A simple, analytic model of polymer electrolyte membrane fuel cell anode recirculation at operating power including nitrogen crossover

Model-based fuel pressure regulation algorithm for a hydrogen-injected PEM fuel cell engine

“…Convective flow along the gas channel and liquid water transportation is not considered in this study. In real anodic system, nitrogen will penetrate from cathode to anode [23], convective flow caused by hydrogen consumption will influence the distribution of nitrogen concentration along the gas channel, which will further affect the gas dynamics during fuel cell operation. Further study will consider applying the controller and hydrogen injection system on real fuel cell systems.…”

Observer Based Fuel Delivery Control for PEM Fuel Cells with a Segmented Anode Model

“…As l min can be designed sufficiently large, observation errord i (t) can converge to arbitrary small domain. However, the unknown observer (15) is not practical because of the unavailable variableẋ(t). To settle this problem, an auxiliary variable is introduced as…”

“…Another way to eliminate the nitrogen crossover is called anode bleeding which utilizes a permanent and managed leak, and is more flexible in the control design. An analytic model of PEM fuel cells is developed in . It is shown that even a small outlet bleed can greatly decrease the nitrogen crossover effect, and an optimal bleed rate is presented.…”

A nonlinear control strategy for fuel delivery in PEM fuel cells considering nitrogen permeation

“…Then, based on the fact that Q v is positive definite, (30), and (31), _ VðtÞ is negative. Therefore, from the previous facts, the errors  eðtÞ T ;x 2 ðtÞ;x 4 ðtÞ Ã are uniformly ultimately bounded under the regulation of the control law (26) and (27) [34].…”

“…Meanwhile, anode bleeding techniques was studied in Ref. [30] to identify the optimal bleed rates at several different current densities, and utilized in Ref. [31] to mitigate the effect of carbon monoxide poisoning with low quality hydrogen operating conditions of PEM fuel cells.…”