Assessing the Impact of Inverter Current-Ripple on SOFC Performance

2003 ◽  
Author(s):  
Randall S. Gemmen ◽  
Parviz Famouri ◽  
Christopher Johnson
Keyword(s):  
Fuel Cell ◽  
Transient Model ◽  
One Dimensional ◽  
Fuel Cell Stack ◽  
First Order ◽  
A Cell ◽  
Current Loading ◽  
Dc Current ◽  
The Impact ◽  
Current Ripple

The effect of inverter ripple current on fuel cell stack performance is not well understood. This paper provides a first-order examination of the impact of inverter load dynamics on SOFC fuel cell operation. Previous work using steady-state fuel cell loading has shown that DC-current loading itself results in degradation of the fuel cell, albeit in ways yet to be fully understood. This result suggests that the varying reactant conditions that result from ripple may modify degradation processes, and, therefore, the lifetime of the cells. This paper investigates these conditions through the use of a dynamic one-dimensional model for the detailed mass transport occurring within the electrode of a cell. In this work, the inverter load is imposed as a boundary condition to the transient model. Results show the behavior of the reactant concentrations within the stack electrodes under inverter loads with frequencies between 60 Hz and 1250 Hz. It is concluded that a ripple factor of less than 6% be used to ensure minor impact to the conditions at the electrode-electrolyte interface.

Analysis for the Effect of Inverter Ripple Current on Fuel Cell Operating Condition

2001 ◽  
Author(s):  
Randall S. Gemmen
Keyword(s):  
Boundary Condition ◽  
Fuel Cell ◽  
Mass Transport ◽  
Transient Behavior ◽  
Mechanical State ◽  
Dimensional Model ◽  
One Dimensional ◽  
Fuel Cell Stack ◽  
A Cell ◽  
The Impact

Abstract The effect of inverter ripple current on fuel cell stack performance and stack lifetime remains uncertain. This paper provides a first attempt to examine the impact of inverter load dynamics on the fuel cell. Since reactant utilization is known to impact the mechanical state of a fuel cell, it is suggested that the varying reactant conditions surrounding the cell govern, at least in part, the lifetime of the cells. This paper investigates these conditions through the use of a dynamic model for the bulk conditions within the stack, as well as a one-dimensional model for the detailed mass transport occurring within the electrode of a cell. These two independent modeling approaches help to verify their respective numerical procedures. In this work, the inverter load is imposed as a boundary condition to the models. Results show the transient behavior of the reactant concentrations within the stack, and of the mass diffusion within the electrode under inverter loads with frequencies between 30 Hz and 1250 Hz.

Analysis for the Effect of Inverter Ripple Current on Fuel Cell Operating Condition

2003 ◽  
Vol 125 (3) ◽  
pp. 576-585 ◽  
Author(s):  
Randall S. Gemmen
Keyword(s):  
Boundary Condition ◽  
Fuel Cell ◽  
Mass Transport ◽  
Transient Behavior ◽  
Dimensional Model ◽  
One Dimensional ◽  
Fuel Cell Stack ◽  
A Cell ◽  
The Impact ◽  
Mechanical Nature

The effect of inverter ripple current on fuel cell stack performance and stack lifetime remains uncertain. This paper provides a first attempt to examine the impact of inverter load dynamics on the fuel cell. Since reactant utilization is known to impact the mechanical nature of a fuel cell, it is suggested that the varying reactant conditions surrounding the cell govern, at least in part, the lifetime of the cells. This paper investigates these conditions through the use of a dynamic model for the bulk conditions within the stack, as well as a one-dimensional model for the detailed mass transport occurring within the electrode of a cell. These two independent modeling approaches are used to verify their respective numerical procedures. In this work, the inverter load is imposed as a boundary condition to the models. Results show the transient behavior of the reactant concentrations within the stack, and of the mass diffusion within the electrode under inverter loads with frequencies between 30 Hz and 1250 Hz.

scholarly journals Overcoming the Challenges for a Mass Manufacturing Machine for the Assembly of PEMFC Stacks

Machines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 66 ◽  
Author(s):  
Porstmann ◽  
Wannemacher ◽  
Richter
Keyword(s):  
Fuel Cell ◽  
Economies Of Scale ◽  
Polymer Electrolyte Membrane ◽  
Cell System ◽  
Active Components ◽  
Fuel Cell Stack ◽  
Electrolyte Membrane ◽  
Modular Concept ◽  
A Cell ◽  
Manufacturing Machine

One of the major obstacles standing in the way of a break-through in fuel cell technology is its relatively high costs compared to well established fossil-based technologies. The reasons for these high costs predominantly lie in the use of non-standardized components, complex system components, and non-automated production of fuel cells. This problem can be identified at multiple levels, for example, the electrochemically active components of the fuel cell stack, peripheral components of the fuel cell system, and eventually on the level of stack and system assembly. This article focused on the industrialization of polymer electrolyte membrane fuel cell (PEMFC) stack components and assembly. To achieve this, the first step is the formulation of the requirement specifications for the automated PEMFC stack production. The developed mass manufacturing machine (MMM) enables a reduction of the assembly time of a cell fuel cell stack to 15 minutes. Furthermore the targeted automation level is theoretically capable of producing up to 10,000 fuel cell stacks per year. This will result in a ~50% stack cost reduction through economies of scale and increased automation. The modular concept is scalable to meet increasing future demand which is essential for the market ramp-up and success of this technology.

scholarly journals A STUDY OF THE DEFLECTIONS OF METAL ROAD GUARDRAIL ELEMENTS

Transport ◽  
2009 ◽  
Vol 24 (3) ◽  
pp. 225-233 ◽  
Author(s):  
Olegas Prentkovskis ◽  
Andrey Beljatynskij ◽  
Rasa Prentkovskienė ◽  
Ivan Dyakov ◽  
Laima Dabulevičienė
Keyword(s):  
Mathematical Model ◽  
Finite Elements ◽  
Traffic Accidents ◽  
Statistical Data ◽  
Elastic Deformations ◽  
One Dimensional ◽  
First Order ◽  
Horizontal Beam ◽  
Deformation Processes ◽  
The Impact

Statistical data on traffic accidents in 2008 in Lithuania is presented. Referring to statistical data, grounding on an obstacle’ makes one‐tenth of all registered traffic accidents ‐ 9.4% (an obstacle may be a road guardrail, a lamp post, a tree, a bar, a gate, etc.). Road guardrails of various types are installed on the shoulders and dividing strips of urban and suburban roads. They are as follows: reinforced concrete guardrails, cable guardrails and metal guardrails. Metal guardrails, consisting of S‐shape metal posts and a protective W‐shape horizontal beam, are most popular. The authors of the present paper examine the deformation processes of the elements of the above mentioned guardrail. A mathematical model of metal road guardrail was developed. Metal road guardrail was modelled using one‐dimensional first‐order finite elements, taking into account only elastic deformations, as well as the effect of soil on the buried post section of the guardrail. Based on the developed mathematical model of metal road guardrail, the deflections of its elements caused by the impact of a vehicle moving at varying speed were determined. The obtained values of deflections of guardrail elements (a protective W‐shape horizontal beam and a S‐shape post) presented in paper do not exceed the admissible values (of beam deflections).

Modelling the impact of creep on the probability of failure of a solid oxide fuel cell stack

2014 ◽  
Vol 34 (11) ◽  
pp. 2695-2704 ◽  
Author(s):  
Fabio Greco ◽  
Henrik Lund Frandsen ◽  
Arata Nakajo ◽  
Mads Find Madsen ◽  
Jan Van herle
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Probability Of Failure ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell Stack ◽  
The Impact

Hardware-Based Simulation of a Fuel Cell Turbine Hybrid Response to Imposed Fuel Cell Load Transients

2006 ◽  
Author(s):  
Thomas P. Smith ◽  
Comas L. Haynes ◽  
William J. Wepfer ◽  
David Tucker ◽  
Eric A. Liese
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Pressure Vessels ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Electrical Load ◽  
Fuel Cell Stack ◽  
Thermal Transients ◽  
The Impact

Electrical load transients imposed on the cell stack of a solid oxide fuel cell/gas turbine hybrid power system are studied using the Hybrid Performance (HyPer) project. The hardware simulation facility is located at the U.S. Department of Energy, National Energy Technology Laboratory (NETL). A computational fuel cell model capable of operating in real time is integrated with operating gas turbine hardware. The thermal output of a modeled 350 kW solid oxide fuel cell stack is replicated in the facility by a natural gas fired burner in a direct fired hybrid configuration. Pressure vessels are used to represent a fuel cell stack's cathode flow and post combustion volume and flow impedance. This hardware is used to simulate the fuel cell stack and is incorporated with a modified turbine, compressor, and 120 kW generator on a single shaft. For this study, a simulation was started with a simulated current demand of 307 A on the fuel cell at approximately 0.75 V and an actual 45 kW electrical load on the gas turbine. An open loop response, allowing the turbine rotational speed to respond to thermal transients, was successfully evaluated for a 5% current reduction on the fuel cell followed by a 5% current increase. The impact of the fuel cell load change on system process variables is presented. The test results demonstrate the capabilities of the hardware-in-the-loop simulation approach in evaluating hybrid fuel cell turbine dynamics and performance.

scholarly journals The Impact of Humidification Temperature on a 1 kW Proton Exchange Membrane Fuel Cell Stack

2017 ◽  
Vol 142 ◽  
pp. 1661-1667 ◽  
Author(s):  
Aleksandra Sveshnikova ◽  
Gioele Di Marcoberardino ◽  
Claudio Pirrone ◽  
Aldo Bischi ◽  
Gianluca Valenti ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Fuel Cell Stack ◽  
Exchange Membrane ◽  
The Impact

Intelligent Control of the Energy Generation Systems

2010 ◽  
pp. 40-96
Author(s):  
Nicu Bizon
Keyword(s):  
Fuzzy Logic ◽  
Fuel Cell ◽  
Intelligent Control ◽  
Fuzzy Logic Controller ◽  
Energy Generation ◽  
Control Law ◽  
Battery Voltage ◽  
Fuel Cell Stack ◽  
Cell Current ◽  
Current Ripple

In this book chapter are analyzed the Energy Generation System (EGS) topologies, used in automotive systems, and the grid inverter systems, with intelligent control algorithms (fuzzy logic controller, genetic algorithm, etc.). The EGS blocks are modelled using Matlab & Simulink ® program. A necessary block is the EGS power interface between the fuel cell stack and the batteries stack, usually a boost converter that uses a Peak Current Controller (PCC) with a Boundary Control with Current Taper (BCCT). The control law is a function of fuel cell current and battery voltage, which prevents the “boiling” of the batteries. The control objective for this power interface is also the fuel cell current ripple minimization, used in order to improve the fuel cell stack life cycle. Clocked and non-clocked control methods are tested in order to obtain a small fuel cell current ripple, better a dynamic response, and robustness against system uncertainty disturbances. The EGS behaviour is tested by bifurcation diagrams. It is shown that performances increase if the control law is a function that depends by the fuel cell current ripple and battery voltage. The clocked PCC using the BCCT 2-D law is implemented by a fuzzy logic controller. The power load dynamic is compensated using an ultracapacitors stack as a dynamic energy compensator, connected by a bi-directional converter to the batteries stack bus. Small fuel cell current ripple using compact batteries and ultracapacitors stacks will be obtained by the appropriate design of the control surface, using an Integrated Fuzzy Control (IFC) for both power interfaces.

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