Patents by Inventor Leif Svinth CHRISTENSEN
Leif Svinth CHRISTENSEN 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: 11855458Abstract: A method for controlling a renewable energy generator, the renewable energy generator being connected to a Point of Interconnection of an external power grid by a connecting network, wherein the connecting network has an associated impedance level. The method comprising: monitoring at least one parameter of the connecting network and the voltage level at the Point of Interconnection; generating, during normal operating conditions, at least one current injection profile based upon the at least one measured parameter and a predetermined injection profile; and operating the renewable energy generator, during a grid fault, to output current according to the at least one current injection profile, so as to achieve a current set point at the Point of Interconnection.Type: GrantFiled: November 20, 2018Date of Patent: December 26, 2023Assignee: VESTAS WIND SYSTEMS A/SInventors: Leif Svinth Christensen, Brian W. Andersen, Federico Rueda Londono
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Publication number: 20230350663Abstract: A method for validating a version of wind turbine control software is disclosed. A first version of the wind turbine control software and a second version of the wind turbine control software are running simultaneously on a controller, by applying identical control input to the first version and to the second version, and the first and the second versions of the wind turbine control software each generating control output, based on the received control input. The wind turbine or wind farm is controlled based on the control output generated by the first version of the wind turbine control software. The control output generated by the first version and by the second version of the wind turbine control software are compared, during a time interval, and the second version of the wind turbine control software is validated, based on the comparison.Type: ApplicationFiled: May 1, 2023Publication date: November 2, 2023Inventors: Jacob Barsøe KJÆRGAARD, Anders REIMER, Leif Svinth CHRISTENSEN
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Patent number: 11233400Abstract: Aspects of the present invention relate to a method for controlling an amount of reactive current provided from a wind turbine generator to a power grid during an abnormal power grid event, said wind turbine generator comprising a doubly-fed induction generator having a rotor and a stator, and a power converter coupling the rotor to the power grid, the power converter comprising a grid-side inverter, wherein the method comprises the step of balancing the reactive current provided to the power grid between a reactive stator current and a reactive grid-side inverter current, wherein the reactive grid-side inverter current is controlled in accordance with a reactive current capacity of a grid breaker receiving the reactive current provided by the grid-side inverter. Aspects of the present invention also relate to a wind turbine generator being capable of performing the method.Type: GrantFiled: May 16, 2017Date of Patent: January 25, 2022Assignee: VESTAS WIND SYSTEMS A/SInventors: Ciprian Biris, Uffe C. Merrild, Leif Svinth Christensen, Gert Karmisholt Andersen
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Patent number: 11171487Abstract: A control system for controlling the power output of a plurality of renewable energy generators, a power network connecting those generators to a Point of Interconnection (PoI) with which the power network is connected to an external power grid, and measurement means configured to measure electrical parameters associated with the Point of Interconnection, wherein the control system is configured to: operate each renewable energy generator to achieve a respective current level at a terminal of the generator that is equal to a current set point; implement, during a grid fault event, a feedback control routine in which the control system: determines a measured value of an electrical parameter at the Point of Interconnection, determines a target value of the electrical parameter; and modifies the current set point based on the measured value and the target value of the electrical parameter.Type: GrantFiled: September 3, 2018Date of Patent: November 9, 2021Assignee: VESTAS WIND SYSTEMS A/SInventors: Manoj Gupta, Janakiraman Sivasankaran, Leif Svinth Christensen
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Patent number: 10855082Abstract: Aspects of the present invention relate to a method for controlling an amount of power to be delivered from a wind turbine generator to a power grid during an abnormal power grid event, the method comprising the steps of detecting an abnormal power grid event; controlling an active current delivered to the power grid in response to a measured or determined total active current; and controlling a reactive current delivered to the power grid in response to a measured or determined total reactive current. Aspects of the present invention further relate to a computer program product for carrying out the method as well as a wind turbine generator being capable of carrying out embodiments of the invention.Type: GrantFiled: May 16, 2017Date of Patent: December 1, 2020Assignee: VESTAS WIND SYSTEMS A/SInventors: Ciprian Biris, Gert Karmisholt Andersen, Uffe C. Merrild, Leif Svinth Christensen
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Publication number: 20200350765Abstract: A method for controlling a renewable energy generator, the renewable energy generator being connected to a Point of Interconnection of an external power grid by a connecting network, wherein the connecting network has an associated impedance level. The method comprising: monitoring at least one parameter of the connecting network and the voltage level at the Point of Interconnection; generating, during normal operating conditions, at least one current injection profile based upon the at least one measured parameter and a predetermined injection profile; and operating the renewable energy generator, during a grid fault, to output current according to the at least one current injection profile, so as to achieve a current set point at the Point of Interconnection.Type: ApplicationFiled: November 20, 2018Publication date: November 5, 2020Inventors: Leif Svinth CHRISTENSEN, Brian W. ANDERSEN, Federico Rueda LONDONO
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Publication number: 20200287386Abstract: A control system for controlling the power output of a plurality of renewable energy generators, a power network connecting those generators to a Point of Interconnection (PoI) with which the power network is connected to an external power grid, and measurement means configured to measure electrical parameters associated with the Point of Interconnection, wherein the control system is configured to: operate each renewable energy generator to achieve a respective current level at a terminal of the generator that is equal to a current set point; implement, during a grid fault event, a feedback control routine in which the control system: determines a measured value of an electrical parameter at the Point of Interconnection, determines a target value of the electrical parameter; and modifies the current set point based on the measured value and the target value of the electrical parameter.Type: ApplicationFiled: September 3, 2018Publication date: September 10, 2020Inventors: Manoj GUPTA, Janakiraman SIVASANKARAN, Leif Svinth CHRISTENSEN
