Patents by Inventor Georgios Papafotiou
Georgios Papafotiou 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: 9806595Abstract: A method for controlling an electrical converter comprises the acts of determining an error value based on a difference between an estimated output value and a reference output value, the estimated output value being based on measurements in the electrical converter; comparing the error value with an error band and in the case of the error value exceeds the error band, controlling the electrical converter by switching to a different control scheme. The converter is controlled with the modified pre-calculated switching by determining a pre-calculated switching sequence for the converter based on an actual state of the electrical converter, the switching sequence comprising a sequence of switching transitions of the converter; modifying the pre-calculated switching sequence by modifying transition times of switching transitions of the pre-calculated switching sequence, such that the error value is minimized; and applying at least a part of the modified switching sequence to the electrical converter.Type: GrantFiled: May 31, 2016Date of Patent: October 31, 2017Assignee: ABB Schweiz AGInventors: Tobias Geyer, Nikolaos Oikonomou, Georgios Papafotiou
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Publication number: 20160276919Abstract: A method for controlling an electrical converter comprises the acts of determining an error value based on a difference between an estimated output value and a reference output value, the estimated output value being based on measurements in the electrical converter; comparing the error value with an error band and in the case of the error value exceeds the error band, controlling the electrical converter by switching to a different control scheme. The converter is controlled with the modified pre-calculated switching by determining a pre-calculated switching sequence for the converter based on an actual state of the electrical converter, the switching sequence comprising a sequence of switching transitions of the converter; modifying the pre-calculated switching sequence by modifying transition times of switching transitions of the pre-calculated switching sequence, such that the error value is minimized; and applying at least a part of the modified switching sequence to the electrical converter.Type: ApplicationFiled: May 31, 2016Publication date: September 22, 2016Inventors: Tobias Geyer, Nikolaos Oikonomou, Georgios Papafotiou
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Patent number: 9450442Abstract: A modular converter is disclosed for a battery charging station, having at least two charging modules connected in parallel. Each of the charging modules can be configured for generating an output current I1, I2, I3 for charging a battery. Each charging module can have a local controller for controlling the charging module. Each local controller of a charging module can be configured for determining a global charging current I and for determining the output current I1, I2, I3 of the charging module.Type: GrantFiled: August 5, 2014Date of Patent: September 20, 2016Assignee: ABB Technology AGInventors: Daniel Aggeler, Francisco Canales, Georgios Papafotiou, River-TinHo Li, Oscar Apeldoorn
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Patent number: 9385585Abstract: In a method based on the MPDTC algorithm for controlling an inverter of an electrical system, the harmonics and resonances in the inverter can be damped by extracting frequency information from predicted data of the MPDTC algorithm and by damping harmonic distortion of the electrical system by reintroducing the extracted frequency information into a control loop of the inverter.Type: GrantFiled: January 15, 2014Date of Patent: July 5, 2016Assignee: ABB Research Ltd.Inventors: Tobias Geyer, Georgios Papafotiou, Silvia Mastellone
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Publication number: 20140340041Abstract: A modular converter is disclosed for a battery charging station, having at least two charging modules connected in parallel. Each of the charging modules can be configured for generating an output current I1, I2, I3 for charging a battery. Each charging module can have a local controller for controlling the charging module. Each local controller of a charging module can be configured for determining a global charging current I and for determining the output current I1, I2, I3 of the charging module.Type: ApplicationFiled: August 5, 2014Publication date: November 20, 2014Inventors: Daniel AGGELER, Francisco Canales, Georgios Papafotiou, RiverTinHo LI, Oscar Apeldoorn
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Patent number: 8866418Abstract: A system and method are disclosed for controlling electrical machines including a controller component which receives a first signal providing a measured parameter of the electrical machine and a second signal providing a reference parameter of the electrical machine, using the first and second signals being used to produce a first control signal. A first filter component receives the first signal from the electrical machine and uses the first signal to produce a second control signal. A second filter component receives a third signal which relates to a reference parameter of a second electrical machine and uses the third signal to produce a third control signal. The system and second control signals are used to produce a first output control signal for provision to the first electrical machine, and the first and third control signals are used produce a second output control signal for provision to the second electrical machine.Type: GrantFiled: February 11, 2013Date of Patent: October 21, 2014Assignee: ABB Research LtdInventors: Robert Keller, Mehmet Mercangoez, Georgios Papafotiou
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Patent number: 8766570Abstract: Exemplary embodiments are directed to a converter for an electrical system that is controlled in such that switching sequences for the converter, determined with respect to an optimization goal are modified such that by correcting a flux error resulting from assumptions on which the first optimization of the switching sequence is based.Type: GrantFiled: December 22, 2011Date of Patent: July 1, 2014Assignee: ABB Research LtdInventors: Tobias Geyer, Frederick Kieferndorf, Georgios Papafotiou, Nikolaos Oikonomou
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Patent number: 8737103Abstract: A method is provided for predicting pulse width modulated switching sequences for a multi-phase multi-level converter. With a first predicted switching sequence, due to multi-phase redundancies, equivalent switching sequences are determined. From the equivalent switching sequences, one switching sequence optimal with respect to a predefined optimization goal is selected. The selected switching sequence is used to switch the converter.Type: GrantFiled: July 25, 2012Date of Patent: May 27, 2014Assignee: ABB Research LtdInventors: Frederick Kieferndorf, Georgios Papafotiou, Nikolaos Oikonomou, Tobias Geyer
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Publication number: 20140126252Abstract: In a method based on the MPDTC algorithm for controlling an inverter of an electrical system, the harmonics and resonances in the inverter can be damped by extracting frequency information from predicted data of the MPDTC algorithm and by damping harmonic distortion of the electrical system by reintroducing the extracted frequency information into a control loop of the inverter.Type: ApplicationFiled: January 15, 2014Publication date: May 8, 2014Applicant: ABB RESEARCH LTDInventors: Tobias GEYER, Georgios PAPAFOTIOU, Silvia MASTELLONE
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Patent number: 8498133Abstract: The present disclosure is directed to a High Voltage Direct Current (HVDC) link with Voltage Source Converters VSC and interconnecting two power systems. A model-predictive control with a receding horizon policy is employed for controlling the outer loop of a two-loop or two-layer control scheme or setup for the HVDC link. The two-loop control scheme takes advantage of the difference in speed of the dynamics of the various system variables of the HVDC link and the interconnected power systems. Model-based prediction representative of the interconnected power systems' behavior enables comparison of the future effect of different control inputs applied within the control scheme, while taking into account any physical, safety and operating constraints. It is valid for a complete operating range, e.g., it avoids performance degradation when moving away from the nominal operating point of the control scheme for a HVDC link.Type: GrantFiled: July 27, 2011Date of Patent: July 30, 2013Assignee: ABB Research Ltd.Inventors: Georgios Papafotiou, Giovanni Beccuti, Lennart Harnefors
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Patent number: 8364459Abstract: A method is disclosed for estimating states of a power electronic system, the system having a converter circuit. An exemplary method includes varying a system state vector x(k) and a system state vector x(k+1) for each of sampling times k=?N+1 to k=0 in such a manner that a sum formed by an addition of a first vector norm obtained by subtracting a first system model function f(x(k), u(k)) from the system state vector x(k+1), and another vector norm obtained by subtracting a second system model function g(x(k), u(k)) from the output variable vector y(k), becomes minimal over the sampling times k=?N+1 to k=0. A desired system state vector x(k) at the sampling time k=0 can then be selected.Type: GrantFiled: September 11, 2009Date of Patent: January 29, 2013Assignee: ABB Research Ltd.Inventors: Sebastian Gaulocher, Georgios Papafotiou
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Publication number: 20130016549Abstract: A method is provided for predicting pulse width modulated switching sequences for a multi-phase multi-level converter. With a first predicted switching sequence, due to multi-phase redundancies, equivalent switching sequences are determined. From the equivalent switching sequences, one switching sequence optimal with respect to a predefined optimization goal is selected. The selected switching sequence is used to switch the converter.Type: ApplicationFiled: July 25, 2012Publication date: January 17, 2013Applicant: ABB RESEARCH LTD.Inventors: Frederick KIEFERNDORF, Georgios Papafotiou, Nikolaos Oikonomou, Tobias Geyer
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Patent number: 8222845Abstract: A method is disclosed for operating a rotating electric machine, wherein the rotating electric machine is connected by phases to a converter circuit having a direct-current circuit for switching at least two voltage levels, and the phases of the converter circuit are connected to the direct-current circuit according to a selected switch state combination of switch states of power semi-conductor switches of the converter circuit. Exemplary embodiments can reduce the switching frequency of the power semi-conductor switches, based on a prediction of further behavior of the overall system, and selection of an optimum switching state combination.Type: GrantFiled: June 17, 2010Date of Patent: July 17, 2012Assignee: ABB Research LtdInventors: Georgios Papafotiou, Franz Zurfluh
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Publication number: 20120161685Abstract: Exemplary embodiments are directed to a converter for an electrical system that is controlled in such that switching sequences for the converter, determined with respect to an optimization goal are modified such that by correcting a flux error resulting from assumptions on which the first optimization of the switching sequence is based.Type: ApplicationFiled: December 22, 2011Publication date: June 28, 2012Applicant: ABB RESEARCH LTDInventors: Tobias GEYER, Frederick KIEFERNDORF, Georgios PAPAFOTIOU, Nikolaos OIKONOMOU
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Publication number: 20120033461Abstract: The present disclosure is directed to a High Voltage Direct Current (HVDC) link with Voltage Source Converters VSC and interconnecting two power systems. A model-predictive control with a receding horizon policy is employed for controlling the outer loop of a two-loop or two-layer control scheme or setup for the HVDC link. The two-loop control scheme takes advantage of the difference in speed of the dynamics of the various system variables of the HVDC link and the interconnected power systems. Model-based prediction representative of the interconnected power systems' behavior enables comparison of the future effect of different control inputs applied within the control scheme, while taking into account any physical, safety and operating constraints. It is valid for a complete operating range, e.g., it avoids performance degradation when moving away from the nominal operating point of the control scheme for a HVDC link.Type: ApplicationFiled: July 27, 2011Publication date: February 9, 2012Applicant: ABB RESEARCH LTDInventors: Georgios Papafotiou, Giovanni Beccuti, Lennart Harnefors
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Patent number: 8004227Abstract: A method is specified for operating a rotating electrical machine, in which the rotating electrical machine is connected in terms of phase to a converter circuit, having a DC voltage circuit, for connecting at least two voltage levels, and the phases of the converter circuit are connected to the DC voltage circuit in accordance with a selected switching state combination of switching states for power semiconductor switches in the converter circuit. In order for operation of the rotating electrical machine to be possible in an event, over a number L of sampling times various values are determined, and a switching state combination is set as the selected switching state combination with which a sum of determined values is at its smallest.Type: GrantFiled: September 10, 2008Date of Patent: August 23, 2011Assignee: ABB Research LtdInventors: Jonas Kley, Georgios Papafotiou
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Publication number: 20100253269Abstract: A method is disclosed for operating a rotating electric machine, wherein the rotating electric machine is connected by phases to a converter circuit having a direct-current circuit for switching at least two voltage levels, and the phases of the converter circuit are connected to the direct-current circuit according to a selected switch state combination of switch states of power semi-conductor switches of the converter circuit. Exemplary embodiments can reduce the switching frequency of the power semi-conductor switches, based on a prediction of further behavior of the overall system, and selection of an optimum switching state combination.Type: ApplicationFiled: June 17, 2010Publication date: October 7, 2010Applicant: ABB Research LtdInventors: Georgios PAPAFOTIOU, Franz Zurfluh
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Publication number: 20100070247Abstract: A method is disclosed for estimating states of a power electronic system, the system having a converter circuit. An exemplary method includes varying a system state vector x(k) and a system state vector x(k+1) for each of sampling times k=?N+1 to k=0 in such a manner that a sum formed by an addition of a first vector norm obtained by subtracting a first system model function f(x(k), u(k)) from the system state vector x(k+1), and another vector norm obtained by subtracting a second system model function g(x(k), u(k)) from the output variable vector y(k), becomes minimal over the sampling times k=?N+1 to k=0. A desired system state vector x(k) at the sampling time k=0 can then be selected.Type: ApplicationFiled: September 11, 2009Publication date: March 18, 2010Applicant: ABB Research Ltd.Inventors: Sebastian Gaulocher, Georgios Papafotiou
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Publication number: 20090066276Abstract: A method is specified for operating a rotating electrical machine, in which the rotating electrical machine is connected in terms of phase to a converter circuit, having a DC voltage circuit, for connecting at least two voltage levels, and the phases of the converter circuit are connected to the DC voltage circuit in accordance with a selected switching state combination of switching states for power semiconductor switches in the converter circuit. In order for operation of the rotating electrical machine to be possible in an event, over a number L of sampling times various values are determined, and a switching state combination is set as the selected switching state combination with which a sum of determined values is at its smallest.Type: ApplicationFiled: September 10, 2008Publication date: March 12, 2009Applicant: ABB Research LtdInventors: Jonas Kley, Georgios Papafotiou
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Patent number: 7256561Abstract: A method is specified for operating a rotating electrical machine, in which the rotating electrical machine is connected in terms of phase to a converter circuit, having a DC voltage circuit, for connecting at least two voltage levels, and the phases of the converter circuit are connected to the DC voltage circuit in accordance with a selected switching state combination of switching states for power semiconductor switches in the converter circuit.Type: GrantFiled: December 7, 2005Date of Patent: August 14, 2007Assignees: ABB Research Ltd, Eidgenossische Technische Hochschule ZurichInventors: Tobias Geyer, Georgios Papafotiou, Manfred Morari