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  • 1.
    Bessman, Alexander
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Soares, Rudi
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknisk teori och konstruktion.
    Software documentation for current-rippleequipment2018Rapport (Annet (populærvitenskap, debatt, mm))
  • 2.
    Bessman, Alexander
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Soares, Rúdi Cavalerio
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Behm, Mårten
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Leksell, Mats
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Svens, P.
    Investigating the aging effect of current ripple on lithium-ion cells2015Inngår i: ECS Transactions, Electrochemical Society, 2015, Vol. 69, nr 18, s. 101-106Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We have built an experimental setup which exposes twelve cells to a well-defined ripple current. It consists of a system for cycling high capacity cells in parallel with a triangular current waveform superimposed on top of the direct current. The frequency of the waveform is variable up to 50 Hz, and the sum of the DC and AC components can have a magnitude of -40 A to 40 A. Current is measured over a 500 μω shunt resistor. The voltage and current of each cell is read simultaneously at a sample rate up to 4 MS/s, allowing for precise impedance measurements even for high frequency harmonics. The cells are cycled at 40 °C. The experiment has been designed to eliminate indirect effects of the AC harmonics as far as possible. This system is being used to test whether or not AC harmonics affect Li-ion aging.

  • 3.
    Bessman, Alexander
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Soares, Rúdi
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Vadivelu, Sunilkumar
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Svens, Pontus
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Ekström, Henrik
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Challenging Sinusoidal Ripple-Current Charging of Lithium-Ion Batteries2018Inngår i: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 65, nr 6, s. 4750-4757Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sinusoidal ripple-current charging has previously been reported to increase both charging efficiency and energy efficiency and decrease charging time when used to charge lithium-ion battery cells. In this paper, we show that no such effect exists in lithium-ion battery cells, based on an experimental study of large-size prismatic cells. Additionally, we use a physics-based model to show that no such effect should exist, based on the underlying electrochemical principles.

  • 4.
    Bessman, Alexander
    et al.
    KTH.
    Soares, Rúdi
    KTH.
    Wallmark, Oskar
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Svens, Pontus
    KTH.
    Lindbergh, Göran
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik.
    Aging effects of AC harmonics on lithium-ion cellsManuskript (preprint) (Annet vitenskapelig)
  • 5.
    Bessman, Alexander
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Soares, Rúdi
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik.
    Wallmark, Oskar
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik.
    Svens, Pontus
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Aging effects of AC harmonics on lithium-ion cells2019Inngår i: Journal of Energy Storage, E-ISSN 2352-152X, Vol. 21, s. 741-749Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    With the vehicle industry poised to take the step into the era of electric vehicles, concerns have been raised that AC harmonics arising from switching of power electronics and harmonics in electric machinery may damage the battery. In light of this, we have studied the effect of several different frequencies on the aging of 28 Ah commercial NMC/graphite prismatic lithium-ion battery cells. The tested frequencies are 1 Hz, 100 Hz, and 1 kHz, all with a peak amplitude of 21 A. Both the effect on cycled cells and calendar aged cells is tested. The cycled cells are cycled at a rate of 1C:1C, i.e., 28 A during both charging and discharging, with the exception of a period of constant voltage at the end of every charge. After running for one year, the cycled cells have completed approximately 2000 cycles. The cells are characterized periodically to follow how their capacities and power capabilities evolve. After completion of the test about 80% of the initial capacity remained and no increase in resistance was observed. No negative effect on either capacity fade or power fade is observed in this study, and no difference in aging mechanism is detected when using non-invasive electrochemical methods of post mortem investigation.

  • 6.
    Soares, Rudi
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Bessman, Alexander
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Leksell, Mats
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Behm, Mårten
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Svens, Pontus
    Design Aspects of an Experimental Setup for Investigating Current Ripple Effects in Lithium-ion Battery Cells2015Inngår i: Power Electronics and Applications (EPE'15 ECCE-Europe), 2015 17th European Conference on, IEEE conference proceedings, 2015, s. 1-8Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper describes an experimental setup for investigating the effects of current ripple on lithium-ion battery cells. The experimental setup is designed so that twelve li-ion cells can be simultaneously tested in a controlled environment. The experimental setup allows for a wide range of current ripple in terms of frequency and amplitude. Additionally, the quantification of the current ripple effects such as the aging of li-ion cells implies that a precise measurement system has to be designed which also are discussed in the paper.

