@article{KomsiyskaBuchbergerDiehletal.2021, author = {Komsiyska, Lidiya and Buchberger, Tobias and Diehl, Simon and Ehrensberger, Moritz and Hanzl, Christian and Hartmann, Christoph and H{\"o}lzle, Markus and Kleiner, Jan and Lewerenz, Meinert and Liebhart, Bernhard and Schmid, Michael and Schneider, Dominik and Speer, Sascha and St{\"o}ttner, Julia and Terbrack, Christoph and Hinterberger, Michael and Endisch, Christian}, title = {Critical review of intelligent battery systems}, volume = {14}, pages = {5989}, journal = {Energies}, subtitle = {challenges, implementation, and potential for electric vehicles}, number = {18}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en14185989}, year = {2021}, abstract = {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.}, language = {en} } @article{StoettnerHanzlTerbracketal.2025, author = {St{\"o}ttner, Julia and Hanzl, Christian and Terbrack, Christoph and Endisch, Christian}, title = {Holistic evaluation and optimization of multilevel inverter designs for electric vehicle applications}, volume = {2025}, journal = {Energy Reports}, number = {13}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-4847}, doi = {https://doi.org/10.1016/j.egyr.2025.03.001}, pages = {3561 -- 3573}, year = {2025}, abstract = {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.}, language = {en} } @inproceedings{KleinerHeiderHanzletal.2020, author = {Kleiner, Jan and Heider, Alexander and Hanzl, Christian and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Thermal behavior of an intelligent li-ion cell under vehicle conditions}, booktitle = {Proceedings: IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-5414-5}, issn = {2577-1647}, doi = {https://doi.org/10.1109/IECON43393.2020.9254336}, pages = {2081 -- 2086}, year = {2020}, language = {en} } @article{SchmidGebauerHanzletal.2020, author = {Schmid, Michael and Gebauer, Emanuel and Hanzl, Christian and Endisch, Christian}, title = {Active model-based fault diagnosis in reconfigurable battery systems}, volume = {36}, journal = {IEEE Transactions on Power Electronics}, number = {3}, publisher = {IEEE}, address = {Piscataway}, issn = {1941-0107}, doi = {https://doi.org/10.1109/TPEL.2020.3012964}, pages = {2584 -- 2597}, year = {2020}, language = {en} } @article{HanzlHartmannHoelzleetal.2021, author = {Hanzl, Christian and Hartmann, Christoph and H{\"o}lzle, Markus and Liebhart, Bernhard and Schmid, Michael and Endisch, Christian}, title = {Current commutation in a switched lithium-ion cell used in cascaded half-bridge multilevel inverters}, volume = {14}, journal = {IET Power Electronics}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {1755-4543}, doi = {https://doi.org/10.1049/pel2.12088}, pages = {1073 -- 1088}, year = {2021}, abstract = {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.}, language = {en} } @inproceedings{MayerArnetGankinetal.2019, author = {Mayer, Sebastian and Arnet, Christian and Gankin, Dennis and Endisch, Christian}, title = {Standardized framework for evaluating centralized and decentralized control systems in modular assembly systems}, booktitle = {2019 IEEE International Conference on Systems, Man and Cybernetics (SMC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-4569-3}, doi = {https://doi.org/10.1109/SMC.2019.8914314}, pages = {113 -- 119}, year = {2019}, language = {en} } @inproceedings{MayerGankinArnetetal.2019, author = {Mayer, Sebastian and Gankin, Dennis and Arnet, Christian and Endisch, Christian}, title = {Adaptive production control with negotiating agents in modular assembly systems}, booktitle = {2019 IEEE International Conference on Systems, Man and Cybernetics (SMC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-4569-3}, doi = {https://doi.org/10.1109/SMC.2019.8914498}, pages = {120 -- 127}, year = {2019}, language = {en} } @inproceedings{GerngrossHerrmannWestermaieretal.2017, author = {Gerngroß, Martin and Herrmann, Patrick and Westermaier, Christian and Endisch, Christian}, title = {Highly flexible needle winding kinematics for traction stators based on a standard industrial robot}, booktitle = {2017 7th International Electric Drives Production Conference (EDPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-1069-5}, doi = {https://doi.org/10.1109/EDPC.2017.8328147}, year = {2017}, language = {en} } @inproceedings{GerngrossHerrmannEndischetal.2019, author = {Gerngroß, Martin and Herrmann, Patrick and Endisch, Christian and Westermaier, Christian}, title = {Optimization of the End Winding Patterns in Needle Wound Traction Stators}, booktitle = {Proceedings, 2019 IEEE International Conference on Mechatronics (ICM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6959-4}, doi = {https://doi.org/10.1109/ICMECH.2019.8722897}, pages = {314 -- 320}, year = {2019}, language = {en} } @article{StoettnerHanzlEndisch2023, author = {St{\"o}ttner, Julia and Hanzl, Christian and Endisch, Christian}, title = {Experimental investigation of parasitic side effects in MOSFET-based multilevel inverter for electric vehicle applications}, volume = {2023}, pages = {109197}, journal = {Electric Power Systems Research}, number = {218}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2046}, doi = {https://doi.org/10.1016/j.epsr.2023.109197}, year = {2023}, language = {en} } @article{WilliamsNgaleuTheilerStrasseretal.2022, author = {Williams Ngaleu, Guy and Theiler, Michael and Straßer, Xenia and Hanzl, Christian and Komsiyska, Lidiya and Endisch, Christian and Lewerenz, Meinert}, title = {Influence of Switching on the Aging of High Power Lithium-Ion Cells}, volume = {8}, pages = {33}, journal = {Batteries}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries8040033}, year = {2022}, abstract = {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.}, language = {en} } @inproceedings{HanzlStoettnerHoelzleetal.2023, author = {Hanzl, Christian and St{\"o}ttner, Julia and H{\"o}lzle, Markus and Endisch, Christian}, title = {Experimental Investigation and Analytical Modeling of Half-Bridge Switching Losses in Reconfigurable Lithium-Ion Cells}, booktitle = {ICPE 2023 - ECCE Asia: 11th International Conference on Power Electronics - ECCE Asia}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-89-5708-350-5}, doi = {https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213901}, pages = {1058 -- 1065}, year = {2023}, language = {en} } @inproceedings{KohlerHerreraGerngrossetal.2024, author = {Kohler, Markus and Herrera, Christian and Gerngroß, Martin and Kennel, Ralph and Endisch, Christian}, title = {Empirical Investigation and Feed-Forward Control of Wire Tension in Needle Winding Processes}, booktitle = {2024 IEEE 33rd International Symposium on Industrial Electronics (ISIE), Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3503-9408-5}, doi = {https://doi.org/10.1109/ISIE54533.2024.10595747}, year = {2024}, language = {en} } @article{StrasserWilliamsNgaleuHanzletal.2023, author = {Straßer, Xenia and Williams Ngaleu, Guy and Hanzl, Christian and Azzam, Mohamed and Endisch, Christian and Lewerenz, Meinert}, title = {Influence of Switching on the Aging of High Energy Lithium-Ion Cells}, volume = {9}, pages = {139}, journal = {Batteries}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries9020139}, year = {2023}, abstract = {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.}, language = {en} } @inproceedings{HanzlEndisch2026, author = {Hanzl, Christian and Endisch, Christian}, title = {Closed-Form Modeling of MOSFET Switching Losses Including Variable Gate-Drain Capacitance and Zero-Voltage Switching}, booktitle = {Proceedings of the 2025 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific)}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3315-5984-7}, doi = {https://doi.org/10.1109/ITECAsia-Pacific63742.2025.11345027}, year = {2026}, language = {en} } @article{StoettnerHanzlEndisch2022, author = {St{\"o}ttner, Julia and Hanzl, Christian and Endisch, Christian}, title = {Extensive investigation of symmetrical and asymmetrical cascaded multilevel inverters for electric vehicle applications}, volume = {2022}, pages = {108009}, journal = {Electric Power Systems Research}, number = {209}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2046}, doi = {https://doi.org/10.1016/j.epsr.2022.108009}, year = {2022}, language = {en} } @article{SchwertnerBuchbergerDiehletal.2025, author = {Schwertner, Stefan and Buchberger, Tobias and Diehl, Simon and Ferg, Rebekka and Hanzl, Christian and Hartmann, Christoph and H{\"o}lzle, Markus and Kleiner, Jan and Komsiyska, Lidiya and Lewerenz, Meinert and Liebhart, Bernhard and Schmid, Michael and Schneider, Dominik and Scholz, Florian and Speer, Sascha and St{\"o}ttner, Julia and Terbrack, Christoph and Hinterberger, Michael and Endisch, Christian}, title = {Design and Implementation of an Intelligent Reconfigurable High-Voltage Battery System for Next-Generation Electric Vehicles}, volume = {11}, pages = {11110424}, journal = {Batteries}, number = {11}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries11110424}, year = {2025}, abstract = {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.