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Virtual Component Testing for PEM Fuel Cell Systems:An Efficient, High-Quality and Safe Approach forSuppliers and OEM´s
KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).ORCID iD: 0000-0001-7048-0108
2005 (English)In: 3rd European PEFC Forum, Session B09, 7July, 09:15h, File No. B092, 2005, 103-120 p.Conference paper, Published paper (Refereed)
Abstract [en]

The successful introduction of fuel cell systems for future generation automotiveapplications will significantly depend on the development and realization of reliable lowcost components, which have to be highly integrated in the fuel cell system.Hence, in the course of the project NFCCPP (Numerical Fuel Cell ComponentPerformance Prediction tool) funded by the European Union, a simulation environment hasbeen worked out and a modular component tool box created, which allows the – virtual –testing of components of fuel cell systems in a highly realistic, most advanced and precise,but nevertheless confidential simulation environment. Confidentiality – in fact modelprotection - enables the combination of best state of the art simulation modules fromdifferent partners in an overall system simulation model without having access toconfidential information and data of other individual components. Even competitors cantest their components together in such an environment. Moreover, this approach enablesinvestigations based on overall system simulations (or a fixed set thereof), which have theadvantage of providing a sound reference for comparing results.

Place, publisher, year, edition, pages
2005. 103-120 p.
National Category
Reliability and Maintenance
Identifiers
URN: urn:nbn:se:kth:diva-19444OAI: oai:DiVA.org:kth-19444DiVA: diva2:337952
Conference
3rd European PEFC Forum
Note

QC 20100810

Available from: 2010-08-10 Created: 2010-08-10 Last updated: 2017-11-16Bibliographically approved
In thesis
1. Modeling and Simulation of Physical Systems in a Mechatronic Context
Open this publication in new window or tab >>Modeling and Simulation of Physical Systems in a Mechatronic Context
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis gives different views on the modeling and simulation of physical systems, especially together with embedded systems, forming mechatronic systems. The main considered application domain is automotive. One motivation behind the work is to find suitable representations of physical systems to be used in an architectural description language for automotive embedded systems, EAST-ADL2, which is implemented as a UML2 profile, and uses concepts from both UML and SysML. As a part of the thesis, several languages and tools are investigated, including bond graphs, MATLAB/Simulink, Ptolemy II, Modelica, MATLAB/Simscape and SysML. For SysML, the modeling of continuous-time systems and how it relates to MATLAB/Simulink and Modelica is evaluated. A case study of an electric power assisted steering is modeled to show the differences, the similarities and the usage of the above mentioned languages and tools. To be able to classify the tools and languages, five realization levels were developed:

  • Physical modeling models
  • Constraint models
  • Continuous causal models
  • Discretized models
  • Discretized models with solver and platform implementation

By using these realization levels, models, tools and modeling languages can be classified, and transformations between them can be set up and analyzed. As a result, a method to describe the simulation behavior of a MATLAB/Simulink model has been developed using SysML activity diagrams as an approach to achieve integrated system models. Another result is an evaluation of the parametric diagrams of SysML for continuous-time modeling, which shows that they do not enable “physical modeling”, i.e. modeling the topology of the system and getting the underlying equations out of this topology. By including physical ports and physical connectors to SysML internal block diagrams, this could be solved. The comparison also shows many similarities between the languages. The results led to a more detailed investigation on conjugate variables, such as force and velocity, and electric current and voltage, and how these are treated in various languages. The thesis also includes two industrial case studies: one of a twin-screw compressor, and one of a simulation environment for automotive fuel-cell systems. Conclusions are drawn from these models, referring to the realization levels.

Place, publisher, year, edition, pages
Stockholm: KTH, 2009. ix, 85 p.
Series
Trita-MMK, ISSN 1400-1179 ; 2009:12
Keyword
mechatronics, MATLAB/Simulink, SysML, bond graphs, Modelica, Simscape, simulation, modeling, EAST-ADL2, physical modeling
Identifiers
urn:nbn:se:kth:diva-10522 (URN)978-91-7415-361-3 (ISBN)
Public defence
2009-06-09, KTHB, Salongen, Osquars Backe 31, Stockholm, 13:00 (English)
Opponent
Supervisors
Note
QC 20100810Available from: 2009-06-03 Created: 2009-05-20 Last updated: 2010-08-10Bibliographically approved
2. On the modular modelling for dynamical simulation with application to fluid systems
Open this publication in new window or tab >>On the modular modelling for dynamical simulation with application to fluid systems
2005 (English)Licentiate thesis, comprehensive summary (Other scientific)
Abstract [en]

This licentiate thesis highlights some topics on modular modelling for dynamical simulation with application to fluid systems. The results are based on experience from the development of the fuel cell component simulation environment NFCCPP. The general application is cross-enterprise simulation of technical systems. There are four main topics: component definition including selection of interfaces, lumped modelling of fluid components, the use of dynamical equations to reduce simulation time in large systems and methods of to protect the intellectual property (IP) of a component.

An overview of different dynamical fluid simulation tools such as HOPSAN, MATLAB/Simulink and Easy5 is presented. Special focus is on interfaces, where different approaches for representing interfaces are presented using an illustrative example. Selecting interfaces is however not a separated task from how to set up and solve the underlying equations, which also is shown. Equations to model a lumped component are derived, to get a mathematical background to what problems there are to solve. These equations are derived especially to be applicable in block model software simulation tools such as MATLAB/Simulink. The equations are also compared with the bond-graph approach of representing dynamical systems. A twinscrew compressor is modelled in MATLAB/Simulink as an implementation of these equations. A method to decrease the simulation time in dynamical fluid system is also presented. The technique is to add virtual mass in the force equation to get a slower acceleration of the fluid. Using this slower response, it is possible to use larger time-steps when integrating the equations and thus the total simulation time can be reduced. The error introduced using this method is a modelling error in the time domain, and it is comparable with using unit transmission lines (UTL:s), as does HOPSAN.

The protection of the intellectual property (IP) of a component model is presented. The concept of clamping is thoroughly explained, as it often is overlooked in conventional IPprotection. Three concepts for code protection are presented: “Centralised simulation with remote user control”, “Localised simulation with simulation-time model usage control” and “Parallel distributed simulation”. The NFCCPP implementation of the concept “Localised simulation with simulation-time model usage control” is presented in more detail.

Place, publisher, year, edition, pages
Stockholm: KTH, 2005. viii, 20 p.
Series
Trita-MMK, ISSN 1400-1179 ; 2005:30
National Category
Computer Sciences
Identifiers
urn:nbn:se:kth:diva-566 (URN)
Presentation
2005-12-06, sal A425, KTH, Brinellvägen 83, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20101221Available from: 2005-12-28 Created: 2005-12-28 Last updated: 2018-01-13Bibliographically approved

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