Patents by Inventor Christian Stulz

Christian Stulz 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: 11527973
    Abstract: A method for starting a synchronous motor is provided. The synchronous motor includes a rotor for creating a first magnetic field and a stator with stator windings connected to an electrical energy converter for converting a supply voltage into a stator voltage to be applied to the stator windings to create a rotating second magnetic field interacting with the first magnetic field. The method includes applying reference stator voltages to the stator windings, where the reference stator voltages are determined from a reference current vector and a reference rotor speed, measuring stator currents, calculating an estimated rotor speed and rotor position from the applied stator voltages and the measured stator currents, calculating a speed error by subtracting the estimated rotor speed from the reference rotor speed, determining a reference torque producing current component from the speed error, and modifying the reference current vector with the reference torque producing current component.
    Type: Grant
    Filed: October 15, 2020
    Date of Patent: December 13, 2022
    Assignee: ABB Schweiz AG
    Inventors: Andrey Kalygin, Christian Stulz
  • Publication number: 20210111647
    Abstract: The invention relates to a method for starting a synchronous motor. The synchronous motor includes a rotor for creating a first magnetic field and a stator with stator windings connected to an electrical energy converter for converting a supply voltage into a stator voltage to be applied to the stator windings to create a rotating second magnetic field interacting with the first magnetic field.
    Type: Application
    Filed: October 15, 2020
    Publication date: April 15, 2021
    Inventors: Andrey Kalygin, Christian Stulz
  • Patent number: 10819255
    Abstract: A method for starting an induction machine without residual flux includes: scanning a state of the induction machine with different stator frequencies by controlling a supply voltage applied to the induction machine; determining whether a slip value, being a difference between a rotor frequency and a stator frequency, is within a slip interval; and, when it has been determined that the slip value is in the slip interval, regulating the slip value towards zero and magnetising the machine to the required level.
    Type: Grant
    Filed: January 2, 2019
    Date of Patent: October 27, 2020
    Assignee: ABB Schweiz AG
    Inventors: Andrey Kalygin, Christian Stulz, Christof Gutscher, Marc Rauer, Mate Jelavic
  • Publication number: 20190140563
    Abstract: A method for starting an induction machine without residual flux includes: scanning a state of the induction machine with different stator frequencies by controlling a supply voltage applied to the induction machine; determining whether a slip value, being a difference between a rotor frequency and a stator frequency, is within a slip interval; and, when it has been determined that the slip value is in the slip interval, regulating the slip value towards zero and magnetising the machine to the required level.
    Type: Application
    Filed: January 2, 2019
    Publication date: May 9, 2019
    Inventors: Andrey Kalygin, Christian Stulz, Christof Gutscher, Marc Rauer, Mate Jelavic
  • Patent number: 9915517
    Abstract: A method is disclosed for determining a rotor position of an electrically excited electrical machine by injecting voltage test signals at a plurality of space vector angles with a fundamental frequency which lies in a frequency range in which there is a difference in admittance in space vector angles; calculating resulting values of an excitation current indicator variable as Fourier coefficients of the excitation current resulting from the voltage test signal with reference to the fundamental frequency of the voltage test signal at the corresponding space vector angles; and determining the rotor position on the basis of the profile of the excitation current indicator variable.
    Type: Grant
    Filed: August 25, 2014
    Date of Patent: March 13, 2018
    Assignee: ABB Schweiz AG
    Inventors: Simon Feuersaenger, Mario Pacas, Christian Stulz
  • Patent number: 9837922
    Abstract: A method is disclosed in one embodiment for discharging DC link capacitors. In one form the method includes switching a first half bridge of a first converter unit to a positive state, in which its AC output is connected with its positive DC output, and simultaneously switching a second half bridge of a second converter unit to a negative state, in which its AC output is connected with its negative DC output, such that a DC link capacitor of the first converter unit and a DC link capacitor of the second converter unit are interconnected oppositely to each other and discharged via the electrical filter.
    Type: Grant
    Filed: October 28, 2016
    Date of Patent: December 5, 2017
    Assignee: ABB Technology Oy
    Inventors: Matthias Lüscher, Juerg Rauchenstein, Christian Stulz
  • Publication number: 20170047856
    Abstract: A method is disclosed in one embodiment for discharging DC link capacitors. In one form the method includes switching a first half bridge of a first converter unit to a positive state, in which its AC output is connected with its positive DC output, and simultaneously switching a second half bridge of a second converter unit to a negative state, in which its AC output is connected with its negative DC output, such that a DC ink capacitor of the first converter unit and a DC link capacitor of the second converter unit are interconnected oppositely to each other arid discharged via the electrical filter.
    Type: Application
    Filed: October 28, 2016
    Publication date: February 16, 2017
    Inventors: Matthias Lüscher, Juerg Rauchenstein, Christian Stulz
  • Publication number: 20150057970
    Abstract: A method is disclosed for determining a rotor position of an electrically excited electrical machine by injecting voltage test signals at a plurality of space vector angles with a fundamental frequency which lies in a frequency range in which there is a difference in admittance in space vector angles; calculating resulting values of an excitation current indicator variable as Fourier coefficients of the excitation current resulting from the voltage test signal with reference to the fundamental frequency of the voltage test signal at the corresponding space vector angles; and determining the rotor position on the basis of the profile of the excitation current indicator variable.