  • 7.
    Soares, Rudi
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik. KTH.
    Bessman, Alexander
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Wallmark, Oskar
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Lindbergh, Göran
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Svens, Pontus
    Scania.
    An Experimental Setup with Alternating Current Capability for Evaluating Large Lithium-Ion Battery Cells2018Inngår i: Batteries-Basel, ISSN 2313-0105, Vol. 4, nr 3, artikkel-id 38Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the majority of applications using lithium-ion batteries, batteries are exposed to some harmonic content apart from the main charging/discharging current. The understanding of the effects that alternating currents have on batteries requires specific characterization methods and accurate measurement equipment. The lack of commercial battery testers with high alternating current capability simultaneously to the ability of operating at frequencies above 200 Hz, led to the design of the presented experimental setup. Additionally, the experimental setup expands the state-of-the-art of lithium-ion batteries testers by incorporating relevant lithium-ion battery cell characterization routines, namely hybrid pulse power current, incremental capacity analysis and galvanic intermittent titration technique. In this paper the hardware and the measurement capabilities of the experimental setup are presented. Moreover, the measurements errors due to the setup’s instruments were analysed to ensure lithium-ion batteries cell characterization quality. Finally, this paper presents preliminary results of capacity fade tests where 28 Ah cells were cycled with and without the injection of 21 A alternating at 1 kHz. Up to 300 cycles, no significant fade in cell capacity may be measured, meaning that alternating currents may not be as harmful for lithium-ion batteries as considered so far.

  • 8.
    Soares, Rúdi
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik. KTH.
    Wallmark, Oskar
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg. KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik.
    Lindbergh, Göran ()
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Svens, Pontus ()
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Analysis and Prediction of the Harmonic Content in the Battery Currentof a Commercial Hybrid-Electric BusInngår i: IEEE Transactions on Transportation ElectrificationArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a comparison of the harmoniccontent in the battery current in two, commercialhybrid electric vehicles (HEVs) (intercity passenger buses)when operated in realistic drive scenarios. These harmonicscan contribute to issues related to electromagnetic compatibilityand indirectly accelerate the aging of the battery dueto elevated cell temperatures caused by associated ohmiclosses. A key finding is that low-frequency harmonics (upto approximately 130 Hz) attributed to resolver eccentricityand non-ideal effects in the voltage-source inverter (VSI) (upto approximately 260 Hz) were significant in terms of magnitudes.Also, the variation between the two HEVs (in termsof current magnitude) were substantial for these harmonics.This is an important observation since it demonstratesthat significant, low-frequency harmonics can be presentin the battery current and that modeling and collectingexperimental data from a single corresponding vehicle maynot sufficiently represent the harmonic content in the batterycurrent for a fleet of vehicles.

  • 9.
    Soares, Rúdi
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik.
    Wallmark, Oskar
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg. KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik.
    Loh, Poh Chiang ()
    Chinese University of Hong Kong.
    Integration of Magnified Alternating Current in Battery Fast Chargers based on DC-DC Converters using Transformerless Resonant Filter DesignInngår i: IEEE Transactions on Transportation ElectrificationArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For safety and longevity reasons, in subzero temperatures, lithium-ion batteries can only be charged after precommissioningtheir temperature. Therefore, in such conditions fast charging depends on fast heating. Recently,the injection of AC currents into lithium-ion batteries has been reported as a technique with potential to decreaseheating time. This paper proposes a method based on a multi-objective algorithm for DC-DC converter designusing transformerless resonant filters. The method enables the DC-DC converters to produce magnified AC currentin addition to the DC current. Using the proposed design method, a topological survey of DC-DC converters withmagnified AC current capability composed of either half- or full-bridge switch arrangements is carried out. Inthe presented experimental setup, it is demonstrated that by using an LCL circuit with specific component valuesand a full-bridge switch arrangement, magnifications of up to 15.7 may be reached. Further, by matching theswitching frequency with the frequency where the LCL and the battery resonate, for the same injected AC current,the current flowing in the semiconductors and the switching frequency could be reduced. This allowed a lossreduction in the semiconductors of up to 75%, when compared with an equivalent DC-DC converter enabled toproduce a non-magnified AC current.

