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Hirofumi Akagi - One of the best experts on this subject based on the ideXlab platform.

  • mechanism of shaft End to End Voltage generation by asymmetry in an inverter driven motor
    Electrical Engineering in Japan, 2013
    Co-Authors: Yusuke Asakura, Hirofumi Akagi
    Abstract:

    Summary This paper deals with the shaft End-to-End Voltage resulting from asymmetric stray capacitances in an inverter-driven motor. The origin of the Voltage can be any of the following: a ground leakage current, dielectric breakdown in the bearings, and asymmetric stray capacitances on the stator windings. The third origin seems to be related to the differential-mode current, but the details of the relationship have not been clarified. In this study, differential-mode tests are carried out on an ungrounded motor rated at 400 V and 15 kW, and shaft End-to-End Voltage generation by the asymmetric stray capacitances is theoretically discussed. Finally, a winding model is presented for the purpose of understanding the mechanism responsible for the shaft End-to-End Voltage. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 185(1): 48–56, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22415

  • mechanism of shaft End to End Voltage generation by asymmetry in an inverter driven motor
    Ieej Transactions on Industry Applications, 2012
    Co-Authors: Yusuke Asakura, Hirofumi Akagi
    Abstract:

    This paper deals with the shaft End-to-End Voltage resulting from asymmetric stray capacitances in an inverter-driven motor. The origin of the Voltage can be any of the following: a ground leakage current, dielectric breakdown in bearings, and asymmetric stray capacitances on stator windings. The third origin seems to be related to the differential-mode current, but the details of the relationship have not been clarified. In this study, differential-mode tests are carried out on an ungrounded motor rated at 400V and 15kW, and the shaft End-to-End Voltage generation by the asymmetric stray capacitances is theoretically discussed. Finaly, a winding model is presented for the purpose of understanding the mechanism responsible for the shaft End-to-End Voltage.

  • identification and discussion of the origin of a shaft End to End Voltage in an inverter driven motor
    IEEE Transactions on Power Electronics, 2010
    Co-Authors: Umar Tabrez Shami, Hirofumi Akagi
    Abstract:

    This paper addresses shaft End-to-End and shaft-to-frame Voltages that appear in the 400-V 15-kW induction motor driven by a Voltage-source pulsewidth modulation inverter. It has been known that an inverter-fed common-mode Voltage causes both shaft Voltages. Extensive experiments are performed with an ungrounded motor subjected to a differential-mode Voltage. Experimental results show that the differential-mode Voltage applied across three-phase, two-phase, or single-phase stator windings also causes a shaft End-to-End Voltage. It is concluded that the combination of a steep change in differential-mode Voltage and high-frequency motor asymmetry causes a shaft End-to-End Voltage. A motor model is presented to explain the generation of shaft End-to-End Voltage.

  • experimental discussions on a shaft End to End Voltage appearing in an inverter driven motor
    IEEE Transactions on Power Electronics, 2009
    Co-Authors: Umar Tabrez Shami, Hirofumi Akagi
    Abstract:

    This paper addresses shaft End-to-End and shaft-to-frame Voltages that appear in the 400-V, 15-kW induction motor driven by a Voltage-source pulsewidth modulation (PWM) inverter. A shaft-to-frame Voltage can be observed at either shaft End with respect to the grounded motor frame. A shaft End-to-End Voltage can be observed as a Voltage difference between the shaft-to-frame Voltage at the drive End (DE) and that at the nondrive End (NDE). Experimental waveforms lead to the following interesting observations: motor internal coupling and parasitic capacitance, along with the high-frequency common-mode Voltage generated by the PWM inverter, cause a shaft-to-frame Voltage with a peak of 8 V at both DE and NDE. When the shaft-to-frame Voltage at either DE or NDE exceeds a dielectric breakdown Voltage of thin bearing lubricating grease films, a shaft End-to-End Voltage with a peak of 2 V and a width of 30 ns occurs along the motor shaft. This paper makes experimental discussions on the shaft End-to-End Voltage generation. Installing a differential-mode filter and/or a common-mode filter on the motor drive system gives a hint on the mechanisms of the occurrence of the shaft End-to-End Voltage.

Umar Tabrez Shami - One of the best experts on this subject based on the ideXlab platform.

  • identification and discussion of the origin of a shaft End to End Voltage in an inverter driven motor
    IEEE Transactions on Power Electronics, 2010
    Co-Authors: Umar Tabrez Shami, Hirofumi Akagi
    Abstract:

    This paper addresses shaft End-to-End and shaft-to-frame Voltages that appear in the 400-V 15-kW induction motor driven by a Voltage-source pulsewidth modulation inverter. It has been known that an inverter-fed common-mode Voltage causes both shaft Voltages. Extensive experiments are performed with an ungrounded motor subjected to a differential-mode Voltage. Experimental results show that the differential-mode Voltage applied across three-phase, two-phase, or single-phase stator windings also causes a shaft End-to-End Voltage. It is concluded that the combination of a steep change in differential-mode Voltage and high-frequency motor asymmetry causes a shaft End-to-End Voltage. A motor model is presented to explain the generation of shaft End-to-End Voltage.

