TY - JOUR A1 - Komsiyska, Lidiya A1 - Buchberger, Tobias A1 - Diehl, Simon A1 - Ehrensberger, Moritz A1 - Hanzl, Christian A1 - Hartmann, Christoph A1 - Hölzle, Markus A1 - Kleiner, Jan A1 - Lewerenz, Meinert A1 - Liebhart, Bernhard A1 - Schmid, Michael A1 - Schneider, Dominik A1 - Speer, Sascha A1 - Stöttner, Julia A1 - Terbrack, Christoph A1 - Hinterberger, Michael A1 - Endisch, Christian T1 - Critical review of intelligent battery systems BT - challenges, implementation, and potential for electric vehicles JF - Energies N2 - This review provides an overview of new strategies to address the current challenges of automotive battery systems: Intelligent Battery Systems. They have the potential to make battery systems more performant and future-proof for coming generations of electric vehicles. The essential features of Intelligent Battery Systems are the accurate and robust determination of cell individual states and the ability to control the current of each cell by reconfiguration. They enable high-level functions like fault diagnostics, multi-objective balancing strategies, multilevel inverters, and hybrid energy storage systems. State of the art and recent advances in these topics are compiled and critically discussed in this article. A comprising, critical discussion of the implementation aspects of Intelligent Battery Systems complements the review. We touch on sensing, battery topologies and management, switching elements, communication architecture, and impact on the single-cell. This review contributes to transferring the best technologies from research to product development. UR - https://doi.org/10.3390/en14185989 KW - smart battery KW - intelligent battery system KW - advanced monitoring KW - reconfigurable battery KW - battery management system KW - electric vehicle Y1 - 2021 UR - https://doi.org/10.3390/en14185989 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-10132 SN - 1996-1073 VL - 14 IS - 18 PB - MDPI CY - Basel ER - TY - JOUR A1 - Stöttner, Julia A1 - Hanzl, Christian A1 - Terbrack, Christoph A1 - Endisch, Christian T1 - Holistic evaluation and optimization of multilevel inverter designs for electric vehicle applications JF - Energy Reports N2 - To advance the development of multilevel inverters (MLIs) for electric vehicle applications, this study introduces novel asymmetric MLI (AMLI) configurations featuring buffer modules to enhance efficiency. A comprehensive comparative analysis of 125 distinct inverter systems is conducted, integrating five different microtopologies and 25 representative symmetrical MLI (SMLI) and AMLI systems. Unlike previous studies, this work employs a successive design process with a graph-based approach to systematically minimize conduction losses. Furthermore, experimental loss measurements ensure practical relevance. By applying Pareto optimization with cost, energy losses, and total harmonic distortion as objective functions, the study identifies the most promising MLI systems among all considered ones. While the cascaded H-bridge MLI emerges as the most cost-effective solution, specific SMLI configurations with 12 or 18 battery cells per module and AMLI designs featuring buffer modules exhibit lower inverter losses. In both cases, the incorporation of microtopologies that enable parallel operation leads to a remarkable reduction in inverter losses by more than 30 % compared to the least efficient MLI systems. Finally, a comparative assessment against a conventional B6-bridge SiC inverter highlights the significant advantages of these optimized MLI configurations in terms of efficiency and system performance. UR - https://doi.org/10.1016/j.egyr.2025.03.001 Y1 - 2025 UR - https://doi.org/10.1016/j.egyr.2025.03.001 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-58297 SN - 2352-4847 VL - 2025 IS - 13 SP - 3561 EP - 3573 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Kleiner, Jan A1 - Heider, Alexander A1 - Hanzl, Christian A1 - Komsiyska, Lidiya A1 - Elger, Gordon A1 - Endisch, Christian T1 - Thermal behavior of an intelligent li-ion cell under vehicle conditions T2 - Proceedings: IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society UR - https://doi.org/10.1109/IECON43393.2020.9254336 KW - Li-ion KW - electro-thermal model KW - intelligent battery KW - reconfigurable system KW - smart cell Y1 - 2020 UR - https://doi.org/10.1109/IECON43393.2020.9254336 SN - 978-1-7281-5414-5 SN - 2577-1647 SP - 2081 EP - 2086 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Schmid, Michael A1 - Gebauer, Emanuel A1 - Hanzl, Christian A1 - Endisch, Christian T1 - Active model-based fault diagnosis in reconfigurable battery systems JF - IEEE Transactions on Power Electronics UR - https://doi.org/10.1109/TPEL.2020.3012964 KW - active fault isolation KW - active hypothesis testing KW - constrained parameter estimation KW - fault tolerance KW - fuzzy clustering KW - reconfigurable battery