An Advanced Control Strategy for Power Flow Management, Optimal Dc Capacitor Utilization and Compensating Harmonics in Fuel Cell Electric Vehicle Powertrain Converters

Abstract

Electric vehicles (EVs), particularly fuel cell electric vehicles (FCEVs) powered by hydrogen, are gaining significant attention due to their environmental benefits, minimal maintenance, and superior motor efficiency. However, the integration of power converters into EVs results in challenges related to power quality (PQ), including voltage and current harmonics, power factor, power losses, and DC-link ripples. This paper proposes a comprehensive control strategy to enhance power management through active-reactive power control, achieving unity power factor (UPF) operation, compensating for reactive power load demand, stabilizing DC-link voltage, and mitigating harmonics to meet IEEE standards in FCEV powertrain converters. This control strategy incorporates advanced techniques, including a multiple orthogonal vector (MOV)-based linear Kalman filter (LKF) for precise harmonic current extraction and a sliding mode-based proportional-integral (SM-PI) control approach for DC capacitor voltage regulation. These techniques ensure efficient operation, optimal DC capacitor utilization, and accurate DC-link voltage tracking, leading to improved system performance and stability. The proposed control method effectively compensates for reactive power, reducing the grid's burden compared to the conventional methods. The proposed control strategy significantly reduces total harmonic distortion (THD) in grid currents to between 0.30% and 0.85%, well below the 5% IEEE-519 standard, and improves the power factor to near unity (0.989-1.0) compared to the conventional method's 0.81-0.992. Additionally, DC-link voltage stability has been enhanced, with voltage ripple reduced from Delta v = 10.1 V to Delta v = 2.0 V, achieving faster response times under 50 ms, reduced overshoot, and improved PQ. Theoretical analyses and the proposed approach are validated through simulations and processor-in-the-loop (PIL) semi-experiments conducted on the digital signal processor (DSP) TMS320F2835 board, demonstrating enhanced reliability, efficiency, and compatibility with the grid for FCEV powertrain systems. This work contributes to the advancement of FCEV technology by addressing critical challenges in PQ and system efficiency.