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).
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Publication number: 20190360470Abstract: 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: ApplicationFiled: October 17, 2017Publication date: November 28, 2019Inventors: Torsten LUND, John Godsk NIELSEN
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Patent number: 10483865Abstract: 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: GrantFiled: October 14, 2014Date of Patent: November 19, 2019Assignee: VESTAS WIND SYSTEMS A/SInventors: Tusitha Abeyasekera, Duy Duc Doan, Lars Helle, Allan Holm Jørgensen, John Godsk Nielsen, Søren Andersen
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Publication number: 20190338753Abstract: 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: ApplicationFiled: November 29, 2017Publication date: November 7, 2019Inventors: Ciprian BIRIS, Duy Duc DOAN, John Godsk NIELSEN
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Patent number: 10359025Abstract: 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: GrantFiled: July 2, 2015Date of Patent: July 23, 2019Assignee: VESTAS WIND SYSTEMS A/SInventors: Duy Duc Doan, John Godsk Nielsen, Per Bisgaard
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Publication number: 20190181787Abstract: 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: ApplicationFiled: August 11, 2017Publication date: June 13, 2019Inventors: Gert Karmisholt ANDERSEN, Kent TANGE, Søren ANDERSEN, Duy Duc DOAN, Jens Peter BILTOFT, Lars HELLE, John Godsk NIELSEN
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Patent number: 10298140Abstract: 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: GrantFiled: April 11, 2016Date of Patent: May 21, 2019Assignee: VESTAS WIND SYSTEMS A/SInventors: John Godsk Nielsen, Søren Andersen, Lars Helle, Duy Duc Doan
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Patent number: 10250042Abstract: 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: GrantFiled: October 19, 2015Date of Patent: April 2, 2019Assignee: VESTAS WIND SYSTEMS A/SInventors: Tusitha Abeyasekera, Duy Duc Doan, Lars Helle, Søren Andersen, John Godsk Nielsen
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Patent number: 10236687Abstract: 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: GrantFiled: April 11, 2016Date of Patent: March 19, 2019Assignee: VESTAS WIND SYSTEMS A/SInventors: John Godsk Nielsen, Søren Andersen, Lars Helle, Duy Duc Doan
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Patent number: 10236686Abstract: 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: GrantFiled: September 22, 2015Date of Patent: March 19, 2019Assignee: VESTAS WIND SYSTEMS A/SInventors: John Godsk Nielsen, Søren Andersen, Duy Duc Doan, Lars Helle
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Patent number: 10236810Abstract: 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: GrantFiled: January 6, 2016Date of Patent: March 19, 2019Assignee: VESTAS WIND SYSTEMS A/SInventors: Søren Andersen, John Godsk Nielsen, Duy Duc Doan
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Publication number: 20180335017Abstract: A method for controlling a wind turbine system including an electrical generator, a power converter system, a DC-link, and at least a grid-side breaker arrangement controllable between open and closed states, wherein the method comprises monitoring for the presence of a shutdown event and, in response to identifying the presence of a shutdown event, controlling the wind turbine into a production-ready state, comprising: i) controlling the grid-side breaker arrangement in the closed state; ii) disabling one or more drive signals to the power converter system; and iii) controlling the DC-link of the power converter system in a charged state. Advantageously, this approach reduces the frequency of use of the grid-side breaker arrangement which extends serviceable life considerably, and also allows the wind turbine system to be transitioned rapidly between an operating state and a production-ready state.Type: ApplicationFiled: December 1, 2016Publication date: November 22, 2018Inventors: John Godsk NIELSEN, Duy Duc DOAN, Søren ANDERSEN, Gert Karmisholt ANDERSEN
