Patents by Inventor STEFAN VÖLKEL

STEFAN VÖLKEL has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9748888
    Abstract: A method for operating power semiconductors arranged in converters, includes measuring with a temperature sensor a temperature of at least one of the power semiconductors, performing a comparison of the temperature of the at least one power semiconductor with a reference temperature and providing a result of the comparison; activating a pre-heating phase for preheating the power semiconductors as a function of the result; during the pre-heating phase, defining a pre-heating current; and impressing the pre-heating current into an electrical load.
    Type: Grant
    Filed: September 24, 2015
    Date of Patent: August 29, 2017
    Assignee: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Gunnar Dietz, Holger Hoffmann, Harald Hofmann, Michael Leipenat, Stefan Völkel
  • Patent number: 9553441
    Abstract: A method for protecting an intermediate circuit capacitor in a power converter circuit is disclosed. The power converter circuit includes at least two submodules in a series circuit, which draws electrical power from a power source outputting a DC voltage via an inductance, wherein each submodule has, on the input side, a single-phase half bridge and, on the load side, a single-phase full bridge, and wherein the half bridge, the full bridge and an intermediate circuit capacitor are connected in parallel with one another on the DC voltage side. When a fault in one of the submodules is detected, transmission of electrical power from the load-side output of the full bridge of the submodule with the detected fault into the submodule with the detected fault is blocked.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: January 24, 2017
    Assignee: SIEMENS AKTIENGESELLSCHAFT
    Inventor: Stefan Völkel
  • Publication number: 20160280373
    Abstract: An interior aircraft LED light unit includes at least one LED and a lens cover arranged over the at least one LED, the lens cover having a proximal side facing towards the at least one LED and a distal side forming an outside portion of the interior aircraft LED light unit, with the lens cover being made from a lens cover material exhibiting material-specific light transfer properties. The lens cover comprises a pattern of dots on the distal side, with each of the pattern of dots locally altering the material-specific light transfer properties of the lens cover.
    Type: Application
    Filed: March 25, 2016
    Publication date: September 29, 2016
    Inventors: Christian Schoen, Stefan Voelkel
  • Publication number: 20160094178
    Abstract: A method for operating power semiconductors arranged in converters, includes measuring with a temperature sensor a temperature of at least one of the power semiconductors, performing a comparison of the temperature of the at least one power semiconductor with a reference temperature and providing a result of the comparison; activating a pre-heating phase for preheating the power semiconductors as a function of the result; during the pre-heating phase, defining a pre-heating current; and impressing the pre-heating current into an electrical load.
    Type: Application
    Filed: September 24, 2015
    Publication date: March 31, 2016
    Applicant: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Gunnar Dietz, HOLGER HOFFMANN, HARALD HOFMANN, MICHAEL LEIPENAT, STEFAN VÖLKEL
  • Patent number: 8947037
    Abstract: A method for estimating a torque of a three-phase motor for a vehicle includes measuring a respective current strength in at least two of three phase lines, wherein the three-phase motor is supplied with power by a converter, and wherein the three phase lines lead from the converter to the three-phase motor of the vehicle, measuring a respective voltage at each of the three phase lines, determining a rotating field frequency as a function of the measured current strengths or the measured voltages; and determining an estimated value for the torque as a function of the measured current strengths, the measured voltages and the determined rotating field frequency.
    Type: Grant
    Filed: July 6, 2012
    Date of Patent: February 3, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventors: Enrico Fuchs, Thomas Götze, Steffen Hellmich, Hans-Georg Köpken, Stefan Völkel
  • Patent number: 8908402
    Abstract: A modular high-frequency converter includes submodules, each having an input-side half bridge and a DC link circuit with a DC link capacitance connected in parallel to the half bridge. A DC link circuit voltage drop across the DC link capacitance of each submodule is controlled to a target voltage by adjusting a duty cycle with a closed-loop control structure having a pilot control and a downstream closed-loop error control. Within the framework of the pilot control, a target value for each duty cycle and a target value for the supply current are determined, using a mathematical model of the converter, based on the load-side output currents flowing out of the DC link voltage circuits and on target values of the DC link circuit voltages. Switch position parameters, which map the effect of the switch positions of the input-side half bridges, are each replaced by an associated duty cycle.
    Type: Grant
    Filed: March 4, 2014
    Date of Patent: December 9, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Michael Kopf, Marcel Lutze, Mirjam Mantel, Markus Reinhard, Stefan Völkel
  • Publication number: 20140254229
    Abstract: A modular high-frequency converter includes submodules, each having an input-side half bridge and a DC link circuit with a DC link capacitance connected in parallel to the half bridge. A DC link circuit voltage drop across the DC link capacitance of each submodule is controlled to a target voltage by adjusting a duty cycle with a closed-loop control structure having a pilot control and a downstream closed-loop error control. Within the framework of the pilot control, a target value for each duty cycle and a target value for the supply current are determined, using a mathematical model of the converter, based on the load-side output currents flowing out of the DC link voltage circuits and on target values of the DC link circuit voltages. Switch position parameters, which map the effect of the switch positions of the input-side half bridges, are each replaced by an associated duty cycle.
    Type: Application
    Filed: March 4, 2014
    Publication date: September 11, 2014
    Applicant: Siemens Aktiengesellschaft
    Inventors: MICHAEL KOPF, MARCEL LUTZE, MIRJAM MANTEL, MARKUS REINHARD, STEFAN VÖLKEL
  • Publication number: 20130175965
    Abstract: A method for estimating a torque of a three-phase motor for a vehicle includes measuring a respective current strength in at least two of three phase lines, wherein the three-phase motor is supplied with power by a converter, and wherein the three phase lines lead from the converter to the three-phase motor of the vehicle, measuring a respective voltage at each of the three phase lines, determining a rotating field frequency as a function of the measured current strengths or the measured voltages; and determining an estimated value for the torque as a function of the measured current strengths, the measured voltages and the determined rotating field frequency.
    Type: Application
    Filed: July 6, 2012
    Publication date: July 11, 2013
    Applicant: Siemens Aktiengesellschaft
    Inventors: ENRICO FUCHS, THOMAS GÖTZE, STEFAN VÖLKEL, STEFFEN HELLMICH, HANS-GEORG KÖPKEN