  • experimental discussions on a shaft End to End Voltage appearing in an inverter driven motor
    IEEE Transactions on Power Electronics, 2009
    Co-Authors: Umar Tabrez Shami, Hirofumi Akagi
    Abstract:

    This paper addresses shaft End-to-End and shaft-to-frame Voltages that appear in the 400-V, 15-kW induction motor driven by a Voltage-source pulsewidth modulation (PWM) inverter. A shaft-to-frame Voltage can be observed at either shaft End with respect to the grounded motor frame. A shaft End-to-End Voltage can be observed as a Voltage difference between the shaft-to-frame Voltage at the drive End (DE) and that at the nondrive End (NDE). Experimental waveforms lead to the following interesting observations: motor internal coupling and parasitic capacitance, along with the high-frequency common-mode Voltage generated by the PWM inverter, cause a shaft-to-frame Voltage with a peak of 8 V at both DE and NDE. When the shaft-to-frame Voltage at either DE or NDE exceeds a dielectric breakdown Voltage of thin bearing lubricating grease films, a shaft End-to-End Voltage with a peak of 2 V and a width of 30 ns occurs along the motor shaft. This paper makes experimental discussions on the shaft End-to-End Voltage generation. Installing a differential-mode filter and/or a common-mode filter on the motor drive system gives a hint on the mechanisms of the occurrence of the shaft End-to-End Voltage.

Rudiger Wolf - One of the best experts on this subject based on the ideXlab platform.

  • primary batteries for implantable pacemakers and defibrillators
    Journal of Power Sources, 2001
    Co-Authors: Jurgen Dr Drews, Gerd Fehrmann, Roland Staub, Rudiger Wolf
    Abstract:

    Abstract The lithium-iodine battery is established as the standard system for low-rate implantable applications, namely pacemakers because of its excellent volumetric energy density. Within defibrillators/cardioverters lithium-silver-oxovanadium (SVO) and lithium-manganese-dioxide (MDX) high-rate batteries are in use. The concept of a hybrid system which makes use of a high-rate battery and a low-rate battery within one application is described. Experimental results obtained from a MDX battery and a lithium-iodine battery, both with the same dimensions, are showing that MDX batteries of that size are able to combine excellent volumetric energy density and medium power ratings. Energy densities of 650 mWh/cm3 for the MDX battery with a lode of 30 kΩ to an End Voltage of 2.5 V have been confirmed. These results show the potential of lithium-manganese-dioxide batteries to be used as low-rate and medium-rate sources within implantable applications.

Hu Jun - One of the best experts on this subject based on the ideXlab platform.

  • lithium ion battery pack state of health evaluation method and lithium ion battery pack state of health evaluation system
    2016
    Co-Authors: Hu Jun
    Abstract:

    The invention discloses a lithium ion battery pack state-of-health evaluation method and a lithium ion battery pack state-of-health evaluation system. According to the method, first, the state of health of a battery pack is preliminarily judged according to the End Voltage of each battery string in the battery pack, and then, the state of health of the battery pack is comprehensively evaluated from the discharge capacity, internal resistance and temperature of the battery pack. The system comprises a control unit, a battery charging and discharging unit, a protection unit and a sound-light-electricity display unit. The control unit comprises a data reading unit, a data storing unit, a data processing unit and a data sEnding unit. According to the evaluation method and the evaluation system provided by the invention, all kinds of complicated environmental influences facing the battery pack in the using process are considered, comprehensive evaluation of the state of health of the batteries in the battery pack is completed, and the accuracy of test results is improved.

Jurgen Dr Drews - One of the best experts on this subject based on the ideXlab platform.

  • primary batteries for implantable pacemakers and defibrillators
    Journal of Power Sources, 2001
    Co-Authors: Jurgen Dr Drews, Gerd Fehrmann, Roland Staub, Rudiger Wolf
    Abstract:

    Abstract The lithium-iodine battery is established as the standard system for low-rate implantable applications, namely pacemakers because of its excellent volumetric energy density. Within defibrillators/cardioverters lithium-silver-oxovanadium (SVO) and lithium-manganese-dioxide (MDX) high-rate batteries are in use. The concept of a hybrid system which makes use of a high-rate battery and a low-rate battery within one application is described. Experimental results obtained from a MDX battery and a lithium-iodine battery, both with the same dimensions, are showing that MDX batteries of that size are able to combine excellent volumetric energy density and medium power ratings. Energy densities of 650 mWh/cm3 for the MDX battery with a lode of 30 kΩ to an End Voltage of 2.5 V have been confirmed. These results show the potential of lithium-manganese-dioxide batteries to be used as low-rate and medium-rate sources within implantable applications.