@article{StegerNitscheArbesmeieretal.2020, author = {Steger, Fabian and Nitsche, Alexander and Arbesmeier, Alexander and Brade, Katja and Schweiger, Hans-Georg and Belski, Iouri}, title = {Teaching Battery Basics in Laboratories: Hands-On Versus Simulated Experiments}, volume = {63}, journal = {IEEE Transactions on Education}, number = {3}, publisher = {IEEE}, address = {Piscataway}, issn = {1557-9638}, doi = {https://doi.org/10.1109/TE.2020.2970554}, pages = {198 -- 208}, year = {2020}, abstract = {Contribution: Prior studies comparing the effectiveness of different laboratory learning modes do not allow one to draw a universally valid conclusion, as other influences are mixed with the learning modes. In order to contribute to the existing body of work and to add another piece to the puzzle, this article demonstrates an improved methodology to evaluate the effectiveness of computer-simulated laboratories in comparison to hands-on exercises using a battery basics practical course as a case study. Background: Computer-simulated experiments are becoming increasingly popular for conducting laboratory exercises in higher education and vocational training institutions. To ensure the consistent quality of laboratory learning, an accurate comparison between the results of simulated experiments and practical hands-on experiments is required. Intended Outcomes: In this article, the achievement of the following learning objectives were compared between the two laboratory modes: 1) comprehension of the most important parameters of battery cells and 2) knowledge on how these parameters can be determined using adequate experimental procedures. Application Design: To avoid interference of factors other than laboratory mode on the learning, laboratory instructions and experimental interfaces ensured identical execution of the experiments in the compared modes. Using a counterbalanced methodology, the two laboratory modes alternated by the session, while the experimental procedures remained constant regardless of the respective modes. Findings: Tests taken by the participants after conducting the laboratory experiments revealed that hands-on laboratories resulted in statistically significantly better student performance than simulated laboratories. This difference was even more pronounced for the participants that finished a vocational education and training program before the university studies.}, language = {en} } @article{KimStegerKotaketal.2019, author = {Kim, Woong-Ki and Steger, Fabian and Kotak, Bhavya and Knudsen, Peter V. R. and Girgsdies, Uwe and Schweiger, Hans-Georg}, title = {Water Condensation in Traction Battery Systems}, volume = {12}, pages = {1171}, journal = {Energies}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en12061171}, year = {2019}, abstract = {Lithium-ion traction battery systems of hybrid and electric vehicles must have a high level of durability and reliability like all other components and systems of a vehicle. Battery systems get heated while in the application. To ensure the desired life span and performance, most systems are equipped with a cooling system. The changing environmental condition in daily use may cause water condensation in the housing of the battery system. In this study, three system designs were investigated, to compare different solutions to deal with pressure differences and condensation: (1) a sealed battery system, (2) an open system and (3) a battery system equipped with a pressure compensation element (PCE). These three designs were tested under two conditions: (a) in normal operation and (b) in a maximum humidity scenario. The amount of the condensation in the housing was determined through a change in relative humidity of air inside the housing. Through PCE and available spacing of the housing, moisture entered into the housing during the cooling process. While applying the test scenarios, the gradient-based drift of the moisture into the housing contributed maximum towards the condensation. Condensation occurred on the internal surface for all the three design variants.}, language = {en} } @article{StegerKroghMeegahapolaetal.2022, author = {Steger, Fabian and Krogh, Jonathan and Meegahapola, Lasantha and Schweiger, Hans-Georg}, title = {Calculating Available Charge and Energy of Lithium-Ion Cells Based on OCV and Internal Resistance}, volume = {15}, pages = {7902}, journal = {Energies}, number = {21}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en15217902}, year = {2022}, abstract = {The design and operation of performant and safe electric vehicles depend on precise knowledge of the behavior of their electrochemical energy storage systems. The performance of the battery management systems often relies on the discrete-time battery models, which can correctly emulate the battery characteristics. Among the available methods, electric