Patents by Inventor Lars Helle
Lars Helle 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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Patent number: 9722520Abstract: A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.Type: GrantFiled: August 28, 2009Date of Patent: August 1, 2017Assignee: VESTAS WIND SYSTEMS A/SInventors: Anshuman Tripathi, Cao Shu Yu, Allan Holm Jörgensen, Lars Helle
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Patent number: 9698593Abstract: A method is provided for reducing an impact of an unbalanced short circuit event that occurs in a polyphase permanent magnet generator of a wind turbine. According to the method, an unbalanced short circuit event is detected in the generator of the wind turbine, and, in response to detecting the unbalanced short circuit event, at least one phase of the generator is shorted at a switch-point between the generator and a converter of the wind turbine to create a balanced short circuit in the generator. By doing so, the torque response of the generator is altered to avoid high amplitude torque oscillations that would otherwise occur as a result of the unbalanced short circuit event.Type: GrantFiled: November 13, 2013Date of Patent: July 4, 2017Assignee: VESTAS WIND SYSTEMS A/SInventors: Victor Donescu, Lars Helle
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Patent number: 9476408Abstract: A method of controlling a wind turbine generator is provided, the wind turbine generator converting mechanical energy to electrical. The method comprises: determining an electromagnetic power reference representing the electromagnetic power generated by the wind turbine generator, wherein the electromagnetic power reference is determined based on a desired output of the wind turbine generator; controlling the electrical power generated by the wind turbine generator using a control signal, wherein the control signal is derived from the electromagnetic power reference and is modified in dependence on an inverse power function of the wind turbine generator by incorporating minimal copper loss constraint and stator voltage limiting constraint such that non-linearity of the wind turbine generator is compensated in the control loop and it operates at its maximum efficiency. One effect of the method is that classical linear control loop design can be employed in spite of the plant being a non-linear identity.Type: GrantFiled: March 12, 2014Date of Patent: October 25, 2016Assignee: VESTAS WIND SYSTEMS A/SInventors: Shu Yu Cao, Anshuman Tripathi, Kim B. Larsen, Gert Karmisholt Andersen, Lars Helle
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Patent number: 9306473Abstract: The invention relates to a variable rotor speed wind turbine transmitting AC electric power to a utility grid. The wind turbine includes at least one AC generator and at least two power electronic converter units. Further, it includes means for transforming at least one nominal output value of the generator to at least one different nominal input value of the at least two power electronic converter units. The invention also relates to a wind park and a method of transmitting AC electric power to a utility grid from a variable rotor speed wind turbine as well as a method of servicing or inspecting a variable rotor speed wind turbine.Type: GrantFiled: July 1, 2005Date of Patent: April 5, 2016Assignee: Vestas Wind Systems A/SInventors: Philip Richard Jacobsen Carne Kjaer, Lars Helle
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Patent number: 9252601Abstract: A method for controlling a power converter in a wind turbine generator, the power converter being connected to a power grid, the method comprising obtaining an alternating current (AC) line voltage at a connection point between the power converter and the power grid, obtaining a frequency of the power grid based on the AC line voltage, dynamically adapting the AC line voltage to the frequency of the power grid, generating a reference signal based on at least the frequency-adapted AC line voltage, and determining a converter control signal to be provided to the power converter based on the reference signal and the grid frequency in order to generate a power at the frequency of the power grid. Further, a wind turbine generator implementing the method is provided.Type: GrantFiled: September 20, 2010Date of Patent: February 2, 2016Assignee: Vestas Wind Systems A/SInventors: Yin Bo, Heng Deng, Kim B. Larsen, Lars Helle, Mogens Lau
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Publication number: 20150263526Abstract: The present invention relates to a connection system for connecting a power generator to a DC electrical power system, with a controllable voltage source unit functionally connected in series with the power generator to receive AC electrical power from the power generator, and to generate an AC electrical power output accordingly, and a rectifier arranged to receive AC electrical power output from said voltage source unit and to rectify the AC electrical power output to a DC electrical power to be provided to the DC electrical power system. The invention also relates to method for connecting a power generator to a DC electrical power system.Type: ApplicationFiled: September 3, 2012Publication date: September 17, 2015Applicant: VESTAS WIND SYSTEMS A/SInventors: Philip Carne Kjær, Dumitru-Mihai Valcan, Lars Helle
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Patent number: 9115634Abstract: The invention relates to a fail-safe rotary actuator (1) for a coolant circuit, in particular for a coolant circuit of an internal combustion engine (2) having a plurality of sub-circuits (3) and (4), includes a coolant delivery pump (5) for circulating the coolant within the coolant circuit, and having a rotary-slide housing (8) which has a plurality of housing pass-through openings (6) and (7) and in which at least one rotary slide (9) having at least one rotary slide pass-through opening (11) and (12) is rotatably supported, wherein the housing pass-through openings (6) and/or (7) are fluidly connected to at least one sub-circuit (3) and/or (4), and can be brought into at least partial coincidence with the rotary slide pass-through openings (11) and/or (12) by a rotary motion of the rotary slide (9), wherein a thermostat valve (13) opens a flow path running parallel to the rotary slide (9) from one of the sub-circuits (3) or (4) to the coolant delivery pump (5), when a temperature limit of the coolant is eType: GrantFiled: May 4, 2010Date of Patent: August 25, 2015Assignee: AUDI AGInventors: Steffen Triebe, Michael Staiger, Lars Helling, Dieter Lachner
