@article{ZieglerOeserHeinetal., author = {Ziegler, Andreas and Oeser, David and Hein, Thiemo and Montesinos Miracle, Daniel and Ackva, Ansgar}, title = {Reducing Cell to Cell Variation of Lithium-Ion Battery Packs During Operation}, volume = {9}, doi = {10.1109/ACCESS.2021.3057125}, pages = {24994 -- 25001}, language = {en} } @article{ZieglerOeserHeinetal., author = {Ziegler, Andreas and Oeser, David and Hein, Thiemo and Montesinos Miracle, Daniel and Ackva, Ansgar}, title = {Run to Failure: Aging of Commercial Battery Cells beyond Their End of Life}, series = {Energies}, volume = {13}, journal = {Energies}, number = {8}, doi = {10.3390/en13081858}, language = {en} } @article{OeserHeinZiegleretal., author = {Oeser, David and Hein, Thiemo and Ziegler, Andreas and Seefried, Michael and Gielinger, Sebastian and Montesinos-Miracle, Daniel and Bohn, Gunther and Ackva, Ansgar}, title = {Age-related development of cell-to-cell variation under various operating conditions in commercial NMC/graphite lithium-ion cells}, series = {Journal of Energy Storage}, volume = {101}, journal = {Journal of Energy Storage}, publisher = {Elsevier}, doi = {10.1016/j.est.2024.113787}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:863-opus-57585}, pages = {10}, abstract = {In real applications, lithium-ion cells are usually used in individual interconnections, with the worst cell determining capacity, performance and service life. Due to different ageing rates of the assembled cells, cell-to-cell variation changes over lifetime. In literature, cell-to-cell variation is usually investigated near room temperature under one operating condition. Data regarding cell-to-cell variation above and below room temperature under different operating conditions are hard to find. To fill the gap in literature, this study considers cell-to-cell variation as a function of different charge/discharge currents at ambient temperatures between 0 °C and 40 °C on commercial NMC/graphite cells (Samsung SDI ICR18650-26J). The results demonstrate that cell-to-cell variation strongly depends on the selected operating conditions. In particular, operating conditions near the lithium plating boundary at the beginning of the ageing process have a particularly high risk of developing a pronounced variation. Fast charging or charging at lower temperatures should therefore be avoided. Operation at moderate temperatures and currents, on the other hand, only leads to a slight increase in cell-to-cell variation in the tests carried out. A 24-month storage during the testing period at 30\% SOC and room temperature of the same cells shows even a slight reduction in cell-to-cell variation.}, language = {en} } @article{HeinOeserZiegleretal., author = {Hein, Thiemo and Oeser, David and Ziegler, Andreas and Montesinos-Miracle, Daniel and Ackva, Ansgar}, title = {Aging Determination of Series-Connected Lithium-Ion Cells Independent of Module Design}, series = {Batteries}, volume = {9}, journal = {Batteries}, number = {3}, doi = {10.3390/batteries9030172}, abstract = {In this work, a battery consisting of eight commercial NMC/graphite cells connected in series was cycled to 60\% of its initial capacity. During the test, special care was taken to ensure that the results were not influenced by either the module assembly or the module design. For this purpose, the cells were virtually connected in a laboratory environment with the help of the test device as if they were operated together in a battery. Extrinsic influences that affect cell aging were thus reduced to a minimum. Differential Voltage Analysis (DVA), Electrochemical Impedance Spectrum (EIS), and relaxation measurements were performed to analyze the aging behavior of each cell. The results show that despite a theoretically perfect module design, Cell-to-Cell Variations (CtCV) occurred during aging. The shifting Depth of Discharge (DoD) values among the cells further amplify CtCV. Lithium plating was also observed in the faster aging cells after cyclic aging, suggesting that this aging effect contributes significantly to the development of CtCV. After the aging test, the battery was equipped with an active balancing system that maximizes capacity utilization. More important, the balancing charges which are calculated iteratively within the used balancing algorithm show a strong correlation to the pure capacity losses and thus provide a new way to determine the capacity values of each cell individually without disassembling the battery.}, language = {en} } @article{SchaeferGoetzeHofmannetal., author = {Sch{\"a}fer, Markus and Goetze, Wolf and Hofmann, Martin and Bayer, Fabian and Montesinos Miracle, Daniel and Ackva, Ansgar}, title = {Direct current control for grid connected diode-clamped inverters}, series = {IEEE transactions on industrial electronics}, volume = {64}, journal = {IEEE transactions on industrial electronics}, number = {4}, issn = {0278-0046}, doi = {10.1109/TIE.2016.2636127}, pages = {3067 -- 3074}, language = {en} } @article{SchaeferGoetzeHofmannetal., author = {Sch{\"a}fer, Markus and Goetze, Wolf and Hofmann, Martin and Montesinos Miracle, Daniel and Ackva, Ansgar}, title = {Three phase transformation for simplified space vector control of multilevel inverters}, series = {Control and Modeling for Power Electronics (COMPEL), 2015 IEEE 16th Workshop on}, journal = {Control and Modeling for Power Electronics (COMPEL), 2015 IEEE 16th Workshop on}, isbn = {978-1-4673-6847-6}, doi = {10.1109/COMPEL.2015.7236453}, pages = {1 -- 7}, language = {en} } @article{HofmannSchaeferMontesinosMiracleetal., author = {Hofmann, Martin and Sch{\"a}fer, Markus and Montesinos Miracle, Daniel and Ackva, Ansgar}, title = {Improved Direct Current Control for Grid Connected Multilevel Inverters}, series = {IEEE transactions on industrial electronics}, journal = {IEEE transactions on industrial electronics}, issn = {0278-0046}, doi = {10.1109/TIE.2020.3018055}, pages = {1 -- 1}, language = {en} }