Patents by Inventor John Godsk Nielsen

John Godsk Nielsen 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).

  • Publication number: 20220085740
    Abstract: The invention relates to a method for controlling a wind turbine as virtual synchronous machine by determining the synchronous machine rotational speed rotational speed and the synchronous machine angle. The virtual synchronous machine rotational speed is determined based on a combination of a feedback of a damping power, a power reference for a desired power output of the wind turbine, a grid power supplied by the wind turbine to a power grid and a chopper power dissipated by the chopper and an inertial integration model, the synchronous machine angle is determined based on an integration of the synchronous machine rotational speed, and the damping power is determined based on the virtual synchronous machine rotational speed.
    Type: Application
    Filed: December 16, 2019
    Publication date: March 17, 2022
    Inventors: John Godsk NIELSEN, Torsten LUND, Esmaeil EBRAHIMZADEHVESHAREH
  • Publication number: 20220069580
    Abstract: The invention relates to a method for controlling a power generating unit such as a wind turbine which is configured as a virtual synchronous machine. Capacitor voltage signals obtained from voltage measurements of output capacitors are filtered in order to reduce a magnitude of an impedance peak and/or shift the impedance peak where the impedance peak is present in an impedance characteristic of the output of the power generating unit. Filter compensated voltage signals obtained from the output capacitors are combined with a voltage magnitude reference to obtain filtered capacitor voltage signals used for controlling the line side converter and thereby affect the impedance peak in a desired way.
    Type: Application
    Filed: December 16, 2019
    Publication date: March 3, 2022
    Inventors: John Godsk NIELSEN, Torsten LUND, Esmaeil EBRAHIMZADEHVESHAREH
  • Publication number: 20220014023
    Abstract: The invention relates to a method for operating a power system of a wind turbine. The power system comprises first and second parallel connected DC-to-AC converters and at least one transformer, where each transformer comprises a primary section connected to a power line, and where the at least one transformer comprises first and second secondary sections connected to outputs of the respective first and second DC-to-AC converters. The method comprises providing a reactive correction reference, changing first and second reactive powers generated by the respective first and second DC-to-AC converters according to the reactive correction reference, so that one of the first and second reactive powers is increased while the other is decreased with amounts corresponding to the reactive correction reference so that the first and second reactive powers are unequal.
    Type: Application
    Filed: July 9, 2021
    Publication date: January 13, 2022
    Inventors: John Godsk NIELSEN, Torben Møller HANSEN
  • Patent number: 11143167
    Abstract: A method and apparatus for estimating a characteristic of a wind turbine electrical signal comprises buffering a sequence of sample values of the wind turbine electrical signal and a sequence of sample times corresponding with the sequence of sample values. The time periods represented by the sample times are variable. A sub-sequence of the buffered sample values to integrate is determined, based at least in part on a sum of the time periods. The characteristic is estimated by integrating the sample values in the sub-sequence.
    Type: Grant
    Filed: October 17, 2017
    Date of Patent: October 12, 2021
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Torsten Lund, John Godsk Nielsen
  • Patent number: 10958071
    Abstract: A method for operating a renewable energy power plant comprising a plurality of renewable energy generators. The method comprises: identifying a predetermined condition of the renewable energy power plant, of the grid, or of the connection between the renewable energy power plant and the grid, the predetermined condition indicating a weak grid interconnection between the renewable energy power plant and the grid; and controlling each renewable energy generator in an adaptive active power mode in response to recovery of the grid from a voltage deviation. The adaptive active power mode comprises: determining a thermal capacity of a chopper resistor of the renewable energy generator; calculating, based upon the determined thermal capacity, a limit level of rate of change of active power output that may be implemented by the renewable energy generator; and operating the renewable energy generator to output active power at the calculated rate of change limit level.
