Voltage Regulation in a DC Micrigrid with Renewable Energy Resources, Energy Storage Systems and Electric Vehicles Station using Hierarchical Control Method

In recent years, the use of renewable energy resources (RESs) has been increasing widely. In microgrids, to supply the consumers demand energy, RESs such as photovoltaic systems and fuel cells are utilized in addition to conventional power generation sources as generation units. DC microgrids have many advantages such as increasing power transmission capacity, reducing fuel costs by using RES units, and improving power quality and energy efficiency. Also, energy storage systems (ESSs) such as, battery storages, supercapacitors and etc. have DC output. In this paper, a DC microgrid including a PV as a RES, flywheel and battery as ESS is used to stabilize frequency fluctuations and regulate DC bus voltage. Also, an electric vehicle (EV) charging station is considered with hierarchical control. The performance of the studied system is examined in MATLAB/Simulink software. It is concluded that using the proposed control method in the DC microgrid maintains the voltage balance in presence of the unbalanced load condition. Therefore, the flexibility and reliability of the DC microgrid will be achieved.