluctuated according to the sunlight intensity. Contrary with the PVs outputs, the Microgrid networks are required continuous power for supplying their load demands. To overcome this issue, the Electrical Energy Storages (ESSs) are introduced in the DC Microgrid network. Introducing PVs and ESSs in the same network poses several issues. The control of the voltages, currents and powers outputs among PVs and ESSs during load demand fluctuations is one of the critical issue which should be considered. On the other hand, The PVs and ESSs have different generated power capacities and hence, the suitable control candidate should be able to adjust the generated power by PVs and ESSs according to their capacities. There are three operational modes options in DC Microgrid based PVs and ESSs. These operational modes are introduced, analyzed, simulated and discussed in this paper. The performance of the proposed method is conducted via computer simulation of Simulink during fluctuations of the load demands. The simulation results indicate that the proposed method is successful to maintain the network voltages are within acceptable limit during load demands fluctuations. And the generated power by PVs and ESSs are regulated within designated capacities as well.