    Type: Grant
    Filed: November 20, 2018
    Date of Patent: March 23, 2021
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Manoj Gupta, Ravi Kumar, Janakiraman Sivasankaran, Thomas Schmidt Grau, Martin Ansbjerg Kjær, Kouroush Nayebi, John Godsk Nielsen, Jesper Sandberg Thomsen
  • Patent number: 10859064
    Abstract: A power conversion system for a wind turbine generator, comprising a machine-side converter having an AC voltage input from a generator and a DC voltage output to a DC link, wherein the machine-side converter is a modular multi-level converter comprising one or more converter legs corresponding to a respective one or more electrical phases of the generator, each of the converter legs comprising a plurality of converter cells, the system further comprising: a converter control module which provides the machine-side converter with a gate signal, and an electrical frequency estimation module configured to estimate the mean electrical frequency of the generator; wherein the gate signal has at least one mean switching frequency corresponding to at least one electrical phase of the generator; wherein the converter control module is configured to modulate the mean switching frequency of the gate signal in dependence on the mean electrical frequency of the generator.
    Type: Grant
    Filed: November 29, 2017
    Date of Patent: December 8, 2020
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Ciprian Biris, Duy Duc Doan, John Godsk Nielsen
  • Patent number: 10700624
    Abstract: A method of controlling a wind turbine generator (1) comprising an electrical generator (10) and a power converter (12), the power converter (12) comprising an electrical switch (14a, 14b) that is configured to process electrical power produced by the electrical generator (10), the method comprising: controlling an output from the electrical switch (14a, 14b) using a variable pulse-width modulated control signal, thereby to control characteristics of output power from the power converter (12); acquiring sample data (26) relating to an electronic signal within the wind turbine generator (1), wherein the sample data (26) is used for controlling the wind turbine generator (1); and dynamically adjusting a frequency (30) at which the sample data is acquired to synchronise data acquisition with a carrier frequency (24) of the control signal.
    Type: Grant
    Filed: August 11, 2017
    Date of Patent: June 30, 2020
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Gert Karmisholt Andersen, Kent Tange, Søren Andersen, Duy Duc Doan, Jens Peter Biltoft, Lars Helle, John Godsk Nielsen
  • Patent number: 10598701
    Abstract: A method for operating a power generation system coupled to a power grid during a grid unbalance event, a method for determining an injection current to be supplied into a power grid by a power generation system, and a method for addressing an asymmetric grid fault in a power grid connected to a power generation system are provided. The methods may be carried out based on a reactive or an active power/current priority.
    Type: Grant
    Filed: July 10, 2017
    Date of Patent: March 24, 2020
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Amit Kumar Gupta, John Godsk Nielsen, Liang Yang
  • Patent number: 10590914
    Abstract: A method, converter arrangement, and controller are disclosed for connecting an output of a converter with an electrical grid to control inrush currents into a grid filter assembly connected with the output of the converter, the electrical grid carrying an alternating current (AC) signal having one or more phases. The method includes determining a voltage of the AC signal and operating, after pre-charging a direct current (DC) link of the converter to a predetermined voltage, the converter using open-loop voltage control to produce an AC output signal that substantially matches the AC signal of the electrical grid. The open-loop voltage control is based on the determined voltage of the AC signal. The method further includes closing, after a predetermined amount of time of operating the converter using the open-loop voltage control, a switching device to thereby connect the output of the converter with the electrical grid.
    Type: Grant
    Filed: June 8, 2016
    Date of Patent: March 17, 2020
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Tusitha Abeyasekera, Duy Duc Doan, Gert Karmisholt Andersen, Lars Helle, Søren Andersen, Tune Pedersen, John Godsk Nielsen
  • Publication number: 20190369145
    Abstract: A method for operating a power generation system coupled to a power grid during a grid unbalance event, a method for determining an injection current to be supplied into a power grid by a power generation system, and a method for addressing an asymmetric grid fault in a power grid connected to a power generation system are provided. The methods may be carried out based on a reactive or an active power/current priority.
    Type: Application
    Filed: July 10, 2017
    Publication date: December 5, 2019
    Inventors: Amit Kumar GUPTA, John Godsk NIELSEN, Liang YANG
  • Publication number: 20190360470
    Abstract: A method and apparatus for estimating a characteristic of a wind turbine electrical signal comprises buffering a sequence of sample values of the wind turbine electrical signal and a sequence of sample times corresponding with the sequence of sample values. The time periods represented by the sample times are variable. A sub-sequence of the buffered sample values to integrate is determined, based at least in part on a sum of the time periods. The characteristic is estimated by integrating the sample values in the sub-sequence.
    Type: Application
    Filed: October 17, 2017
    Publication date: November 28, 2019
    Inventors: Torsten LUND, John Godsk NIELSEN
  • Patent number: 10483865
    Abstract: A wind turbine generator 1 supplies three-phase a.c. current of variable voltage and variable frequency to two pairs of rectifiers 4a, 4b and 4c, 4d which generate respective d.c. outputs connected to positive, negative and neutral d.c. conductors 6, 7, 8. The outputs from each pair of rectifiers are connected together, and the outputs from the two pairs are connected in series to create a high-voltage d.c. output. Inverters 10a, 10b, 10c, 10d then convert the d.c. power to a.c. at a fixed frequency and voltage suitable for connection to the mains grid. To reduce the effect of common-mode noise, a capacitor is connected between the 1 neutral conductor 7 and earth, and a respective filter circuit 30 is connected between each of the a.c. outputs of the inverters 10a, 10b, 10c, 10d and earth. To reduce the effect of voltage surges during lightning, a surge protection device is also connected between the neutral d.c. conductor 7 and earth.
    Type: Grant
    Filed: October 14, 2014
    Date of Patent: November 19, 2019
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Tusitha Abeyasekera, Duy Duc Doan, Lars Helle, Allan Holm Jørgensen, John Godsk Nielsen, Søren Andersen
  • Publication number: 20190338753
    Abstract: A power conversion system for a wind turbine generator, comprising a machine-side converter having an AC voltage input from a generator and a DC voltage output to a DC link, wherein the machine-side converter is a modular multi-level converter comprising one or more converter legs corresponding to a respective one or more electrical phases of the generator, each of the converter legs comprising a plurality of converter cells, the system further comprising: a converter control module which provides the machine-side converter with a gate signal, and an electrical frequency estimation module configured to estimate the mean electrical frequency of the generator; wherein the gate signal has at least one mean switching frequency corresponding to at least one electrical phase of the generator; wherein the converter control module is configured to modulate the mean switching frequency of the gate signal in dependence on the mean electrical frequency of the generator.
    Type: Application
    Filed: November 29, 2017
    Publication date: November 7, 2019
    Inventors: Ciprian BIRIS, Duy Duc DOAN, John Godsk NIELSEN
  • Patent number: 10359025
    Abstract: The present invention relates to a method for shutting down a wind power facility, said wind power facility comprising a power generator, a power converter comprising generator side and grid side converters being separated by an intermediate DC circuit, and power dissipation or power storage means being operatively connected to the intermediate DC circuit, the method comprising the steps of determining that the wind power facility needs to be shut down, and operating the generator side converter in accordance with a load time curve during shutdown of the wind power facility in order to avoid overloading of selected generator side converter components and the power dissipation or power storage means. Moreover, the present invention relates to a wind power facility for performing this method.
    Type: Grant
    Filed: July 2, 2015
    Date of Patent: July 23, 2019
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Duy Duc Doan, John Godsk Nielsen, Per Bisgaard
  • Publication number: 20190181787
    Abstract: A method of controlling a wind turbine generator (1) comprising an electrical generator (10) and a power converter (12), the power converter (12) comprising an electrical switch (14a, 14b) that is configured to process electrical power produced by the electrical generator (10), the method comprising: controlling an output from the electrical switch (14a, 14b) using a variable pulse-width modulated control signal, thereby to control characteristics of output power from the power converter (12); acquiring sample data (26) relating to an electronic signal within the wind turbine generator (1), wherein the sample data (26) is used for controlling the wind turbine generator (1); and dynamically adjusting a frequency (30) at which the sample data is acquired to synchronise data acquisition with a carrier frequency (24) of the control signal.