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Publication number: 20200274360Abstract: Aspects of the present invention relate to a method for controlling an amount of reactive current provided from a wind turbine generator to a power grid during an abnormal power grid event, said wind turbine generator comprising a doubly-fed induction generator having a rotor and a stator, and a power converter coupling the rotor to the power grid, the power converter comprising a grid-side inverter, wherein the method comprises the step of balancing the reactive current provided to the power grid between a reactive stator current and a reactive grid-side inverter current, wherein the reactive grid-side inverter current is controlled in accordance with a reactive current capacity of a grid breaker receiving the reactive current provided by the grid-side inverter. Aspects of the present invention also relate to a wind turbine generator being capable of performing the method.Type: ApplicationFiled: May 16, 2017Publication date: August 27, 2020Inventors: Ciprian BIRIS, Uffe C. MERRILD, Leif Svinth CHRISTENSEN, Gert Karmisholt ANDERSEN
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Patent number: 10704534Abstract: Controlling a wind turbine during a grid fault where the grid voltage drops below a nominal grid voltage. After detection of a grid fault, the total current limit for the power converter output is increased to a total maximum overload current limit. Depending on whether active or reactive current generation is prioritized, an active or reactive current reference is determined. The active current reference is determined in a way so that a reduction in active power production due to the grid voltage drop is minimized and based on the condition that the vector-sum of the active output current and the reactive output current is limited according to the total maximum overload current limit, and a maximum period of time is determined in which the power converter can be controlled based on the active/reactive current references. Afterwards the power converter is controlled based on the active and reactive current references.Type: GrantFiled: September 27, 2018Date of Patent: July 7, 2020Assignee: VESTAS WIND SYSTEMS A/SInventors: Ciprian Biris, Uffe C. Merrild, Leif Svinth Christensen, Martin Ansbjerg Kjær
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Patent number: 10570885Abstract: Controlling a wind turbine during a grid fault where the grid voltage drops below a nominal grid voltage. After detection of a grid fault, the total current limit for the power converter output is increased to a total maximum overload current limit. Depending on whether active or reactive current generation is prioritized, an active or reactive current reference is determined. The active current reference is determined in a way so that a reduction in active power production due to the grid voltage drop is minimized and based on the condition that the vector-sum of the active output current and the reactive output current is limited according to the total maximum overload current limit, and a maximum period of time is determined in which the power converter can be controlled based on the active/reactive current references. Afterwards the power converter is controlled based on the active and reactive current references.Type: GrantFiled: September 27, 2018Date of Patent: February 25, 2020Assignee: VESTAS WIND SYSTEMS A/SInventors: Ciprian Biris, Uffe C. Merrild, Leif Svinth Christensen, Martin Ansbjerg Kjær
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Publication number: 20190148949Abstract: Aspects of the present invention relate to a method for controlling an amount of power to be delivered from a wind turbine generator to a power grid during an abnormal power grid event, the method comprising the steps of detecting an abnormal power grid event; controlling an active current delivered to the power grid in response to a measured or determined total active current; and controlling a reactive current delivered to the power grid in response to a measured or determined total reactive current. Aspects of the present invention further relate to a computer program product for carrying out the method as well as a wind turbine generator being capable of carrying out embodiments of the invention.Type: ApplicationFiled: May 16, 2017Publication date: May 16, 2019Inventors: Ciprian BIRIS, Gert Karmisholt ANDERSEN, Uffe C. MERRILD, Leif Svinth CHRISTENSEN
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Publication number: 20190093634Abstract: Controlling a wind turbine during a grid fault where the grid voltage drops below a nominal grid voltage. After detection of a grid fault, the total current limit for the power converter output is increased to a total maximum overload current limit. Depending on whether active or reactive current generation is prioritized, an active or reactive current reference is determined. The active current reference is determined in a way so that a reduction in active power production due to the grid voltage drop is minimized and based on the condition that the vector-sum of the active output current and the reactive output current is limited according to the total maximum overload current limit, and a maximum period of time is determined in which the power converter can be controlled based on the active/reactive current references. Afterwards the power converter is controlled based on the active and reactive current references.Type: ApplicationFiled: September 27, 2018Publication date: March 28, 2019Inventors: Ciprian BIRIS, Uffe C. MERRILD, Leif Svinth CHRISTENSEN, Martin Ansbjerg KJÆR
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Patent number: 10199970Abstract: The present invention relates to a method for operating a doubly fed induction generator wind power facility during an OVRT event, said the wind turbine facility being adapted to inject active and/or reactive current into an associated grid, the method comprising the steps of determining the occurrence of an over voltage grid event, and maintaining a grid-side inverter of the doubly fed induction generator wind power facility fully operable during the over voltage ride though event so as to maintain a controllable active and/or reactive current capability during the over voltage grid event.Type: GrantFiled: March 8, 2016Date of Patent: February 5, 2019Assignee: VESTAS WIND SYSTEMS A/SInventors: Gert Karmisholt Andersen, Leif Svinth Christensen, Ciprian Biris, Uffe C. Merrild
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Publication number: 20180091077Abstract: The present invention relates to a method for operating a doubly fed induction generator wind power facility during an OVRT event, said the wind turbine facility being adapted to inject active and/or reactive current into an associated grid, the method comprising the steps of determining the occurrence of an over voltage grid event, and maintaining a grid-side inverter of the doubly fed induction generator wind power facility fully operable during the over voltage ride though event so as to maintain a controllable active and/or reactive current capability during the over voltage grid event,?Type: ApplicationFiled: March 6, 2016Publication date: March 29, 2018Applicant: VESTAS WIND SYSTEMS A/SInventors: Gert Karmisholt ANDERSEN, Leif Svinth CHRISTENSEN, Ciprian BIRIS, Uffe C. MERRILD