Parallel Structure-Based Decentralized Model Predictive Control of Vehicle Pemfc Anode Circulation System

Abstract

Excessive pressure difference between the cathode and anode and insufficient hydrogen supply in proton exchange membrane fuel cell (PEMFC) can affect their stability, reliability and operating life. Therefore, in this paper, a decentralized model predictive controller (DMPC) based on the parallel structure of the ejector and hydrogen circulation pump is proposed to resist the disturbance of anode pressure and flow rate caused by current variation and purging. In addition, this structure can make up for the defect of the single ejector structure with too narrow operating range. Simulation results show that the proposed DMPC control strategy has better pressure stability and robustness than the fuzzy proportion integration differentiation controller (Fuzzy-PID), and can achieve the ideal hydrogen excess ratio faster when under low load conditions with step load current, variable reference and purge interference. In particular, even under loading current and purge disturbance condition of PEMFC hybrid vehicles, the DMPC with purge disturbance model has better pressure tracking performance and control stability, with an average absolute error of 0.165 kPa and a root-mean-square error of 1.357 kPa, which is 43.69% lower than that of the Fuzzy-PID controller.

Keywords: PEMFCV, Hydrogen excess ratio (HER), Balance of the pressure difference, model predictive control (MPC), Ejector