  • 10.
    Soares, Rúdi
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elkraftteknik.
    Modeling and Analysis of the Interaction of Batteries and Power Electronic Converters2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis deals with the interaction of batteries and power electronic converters in automotive applications. Even if the additional heating caused by (unwanted) alternating currents is disregarded, there has been a concern that alternating currents can be harmful for batteries. For that reason, alternating currents can be filtered using capacitors and/or by sophisticated hardware. In this work, the concern whether alternating currents are harmful to batteries is studied particular focus on large, lithium-ion cells for use in automotive applications.First, the harmonic content in the battery current of two, commercial hybrid-electric busses were measured and analysed. The most prominent harmonic had a peak magnitude higher than 10% of the maximum direct current level (160 A) arising at frequencies below 150 Hz. The maximum amplitude detected of a harmonic caused by the voltage source converter’s switching action was around 10 A and occurred at a frequency of 2 kHz. An experimental setup with alternating current capability for evaluating large lithium-ion cells has been designed and built. Twelve lithium-ion cells were cycled at a rate if 1 C during approximately 2000 cycles (corresponding to approximately one year). The cells were cycled with an superimposed alternating current of 1 Hz, 100 Hz, or 1 kHz while the rest of the cells were cycled with direct current (only), injected with alternating current (only), or no current at all (calendar aging). No negative effects caused by the alternating current was identified in terms of capacity fade and power fade for the tested lithium-ion cells. A comparison between sinusoidal current-ripple charging and conventional constant-current constant-voltage charging was also carried out. Three lithium-ion cells were cycled (ten times) with different ac currents superimposed during charge. The results were analyzed statistically and no significant improvements in terms of charging time or charging efficiency were observed in any of the charging tests using an superimposed ac current. The injection of alternating currents into batteries for heating purposes has also been studied and a control method for battery heating using an ac current was proposed. The proposed controller is applicable regardless of the LIB’s subsequent impedance nature (capacitive, inductive or resistive). Further, a design process for the generation of magnified alternating currents in dc-dc converters was presented. By matching the switching frequency with the frequency where the LCL filter and the battery resonate, the current flowing in the semiconductors and the switching frequency could be reduced. In a small experimental setup using a single lithium-ion cell, using an LCL-resonant circuit and a full bridges witch arrangement, magnifications of up to 15.7 were reached. This allowed for a loss reduction in the semiconductors of up to 75%, when compared to an equivalent dc-dc converter enabled to produce anon-magnified ac current. 

  • 11.
    Soares, Rúdi
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Bessman, Alexander
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Li-ion battery and dc-link capacitor technologies – Electric drivetrain applications: A literature study2014Rapport (Annet vitenskapelig)
    Abstract [en]

    Modern electrical vehicle drivetrains use a DC-link capacitor to decouple the battery from the power electronics.This topology is thought to be necessary for a number of reasons, including among others preventing damage to the battery and reducing electromagnetic interference.However, the DC-link capacitor is a bulky component which makes the entire drivetrain less modular by its presence.For this reason, an interdisciplinary research project has been launched to investigate the possibility of improving electrical vehicle drivetrains by having PhD students from the fields of electrical engineering and applied electrochemisty working closely together.The initial goal of this project will be to attempt to remove the DC-link capacitor entirely, in order to determine whether this adversely affects the battery longevity.Depending on the results from this initial test, other potential problems with removing the DC-link capacitor will be identfied and addessed.

  • 12.
    Soares, Rúdi
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Bessman, Alexander
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Wallmark, Oskar
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Svens, P.
    Measurements and analysis of battery harmonic currents in a commercial hybrid vehicle2017Inngår i: 2017 IEEE Transportation and Electrification Conference and Expo, ITEC 2017, Institute of Electrical and Electronics Engineers Inc. , 2017, s. 45-50Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, the harmonic content of the battery current in a commercial hybrid vehicle (bus) is measured and analyzed for a number of different driving situations. It is found that the most prominent harmonic reaches peak magnitudes that can be higher than 10% of the maximum dc-current level with a maximum frequency less than 150 Hz. Further, it is found that this harmonic can be approximated using a fitted, simple analytical expression with reasonable agreement for all driving situations considered.

  • 13.
    Soares, Rúdi
    et al.
    KTH.
    Bessman, Alexander
    KTH.
    Wallmark, Oskar
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Lindbergh, Göran
    KTH.
    Svens, Pontus
    KTH.
    A Control Method for Battery Heating Using Alternating CurrentManuskript (preprint) (Annet vitenskapelig)
  • 14.
    Soares, Rúdi
    et al.
    KTH.
    Bessman, Alexander
    KTH.
    Wallmark, Oskar
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Lindbergh, Göran
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik.
    Svens, Pontus
    KTH.
    An Experimental Setup with Alternating Current Capability for Evaluating Large Lithium-ion Batteries CellsManuskript (preprint) (Annet vitenskapelig)
1 - 14 of 14
RefereraExporteraLink til resultatlisten
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Referera
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  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
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  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf