Development of Fuzzy-Adaptive Control Based Energy Management Strategy for PEM Fuel Cell Hybrid Tramway System

Currently, the implementation of hybrid proton-exchange membrane fuel cell (PEMFC)-battery-supercapacitor systems for hybrid tramways to replace conventional internal combustion engines and reduce greenhouse gas emissions has triggered an upward trend in developing energy management strategies (EMSs) to effectively deploy this integration. For this purpose, this paper introduces a comprehensive EMS consisting of high-level and low-level controls to achieve appropriate power distribution and stabilize the operating voltage of the powertrain. In the high-level control, a fuzzy logic technique and adaptive control loop are proposed to determine the reference power for energy sources under different working conditions. Meanwhile, the low-level control aims to generate a pulse-width-modulation (PWM) signal for DC/DC converter, associated with each electric source, to regulate the device's output performance and guarantee the DC bus voltage. Comparisons between the proposed strategy with available approaches are conducted to verify the effectiveness of the proposed EMS through MATLAB/Simulink environment. The simulation results confirm that the proposed EMS not only sufficiently ensures powers distribution even when the abrupt changes of load or high peak power, but also enhance the efficiency of the PEMFC, in which the PEMFC stack efficiency can be exhibited up to 53% with hydrogen consumption less than 21.4%. Moreover, the DC bus voltage can be regulated with a small ripple of around 1%.