}, language = {en} } @article{KleinerKomsiyskaElgeretal.2019, author = {Kleiner, Jan and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Thermal modelling of a prismatic lithium-ion cell in a battery electric vehicle environment}, volume = {13}, pages = {62}, journal = {Energies}, subtitle = {influences of the experimental validation setup}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en13010062}, year = {2019}, abstract = {In electric vehicles with lithium-ion battery systems, the temperature of the battery cells has a great impact on performance, safety, and lifetime. Therefore, developing thermal models of lithium-ion batteries to predict and investigate the temperature development and its impact is crucial. Commonly, models are validated with experimental data to ensure correct model behaviour. However, influences of experimental setups or comprehensive validation concepts are often not considered, especially for the use case of prismatic cells in a battery electric vehicle. In this work, a 3D electro-thermal model is developed and experimentally validated to predict the cell's temperature behaviour for a single prismatic cell under battery electric vehicle (BEV) boundary conditions. One focus is on the development of a single cell's experimental setup and the investigation of the commonly neglected influences of an experimental setup on the cell's thermal behaviour. Furthermore, a detailed validation is performed for the laboratory BEV scenario for spatially resolved temperatures and heat generation. For validation, static and dynamic loads are considered as well as the detected experimental influences. The validated model is used to predict the temperature within the cell in the BEV application for constant current and Worldwide harmonized Light vehicles Test Procedure (WLTP) load profile.}, language = {en} } @article{ErikssonThomassonEkbergetal.2018, author = {Eriksson, Lars and Thomasson, Andreas and Ekberg, Kristoffer and Reig, Alberto and Eifert, Mark and Donatantonio, Fabrizio and D'Amato, Antonio and Arsie, Ivan and Pianese, Cesare and Otta, Pavel and Held, Manne and V{\"o}gele, Ulrich and Endisch, Christian}, title = {Look-ahead controls of heavy duty trucks on open roads — six benchmark solutions}, volume = {2019}, journal = {Control Engineering Practice}, number = {83}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-6939}, doi = {https://doi.org/10.1016/j.conengprac.2018.10.014}, pages = {45 -- 66}, year = {2018}, language = {en} } @article{LiebhartSatzkeKomsiyskaetal.2020, author = {Liebhart, Bernhard and Satzke, Martin and Komsiyska, Lidiya and Endisch, Christian}, title = {Application of nonlinear impedance spectroscopy for the diagnosis of lithium-ion battery cells under various operating conditions}, volume = {2020}, pages = {228673}, journal = {Journal of Power Sources}, number = {480}, publisher = {Elsevier}, address = {New York}, issn = {1873-2755}, doi = {https://doi.org/10.1016/j.jpowsour.2020.228673}, year = {2020}, language = {en} } @article{LiebhartKomsiyskaEndisch2019, author = {Liebhart, Bernhard and Komsiyska, Lidiya and Endisch, Christian}, title = {Passive impedance spectroscopy for monitoring lithium-ion battery cells during vehicle operation}, volume = {2020}, pages = {227297}, journal = {Journal of Power Sources}, number = {449}, publisher = {Elsevier}, address = {New York}, issn = {1873-2755}, doi = {https://doi.org/10.1016/j.jpowsour.2019.227297}, year = {2019}, language = {en} } @article{SchneiderVoegeleEndisch2019, author = {Schneider, Dominik and V{\"o}gele, Ulrich and Endisch, Christian}, title = {Model-based sensor data fusion of quasi-redundant voltage and current measurements in a lithium-ion battery module}, volume = {2019}, pages = {227156}, journal = {Journal of Power Sources}, number = {440}, publisher = {Elsevier}, address = {New York}, issn = {1873-2755}, doi = {https://doi.org/10.1016/j.jpowsour.2019.227156}, year = {2019}, language = {en} } @article{KleinerStuckenbergerKomsiyskaetal.2021, author = {Kleiner, Jan and Stuckenberger, Magdalena and Komsiyska, Lidiya and Endisch, Christian}, title = {Advanced monitoring and prediction of the thermal state of intelligent battery cells in electric vehicles by physics-based and data-driven modeling}, volume = {7}, pages = {31}, journal = {Batteries}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries7020031}, year = {2021}, abstract = {Novel intelligent battery systems are gaining importance with functional hardware on the cell level. Cell-level hardware allows for advanced battery state monitoring and thermal management, but also leads to additional thermal interactions. In this work, an electro-thermal framework for the modeling of these novel intelligent battery cells is provided. Thereby, a lumped thermal model, as well as a novel neural network, are implemented in the framework as thermal submodels. For the first time, a direct comparison of a physics-based and a data-driven thermal battery model is performed in the same framework. The models are compared in terms of temperature estimation with regard to accuracy. Both models are very well suited to represent the thermal behavior in novel intelligent battery cells. In terms of accuracy and computation time, however, the data-driven neural network approach with a Nonlinear AutoregRessive network with eXogeneous input (NARX) shows slight advantages. Finally, novel applications of temperature prediction in battery electric vehicles are presented and the applicability of the models is illustrated. Thereby, the conventional prediction of the state of power is extended by simultaneous temperature prediction. Additionally, temperature forecasting is used for pre-conditioning by advanced cooling system regulation to enable energy efficiency and fast charging.}, language = {en} } @article{TheilerEndischLewerenz2021, author = {Theiler, Michael and Endisch, Christian and Lewerenz, Meinert}, title = {Float Current Analysis for Fast Calendar Aging Assessment of 18650 Li(NiCoAl)O2/Graphite Cells}, volume = {7}, pages = {22}, journal = {Batteries}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries7020022}, year = {2021}, abstract = {Float currents are steady-state self-discharge currents after a transient phase—caused by anode overhang, polarization, etc.—is accomplished. The float current is measured in this study with a standard test bench for five 18650 cells (Samsung 25R) at potentiostatic conditions while the temperature is changed in 5 K steps from 5 °C to 60 °C. The entire test is performed in about 100 days resulting in 12 measurement points per cell potential for an Arrhenius representation. The float current follows the Arrhenius law with an activation energy of about 60 kJ/mol. The capacity loss measured at reference condition shows a high correlation to the results of float currents analysis. In contrast to classical calendar aging tests, the performed float current analysis enables determining the aging rate with high precision down to at least 10 °C. Returning from higher temperatures to 30 °C reference temperature shows reducing float currents at 30 °C for increasing temperature steps that may originate from an hysteresis effect that has to be investigated in future publications.}, language = {en} } @article{MayerClassenEndisch2021, author = {Mayer, Sebastian and Classen, Tobias and Endisch, Christian}, title = {Modular production control using deep reinforcement learning: proximal policy optimization}, volume = {32}, journal = {Journal of Intelligent Manufacturing}, number = {8}, publisher = {Springer Nature}, address = {Cham}, issn = {1572-8145}, doi = {https://doi.org/10.1007/s10845-021-01778-z}, pages = {2335 -- 2351}, year = {2021}, abstract = {EU regulations on CO2 limits and the trend of individualization are pushing the automotive industry towards greater flexibility and robustness in production. One approach to address these challenges is modular production, where workstations are decoupled by automated guided vehicles, requiring new control concepts. Modular production control aims at throughput-optimal coordination of products, workstations, and vehicles. For this np-hard problem, conventional control approaches lack in computing efficiency, do not find optimal solutions, or are not generalizable. In contrast, Deep Reinforcement Learning offers powerful and generalizable algorithms, able to deal with varying environments and high complexity. One of these algorithms is Proximal Policy Optimization, which is used in this article to address modular production control. Experiments in several modular production control settings demonstrate stable, reliable, optimal, and generalizable learning behavior. The agent successfully adapts its strategies with respect to the given problem configuration. We explain how to get to this learning behavior, especially focusing on the agent's action, state, and reward design.