Repetitive control strategy for grid integration of vehicular fuel cells to enhance system stability and robustness

Abstract

In this study, an improved repetitive control strategy is proposed in order to increase the stability and overall system performance for grid-integration of vehicular fuel cells. Unlike traditional synchronous reference frame based controller under harmonic compensation and unstable grid conditions, the proposed control method operates effectively under grid voltage distortions and aims to achieve a smoother sinusoidal output with minimum total harmonic distortion (THD). The proposed method is based on repetitive controller with a delay line mechanism and a feedback loop to provide a precise tracking of reference current while reducing output switching ripples. The effectiveness of the proposed control structure is validated through processor-in-the-loop based digital implementation using a Delfino TMS320F28379D evaluation board. Comparative analysis results show that the proposed repetitive control method achieves lower THD values and improved power quality in comparison with conventional control method. The THD value of 1.59% in the conventional method decreases to 1.07% THD with the proposed controller. The performance results confirm the robustness of the proposed control method in handling dynamic load variations and maintaining stable power injection into the electrical grid.