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Patent number: 10135354Abstract: A method of setting a reference DC-link voltage of a wind-turbine converter system is provided. At least at least one DC voltage demand from at least one generator-side inverter and at least one DC voltage demand are received from at least one grid-side inverter. A generator-side DC voltage demand value on the basis of the at least one DC voltage demand received from the at least one generator-side inverter. Also a grid-side DC voltage demand value is determined on the basis of the at least one DC voltage demand received from the at least one grid-side inverter. The highest DC voltage demand value out of the generator-side and grid-side DC voltage demand values is chosen. This chosen value corresponds to the set reference DC-link voltage.Type: GrantFiled: December 8, 2015Date of Patent: November 20, 2018Assignee: VESTAS WIND SYSTEMS A/SInventors: Søren Andersen, Gert Karmisholt Andersen, Duy Duc Doan, John Godsk Nielsen
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Publication number: 20180123470Abstract: 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: ApplicationFiled: April 11, 2016Publication date: May 3, 2018Inventors: John Godsk NIELSEN, Søren ANDERSEN, Lars HELLE, Duy Duc DOAN
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Publication number: 20180115163Abstract: 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: ApplicationFiled: April 11, 2016Publication date: April 26, 2018Inventors: John Godsk NIELSEN, Søren ANDERSEN, Lars HELLE, Duy Duc DOAN
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Publication number: 20170373625Abstract: 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: ApplicationFiled: January 6, 2016Publication date: December 28, 2017Inventors: Søren ANDERSEN, John Godsk NIELSEN, Duy Duc DOAN
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Publication number: 20170358997Abstract: A method of setting a reference DC-link voltage of a wind-turbine converter system is provided. At least at least one DC voltage demand from at least one generator-side inverter and at least one DC voltage demand are received from at least one grid-side inverter. A generator-side DC voltage demand value on the basis of the at least one DC voltage demand received from the at least one generator-side inverter. Also a grid-side DC voltage demand value is determined on the basis of the at least one DC voltage demand received from the at least one grid-side inverter. The highest DC voltage demand value out of the generator-side and grid-side DC voltage demand values is chosen. This chosen value corresponds to the set reference DC-link voltage.Type: ApplicationFiled: December 8, 2015Publication date: December 14, 2017Inventors: Søren ANDERSEN, Gert Karmisholt ANDERSEN, Duy Duc DOAN, John Godsk NIELSEN
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Publication number: 20170331295Abstract: 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: ApplicationFiled: October 19, 2015Publication date: November 16, 2017Inventors: Tusitha ABEYASEKERA, Duy Duc DOAN, Lars HELLE, Søren ANDERSEN, John Godsk NIELSEN
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Publication number: 20170244251Abstract: The present invention relates to a method for operating a wind power facility in order to provide reactive power support to a power grid, the method comprising the step of 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 essentially said certain amount of active power in power dissipation and/or power storage means. The wind power facility may comprise a wind turbine or a wind power plant.Type: ApplicationFiled: September 22, 2015Publication date: August 24, 2017Inventors: John Godsk NIELSEN, Søren ANDERSEN, Duy Duc DOAN, Lars HELLE
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Patent number: 9722416Abstract: According to an embodiment, a power generation system is provided comprising a power generator; a plurality of converter modules, each converter module having a DC link, wherein the DC link of each converter module is connected to the DC links of the other converter modules of the plurality of converter modules via a fuse associated with the converter module; and a controller configured to, if it is detected that there is a fault in one of the converter modules, disconnect the converter module in which there is a fault from the power generator and connect two or more other converters module of the plurality of converter modules to the power generator and to control the power generation system to supply power to the DC links of the two or more other converter modules such that power is supplied to the converter module in which there is a fault via the fuse associated with the converter module such that the fuse associated with the converter module melts.Type: GrantFiled: July 11, 2012Date of Patent: August 1, 2017Assignee: VESTAS WIND SYSTEMS A/SInventors: John Godsk Nielsen, Ove Styhm
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Publication number: 20170211546Abstract: 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: ApplicationFiled: July 2, 2015Publication date: July 27, 2017Inventors: Duy Duc DOAN, John Godsk NIELSEN, Per BISGAARD