Energy management strategy for fuel cell hybrid power system using fuzzy logic and frequency decoupling methods

Proton-exchange membrane fuel cell (PEMFC) has become a potential renewable energy source to replace fossil fuels and reduce greenhouse gas emissions. However, slow power density and slow power response are drawbacks of the PEMFC. In order to overcome these shortcomings and improve the fuel economy, this paper presents an innovative energy management strategy (EMS) using a fuzzy logic control (FLC) and frequency decoupling (FD) for a hybrid power system (HPS) with PEMFC, battery (BAT), and supercapacitor (SC). Based on the power response of energy sources, the combination of FLC and FD is applied to determine the appropriate power distribution for load power demand. Besides, a DC bus control loop was designed by using the BAT to guarantee a stable DC output voltage. Comparisons between the proposed strategy with a conventional approach are conducted to verify the strategy's effectiveness through MATLAB/Simulink environment. Simulation results show that the proposed EMS can be guaranteed to not only sufficiently coordinate powers even when the abrupt changes of load or high peak power, but also enhance the efficiency of the PEMFC in comparison with the conventional EMS.