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Patent number: 9065329Abstract: Embodiments provide a reconfigurable power converter module for a wind turbine facility adapted to supply electric power to an associated power supply grid. The reconfigurable power converter module includes a frequency converter operatively connected to filter means, wherein the frequency converter and the filter means are mutually reconfigurable so as to suppress internal and/or external resonances or harmonics.Type: GrantFiled: January 12, 2010Date of Patent: June 23, 2015Assignee: Vestas Wind Systems A/SInventors: Philip Carne Kjær, Lars Helle
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Patent number: 8994202Abstract: A method of operating a wind turbine is disclosed, the wind turbine comprising a power generator, a machine-side converter connected to the power generator, a line-side converter connected to a power grid through associated power components, and a DC-link connected between the machine-side converter and the line-side converter. The method includes monitoring the power grid for overvoltage events, and upon detecting an overvoltage event: (1) disabling active operation of the machine-side converter and the line-side converter, (2) enabling an AC load dump connected between the machine side converter and the power generator in order to dissipate power output from the power generator, (3) waiting for a waiting period, and (4) enabling active operation of the line-side converter and the machine converter when the overvoltage event ends within the waiting period.Type: GrantFiled: December 7, 2011Date of Patent: March 31, 2015Assignee: Vestas Wind Systems A/SInventors: Amit Kumar Gupta, Anshuman Tripathi, Ove Styhm, Lars Helle, Yugarajan Karuppanan, Gil Lampong Opina, Jr.
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Patent number: 8970057Abstract: According to an embodiment, a method of operating a wind turbine comprising a DC-to-AC voltage converter is provided, the wind turbine being connectable to a grid via the DC-to-AC voltage converter, the method comprising: determining a line voltage of a power line connecting the DC-to-AC voltage converter to the grid; if the determined line voltage exceeds a predefined voltage threshold value, injecting reactive current into the power line, wherein the amount of reactive current injected is chosen such that an output voltage of the DC-to-AC voltage converter is kept within a predetermined voltage range.Type: GrantFiled: March 23, 2011Date of Patent: March 3, 2015Assignee: Vestas Wind Systems A/SInventors: Bing Li, Anshuman Tripathi, Shu Yu Cao, Amit Kumar Gupta, Eng Kian Kenneth Sng, Lars Helle
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Patent number: 8933584Abstract: A method for providing dynamic load sharing between a first and a second three phase system is disclosed, wherein the first and second three phase system are connected to a first and second three phase interleaved winding in a generator. The method comprises determining a first q-axis control signal for the first three phase system and a second q-axis control signal for the second three phase system based on a torque and/or power demand for the generator, determining a first d-axis control signal for the first three phase system and a second d-axis control signal for the second three phase system based on a coupling effect between the first and second three phase systems, and adjusting the q-axis control signals and d-axis control signals by including at least one feed forward compensation signal, wherein said at least one feed forward compensation signal is based on a coupling effect between the first and second three phase systems.Type: GrantFiled: September 25, 2009Date of Patent: January 13, 2015Assignee: Vestas Wind Systems A/SInventors: Lars Helle, Kim B. Larsen, Anshuman Tripathi, Shu Yu Cao
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Patent number: 8884566Abstract: A position sensorless control methodology for electrical machines using high frequency flux vector signal injection in the estimated rotor flux rotational reference frame is provided. In one aspect, the estimated position error function is derived directly from the stator flux equation without any simplification. The method is applicable for electrical generator motoring mode operation from standstill and power generation mode operation.Type: GrantFiled: July 27, 2012Date of Patent: November 11, 2014Assignee: Vestas Wind Systems A/SInventors: Shu Yu Cao, Bing Li, Anshuman Tripathi, Lars Helle
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Patent number: 8759994Abstract: A method of controlling a wind turbine generator is provided, the wind turbine generator converting mechanical energy to electrical. The method comprises: determining an electromagnetic power reference representing the electromagnetic power generated by the wind turbine generator, wherein the electromagnetic power reference is determined based on a desired output of the wind turbine generator; controlling the electrical power generated by the wind turbine generator using a control signal, wherein the control signal is derived from the electromagnetic power reference and is modified in dependence on an inverse power function of the wind turbine generator by incorporating minimal copper loss constraint and stator voltage limiting constraint such that non-linearity of the wind turbine generator plant is compensated in the control loop and it operates at its maximum efficiency. One effect of the method is that classical linear control loop design can be employed in spite of the plant being a non-linear identity.Type: GrantFiled: September 14, 2010Date of Patent: June 24, 2014Assignee: Vestas Wind Systems A/SInventors: Shu Yu Cao, Anshuman Tripathi, Kim B. Larsen, Gert Karmisholt Andersen, Lars Helle