system (RBS) Y1 - 2020 UR - https://doi.org/10.1109/TPEL.2020.3012964 SN - 1941-0107 SN - 0885-8993 VL - 36 IS - 3 SP - 2584 EP - 2597 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Hanzl, Christian A1 - Hartmann, Christoph A1 - Hölzle, Markus A1 - Liebhart, Bernhard A1 - Schmid, Michael A1 - Endisch, Christian T1 - Current commutation in a switched lithium-ion cell used in cascaded half-bridge multilevel inverters JF - IET Power Electronics N2 - In order to improve the efficiency of battery electric vehicles, the utilization of reconfigurable batteries and multilevel inverters based on low-voltage Si MOSFETs gains growing attention. Focusing on the half-bridge as basic switching unit, this paper examines voltage and current waveforms during switching. It is shown that the current commutation speed depends on various factors such as sign and amplitude of the current as well as the particular switching scenario. For instance, turning off a positive cell current takes 0.21 𝜇s while turning it on takes 0.9 𝜇s. In addition, it is revealed that depending on the switching scenario and current direction, the lithium-ion cell supports or opposes the remagnetization of the parasitic inductances and therefore the switching losses of the MOSFETs. Switching a positive load current of 125 A from active to bypass converts 276 𝜇J into heat while switching from bypass to active converts merely 32.5 𝜇J into heat. UR - https://doi.org/10.1049/pel2.12088 Y1 - 2021 UR - https://doi.org/10.1049/pel2.12088 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-13364 SN - 1755-4543 VL - 14 IS - 6 SP - 1073 EP - 1088 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Stöttner, Julia A1 - Hanzl, Christian A1 - Endisch, Christian T1 - Experimental investigation of parasitic side effects in MOSFET-based multilevel inverter for electric vehicle applications JF - Electric Power Systems Research UR - https://doi.org/10.1016/j.epsr.2023.109197 Y1 - 2023 UR - https://doi.org/10.1016/j.epsr.2023.109197 SN - 1873-2046 SN - 0378-7796 VL - 2023 IS - 218 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Williams Ngaleu, Guy A1 - Theiler, Michael A1 - Straßer, Xenia A1 - Hanzl, Christian A1 - Komsiyska, Lidiya A1 - Endisch, Christian A1 - Lewerenz, Meinert T1 - Influence of Switching on the Aging of High Power Lithium-Ion Cells JF - Batteries N2 - For intelligent battery systems that are able to control the current flow for each individual cell, the multilevel inverter is an interesting approach to replace the bidirectional AC/DC-converter and improve flexibility of charging system and signal quality in both directions. Therefore, the cells are modulated by switching varying the duty cycle, the current and the frequency up to the kHz-range. This is only beneficial if the switching does not lead to a significant additional aging. The scientific gap to assess and understand the impact of switching is investigated in this paper by testing 22 high-power 18650 lithium-ion cells (Samsung 25R). The cells are tested at 50 Hz and 10 kHz switching frequency during charge, discharge and charge/discharge at 50% duty cycle. The tests are compared to eight reference tests with continuous current flow performed at the average and the maximum current for charge and discharge, respectively. The results are obtained by evaluating the remaining capacity, resistance, electrochemical impedance spectroscopy and dV/dQ analysis. Before reaching rollover, the investigated cells lose homogeneity and cathode capacity but no significant difference for the aging parameters are found. After rollover, the cell-to-cell variation is greater than the aging induced by the different cycling parameters. UR - https://doi.org/10.3390/batteries8040033 KW - 18650 KW - NCA KW - graphite KW - switching KW - multilevel inverter KW - frequency KW - cycle life Y1 - 2022 UR - https://doi.org/10.3390/batteries8040033 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-22861 SN - 2313-0105 VL - 8 IS - 4 PB - MDPI CY - Basel ER - TY - CHAP A1 - Hanzl, Christian A1 - Stöttner, Julia A1 - Hölzle, Markus A1 - Endisch, Christian T1 - Experimental Investigation and Analytical Modeling of Half-Bridge Switching Losses in Reconfigurable Lithium-Ion Cells T2 - ICPE 2023 - ECCE Asia: 11th International Conference on Power Electronics - ECCE Asia UR - https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213901 KW - half-bridge KW - lithium-ion cell KW - MOSFET switching losses KW - multilevel inverter Y1 - 2023 UR - https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213901 SN - 978-89-5708-350-5 SP - 1058 EP - 1065 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Straßer, Xenia A1 - Williams Ngaleu, Guy A1 - Hanzl, Christian A1 - Azzam, Mohamed A1 - Endisch, Christian A1 - Lewerenz, Meinert T1 - Influence of Switching on the Aging of High Energy Lithium-Ion Cells JF - Batteries N2 - An AC-battery or multilevel inverter