Patents by Inventor Martin Ansbjerg Kjær

Martin Ansbjerg Kjær 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: 10012214
    Abstract: According to an aspect of the invention, a wind farm is provided. The wind farm includes a plurality of wind turbines and a wind farm controller. The controller is configured to detect a high wind condition from at least one wind turbine in the wind farm, reduce a parameter setpoint of at least one other wind turbine, and increase a cut-out wind speed threshold of the at least one other wind turbine.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: July 3, 2018
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Martin Ansbjerg Kjær, Ali Zaib, Erik Carl Lehnskov Miranda
  • Publication number: 20180171977
    Abstract: The present invention relates to a method for controlling a wind turbine, the wind turbine comprises a rotor connected to a generator, and a rotational speed controller configured to control a speed of the rotor in response to a generator speed reference, and a power controller to control an electric power production, the method comprises the step for receiving a boost command to request a power boost event, so to increase the electrical power production, and imposing a dead band with a dead zone value limit to the rotational speed controller, and wherein the dead band imposes a zero signal to be send to the rotational speed controller, when a speed error is within the dead zone value limit and wherein the dead band imposes an error signal to be send to the rotational speed controller, when a speed error is greater than the dead zone value limit, the error signal being a function of the speed error and the dead zone value limit.
    Type: Application
    Filed: June 22, 2016
    Publication date: June 21, 2018
    Inventors: Martin Ansbjerg KJÆR, Eik HERBSLEB, Jan Vestergaard KNUDSEN, Jesper Sandberg THOMSEN
  • Publication number: 20180171974
    Abstract: The invention relates to a control system for a wind turbine. The wind turbine comprises a power generator configured to generate power dependent on a power request. The control system comprises a ramp rate limiter configured to restrict a rate of change of the power request according to a rate of change limit and configured to determine the rate of change limit dependent on a power difference between the power request and an estimated available wind power.
    Type: Application
    Filed: June 9, 2016
    Publication date: June 21, 2018
    Inventors: Martin Ansbjerg KJÆR, Jesper Sandberg THOMSEN, Jacob Krogh KRISTOFFERSEN, Jacob Deleuran GRUNNET
  • Publication number: 20180156196
    Abstract: The invention relates to a control system for a wind turbine. The wind turbine comprises a power generator configured to generate power dependent on a power reference and a pitch system configured to adjust the pitch of a blade of the wind turbine dependent on a pitch request. The control system comprises a controller configured to determine the pitch request dependent on an adjustable gain. A gain scheduler comprised by the control system is configured to set the adjustable gain to an increased gain value if a rate of change of the power reference, e.g. an external power reference, exceeds a threshold.
    Type: Application
    Filed: June 9, 2016
    Publication date: June 7, 2018
    Inventors: Martin Ansbjerg KJÆR, Jesper Sandberg THOMSEN, Jacob Krogh KRISTOFFERSEN, Jacob Deleuran GRUNNET, Eik HERBSLEB
  • Publication number: 20180051675
    Abstract: Embodiments herein describe varying the rotor speed based on the current wind speed when operating in a low power mode. Generally, as the wind speed increases above the rated wind speed (i.e., the wind speed at which the turbine is capable of producing its rated or maximum output power), the rotor speed can be reduced thereby minimizing the risk that the turbine experiences smearing or torque reversals. In one embodiment, as the rotor speed decreases, the turbine maintains the ability to ramp to the rated power of the turbine only by pitching in the blades to an optimal blade pitch angle. Thus, upon receiving a request to cease operating in the low power mode, the turbine can increase the output power to the rated power without first increasing the rotor speed.