}, language = {en} } @article{MoralesTorricosBergFiggemeieretal.2025, author = {Morales Torricos, Pablo and Berg, Sascha and Figgemeier, Egbert and Endisch, Christian and Lewerenz, Meinert}, title = {The important role of lithiation-induced pressure change on apparent aging of lithium-ion batteries during accelerated cyclic aging tests}, volume = {2025}, pages = {117323}, journal = {Journal of Energy Storage}, number = {131, Part A}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1538}, doi = {https://doi.org/10.1016/j.est.2025.117323}, year = {2025}, abstract = {In assessing the lifespan of lithium-ion batteries in laboratory conditions, the measured capacity declines during accelerated cyclic aging tests but increases when the cells are left idle. This recoverable capacity loss, known in literature as apparent aging, results from an inhomogeneous lithium distribution in the anode appearing in dV/dQ and capacity difference analysis. This study explores the origin of the apparent aging by correlating lithium distribution in the anode and recoverable capacity loss, with the lithiation induced pressure change and generated electrolyte motion during cycling. To this end, we compressed five commercial pouch lithium-ion cells (NMC/Gr) with holder stiffnesses ranging from 0.9 to 15.4 MPa/mm and offset pressure from 289 to 681 kPa and subjected them to continuous cyclic aging tests. While offset pressure had no significant impact, we observed, that holder stiffnesses over 3.3 MPa/mm induces an apparent capacity loss, which is recoverable by 35 \% during a resting phase. The root cause is the so-called electrolyte motion induced salt inhomogeneity (EMSI), driven by continuous high current cycling and electrolyte motion, which is intensified by higher holder stiffness but not by offset pressure. These insights are crucial for improving the accuracy of accelerated aging tests and enhancing battery lifespan predictions.}, language = {en} } @article{YuKiranEhrensbergeretal.2025, author = {Yu, Qing and Kiran, Iqra and Ehrensberger, Moritz and Streck, Luiza and Roth, Thomas and Jossen, Andreas and Endisch, Christian and Lewerenz, Meinert}, title = {Assigning Calendar Aging during Open Circuit and Float Current Analysis to Anode and Cathode Aging Using Three-Electrode Cells}, volume = {172}, pages = {060523}, journal = {Journal of the Electrochemical Society}, number = {6}, publisher = {IOP Publishing}, address = {Bristol}, issn = {1945-7111}, doi = {https://doi.org/10.1149/1945-7111/ade295}, year = {2025}, abstract = {Analyzing calendar aging by float current analysis, instead of solely repeating capacity tests, gains more insights into aging. However, the underlying mechanisms of the recharge current required to keep the voltage constant are not yet fully understood. Therefore, this study performs float current and additional open circuit voltage (OCV) tests on 3-electrode cells for four different voltages at 30 °C. By monitoring the potentials of the anode and the cathode over time individually, the aging rate on both electrodes and the present capacity can be calculated based on adjusting the electrode-specific OCV curves according to the voltage slippery theory. The electrode-specific aging and the capacity prediction show high agreement among both methods and the capacity tests at the end of the experiment. As a result, the capacity loss appears linear-like and is associated with the loss of active lithium mainly due to SEI formation on the anode. Additionally, a significant cathode voltage decay is observed especially for higher cell voltage. According to the literature, this is associated with cathode lithiation where the conductive salt is decomposed by inserting active lithium into the cathode masking SEI losses. Finally, OCV and float current analysis return comparable results and support present 2-electrode evaluation approaches.}, language = {en} } @inproceedings{RauscherStenzelEndisch2025, author = {Rauscher, Andreas and Stenzel, Peer and Endisch, Christian}, title = {Investigation of Factors Influencing the End-of-Line Partial Discharge Testing of Electrical Machines}, booktitle = {2025 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD)}, publisher = {IEEE}, address = {Piscataway}, doi = {https://doi.org/10.1109/WEMDCD61816.2025.11014117}, year = {2025}, language = {en} } @article{SchreiberLinSommeretal.2025, author = {Schreiber, Markus and Lin, Yilei and Sommer, Alessandro and Wassiliadis, Nikolaos and Morales Torricos, Pablo and Rogge, Marcel and Lewerenz, Meinert and Grosu, Cristina and Endisch, Christian and Jossen, Andreas and Lienkamp, Markus}, title = {Apparent vs. true battery aging: Impact of various load characteristics on accelerated aging tests}, volume = {2025}, pages = {116924}, journal = {Journal of Energy Storage}, number = {127}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1538}, doi = {https://doi.org/10.1016/j.est.2025.116924}, year = {2025}, abstract = {Vehicle applications involve highly dynamic and variable operating conditions. These result from changing driving profiles and diverse driving behaviors. To accelerate battery aging tests, experiments are often based on constant load cycles. While efficient, this approach distorts the natural degradation behavior of the cells. This study compares cell aging under real-world and laboratory load conditions. For this purpose, we compare realistic driving profiles measured in a test vehicle in the field with synthetic constant power cycles. Average discharge power and charging sequences are kept identical for comparability. Results show that constant power cycles cause stronger cell aging than dynamic loads. Differential voltage analysis indicates more lithium inventory loss and active material loss at the negative electrode under static loads. Static loading also leads to strong inhomogeneity in the negative electrode and altered charge transfer and diffusion kinetics, as shown by impedance data. After 15 months of rest, the cells recovered up to 52 of lost capacity and 66 of the resistance increase. Impedance assessment and differential voltage analysis confirm the recovery and rehomogenization of the negative electrode. These findings show that conventional accelerated tests are strongly influenced by relaxation and load dynamics. As a result, their applicability to specific use cases, such as automotive applications, is strongly limited . Therefore, andraditional test strategies require reconsideration and redesign.}, language = {en} } @article{AzzamAydinEndischetal.2025, author = {Azzam, Mohamed and Aydin, Atakhan and Endisch, Christian and Sauer, Dirk Uwe and Lewerenz, Meinert}, title = {Float Current Analysis for Lithium-Ion Battery Aging: Insights into SEI Growth and Cathode Lithiation with EIS and ICP OES}, volume = {172}, pages = {070529}, journal = {Journal of The Electrochemical Society}, number = {7}, publisher = {IOP Publishing}, address = {Bristol}, issn = {1945-7111}, doi = {https://doi.org/10.1149/1945-7111/adef85}, year = {2025}, abstract = {This study investigates calendar-aging mechanisms in lithium-ion batteries, focusing on cathode lithiation due to decomposition of conductive salt and SEI growth, by correlating quantified float currents, capacity loss rates, and pulse resistances with changes in electrochemical impedance spectroscopy (EIS) spectra. Seven SamSung 25 R cells are aged at different float voltages with periodic EIS measurements at 30 °C. Using a pre-characterization cell, the internal processes via EIS are allocated across various states of charge and temperatures and GITT measurements are performed to derive scaling factors. GITT, float currents and capacity loss rate measurements at 30 °C enables the separation of SEI growth ISEI growth and cathode lithiation current ICL based on float current behavior across a temperature range of 5 °C to 50 °C. The distribution of relaxation times (DRT) method is employed to deconvolute overlapping electrochemical processes. EIS and DRT analyses showed significant changes in cathode charge transfer resistance and diffusion, confirming that cathode lithiation correlates substantially to elevated internal resistance at high cell voltages. The theory of ISEI growth and ICL is further supported using inductively coupled plasma atomic emission spectroscopy by quantifying elemental inventory changes and linking phosphorus release and lithium consumption to degradation mechanisms.