An Improved Energy Management Strategy for Fuel Cell Hybrid Power System Based on Compensator Design of DC-DC Converters

This paper introduces an improved energy management strategy (EMS) consisting of low-level and high-level control to adapt the load power demand and stabilize the DC bus voltage for a fuel cell hybrid power system (FCHPS). In high-level control, fuzzy logic rules (FLRs) combined with filtering-based methods and a voltage control loop are employed not only to determine the reference power of energy sources but also to ensure the stability of DC bus voltage. For the low-level control, compensators of DC-DC converters are designed based on their dynamic characteristics to improve the effectiveness of power distribution and the stability of DC bus voltage through the current and voltage control loops. Finally, a comparison of the proposed strategy and previous approaches is conducted through MATLAB/Simulink environment. The obtained results demonstrate that the proposed strategy not only achieves the highest distributed power accuracy but also ensures a stable DC bus voltage with ripple by 1.08 % in comparison to the available approaches.