used to increase safety and flexibility is realizable by switching the cells and modules on and off in a defined way and thus can replace the bidirectional converter. Assessing possible additional aging due to switching, the results of a previous study for a high-power optimized cell showed no influence on the current rates or the switching. In this paper, a highly energy-optimized LG 18650-cell is investigated to discuss the influence of switching during the charge and discharge process, respectively, as well as combining both processes together with clear performance differences when applying higher charge and discharge currents. Moreover, the influence of switching is discussed for the two frequencies (50 Hz and 10 kHz) and different duty cycles. The aging is analyzed by capacity loss and resistance increase, by dV/dQ analysis, and by electrochemical impedance spectroscopy. We found no clear negative influence of switching but a positive effect if the cells are switched during charge. The best performance is found for switching during charge as well as during discharge. The cell aging during switching is clearly determined by the average and not the maximum current applied. This work shows no negative effects of multilevel inverter applications on the tested cells. UR - https://doi.org/10.3390/batteries9020139 KW - 18650 KW - NMC811 KW - Graphite KW - switching KW - multilevel inverter KW - frequency KW - cycle life Y1 - 2023 UR - https://doi.org/10.3390/batteries9020139 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-41074 SN - 2313-0105 VL - 9 IS - 2 PB - MDPI CY - Basel ER - TY - CHAP A1 - Hanzl, Christian A1 - Endisch, Christian T1 - Closed-Form Modeling of MOSFET Switching Losses Including Variable Gate-Drain Capacitance and Zero-Voltage Switching T2 - Proceedings of the 2025 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific) UR - https://doi.org/10.1109/ITECAsia-Pacific63742.2025.11345027 Y1 - 2026 UR - https://doi.org/10.1109/ITECAsia-Pacific63742.2025.11345027 SN - 979-8-3315-5984-7 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Stöttner, Julia A1 - Hanzl, Christian A1 - Endisch, Christian T1 - Extensive investigation of symmetrical and asymmetrical cascaded multilevel inverters for electric vehicle applications JF - Electric Power Systems Research UR - https://doi.org/10.1016/j.epsr.2022.108009 KW - Asymmetrical multilevel inverter (MLI) KW - Symmetrical multilevel inverter (MLI) KW - Level Redundancy KW - Voltage pattern KW - Total harmonic distortion (THD) Y1 - 2022 UR - https://doi.org/10.1016/j.epsr.2022.108009 SN - 1873-2046 SN - 0378-7796 VL - 2022 IS - 209 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schwertner, Stefan A1 - Buchberger, Tobias A1 - Diehl, Simon A1 - Ferg, Rebekka A1 - Hanzl, Christian A1 - Hartmann, Christoph A1 - Hölzle, Markus A1 - Kleiner, Jan A1 - Komsiyska, Lidiya A1 - Lewerenz, Meinert A1 - Liebhart, Bernhard A1 - Schmid, Michael A1 - Schneider, Dominik A1 - Scholz, Florian A1 - Speer, Sascha A1 - Stöttner, Julia A1 - Terbrack, Christoph A1 - Hinterberger, Michael A1 - Endisch, Christian T1 - Design and Implementation of an Intelligent Reconfigurable High-Voltage Battery System for Next-Generation Electric Vehicles JF - Batteries N2 - Battery system engineers face the challenge of balancing competing requirements regarding performance, maintainability, sustainability, safety, and cost—especially in the automotive industry. IBS potentially offer a solution with fewer trade-offs. They feature a battery management system with advanced sensing and data analysis capabilities that facilitate improved battery monitoring and operation. Reconfigurable energy storage units enable sophisticated operating strategies, including complete cell state control, full energy content utilization, and a measured response to faults. This article presents the design, development, and operation of a full-scale intelligent battery system prototype comprising 324 automotive lithium-ion cells with a nominal voltage of 400V. The system exhibits a modular single cell architecture and an advanced centralized battery management system. We detail the system architecture, hardware and software component design, and system integration. Initial tests demonstrate the battery’s operability, extended functionality, and enhanced safety. Our analysis shows that the additional losses introduced by reconfigurability are more than offset by the benefits of full energy utilization—even for new cells, with increasing advantage as aging progresses. The results underscore the potential of intelligent battery systems and motivate further research and development toward economic assessment and industrial adoption. UR - https://doi.org/10.3390/batteries11110424 Y1 - 2025 UR - https://doi.org/10.3390/batteries11110424 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-64086 SN - 2313-0105 VL - 11 IS - 11 PB - MDPI CY - Basel ER -