circuit-based equations have shown to be especially useful in describing the electrical characteristics of batteries. To overcome the existing drawbacks, such as discrete-time simulations for parameter estimation and the usage of look-up tables, a set of equations has been developed in this study that solely relies on the open-circuit voltage and the internal resistance of a battery. The parameters can be obtained from typical cell datasheets or can be easily extracted via standard measurements. The proposed equations allow for the direct analytical determination of available discharge capacity and the available energy content depending on the discharge current, as well as the Peukert exponent. The fidelity of the proposed system was validated experimentally using 18650 NMC and LFP lithium-ion cells, and the results are in close agreement with the datasheet.}, language = {en} } @inproceedings{StegerNitscheSchweigeretal.2017, author = {Steger, Fabian and Nitsche, Alexander and Schweiger, Hans-Georg and Belski, Iouri}, title = {Hands-on Experiments vs. Computer-based Simulations in Energy Storage Laboratories}, booktitle = {Proceedings of the 45th SEFI Annual Conference 2017 : Education Excellence for Sustainability}, editor = {Quadrado, Jos{\´e} Carlos and Bernardino, Jorge and Rocha, Jo{\~a}o}, publisher = {SEFI (Soci{\´e}t{\´e} Europ{\´e}enne pour la Formation des Ing{\´e}nieurs)}, address = {Br{\"u}ssel}, isbn = {978-989-98875-7-2}, url = {https://www.sefi.be/conference/2017-azores/}, pages = {121 -- 128}, year = {2017}, language = {en} } @inproceedings{PourtoulidouStegerBurgeretal.2019, author = {Pourtoulidou, Despoina and Steger, Fabian and Burger, Uli and G{\"o}llinger, Harald and K{\"o}nig, Ludwig and Obermeier, Erwin and Schweiger, Hans-Georg and Frey, Andreas}, title = {Mission-framed Project-based Learning and Teaching}, booktitle = {Varietas delectat… Complexity is the new normality: SEFI 47th Annual Conference Proceedings}, subtitle = {integrating an Electric Powertrain into a Motor Glider}, editor = {Nagy, Bal{\´a}zs Vince and Murphy, Mike and J{\"a}rvinen, Hannu-Matti and K{\´a}lm{\´a}n, Anik{\´o}}, publisher = {SEFI}, address = {Br{\"u}ssel}, isbn = {978-2-87352-018-2}, doi = {https://www.sefi.be/proceedings/?conference=2019-budapest-isbn-978-2-87352-018-2}, pages = {879 -- 888}, year = {2019}, language = {en} } @inproceedings{StegerArbesmeierNitscheetal.2019, author = {Steger, Fabian and Arbesmeier, Alexander and Nitsche, Alexander and Brade, Katja and Schweiger, Hans-Georg and Belski, Iouri}, title = {Laboratory learning}, booktitle = {Varietas delectat… Complexity is the new normality: SEFI 47th Annual Conference Proceedings}, subtitle = {influence of the perceived laboratory mode on learning outcomes}, editor = {Nagy, Bal{\´a}zs Vince and Murphy, Mike and J{\"a}rvinen, Hannu-Matti and K{\´a}lm{\´a}n, Anik{\´o}}, publisher = {SEFI}, address = {Br{\"u}ssel}, isbn = {978-2-87352-018-2}, doi = {https://www.sefi.be/proceedings/?conference=2019-budapest-isbn-978-2-87352-018-2}, pages = {1897 -- 1907}, year = {2019}, language = {en} } @inproceedings{StegerNitscheMileyetal.2017, author = {Steger, Fabian and Nitsche, Alexander and Miley, Cayler and Schweiger, Hans-Georg and Belski, Iouri}, title = {Laboratory Learning: Hands-on versus Simulated Experiments}, booktitle = {Proceedings of the 28th Annual Conference of the Australasian Association for Engineering Education (AAEE 2017)}, editor = {Huda, Nazmul and Inglis, David and Tse, Nicholas and Town, Graham}, publisher = {Macquarie University}, address = {Sydney}, isbn = {978-0-646-98026-3}, url = {https://researchers.mq.edu.au/en/publications/proceedings-of-the-28th-annual-conference-of-the-australasian-ass}, pages = {940 -- 947}, year = {2017}, abstract = {CONTEXT Many universities and vocational training institutions conduct laboratories as simulated experiments. This is due to the costs and supervision needs to conduct hands-on labs safely. Numerous studies have presented mixed opinions on whether hands-on laboratory work is more conducive to learning than a simulated laboratory. Most of the studies put students from experimental and control groups in significantly different conditions. Therefore, it is hard to reach any definite conclusion regarding the influence of the learning mode onto the learning achievements. PURPOSE This study compares learning outcomes of student laboratory work in an energy storages course conducted in two different modes: first as a practical hands-on exercise and second using computer-based simulations. APPROACH In order to provide reliable insights, this study implements optimized research methodology to avoid any other effect (e.g. learning synchronicity/distance learning/instructions) on the learning outcome rather than the effect of the learning mode itself. The student laboratory experiments were created in a manner that they could be conducted in both modes in the same way and using a single set of instructions. To ensure a comparable group environment for the individual student, the students were arranged into two similar groups based on the student's practical experience. In this crossover study, the groups were taught the same topics by means of interchanging learning modes. RESULTS To evaluate the influence of each mode on student learning, short written tests regarding the previous experiment were conducted at the beginning of the subsequent laboratory session. 