Performance comparison of PI and PI-fuzzy controller for grid-connected fuel cell inverter system

This paper presents the modeling, simulation, and performance evaluation of a hybrid proton exchange membrane fuel cell (PEMFC) with an energy storage system utilized in a grid-connected distributed generation (DG) system. To control the fuel cell/battery grid-side voltage source inverter (VSI), the conventional voltage-mode and current-mode control schemes with improved proportional-integral (PI)-fuzzy controller for both inner current and outer voltage control loops have been developed. The proposed PI-fuzzy controller has the advantage of fuzzy control while maintaining the simplicity and robustness of the PI controller. The space-vector pulse width modulation technique has been applied to the VSI control to generate a sinusoidal waveform. A comparison has been made between the PI-fuzzy controller and the PI controller in the VSI in terms of the generated total harmonic distortion (THD). The results showed that by applying PI-Fuzzy controller, the voltage and current THD are reduced to 0.40 % and 3.77 %, respectively compared to 0.43 % voltage THD and 14.08 % current THD using the conventional PI controller.