}, language = {en} } @inproceedings{GankinMayerZinnetal.2021, author = {Gankin, Dennis and Mayer, Sebastian and Zinn, Jonas and Vogel-Heuser, Birgit and Endisch, Christian}, title = {Modular Production Control with Multi-Agent Deep Q-Learning}, booktitle = {Proceedings: 2021 26th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-2989-1}, doi = {https://doi.org/10.1109/ETFA45728.2021.9613177}, year = {2021}, language = {en} } @article{SchmidKneidingerEndisch2020, author = {Schmid, Michael and Kneidinger, Hans-Georg and Endisch, Christian}, title = {Data-driven fault diagnosis in battery systems through cross-cell monitoring}, volume = {21}, journal = {IEEE Sensors Journal}, number = {2}, publisher = {IEEE}, address = {New York}, issn = {1558-1748}, doi = {https://doi.org/10.1109/JSEN.2020.3017812}, pages = {1829 -- 1837}, year = {2020}, language = {en} } @article{KleinerSinghSchmidetal.2020, author = {Kleiner, Jan and Singh, Randeep and Schmid, Michael and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Influence of heat pipe assisted terminal cooling on the thermal behavior of a large prismatic lithium-ion cell during fast charging in electric vehicles}, volume = {2021}, pages = {116328}, journal = {Applied Thermal Engineering}, number = {188}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1359-4311}, doi = {https://doi.org/10.1016/j.applthermaleng.2020.116328}, year = {2020}, language = {en} } @article{SchmidGebauerEndisch2021, author = {Schmid, Michael and Gebauer, Emanuel and Endisch, Christian}, title = {Structural analysis in reconfigurable battery systems for active fault diagnosis}, volume = {36}, journal = {IEEE Transactions on Power Electronics}, number = {8}, publisher = {IEEE}, address = {New York}, issn = {1941-0107}, doi = {https://doi.org/10.1109/TPEL.2021.3049573}, pages = {8672 -- 8684}, year = {2021}, language = {en} } @inbook{AltmannshoferEndisch2017, author = {Altmannshofer, Simon and Endisch, Christian}, title = {Robuste Parametersch{\"a}tzung f{\"u}r reale Anwendungen}, booktitle = {Intelligente Verfahren: Identifikation und Regelung nichtlinearer Systeme}, editor = {Schr{\"o}der, Dierk and Buss, Martin}, edition = {2., erweiterte Auflage}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-55327-5}, doi = {https://doi.org/10.1007/978-3-662-55327-5_12}, pages = {399 -- 472}, year = {2017}, language = {de} } @article{WiedererLeitnerEndischetal.2016, author = {Wiederer, Julian and Leitner, Lukas and Endisch, Christian and Reiss, Hans}, title = {Fast Crank-Angle Based 0D Simulation of Combustion Engine Cold Tests including Manufacturing Faults and Production Spread}, volume = {9}, journal = {SAE International Journal of Passenger Cars - Mechanical Systems}, number = {1}, publisher = {SAE International}, address = {Warrendale}, issn = {1946-4002}, doi = {https://doi.org/10.4271/2016-01-1374}, pages = {321 -- 335}, year = {2016}, language = {en} } @article{JardanStumpfVargaetal.2016, author = {J{\´a}rd{\´a}n, Rafael K. and Stumpf, P{\´e}ter and Varga, Zolt{\´a}n and Endisch, Christian and Sipos, P{\´e}ter and Simon, Mikl{\´o}s}, title = {Laboratory system for measurement of iron losses in high speed drives}, volume = {41}, journal = {International Journal of Hydrogen Energy}, number = {29}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0360-3199}, doi = {https://doi.org/10.1016/j.ijhydene.2016.01.061}, pages = {12650 -- 12658}, year = {2016}, language = {en} } @article{StolzeKaramanakosKenneletal.2014, author = {Stolze, Peter and Karamanakos, Petros and Kennel, Ralph and Manias, Stefanos and Endisch, Christian}, title = {Effective variable switching point predictive current control for ac low-voltage drives}, volume = {88}, journal = {International Journal of Control}, number = {7}, publisher = {Taylor \& Francis}, address = {London}, issn = {0020-7179}, doi = {https://doi.org/10.1080/00207179.2014.942699}, pages = {1366 -- 1378}, year = {2014}, language = {en} } @inproceedings{OkonOpferkuchEndisch2020, author = {Okon, Michael and Opferkuch, Johannes and Endisch, Christian}, title = {Modular gear transmission model for analyzing production tolerances in electric drivetrains}, booktitle = {Proceedings, 2020 IEEE International Conference on Industrial Technology}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-5754-2}, doi = {https://doi.org/10.1109/ICIT45562.2020.9067240}, pages = {709 -- 716}, year = {2020}, language = {en} } @inproceedings{GerngrossKohlerEndischetal.2020, author = {Gerngroß, Martin and Kohler, Markus and Endisch, Christian and Kennel, Ralph}, title = {Model-based control of nonlinear wire tension in dynamic needle winding processes}, booktitle = {Proceedings, 2020 IEEE International Conference on Industrial Technology}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-5754-2}, doi = {https://doi.org/10.1109/ICIT45562.2020.9067168}, pages = {381 -- 388}, year = {2020}, language = {en} } @inproceedings{KleinerKomsiyskaElgeretal.2019, author = {Kleiner, Jan and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Modelling of 3D temperature behavior of prismatic lithium-ion cell with focus on experimental validation under battery electric vehicle conditions}, booktitle = {2019 25th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-2078-2}, doi = {https://doi.org/10.1109/THERMINIC.2019.8923604}, year = {2019}, language = {en} } @inproceedings{SchneiderEndisch2020, author = {Schneider, Dominik and Endisch, Christian}, title = {Robustness and reliability of model-based sensor data fusion in a lithium-ion battery system}, booktitle = {IEEE CCTA 2020, 4th IEEE Conference on Control Technology and Applications}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-7140-1}, doi = {https://doi.org/10.1109/CCTA41146.2020.9206336}, pages = {685 -- 691}, year = {2020}, language = {en} } @inproceedings{SchneiderLiebhartEndisch2021, author = {Schneider, Dominik and Liebhart, Bernhard and Endisch, Christian}, title = {Adaptive Variance Estimation of Sensor Noise within a Sensor Data Fusion Framework}, booktitle = {2021 IEEE International Instrumentation and Measurement Technology Conference (I2MTC 2021) Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-9539-1}, issn = {2642-2077}, doi = {https://doi.org/10.1109/I2MTC50364.2021.9459790}, year = {2021}, language = {en} } @article{TheilerSchneiderEndisch2022, author = {Theiler, Michael and Schneider, Dominik and Endisch, Christian}, title = {Kalman Filter Tuning Using Multi-Objective Genetic Algorithm for State and Parameter Estimation of Lithium-Ion Cells}, volume = {8}, pages = {104}, journal = {Batteries}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries8090104}, year = {2022}, abstract = {To ensure a reliable and safe operation of battery systems in various applications, the system's internal states must be observed with high accuracy. Hereby, the Kalman filter is a frequently used and well-known tool to estimate the states and model parameters of a lithium-ion cell. A strong requirement is the selection of a suitable model and a reasonable initialization, otherwise the algorithm's estimation might be insufficient. Especially the process noise parametrization poses a difficult task, since it is an abstract parameter and often optimized by an arbitrary trial-and-error principle. In this work, a traceable procedure based on the genetic algorithm is introduced to determine the process noise offline considering the estimation error and filter consistency. Hereby, the parameters found are independent of the researcher's experience. Results are validated with a simulative and experimental study, using an NCA/graphite lithium-ion cell. After the transient phase, the estimation error of the state-of-charge is lower than 0.6\% and for internal resistance smaller than 4mΩ while the corresponding estimated covariances fit the error well.