    Type: Application
    Filed: August 11, 2017
    Publication date: June 13, 2019
    Inventors: Gert Karmisholt ANDERSEN, Kent TANGE, Søren ANDERSEN, Duy Duc DOAN, Jens Peter BILTOFT, Lars HELLE, John Godsk NIELSEN
  • Patent number: 10298140
    Abstract: A method of controlling a full-scale converter system in which both the grid-side inverter unit and the generator-side inverter unit have a series-connection of parallel inverters and form a generator-side and grid-side voltage-center-point at a voltage level between the inverters connected in series. The voltage-center-points are electrically connected by a center-line conductor. Conversion operation with a de-rated maximum active power-output is performed in response to at least one of (i) the grid-side inverter and (ii) the generator-side inverter of the first converter-string being disabled, by disabling active power production of at least one of (i) the grid-side inverter and (ii) the generator-side inverter of the second converter-string, or correspondingly reducing active power production of the second converter-string, thereby preventing a compensation current along the center-line conductor.
    Type: Grant
    Filed: April 11, 2016
    Date of Patent: May 21, 2019
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: John Godsk Nielsen, Søren Andersen, Lars Helle, Duy Duc Doan
  • Patent number: 10250042
    Abstract: A wind turbine converter system with a rectifier and an inverter and a converter controller has at least first and second converter strings. The converter system is controlled by a master-converter controller and a slave-converter controller. The master-converter controller controls the first converter string and the slave-converter controller controls the second converter string. The master-converter controller receives commands from a superordinate wind turbine controller, provides the slave-converter controller with string-control commands on the basis of the superordinate control commands, and controls the conversion operation of the first converter string on the basis of the superordinate control command. The slave-converter controller receives the string-control commands from the master-converter controller and controls the conversion operation of the second converter string on the basis of the string-control commands received.
    Type: Grant
    Filed: October 19, 2015
    Date of Patent: April 2, 2019
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Tusitha Abeyasekera, Duy Duc Doan, Lars Helle, Søren Andersen, John Godsk Nielsen
  • Patent number: 10236810
    Abstract: A method of monitoring a split wind-turbine-converter system with at least one generator-side converter and at least one grid-side converter arranged at distant locations, and a DC-link in the form of an elongated conductor arrangement with at least one positive and at least one negative conductor. The impedance of the DC-link conductor arrangement is determined by means of DC-voltage sensors. The voltages between the positive and the negative conductors are determined at the generator-side converter and at the grid-side converter, and the difference between the voltages is determined. The impedance of the DC-link conductor arrangement is determined by putting the determined voltage difference in relation to the DC current flowing through the DC-link conductor arrangement. If the impedance exceeds a given impedance threshold a fault state is recognized.
    Type: Grant
    Filed: January 6, 2016
    Date of Patent: March 19, 2019
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Søren Andersen, John Godsk Nielsen, Duy Duc Doan
  • Patent number: 10236686
    Abstract: Techniques are described for operating a wind power facility in order to provide reactive power support to a power grid. The wind power facility may be a wind turbine or a wind power plant. An exemplary method includes increasing an amount of reactive power injected into the power grid, decreasing an amount of active power injected into the power grid by a certain amount, and dissipating and/or storing substantially the certain amount of active power.
    Type: Grant
    Filed: September 22, 2015
    Date of Patent: March 19, 2019
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: John Godsk Nielsen, Søren Andersen, Duy Duc Doan, Lars Helle
  • Patent number: 10236687
    Abstract: In a full-scale converter system both the grid-side inverter unit and the generator-side inverter unit have a series convection of parallel inverters and form a generator-side and grid-side voltage-center-point at a voltage level between those of the inverters connected in series. The voltage-center-points are electrically connected by a center-line conductor that has a cross-section between 30% and 70% of that of a positive or negative potential conductor. The converter system continues conversion operation in the event of a fault in an inverter of a first converter-string, with non-faulty inverters of the converter system, as the center-line conductor is dimensioned by said cross-section to carry a compensation current resulting from an unbalanced active power-output.
    Type: Grant
    Filed: April 11, 2016
    Date of Patent: March 19, 2019
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: John Godsk Nielsen, Søren Andersen, Lars Helle, Duy Duc Doan