    Type: Application
    Filed: February 29, 2016
    Publication date: February 22, 2018
    Applicant: VESTAS WIND SYSTEMS A/S
    Inventors: Martin Ansbjerg KJÆR, Robert BOWYER, Robert GRØN-STEVENS, Jacob Deleuran GRUNNET, Carsten Nørlund THOMSEN, Jesper Sandberg THOMSEN
  • Patent number: 9856855
    Abstract: Embodiments of the invention generally relate to wind turbine generators, and more specifically to the deactivation of wind turbines in a wind turbine park. A wind park controller may be configured to retrieve data indicating fatigue experienced by each wind turbine of the wind turbine park, and deactivate those turbines determined to be the most fatigued, thereby increasing the lifetime of turbines in the wind turbine park.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: January 2, 2018
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Martin Ansbjerg Kjær, Jesper Sandberg Thomsen, Per Brath, Søren Dalsgaard
  • Publication number: 20170328342
    Abstract: The invention relates to a method for limiting structural loads in a wind turbine in situations where the power produced by the wind turbine is increased or decreased. The limitation of structural loads is achieved by restricting the power ramp rate, i.e. the rate of change of increases or decreases in produced power. The restriction is only invoked if a maximum change of the produced power or the corresponding internal power reference within a time window exceeds a given threshold.
    Type: Application
    Filed: November 30, 2015
    Publication date: November 16, 2017
    Inventors: Martin Ansbjerg KJÆR, Jesper Sandberg THOMSEN, Robert GRØN-STEVENS
  • Publication number: 20170241409
    Abstract: The invention relates to techniques for verifying a nacelle yaw position sensor installed on a wind turbine and for taking restorative action to control the nacelle yaw position. The invention relates to a method performing the comprising determining a first absolute wind direction signal associated with the first wind turbine; determining a second absolute wind signal direction signal associated with the plurality of other wind turbines; comparing the two wind direction signals; and issuing a nacelle yaw position sensor fault signal if the first signal is beyond a predetermined error range of the second signal. A benefit of the invention is that it enables the detection of an inaccurate nacelle yaw sensor without direct measurement or inspection.
    Type: Application
    Filed: September 3, 2015
    Publication date: August 24, 2017
    Inventor: Martin Ansbjerg Kjær
  • Publication number: 20170234299
    Abstract: The present invention relates to a method for controlling a wind power plant, the wind power plant comprising a plurality of wind turbine generators, each wind turbine generator comprising at least one power converter for providing active power and/or reactive power to an electrical grid, wherein the method is determining a required amount of reactive power provided by the plurality of wind turbine generators, and grouping the plurality of wind turbine generators into a first set of wind turbine generators and a second set of wind turbine generators based on a demand for reactive power; and supplying reactive power to the grid (20) from the first set of wind turbine generators and disconnecting the second set of wind turbine generators from the electrical grid (20) in response to a control demand, in order to minimize active power losses. The present invention also relates to a wind power plant arranged to perform the method.
    Type: Application
    Filed: May 19, 2015
    Publication date: August 17, 2017
    Inventors: Martin Ansbjerg Kjær, Henrik Møller Ravn, Jorge Martinez Garcia, Henrik Møller, Kouroush Nayebi
  • Publication number: 20170226988
    Abstract: The invention relates to a method for wind turbine generators for reducing electrical disturbances in the form of power variations which are caused by damping controllers arranged the compensate structural oscillations by inducing shaft torque variations. The shaft torque variations are generated by imposing corresponding variations in a generator set-point, e.g. a power or torque set-point. Variations in the generator set-point cause undesired variations in the power injected to the grid by one or more wind turbine generators. According to an embodiment of the invention the electrical disturbances may be reduced by limiting a damping controller's control action. The amount of limitation or restriction of the damping controller may be determined on basis on electrical disturbance information determined from power measured e.g. at a location on the grid.
    Type: Application
    Filed: October 8, 2015
    Publication date: August 10, 2017
    Applicant: VESTAS WIND SYSTEMS A/S
    Inventors: Martin Ansbjerg KJÆR, Fabio CAPONETTI, Ian COUCHMAN, Jesper Sandberg THOMSEN, Thomas KRÜGER, Jorge Martinez GARCIA
  • Patent number: 9709034
    Abstract: Methods, controllers and computer program products for controlling a wind turbine. Under de-rated operating conditions in which the power requested from a wind turbine is less than the available power, a controller adjusts blade pitch of the wind turbine to reduce the rotor power coefficient. The captured wind power is thereby reduced to be approximately equal to the requested electrical power, which is less than either the available power or the rated power of the wind turbine generator. This reduction in captured power provides the controller with an additional degree of freedom that allows the controller to increase the electrical power output of the wind turbine in response to wind fluctuations without damaging the wind turbine. By allowing increases in power under de-rated conditions, the controller may reduce the amount of pitching necessary to prevent the turbine from exceeding its rated power output level.