}, language = {en} } @inproceedings{NachtsheimHartmannEndisch2022, author = {Nachtsheim, Martin and Hartmann, Thomas and Endisch, Christian}, title = {Physically Inspired Neural Network for Modeling Induction Machine Nonlinear Magnetic Saturation}, booktitle = {ITEC+2022: 2022 IEEE/AIAA Transportation Electrification Conference and Electric Aircraft Technologies Symposium (ITEC+EATS)}, publisher = {IEEE}, address = {Piscataway (NJ)}, isbn = {978-1-6654-0560-7}, doi = {https://doi.org/10.1109/ITEC53557.2022.9813908}, pages = {874 -- 881}, year = {2022}, language = {en} } @inproceedings{KohlerFendtEndisch2022, author = {Kohler, Markus and Fendt, David and Endisch, Christian}, title = {Modeling Geometric Wire Bending Behavior in Needle Winding Processes Using Circular Arcs with Tangential Linear Functions}, booktitle = {ITEC+2022: 2022 IEEE/AIAA Transportation Electrification Conference and Electric Aircraft Technologies Symposium (ITEC+EATS)}, publisher = {IEEE}, address = {Piscataway (NJ)}, isbn = {978-1-6654-0560-7}, doi = {https://doi.org/10.1109/ITEC53557.2022.9814041}, pages = {894 -- 901}, year = {2022}, language = {en} } @inproceedings{MayerHoehmeGankinetal.2020, author = {Mayer, Sebastian and H{\"o}hme, Nikolas and Gankin, Dennis and Endisch, Christian}, title = {Adaptive Production Control in a Modular Assembly System - Towards an Agent-based Approach}, booktitle = {Proceedings, 2019 IEEE 17th International Conference on Industrial Informatics (INDIN)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-2927-3}, doi = {https://doi.org/10.1109/INDIN41052.2019.8972152}, pages = {45 -- 52}, year = {2020}, language = {en} } @inproceedings{MayerEndisch2019, author = {Mayer, Sebastian and Endisch, Christian}, title = {Adaptive production control in a modular assembly system based on partial look-ahead scheduling}, booktitle = {Proceedings, 2019 IEEE International Conference on Mechatronics (ICM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6959-4}, doi = {https://doi.org/10.1109/ICMECH.2019.8722904}, pages = {293 -- 300}, year = {2019}, language = {en} } @inproceedings{HerrmannStenzelVoegeleetal.2016, author = {Herrmann, Patrick and Stenzel, Peer and V{\"o}gele, Ulrich and Endisch, Christian}, title = {Optimization Algorithms for Maximizing the Slot Filling Factor of Technically Feasible Slot Geometries and Winding Layouts}, booktitle = {2016 6th International Electric Drives Production Conference (E|DPC): Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-2909-9}, doi = {https://doi.org/10.1109/EDPC.2016.7851327}, year = {2016}, language = {en} } @inproceedings{MuellerEndisch2016, author = {M{\"u}ller, Tino and Endisch, Christian}, title = {Compensation techniques for iterative rig control in multi-axial durability testing}, booktitle = {2016 IEEE 21st International Conference on Emerging Technologies and Factory Automation (ETFA)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-1314-2}, doi = {https://doi.org/10.1109/ETFA.2016.7733517}, year = {2016}, language = {en} } @inproceedings{LeitnerLagrangeEndisch2016, author = {Leitner, Lukas and Lagrange, Antoine and Endisch, Christian}, title = {End-of-line fault detection for combustion engines using one-class classification}, booktitle = {2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-2065-2}, doi = {https://doi.org/10.1109/AIM.2016.7576768}, pages = {207 -- 213}, year = {2016}, language = {en} } @inproceedings{LeitnerEndisch2018, author = {Leitner, Lukas and Endisch, Christian}, title = {Skewed and Heavy-Tailed Hidden Random Walk Models with Applications in Automated Production Testing}, booktitle = {2018 IEEE 22nd International Conference on Intelligent Engineering Systems (INES)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-1122-7}, doi = {https://doi.org/10.1109/INES.2018.8523927}, pages = {000281 -- 000286}, year = {2018}, language = {en} } @inproceedings{ZiegmannSchmidEndisch2018, author = {Ziegmann, Johannes and Schmid, Michael and Endisch, Christian}, title = {Sensitivity Analysis for Driver Energy Prediction with Environmental Features and Naturalistic Data}, booktitle = {2018 IEEE International Conference on Intelligent Engineering Systems (INES)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-1122-7}, doi = {https://doi.org/10.1109/INES.2018.8523987}, pages = {000199 -- 000206}, year = {2018}, language = {en} } @inproceedings{HerrmannGerngrossEndisch2018, author = {Herrmann, Patrick and Gerngroß, Martin and Endisch, Christian}, title = {Numerical Optimization in Planning of Flexible Needle Winding Trajectories}, booktitle = {2018 IEEE International Conference on Intelligent Engineering Systems (INES)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-1122-7}, doi = {https://doi.org/10.1109/INES.2018.8523924}, pages = {000255 -- 000260}, year = {2018}, language = {en} } @inproceedings{AltmannshoferEndischTrieu2017, author = {Altmannshofer, Simon and Endisch, Christian and Trieu, Khanh Duy}, title = {On-line identification and identifiability analysis of electrical and mechanical parameters of induction machines}, booktitle = {2017 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-6000-9}, issn = {2159-6255}, doi = {https://doi.org/10.1109/AIM.2017.8014079}, pages = {577 -- 583}, year = {2017}, language = {en} } @inproceedings{MuellerEndisch2017, author = {M{\"u}ller, Tino and Endisch, Christian}, title = {An estimation based iterative learning control approach for cross-coupled vehicle test systems}, booktitle = {2017 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-6000-9}, issn = {2159-6255}, doi = {https://doi.org/10.1109/AIM.2017.8014210}, pages = {1375 -- 1381}, year = {2017}, language = {en} } @inproceedings{ZiegmannShiSchnoereretal.2017, author = {Ziegmann, Johannes and Shi, Jieqing and Schn{\"o}rer, Tobias and Endisch, Christian}, title = {Analysis of individual driver velocity prediction using data-driven driver models with environmental features}, booktitle = {2017 IEEE Intelligent Vehicles Symposium}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-4804-5}, doi = {https://doi.org/10.1109/IVS.2017.7995770}, pages = {517 -- 522}, year = {2017}, language = {en} } @inproceedings{VoegeleZiegmannEndisch2017, author = {V{\"o}gele, Ulrich and Ziegmann, Johannes and Endisch, Christian}, title = {Driver adaptive predictive velocity control}, booktitle = {2017 IEEE 20th International Conference on Intelligent Transportation Systems (ITSC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-1526-3}, issn = {2153-0017}, doi = {https://doi.org/10.1109/ITSC.2017.8317668}, year = {2017}, language = {en} } @inproceedings{HerrmannGerngrossEndischetal.2017, author = {Herrmann, Patrick and Gerngroß, Martin and Endisch, Christian and Stenzel, Peer and Uhlmann, Philipp}, title = {Automated contacting technology for needle winding applications with distributed windings}, booktitle = {2017 7th International Electric Drives Production Conference (EDPC) Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-1069-5}, doi = {https://doi.org/10.1109/EDPC.2017.8328169}, year = {2017}, language = {en} } @inproceedings{HerrmannGerngrossEndisch2018, author = {Herrmann, Patrick and Gerngroß, Martin and Endisch, Christian}, title = {NURBS based trajectory generation for an industrial five axis needle winding robot}, booktitle = {Conference Proceedings of 2018 4th International Conference on Control, Automation and Robotics (ICCAR)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6338-7}, doi = {https://doi.org/10.1109/ICCAR.2018.8384640}, pages = {31 -- 36}, year = {2018}, language = {en} } @inproceedings{LeitnerEndisch2018, author = {Leitner, Lukas and Endisch, Christian}, title = {Robust stochastic process models and parameter estimation for industrial end-of-line-testing}, booktitle = {Proceedings: 2018 IEEE International Conference on Industrial Technology (ICIT)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-5949-2}, doi = {https://doi.org/10.1109/ICIT.2018.8352406}, pages = {1520 -- 1525}, year = {2018}, language = {en} } @inproceedings{LiebhartDiehlSchneideretal.2021, author = {Liebhart, Bernhard and Diehl, Simon and Schneider, Dominik and Endisch, Christian and Kennel, Ralph}, title = {Enhancing the Cell Impedance Estimation of a Lithium-Ion Battery System with Embedded Power Path Switches}, booktitle = {APEC 2021: Thirty-Sixth Annual IEEE Applied Power Electronics Conference and Exposition}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-8949-9}, issn = {2470-6647}, doi = {https://doi.org/10.1109/APEC42165.2021.9487173}, pages = {967 -- 974}, year = {2021}, language = {en} } @inproceedings{KleinerHeiderKomsiyskaetal.2021, author = {Kleiner, Jan and Heider, Alexander and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Experimental Study on the Thermal Interactions in Novel Intelligent Lithium-Ion Modules for Electric Vehicles}, booktitle = {Proceedings of the Twentieth InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems: ITherm 2021}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-8539-2}, issn = {2694-2135}, doi = {https://doi.org/10.1109/ITherm51669.2021.9503299}, pages = {556 -- 562}, year = {2021}, language = {en} } @inproceedings{LiebhartDiehlSchmidetal.2021, author = {Liebhart, Bernhard and Diehl, Simon and Schmid, Michael and Endisch, Christian and Kennel, Ralph}, title = {Improved Impedance Measurements for Electric Vehicles with Reconfigurable Battery Systems}, booktitle = {Proceedings of the Energy Conversion Congress and Exposition - Asia, 2021 (ECCE Asia 2021)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-6344-4}, issn = {2150-6086}, doi = {https://doi.org/10.1109/ECCE-Asia49820.2021.9479060}, pages = {1736 -- 1742}, year = {2021}, language = {en} } @inproceedings{HerrmannGerngrossEndisch2019, author = {Herrmann, Patrick and Gerngroß, Martin and Endisch, Christian}, title = {Benefits of numerical optimization and CAD/CAM in needle winding processes}, booktitle = {Proceedings, 2019 IEEE