102 students have taken part in the study in two years. Overall learning results of hands-on experiments were slightly better than those of simulated laboratories (Cohen's d=0.25), the difference in performance was statistically significant (p<0.02). Through solicited feedback on each laboratory session, in hands-on mode more students expressed they have acquired new insights/comprehensions (76\% vs. 66\%, Cohen's d=0.23, small effect, p<0.07). CONCLUSIONS Following the strategy not to optimize the lessons individually to the learning mode, other influences on the learning outcome, which were usually mixed, were excluded. The students' subjective opinions show advantages of the hands-on mode. Based on the objective data, a weak, but significant outcome to better knowledge acquisition with hands-on laboratory experiments was achieved. This observation is against the trend of the literature in the last years towards better or equal learning with nontraditional labs. Some of the excluded factors might have a stronger influence on student learning than estimated previously. To get a clear view, the authors recommend isolated research.}, language = {en} } @inproceedings{StegerNitscheBradeetal.2018, author = {Steger, Fabian and Nitsche, Alexander and Brade, Katja and Belski, Iouri and Schweiger, Hans-Georg}, title = {Energiespeicher-Praktikum an der TH Ingolstadt}, booktitle = {Tagungsband zum Forum der Lehre an der TH Ingolstadt}, subtitle = {reale versus simulierte Experimente}, editor = {Waldherr, Franz and Walter, Claudia}, publisher = {THI / DiZ}, address = {Ingolstadt}, issn = {1612-4537}, url = {https://didaktikzentrum.de/publikationen/dina-und-tagungsbaende}, pages = {90 -- 97}, year = {2018}, language = {de} } @inproceedings{StegerPenichedosSantosBelskietal.2017, author = {Steger, Fabian and Peniche dos Santos, Adriano and Belski, Iouri and Schweiger, Hans-Georg}, title = {Impedance Spectroscopy Upgrade to a Student Battery Cell Test System}, booktitle = {Abstract Book: International Workshop of Impedance Spectroscopy, IWIS 2017}, publisher = {TU Chemnitz}, address = {Chemnitz}, pages = {24 -- 25}, year = {2017}, language = {en} } @inproceedings{StegerNitscheBradeetal.2017, author = {Steger, Fabian and Nitsche, Alexander and Brade, Katja and Belski, Iouri and Schweiger, Hans-Georg}, title = {Teaching Energy Storages by means of a Student Battery Cell Test System}, booktitle = {Proceedings of the 45th SEFI Annual Conference 2017: Education Excellence for Sustainability}, editor = {Quadrado, Jos{\´e} Carlos and Bernardino, Jorge and Rocha, Jo{\~a}o}, publisher = {SEFI (Soci{\´e}t{\´e} Europ{\´e}enne pour la Formation des Ing{\´e}nieurs)}, address = {Br{\"u}ssel}, isbn = {978-989-98875-7-2}, url = {https://www.sefi.be/conference/2017-azores/}, pages = {169 -- 176}, year = {2017}, language = {en} } @article{NeblStegerSchweiger2017, author = {Nebl, Christoph and Steger, Fabian and Schweiger, Hans-Georg}, title = {Discharge Capacity of Energy Storages as a Function of the Discharge Current-Expanding Peukert's equation}, volume = {12}, journal = {International Journal of Electrochemical Science}, number = {6}, publisher = {ESG}, address = {Belgrad}, issn = {1452-3981}, doi = {https://doi.org/10.20964/2017.06.51}, pages = {4940 -- 4957}, year = {2017}, abstract = {In 1897 Wilhelm Peukert tested lead-acid batteries with constant current and observed that a single equation can describe the relationship between the discharge capacity of the battery and a constant discharge current. In this article the dependence of the discharge capacity of lithium-ion battery cells, electrochemical double-layer capacitors and lithium capacitors are investigated from low to very high discharge rates. From low to intermediate discharge rates, these energy storage devices show ideal Peukert behavior, but a deviation was observed at high discharge rates. The cells provide less charge than predicted by Peukert's Law. To describe this deviation, a new equation has been derived by expanding Peukert's law to very discharge rates. It is capable to describe the discharge behavior of lithium-ion battery cells, electrochemical double-layer capacitors and lithium capacitors from low to high discharge rates in an unequivocal way.}, language = {en} }