    Type: Application
    Filed: August 25, 2014
    Publication date: February 26, 2015
    Applicant: ABB TECHNOLOGY AG
    Inventors: Simon FEUERSAENGER, Mario PACAS, Christian STULZ
  • Patent number: 8653768
    Abstract: A method is provided for compensating the flux drift caused by measurement and/or calculation errors when controlling a rotating electrical machine. The flux drift of the estimated flux vector may be compensated for by comparing the length of the flux vector with a reference flux magnitude which already has been determined for controlling the inverter. Depending on the comparison, the length of the estimated flux vector may be lengthened or shortened.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: February 18, 2014
    Assignee: ABB Technology AG
    Inventors: Christian Stulz, Halina Burzanowska
  • Publication number: 20120068640
    Abstract: A method is provided for compensating the flux drift caused by measurement and/or calculation errors when controlling a rotating electrical machine. The flux drift of the estimated flux vector may be compensated for by comparing the length of the flux vector with a reference flux magnitude which already has been determined for controlling the inverter. Depending on the comparison, the length of the estimated flux vector may be lengthened or shortened.
    Type: Application
    Filed: September 15, 2011
    Publication date: March 22, 2012
    Applicant: ABB Technology AG
    Inventors: Christian Stulz, Halina Burzanowska
  • Patent number: 7499297
    Abstract: A polyphase converter circuit having p?3 phases (R, Y, B) and a converter circuit element provided for each phase (R, Y, B) is specified, each converter circuit element having a rectifier unit, a DC voltage circuit which is connected to the rectifier unit and an inverter unit which is connected to the DC voltage circuit. In addition, a first AC voltage output of each inverter unit forms a phase connection, and second AC voltage outputs of the inverter units are star-connected. In order to produce harmonics which are as low as possible with respect to the fundamental of the voltage and the current of an electrical AC voltage system which is connected on the input side to the converter circuit, n transformers are provided, each having a primary winding and m three-phase secondary windings, where n?2 and m?3.
    Type: Grant
    Filed: December 15, 2006
    Date of Patent: March 3, 2009
    Assignee: ABB Schweiz AG
    Inventors: Christian Stulz, Christoph Eichler, Erich Suter, Adrian Zuckerberger, Pieder Jörg, Thomas Berner
  • Publication number: 20070153555
    Abstract: A polyphase converter circuit having p?3 phases (R, Y, B) and a converter circuit element provided for each phase (R, Y, B) is specified, each converter circuit element having a rectifier unit, a DC voltage circuit which is connected to the rectifier unit and an inverter unit which is connected to the DC voltage circuit. In addition, a first AC voltage output of each inverter unit forms a phase connection, and second AC voltage outputs of the inverter units are star-connected. In order to produce harmonics which are as low as possible with respect to the fundamental of the voltage and the current of an electrical AC voltage system which is connected on the input side to the converter circuit, n transformers are provided, each having a primary winding and m three-phase secondary windings, where n?2 and m?3.
    Type: Application
    Filed: December 15, 2006
    Publication date: July 5, 2007
    Applicant: ABB Schweiz AG
    Inventors: Christian Stulz, Christoph Eichler, Erich Suter, Adrian Zuckerberger, Pieder Jorg, Thomas Berner
  • Patent number: 6288915
    Abstract: A converter circuit arrangement having a DC intermediate circuit (3) includes a transformer (8) having at least two windings (9 and 10). This transformer (8) is connected in the intermediate circuit (3) such that the undesirable, unbalanced current components lead to magnetization of the transformer core and are thus reduced. A grounded LC filter (Lf, Cf) is connected upstream of the load (6) and produces a sinusoidal voltage across the load (6). In consequence, the circuit can be used with any desired rotating-field machines, and thus also for retrofitting existing systems.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: September 11, 2001
    Assignee: Asea Brown Boveri AG
    Inventors: Christoph Stemmler, Christian Stulz
  • Patent number: 5999423
    Abstract: A voltage converter having a voltage intermediate circuit and an invertor connected to the output of the voltage intermediate circuit. The invertor produces a three-phase AC voltage at its output and is connected to the output terminals of the voltage converter by a filter arrangement. The filter arrangement includes a filter inductor connected in series with the output terminal and the filter capacitor connected between the output terminal and a common capacitor star point. Attenuation of the DC system is achieved by having the capacitor star point connected to the voltage intermediate circuit by way of an RC element having a capacitor and a resistor.
    Type: Grant
    Filed: August 21, 1998
    Date of Patent: December 7, 1999
    Assignee: Asea Brown Boveri AG
    Inventors: Jurgen Steinke, Christian Stulz
  • Patent number: 5734249
    Abstract: A method and an apparatus for direct torque control are specified for a three-phase machine fed via a harmonic filter, which method manages as far as possible without any major adaptation to already known DTC methods and DTC apparatuses. In addition, the oscillations caused by the filter are intended to be damped effectively. This is achieved in that a current flowing through the filter and/or a filter output voltage are/is measured, and the reference flux value and the reference torque value are corrected on the basis of the measured voltage and/or of the measured current. The correction comprises a transformation of the filter output voltage into a first component at right angles to a stator flux and into a second component parallel to the stator flux, as well as a reduction in the reference torque and flux values in proportion to the oscillating part of the filter output voltage.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: March 31, 1998
    Assignee: Asea Brown Boveri AG
    Inventors: Pasi Pohjalainen, Christian Stulz