International Conference on Mechatronics (ICM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6959-4}, doi = {https://doi.org/10.1109/ICMECH.2019.8722940}, pages = {301 -- 307}, year = {2019}, language = {en} } @inproceedings{OkonEndisch2019, author = {Okon, Michael and Endisch, Christian}, title = {On air-gap approximations for slotted electrical machine models assuming radial magnetic fields}, booktitle = {Proceedings, 2019 IEEE International Conference on Industrial Technology (ICIT)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6376-9}, doi = {https://doi.org/10.1109/ICIT.2019.8755196}, pages = {292 -- 297}, year = {2019}, language = {en} } @inproceedings{GerngrossHerrmannEndisch2019, author = {Gerngroß, Martin and Herrmann, Patrick and Endisch, Christian}, title = {Nonlinear modelling of dynamic wire tension for needle winding processes of distributed windings}, booktitle = {Proceedings, 2019 IEEE International Conference on Industrial Technology (ICIT)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6376-9}, doi = {https://doi.org/10.1109/ICIT.2019.8755052}, pages = {151 -- 156}, year = {2019}, language = {en} } @inproceedings{KohlerGerngrossEndisch2022, author = {Kohler, Markus and Gerngroß, Martin and Endisch, Christian}, title = {A Test Bench Concept and Method for Image-Based Modeling of Geometric Wire Bending Behavior in Needle Winding Processes}, booktitle = {2022 IEEE 31st International Symposium on Industrial Electronics (ISIE)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-8240-0}, issn = {2163-5145}, doi = {https://doi.org/10.1109/ISIE51582.2022.9831494}, pages = {1113 -- 1120}, year = {2022}, language = {en} } @inproceedings{NachtsheimKorkmazSchmoelzetal.2022, author = {Nachtsheim, Martin and Korkmaz, Luetfue and Schmoelz, Martin and Endisch, Christian}, title = {Observability Analysis for Parameter Identification of Induction Machines in Automotive Environment}, booktitle = {2022 IEEE 31st International Symposium on Industrial Electronics (ISIE)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-8240-0}, issn = {2163-5145}, doi = {https://doi.org/10.1109/ISIE51582.2022.9831658}, pages = {206 -- 213}, year = {2022}, language = {en} } @article{StoettnerRauscherEndisch2022, author = {St{\"o}ttner, Julia and Rauscher, Andreas and Endisch, Christian}, title = {Pareto optimization of multilevel inverter structures regarding the DC magnitude, switching frequency and switching angles}, volume = {2022}, pages = {108259}, journal = {International Journal of Electrical Power \& Energy Systems}, number = {142, Part A}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0142-0615}, doi = {https://doi.org/10.1016/j.ijepes.2022.108259}, year = {2022}, language = {en} } @article{TerbrackStoettnerEndisch2022, author = {Terbrack, Christoph and St{\"o}ttner, Julia and Endisch, Christian}, title = {Design and Validation of the Parallel Enhanced Commutation Integrated Nested Multilevel Inverter Topology}, volume = {37}, journal = {IEEE Transactions on Power Electronics}, number = {12}, publisher = {IEEE}, address = {Piscataway}, issn = {1941-0107}, doi = {https://doi.org/10.1109/TPEL.2022.3183859}, pages = {15163 -- 15174}, year = {2022}, language = {en} } @article{RauscherHufnagelEndisch2022, author = {Rauscher, Andreas and Hufnagel, Manuel and Endisch, Christian}, title = {Pareto optimization of wavelet filter design for partial discharge detection in electrical machines}, volume = {2022}, pages = {112163}, journal = {Measurement}, number = {205}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-412X}, doi = {https://doi.org/10.1016/j.measurement.2022.112163}, year = {2022}, abstract = {A reliable detection of partial discharges (PDs) in the insulation system of electrical machines is essential to prevent premature breakdowns. Wavelet filters (WFs) are often recommended for denoising this PD measurement data. However, filtering performance strongly depends on numerous settings, which impedes an optimum filter choice. We propose an approach to systematically select the best filter for denoising PD signals. First, representative PD pulses are determined from measurement data by an averaging and a singular value decomposition method. Next, realistic benchmark signals are generated for filter assessment. Further, all possible WF combinations from a set of different mother wavelet selection methods, decomposition trees, and thresholding approaches are evaluated. On the basis of two contradicting objectives, namely mean square error of noise intervals and pulse amplitude distortion, Pareto optimization is applied to choose optimal WF settings. The corresponding filters dominate several common WF proposals from previous literature.}, language = {en} } @article{KleinerLambauerSinghetal.2022, author = {Kleiner, Jan and Lambauer, Florian and Singh, Randeep and Komsiyska, Lidiya and Hinterberger, Michael and Endisch, Christian}, title = {Experimental study of cell integrated heat pipe cooling with a lithium-ion cell emulator}, volume = {2022}, pages = {105808}, journal = {Journal of Energy Storage}, number = {56, Part A}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1538}, doi = {https://doi.org/10.1016/j.est.2022.105808}, year = {2022}, language = {en} } @inproceedings{SchmidLiebhartKleineretal.2021, author = {Schmid, Michael and Liebhart, Bernhard and Kleiner, Jan and Endisch, Christian and Kennel, Ralph}, title = {Online Detection of Soft Internal Short Circuits in Lithium-Ion Battery Packs by Data-Driven Cell Voltage Monitoring}, booktitle = {Proceedings of the Energy Conversion Congress \& Exposition - Asia, 2021 (ECCE-Asia 2021)}, publisher = {IEEE}, address = {Piscataway (NJ)}, isbn = {978-1-7281-6344-4}, issn = {2150-6086}, doi = {https://doi.org/10.1109/ECCE-Asia49820.2021.9479175}, pages = {1711 -- 1718}, year = {2021}, language = {en} } @article{MoralesTorricosEndischLewerenz2023, author = {Morales Torricos, Pablo and Endisch, Christian and Lewerenz, Meinert}, title = {Apparent Aging during Accelerated Cycling Aging Test of Cylindrical Silicon Containing Li-Ion Cells}, volume = {9}, pages = {230}, journal = {Batteries}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries9040230}, year = {2023}, abstract = {Accelerated cyclic aging tests are very important for research and industry to quickly characterize lithium-ion cells. However, the accentuation of stress factors and the elimination of rest periods lead to an apparent capacity fade, that can be subsequently recovered during a resting phase. This effect is attributed to the inhomogeneous lithium distribution in the anode and is observable with differential voltage analysis (DVA). We tested cylindrical 18,650 cells with Li(NixCoyAlz)O2-graphite/silicon chemistry during two cycling and resting phases. The capacity, the pulse resistance, the DVA, and the capacity difference analysis are evaluated for cells cycled at different average SOC and current rates. An apparent capacity loss of up to 12\% was reported after 200 FCE for cells cycled under the presence of pressure gradients, while only 1\% were at low-pressure gradients. The subsequent recovery was up to 80\% of the apparent capacity loss in some cases. The impact of silicon cannot be estimated as it shows no features in the dV/dQ curves. We observe a recovery of apparent resistance increase, which is not reported for cells with pure graphite anodes. Finally, we demonstrate the strong impact of apparent aging for the lifetime prediction based on standard accelerated cyclic aging tests.}, language = {en} } @article{LechermannKleinerKomsiyskaetal.2023, author = {Lechermann, Lorenz and Kleiner, Jan and Komsiyska, Lidiya and Hinterberger, Michael and Endisch, Christian}, title = {A comparative study of data-driven electro-thermal models for reconfigurable lithium-ion batteries in real-time applications}, volume = {2023}, pages = {107188}, journal = {Journal of Energy Storage}, number = {65}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1538}, doi = {https://doi.org/10.1016/j.est.2023.107188}, year = {2023}, language = {en} } @article{TerbrackSpeerEndisch2023, author = {Terbrack, Christoph and Speer, Sascha and Endisch, Christian}, title = {Control and Implementation of the Parallel Enhanced Commutation Integrated Nested Multilevel Inverter Topology}, volume = {12}, pages = {3130}, journal = {Electronics}, number = {14}, publisher = {MDPI}, address = {Basel}, issn = {2079-9292}, doi = {https://doi.org/10.3390/electronics12143130}, year = {2023}, abstract = {Due to their high efficiency and advanced battery management capability, cascaded multilevel inverters are an exciting option for battery electric powertrains. A promising, new and highly efficient cascaded multilevel inverter is the Parallel Enhanced Commutation Integrated Nested Multilevel Inverter. The inverter, with four semiconductor switches per submodule, can reconfigure individual battery cells in series and parallel and generate positive and negative phase voltages in regular four-quadrant operation. Therefore, emerging degrees of freedom in battery management and inverter operation must be managed and mapped into a specific Switching State for every switch. As controlling the high number of switches is safety-relevant, this publication profoundly explains the inverter's functionality. We introduce a Switching Function that accepts easy-to-understand functional states as input, simplifying research on higher-level control algorithms and advanced single-cell battery-management capabilities. As the Switching Function guarantees safe operation and the correct contribution of every cell to the overall functionality of the inverter, it enables researchers to confidently use and thereby accelerate research on the promising new topology. The method we describe is fast, simple, deterministic and designed to convert setpoint specifications into an executable Switching Pattern. We prove that our Switching Function is operable on an FPGA with a twenty-kilohertz setpoint update operating a 17-level inverter.