    Type: Grant
    Filed: August 14, 2012
    Date of Patent: July 18, 2017
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Martin Ansbjerg Kjær, Eik Herbsleb
  • Publication number: 20170152836
    Abstract: The present invention relates to control of the power output of wind turbine generator that operates in derated mode to generate a produced power output level lower than an available power level. A pitch system 48 sets the blade pitch of a rotor to a pitch value based on the received power reference signal 40. A power system 43 controls the produced power output power level of the wind turbine to the requested power output level. Moreover, the blade pitch of the rotor is further controlled by a pitch feedback control loop 47 that modifies the pitch value based on a difference between the produced power output level 46 and the requested power output level 40.
    Type: Application
    Filed: June 22, 2015
    Publication date: June 1, 2017
    Inventors: Martin Ansbjerg KJÆR, Jesper Sandberg THOMSEN
  • Patent number: 9644610
    Abstract: The disclosure is provides for warning a wind turbine generator (WTG) in a wind park of an extreme wind event. According to one embodiment, one or more front line WTGs of the wind park that detect extreme wind events and provide the warning are adaptively selected based on a measured wind direction. Thus, the selection of front line WTGs is adaptive to changing wind conditions. In another embodiment, a wind park includes a group of one or more WTGs of a first type located in an inner region of the wind park and a plurality of WTGs of a second type located in an outer region of the wind park that at least partially surrounds the inner region. The first type of WTG is structurally weaker and/or rated for higher performance than the second type of WTG.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: May 9, 2017
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Søren Dalsgaard, Jesper Sandberg Thomsen, Per Brath, Martin Ansbjerg Kjær
  • Publication number: 20170051723
    Abstract: The present invention relates to a method for operating a wind power plant in a wake situation, said wind power plant being connected to a power grid, the method comprising the steps of operating the wind power plant in a predetermined power mode of operation, terminating said predetermined power mode of operation, and increasing power generation of the wind power plant to a power level that exceeds an optimized wake power level of the wind power plant, and injecting the increased amount of power into the power grid as a power boost. Thus, the present invention is capable of generating a power boost to an associated power grid, said power boost exceeding the power level normally being available in a wake situation. The present invention further relates to a system for carrying out the method.
    Type: Application
    Filed: January 27, 2015
    Publication date: February 23, 2017
    Inventors: Martin Ansbjerg KJÆR, Lars Finn Sloth LARSEN
  • Patent number: 9556852
    Abstract: This invention relates to a method and a power plant controller arranged to carry out the method. The method is on an intelligent dispatching of the power production to wind turbines and optional compensation equipment of a wind power plant, as the power producing units of a wind power plant. The invention relates to a case where the requested produced power (both active and reactive) is less than the total capacity of the power plant, and the invention relates to utilizing this situation to dispatch set points to the wind turbines and the compensation equipment based on correction factors relating to the operating conditions of the wind park. This method may increase the wind turbines' life time, help in scheduling maintenance and expand the electrical operating range of the wind power plant.
    Type: Grant
    Filed: September 3, 2013
    Date of Patent: January 31, 2017
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Mehrdad Babazadeh, Saed Ehsani, Martin Ansbjerg Kjær, Henrik B. Møller
  • Publication number: 20170022972
    Abstract: Embodiments of the present disclosure generally relate to apparatus and methods for preventing power dips associated with power ramping in wind turbines. One embodiment of the present disclosure provides a method for stabilizing power output in a wind turbine, which includes tracking a rate of change in an external reference, such as an external power reference or external torque reference, computing a feed-forward pitch angle adjustment according to the rate of change in the external power reference, and sending the feed-forward pitch angle adjustment to the wind turbine to adjust a pitch angle of rotor blades simultaneously with adjusting power output according to the external reference.
