The effect of applied control strategy on the current-voltage correlation of a solid oxide fuel cell stack during dynamic operation

Abstract

This paper discusses the transient characteristics of the planar type SOFC cell stack, of which the standard output is 300 W. The transient response of the voltage to the manipulation of an electric current was investigated. The effects of the response and of the operating condition determined by the operating temperature of the stack were studied by mapping a current-voltage (I-V) correlation. The current-based fuel control (CBFC) was adopted for keeping the fuel utilization factor at constant while the value of the electric current was ramped at the constant rate. The present experimental study shows that the transient characteristics of the cell voltage are determined by primarily the operating temperature caused by the manipulation of the current. Particularly, the slope of the I-V curve and the overshoot found on the voltage was remarkably influenced by the operating temperature. The different values of the fuel utilization factor influence the height of the settled voltages. The CBFC has significance in determining the slope of the I-V characteristic, but the different values of the fuel utilization factor does not affect the slope as the operating temperature does. The CBFC essentially does not alter the amplitude of the overshoot on the voltage response, since this is dominated by the operating temperature and its change is caused by manipulating the current.

Dynamic modeling of reversible solid oxide cell stack and control strategy development

“…The review includes an overview of the control strategies and a general description of the control challenges in SOFCs. Szmyd et al [5] experimentally investigated the transient response of the cell voltage to a current ramp. They adopted a current-based fuel control to maintain a constant reactant utilization factor.…”

Local Evolution of Three-Dimensional Microstructure Morphology of Planar Anode-Supported SOFC

“…The bench has control tools for the heaters, mass flow controllers and electronic load. More details about experimental set-up can be found in refs (1)(2)(3)…”