}, language = {en} } @inproceedings{NachtsheimGrundEndischetal.2023, author = {Nachtsheim, Martin and Grund, Karina and Endisch, Christian and Kennel, Ralph}, title = {Online Identification of Induction Machine Parameter Deviations for Aging Detection - A Comparative Study Using Recursive Least Squares Algorithm and Extended Kalman Filter}, booktitle = {2023 IEEE Transportation Electrification Conference \& Expo (ITEC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3503-9742-0}, doi = {https://doi.org/10.1109/ITEC55900.2023.10186964}, year = {2023}, language = {en} } @article{AzzamEhrensbergerScheueretal.2023, author = {Azzam, Mohamed and Ehrensberger, Moritz and Scheuer, Reinhard and Endisch, Christian and Lewerenz, Meinert}, title = {Long-Term Self-Discharge Measurements and Modelling for Various Cell Types and Cell Potentials}, volume = {16}, pages = {3889}, journal = {Energies}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en16093889}, year = {2023}, abstract = {Self-discharge of lithium-ion cells leads to voltage decay over time. In this work, the self-discharge was measured at 30 °C for three cell types at various voltage levels for about 150 days in a constant voltage mode determining the current at a high precision (float current). All cells exhibit a transient part leading to a steady-state, which is no longer influenced by reversible effects. To study the effect of the check-ups on the steady-state float current, the cells, interrupted and not interrupted by check-ups, were compared. The results indicate that both the transient processes and steady-state currents are highly reproducible. In the first period of the float current, the polarization dominates the measured current, followed by the anode overhang effect dominating the process for a period of 5-30 days. After the decline of both processes, a mostly constant steady-state in the order of µA is observed. The check-up interruption generally shows no apparent effect on the reached steady-state and results only in an extended settling time. A model to simulate the transient process and steady-state of float currents was developed. The model shows a high accuracy in reproducing the results and identifying the time needed to reach the steady-state.}, language = {en} } @inproceedings{TerbrackStoettnerEndisch2020, author = {Terbrack, Christoph and St{\"o}ttner, Julia and Endisch, Christian}, title = {Operation of an externally excited synchronous machine with a hybrid multilevel inverter}, booktitle = {2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-9-0758-1536-8}, doi = {https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215895}, year = {2020}, language = {en} } @inproceedings{LiebhartDiehlEndisch2020, author = {Liebhart, Bernhard and Diehl, Simon and Endisch, Christian}, title = {Sensitivity analysis of battery cell aging estimators based on impedance spectroscopy regarding temperature compensation}, booktitle = {IEEE CCTA 2020, 4th IEEE Conference on Control Technology and Applications}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-7140-1}, doi = {https://doi.org/10.1109/CCTA41146.2020.9206395}, pages = {699 -- 705}, year = {2020}, language = {en} } @inproceedings{MuellerVoegeleEndisch2016, author = {M{\"u}ller, Tino and V{\"o}gele, Ulrich and Endisch, Christian}, title = {Disturbance compensation for iterative control of suspension durability test rigs}, booktitle = {2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-2065-2}, doi = {https://doi.org/10.1109/AIM.2016.7577011}, pages = {1675 -- 1681}, year = {2016}, language = {en} } @article{MuellerZiegmannKrueneretal.2016, author = {M{\"u}ller, Tino and Ziegmann, Johannes and Kr{\"u}ner, Simon and Endisch, Christian}, title = {Optimization of inverse model identification for multi-axial test rig control}, volume = {2016}, pages = {01002}, journal = {MATEC Web of Conferences}, number = {42}, publisher = {EDP Sciences}, address = {Les Ulis}, issn = {2261-236X}, doi = {https://doi.org/10.1051/matecconf/20164201002}, year = {2016}, abstract = {Laboratory testing of multi-axial fatigue situations improves repeatability and allows a time condensing of tests which can be carried out until component failure, compared to field testing. To achieve realistic and convincing durability results, precise load data reconstruction is necessary. Cross-talk and a high number of degrees of freedom negatively affect the control accuracy. Therefore a multiple input/multiple output (MIMO) model of the system, capturing all inherent cross-couplings is identified. In a first step the model order is estimated based on the physical fundamentals of a one channel hydraulic-servo system. Subsequently, the structure of the MIMO model is optimized using correlation of the outputs, to increase control stability and reduce complexity of the parameter optimization. The identification process is successfully applied to the iterative control of a multi-axial suspension rig. The results show accurate control, with increased stability compared to control without structure optimization.}, language = {en} } @inproceedings{AltmannshoferEndischMartinetal.2016, author = {Altmannshofer, Simon and Endisch, Christian and Martin, Jan and Gerngroß, Martin and Limbacher, Reimund}, title = {Robust estimation of vehicle longitudinal dynamics parameters}, booktitle = {2016 IEEE Intelligent Vehicles Symposium (IV)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-1821-5}, doi = {https://doi.org/10.1109/IVS.2016.7535443}, pages = {566 -- 571}, year = {2016}, language = {en} } @inproceedings{AltmannshoferEndisch2016, author = {Altmannshofer, Simon and Endisch, Christian}, title = {Robust Vehicle Mass and Driving Resistance Estimation}, booktitle = {2016 American Control Conference (ACC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4673-8682-1}, issn = {2378-5861}, doi = {https://doi.org/10.1109/ACC.2016.7526754}, pages = {6869 -- 6874}, year = {2016}, language = {en} } @inproceedings{AltmannshoferMartinEndisch2015, author = {Altmannshofer, Simon and Martin, Jan and Endisch, Christian}, title = {Robuste, onlinef{\"a}hige Sch{\"a}tzung von Fahrzeugmasse und Fahrwiderst{\"a}nden}, booktitle = {Autoreg 2015: auf dem Weg zum automatisierten Fahren}, publisher = {VDI Verlag}, address = {D{\"u}sseldorf}, isbn = {978-3-18-092233-1}, pages = {29 -- 36}, year = {2015}, language = {de} } @inproceedings{VoegeleEndisch2015, author = {V{\"o}gele, Ulrich and Endisch, Christian}, title = {Potential analysis of predictive optimal velocity control for electric and conventional vehicles}, booktitle = {2015 IEEE International Conference on Vehicular Electronics and Safety (ICVES)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4673-9114-6}, doi = {https://doi.org/10.1109/ICVES.2015.7396917}, pages = {196 -- 201}, year = {2015}, language = {en} } @inproceedings{MartinVoegeleEndisch2015, author = {Martin, Jan and V{\"o}gele, Ulrich and Endisch, Christian}, title = {Effects of errors in position- and navigation data on predictive vehicle operational strategy optimization}, booktitle = {2015 IEEE International Conference on Vehicular Electronics and Safety (ICVES)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4673-9114-6}, doi = {https://doi.org/10.1109/ICVES.2015.7396916}, pages = {190 -- 195}, year = {2015}, language = {en} } @inproceedings{StenzelRichnowFrankeetal.2015, author = {Stenzel, Peer and Richnow, Jan and Franke, J{\"o}rg and Endisch, Christian}, title = {Impact of the needle winding technology on the operational behavior of an asynchronous machine}, booktitle = {2015 5th International Electric Drives Production Conference (EDPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4673-7512-2}, doi = {https://doi.org/10.1109/EDPC.2015.7323193}, year = {2015}, language = {en} } @inproceedings{JardanVargaStumpfetal.2015, author = {J{\´a}rd{\´a}n, Rafael K. and Varga, Zolt{\´a}n and Stumpf, P{\´e}ter and Nagy, Istvan and Endisch, Christian and Sipos, P{\´e}ter and Simon, Mikl{\´o}s}, title = {Development of a Dedicated Laboratory System for Measurement of Iron Losses in High Speed PMSM}, booktitle = {2015 IEEE International Conference on Industrial Technology (ICIT)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4799-7800-7}, doi = {https://doi.org/10.1109/ICIT.2015.7125181}, pages = {708 -- 713}, year = {2015}, language = {en} } @inproceedings{StenzelDollingerRichnowetal.2015, author = {Stenzel, Peer and Dollinger, P. and Richnow, Jan and Bader, T. and Franke, J{\"o}rg and Endisch, Christian}, title = {Experimental investigations of the needle winding technology regarding the influence of the wire guide geometry on the tensile wire force}, booktitle = {2015 IEEE International Conference on Industrial Technology (ICIT)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4799-7800-7}, doi = {https://doi.org/10.1109/ICIT.2015.7125487}, pages = {2642 -- 2649}, year = {2015}, language = {en} } @inproceedings{StenzelDollingerMihajlovicetal.2014, author = {Stenzel, Peer and Dollinger, P. and Mihajlovic, D. and Richnow, Jan and Franke, J{\"o}rg and Endisch, Christian}, title = {Needle winding for distributed round-wire-windings without the use of insulation disks}, booktitle = {Proceedings: 2014 4th International Electric Drives Production Conference (E|DPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4799-5009-6}, doi = {http://doi.org/10.1109/EDPC.2014.6984387}, year = {2014}, language = {en} } @inproceedings{RichnowStenzelRenneretal.2014, author = {Richnow, Jan and Stenzel, Peer and Renner, A. and Gerling, D. and Endisch, Christian}, title = {Influence of different impregnation methods and resins on thermal behavior and lifetime of electrical stators}, booktitle = {Proceedings: 2014 4th International Electric Drives Production Conference (E|DPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4799-5009-6}, doi = {https://doi.org/10.1109/EDPC.2014.6984406}, year = {2014}, language = {en} } @inproceedings{NachtsheimBetzEndisch2022, author = {Nachtsheim, Martin and Betz, Michael and Endisch, Christian}, title = {Explicit analytical approach for electromagnetic modeling of arbitrary pole pair induction machines}, booktitle = {2022 12th International Conference on Power, Energy and Electrical Engineering (CPEEE)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-6654-2049-5}, doi = {https://doi.org/10.1109/CPEEE54404.2022.9738660}, pages = {41 -- 48}, year = {2022}, language = {en} } @inproceedings{SchneiderLiebhartEndischetal.2022, author = {Schneider, Dominik and Liebhart, Bernhard and Endisch, Christian and Kennel, Ralph}, title = {Enhanced state and parameter estimation within reconfigurable battery systems for electric vehicles}, booktitle = {2022 12th International Conference on Power, Energy and Electrical Engineering (CPEEE)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-6654-2049-5}, doi = {https://doi.org/10.1109/CPEEE54404.2022.9738700}, pages = {71 -- 77}, year = {2022}, language = {en} } @article{TheilerSchneiderEndisch2023, author = {Theiler, Michael and Schneider, Dominik and Endisch, Christian}, title = {Experimental Investigation of State and Parameter Estimation within Reconfigurable Battery Systems}, volume = {9}, pages = {145}, journal = {Batteries}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries9030145}, year = {2023}, abstract = {The battery system is one of the most-important, but also -critical components in the electric power-train. The battery's system states and parameters are commonly tracked by the battery monitoring system. However, in reality, the accuracy of the state and parameter estimation may suffer from insufficient excitation of the system. Since the current states and parameters serve as the basis for many battery management system functions, this might lead to incorrect operation and severe damage. Reconfigurable battery systems allow enhancing the system's excitation by applying a switching operation. In this contribution, the state and parameter estimation of a reconfigurable battery module were simulated and tested experimentally. Thereby, a low-exciting and a high-exciting drive cycle were compared. Furthermore, the switching patterns were applied to enhance the excitation and, hence, improve the estimation of an extended Kalman filter. The cells were switched via a pulse-width modulation signal, and the influence of frequency and duty cycle variation on the estimation accuracy were investigated. Compared to the low-excitation input, a significant improvement in the estimation of up to 46\% for the state of charge and 78\% for the internal resistance were achieved. Hereby, low frequencies and duty cycles proved to be particularly advantageous. Switching, however, has only a limited influence on an already highly excited system and may lead to additional aging due to higher heat generation.}, language = {en} } @article{NachtsheimErnstEndischetal.2023, author = {Nachtsheim, Martin and Ernst, Johannes and Endisch, Christian and Kennel, Ralph}, title = {Performance of Recursive Least Squares Algorithm Configurations for Online Parameter Identification of Induction Machines in an Automotive Environment}, volume = {9}, journal = {IEEE Transactions on Transportation Electrification}, number = {3}, publisher = {IEEE}, address = {Piscataway}, issn = {2332-7782}, doi = {https://doi.org/10.1109/TTE.2023.3244619}, pages = {4236 -- 4254}, year = {2023}, language = {en} } @inproceedings{RauscherKalamkarEndisch2024, author = {Rauscher, Andreas and Kalamkar, Siddhanth and Endisch, Christian}, title = {Impact of High Voltage Waveform on Partial Discharge Inception in Electrical Machines}, booktitle = {2024 IEEE 33rd International Symposium on Industrial Electronics (ISIE), Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3503-9408-5}, doi = {https://doi.org/10.1109/ISIE54533.2024.10595712}, year = {2024}, language = {en} } @article{AzzamEhrensbergerEndischetal.2024, author = {Azzam, Mohamed and Ehrensberger, Moritz and Endisch, Christian and Lewerenz, Meinert}, title = {Accelerating float current measurement with temperature ramps revealing entropy insights}, volume = {2024}, pages = {114142}, journal = {Journal of Energy Storage}, number = {102, Part B}, publisher = {Elsevier}, address = {Science}, issn = {2352-1538}, doi = {https://doi.org/10.1016/j.est.2024.114142}, year = {2024}, language = {en} } @article{RauscherKaiserDevarajuetal.2024, author = {Rauscher, Andreas and Kaiser, Johannes and Devaraju, Manoj and Endisch, Christian}, title = {Deep learning and data augmentation for partial discharge detection in electrical machines}, volume = {133}, pages = {108074}, journal = {Engineering Applications of Artificial Intelligence}, number = {Part A}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-6769}, doi = {https://doi.org/10.1016/j.engappai.2024.108074}, year = {2024}, abstract = {Fault testing in the production line of automotive traction machines is essential to ensure the desired lifetime. Since repetitive partial discharges (PDs) caused by anomalies in the insulation system lead to premature breakdowns of electrical machines, a reliable PD detection is of great importance. This paper proposes deep learning (DL) methods to improve the discrimination of PD from background noise in comparison with the state-of-the-art amplitude based PD detection in the production line. First, a systematic data extraction and labeling procedure is introduced to obtain correctly labeled datasets from arbitrary PD measurements. In addition, datasets are enhanced with low signal-to-noise ratio PD pulses by applying a special data augmentation approach. 13 different convolutional, recurrent and fully connected neural networks are compared for various time-frequency representations of the input signals. Hyperparameters for input transform, network topology and solver are optimized for all 13 combinations to ensure a fair case study. As a result, the two-dimensional convolutional neural network with continuous wavelet transform achieves the best accuracy of around 99.76\% on a test dataset of PD signals originating from previously not utilized test objects. All DL models considered in this comparison outperform the state-of-the-art threshold-based PD classification. Even for PD events with an amplitude close to the noise level, the detection rate is still around 95\% for the best network. Furthermore, without applying the proposed data augmentation procedure, the DL models investigated are not able to distinguish small PD pulses from noise.}, language = {en} }