    Type: Application
    Filed: November 27, 2014
    Publication date: January 26, 2017
    Inventors: Martin Ansbjerg KJÆR, Carsten Nørlund THOMSEN, Robert BOWYER, Jesper Sandberg THOMSEN
  • Publication number: 20160230741
    Abstract: The invention relates to a method of controlling a wind turbine, the wind turbine comprising wind turbine blades attached to a rotor hub and a control system for pitching the blades relative to the hub. The method comprises providing wake sectors assigned to different wind directions and providing a normal pitch schedule to control an output parameter of the wind turbine (e.g. power, rotational speed), comprising pitch reference values as a function of the wind speed and at least one of the parameters of thrust coefficient C, and axial induction factor a. Further, is provided a modified pitch schedule to control a modified output parameter of the wind turbine, comprising pitch reference values in dependence of the wind speed and at least one modified parameter of the thrust coefficient and/or the axial induction factor.
    Type: Application
    Filed: September 16, 2014
    Publication date: August 11, 2016
    Inventors: Per BRATH, Martin Ansbjerg KJÆR, Jesper Sandberg THOMSEN
  • Patent number: 9407186
    Abstract: This invention relates to a method and a power plant controller arranged to carry out the method. The method is on an intelligent dispatching of the power production to wind turbines and optional compensation equipment of a wind power plant, as the power producing units of a wind power plant. The invention relates to a case where the requested produced power is less than the total capacity of the power plant, and the invention relates to utilizing this situation to dispatch set points to the wind turbines and the compensation equipment in a flexible way. This flexibility may increase the wind turbines' life time, help in scheduling maintenance and expand the electrical operating range of the wind power plant. The determination of the set points on active and reactive power is a combined determination of both set points for each of the energy producing units of the wind power plant.
    Type: Grant
    Filed: September 5, 2013
    Date of Patent: August 2, 2016
    Assignee: Vestas Wind Systems, A/S
    Inventors: Mehrdad Babazadeh, Saed Ehsani, Martin Ansbjerg Kjær, Henrik B. Møller
  • Publication number: 20160208781
    Abstract: To efficiently nm a wind turbine in varying wind speeds, the wind turbine may be configured to switch between two different electrical configurations that offer different efficiencies depending on wind speed. For example, a star configuration may be preferred during low wind speeds while a delta configuration is preferred for high wind speeds. Before switching, the power output by the turbine's generator may be driven to zero. Doing so, however, removes load from the rotor blades which cause the rotor speed to increase. Instead, the rotor speed may be controlled such that the speed stays at or above the speed of the rotor immediately before the generator power is ramped down. Maintaining rotor speed at or slightly above the current speed while switching between electrical configurations may mitigate the torque change experienced by the turbine and reduce the likelihood of structural failure.
    Type: Application
    Filed: September 3, 2014
    Publication date: July 21, 2016
    Inventors: Martin Ansbjerg KJÆR, Peter KOLDKJÆR, Mølgaard Hviid KNUDSEN, Maryam SOLEIMANZADEH, Martin Møller SØRENSEN, Ali ZAIB, Arvishwa Kumar SINGH, Poul Brandt CHRISTENSEN, Michael Houlind JENSEN
  • Publication number: 20150322926
    Abstract: A method of controlling a wind turbine is described. The method involves forecasting the temperature evolution of a component of the wind turbine based upon the current operating parameters of the wind turbine and upon a required power output; predicting from the temperature forecast a future alarm event caused by the temperature of the component exceeding a first threshold level or falling below a second threshold level; and adjusting the operating parameters of the wind turbine to control the temperature evolution of the component thereby to avoid or delay the predicted alarm event.
    Type: Application
    Filed: January 25, 2013
    Publication date: November 12, 2015
    Applicant: VESTAS WIND SYSTEMS A/S
    Inventors: Fabio CAPONETTI, Martin Ansbjerg KJÆR