Energy Management of PV/FC/BAT/SC and PEM Electrolyzer

Fossil fuel is the primary energy source in the world due to its severe environmental problems and the possibility of depletion. The use of renewable sources has become a pressing need. On the other hand, the intermittency and dynamic response of renewable energy sources are two important issues that must be addressed. To resolve these issues, This paper proposes a frequency separation-based energy management strategy (EMS) of a multi-source system consisting of a photovoltaic array (PV), fuel cell (FC), battery (BAT) for energy storage, and a supercapacitor (SC), this last one maintaining the DC bus voltage. The hybrid electric power system supplies a stand-alone load and a PEM electrolyzer to generate hydrogen fuel for the FC. The energy transfer from the sources to the DC bus is guaranteed by four types of DC/DC converters: classic boost for the PV array; bidirectional DC/DC for the battery and SC; interleaved DC/DC boost for the fuel cell to reduce current ripples; and a buck converter for the hydrogen generator. According to the proposed supervisory algorithm, the incoming solar energy will be used directly either to power the load or to charge the batteries and generate hydrogen. For the other power sources, a proportional- integral (PI) controller is used employed in an inner current control loop. The model of each component was designed under MATLAB/Simulink. The solar irradiance and load power change throughout the day to demonstrate the EMS’s efficiency.