Adaptive operation strategy for voltage stability enhancement in active DMFCs

TL;DR

This paper proposes an adaptive control strategy for active DMFCs that enhances voltage stability and operational flexibility without compromising efficiency, validated through experiments and simulations.

Contribution

It introduces a semi-empirical model integrated into multi-objective optimization for adaptive control of DMFCs, a novel approach for voltage stability enhancement.

Findings

Improved voltage stability without efficiency loss

Extended current density range and reduced voltage deviation

Fast response to operational adjustments

Abstract

An adaptive operation strategy for on-demand control of active direct methanol fuel cells (DMFCs) is proposed as an alternative method to enhance the voltage stability. A simplified semi-empirical model is firstly developed to describe I-V relationships based on uniform-designed experiments. It is then embedded into multi-objective optimizations to construct the adaptive operation strategy. Experimental studies are implemented on different DMFC systems to validate the proposed semi-empirical model, control strategy and system response to operational adjustments. Numerical simulations are also performed to investigate the underlying mechanisms of the proposed adaptive operation strategy. The results show that the adaptive operation strategy provides possibilities for voltage stability enhancement without the sacrifice of energy conversion efficiency. The adaptive operations are also found to be able to extend the range of operating current density or to decrease the voltage deviation according to one's requirements. Moreover, the response of DMFCs to operational adjustments is quick, which further validates the effectiveness and feasibility of the adaptive operation strategy in practical applications. The proposed strategy contributes to a guideline for the better control of output voltage from operating DMFC systems.