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Patent number: 8742609Abstract: A method for operating a wind turbine facility during for example a grid fault, the wind turbine facility comprising a power dissipation/storage being adapted to dissipate or store electrical energy exceeding an amount to be delivered to an associated power supply grid during the grid fault. The method includes operating the wind turbine facility in accordance with an allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage of the wind turbine facility by ensuring that a total amount of electrical energy generated by the wind turbine facility does not exceed a sum of the allowed amount and the amount to be delivered to the power supply grid.Type: GrantFiled: June 30, 2010Date of Patent: June 3, 2014Assignee: Vestas Wind Systems A/SInventors: Lars Helle, Thomas Hjort, Thomas Lundgren Andersen
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Patent number: 8686695Abstract: A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.Type: GrantFiled: October 27, 2009Date of Patent: April 1, 2014Assignee: Vestas Wind Systems A/SInventors: Anshuman Tripathi, Lars Helle, Allan Holm Jörgensen, Cao Shu Yu, Saurabh Gupta
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Patent number: 8686719Abstract: A method for estimating the magnetization level of one or more permanent magnets established in one or more permanent magnet rotors of a wind turbine generator includes the steps of: establishing one or more magnetization sensors at the stator of the generator, connecting the one or more magnetization sensors to a measuring mechanism, processing measured data in the measuring mechanism, and establishing values of magnetization. Furthermore the invention also relates to a wind turbine.Type: GrantFiled: April 26, 2011Date of Patent: April 1, 2014Inventors: Lars Helle, Morten Lindholm, Flemming Buus Bendixen
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Publication number: 20140001759Abstract: According to an embodiment of the present invention, a method of operating a wind turbine including a power generator, a generator/machine side converter connected to the power generator, a grid/line side converter connected to a power grid through power components, and a DC-link connected between the machine side converter and the line side converter, comprises: Monitoring the power grid for overvoltage events; if an overvoltage event is detected disabling active operation of the machine side converter and of the line side converter, enabling an AC-load dump connected between the machine side converter and the power generator in order to dissipate active power output by the power generator into the AC-load dump, waiting for a waiting period, and enabling active operation of the line side converter and the machine side converter if the overvoltage ends within the waiting period.Type: ApplicationFiled: December 7, 2011Publication date: January 2, 2014Applicant: VESTAS WIND SYSTEMS A/SInventors: Amit Kumar Gupta, Anshuman Tripathi, Ove Styhm, Lars Helle, Yugarajan Karuppanan, Gil Lampong Opina
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Publication number: 20130187384Abstract: According to an embodiment, a method of operating a wind turbine comprising a DC-to-AC voltage converter is provided, the wind turbine being connectable to a grid via the DC-to-AC voltage converter, the method comprising: determining a line voltage of a power line connecting the DC-to-AC voltage converter to the grid; if the determined line voltage exceeds a predefined voltage threshold value, injecting reactive current into the power line, wherein the amount of reactive current injected is chosen such that an output voltage of the DC-to-AC voltage converter is kept within a predetermined voltage range.Type: ApplicationFiled: March 23, 2011Publication date: July 25, 2013Inventors: Bing Li, Anshuman Tripathi, Shu Yu Cao, Amit Kumar Gupta, Eng Kian Kenneth Sng, Lars Helle
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Patent number: 8468681Abstract: A method for establishing a wind turbine generator with one or more Permanent Magnet (PM) rotors. The method comprises the steps of: manufacturing a generator prepared for taking one or more PM rotors, manufacturing one or more rotors comprising a plurality of holding means prepared for retaining PM material, mounting substantially non-magnetized PM material prepared for magnetization in said holding means before or after said one or more rotors are mounted in said generator, connecting a magnetization system for magnetizing said PM material in the generator, and magnetizing said PM material with said magnetization system. The invention also relates to a wind turbine nacelle, a wind turbine comprising said wind turbine nacelle and use of a wind turbine.Type: GrantFiled: September 23, 2009Date of Patent: June 25, 2013Assignee: Vestas Wind Systems A/SInventors: Lars Helle, Philip Richard Jacobsen Carne Kjaer, Morten Lindholm, Flemming Buus Bendixen, Ion Boldea
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Patent number: 8466661Abstract: The present invention relates to a wind turbine facility comprising a power generator operationally connected to an AC/AC converter adapted to receive variable frequency AC-power from the power generator, and adapted to generate substantially fixed frequency AC-power. The wind turbine facility further comprises a harmonic filter system, and a grid transformer comprising a primary winding being operationally connected to the AC/AC converter, and a secondary winding adapted to be operationally connected to an associated, substantially fixed frequency AC-power supply grid. The grid transformer further comprises a tertiary winding being operationally connected to the harmonic filter in order to suppress unwanted harmonics, such as selected harmonics generated by the AC/AC converter. The turn ratio between the primary and tertiary windings is selected in such a manner that a voltage of the tertiary winding is lower than a nominal voltage level of the associated AC-power supply grid voltage.Type: GrantFiled: September 14, 2009Date of Patent: June 18, 2013Assignee: Vestas Wind Systems A/SInventors: Lars Helle, Philip Carne Kjaer, John Nieuwenhuizen, Morten Lindholm