Patents by Inventor Ali Khajehoddin
Ali Khajehoddin 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: 11714934Abstract: A method of modeling an equivalent wind turbine generator (WTG) system for a wind farm having a plurality of WTG units includes determining an impact factor of each WTG unit of the plurality of WTG units, determining an equivalent single WTG unit model parameters of the wind farm based on the impact factor of each WTG unit, and determining an effective wind speed of the wind farm to use as the equivalent WTG input wind speed. The method produces a model of static and/or dynamic wind farm behavior. Additionally, a software configured to execute a method of modeling an equivalent wind turbine generator (WTG) system for a wind farm having a plurality of WTG units.Type: GrantFiled: June 18, 2020Date of Patent: August 1, 2023Assignee: The Governors of the University of AlbertaInventors: Sayed Ali Khajehoddin, Ahmadreza Tabesh, Navid Shabanikia
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Patent number: 10971937Abstract: A method for controlling an inverter, and in particular a double stage inverter, for implementing a model of a synchronous generator is provided including implementing a rotor inertia using an intermediate dc-link capacitor without duplicating the emulated inertia in the controller, simulating the rotor speed based on a measured voltage of the dc-link capacitor, while allowing the voltage to change in a defined range, and mapping the changing voltage of the dc-link capacitor into the inverter as an internal frequency. A system for connecting a power generator to a power grid is also provided including a control device for an inverter, the control device implementing a model of a synchronous generator. The control device including a computer processor in electrical communication with a storage device with instructions stored thereon, that when executed on the computer processor, perform the method for controlling an inverter for implementing a model of a synchronous generator.Type: GrantFiled: September 26, 2018Date of Patent: April 6, 2021Assignee: THE GOVERNORS OF THE UNIVERSITY OF ALBERTAInventors: Ali Khajehoddin, Masoud Karimi Ghartemani, Mohammad Ebrahimi
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Publication number: 20200401740Abstract: A method of modeling an equivalent wind turbine generator (WTG) system for a wind farm having a plurality of WTG units includes determining an impact factor of each WTG unit of the plurality of WTG units, determining an equivalent single WTG unit model parameters of the wind farm based on the impact factor of each WTG unit, and determining an effective wind speed of the wind farm to use as the equivalent WTG input wind speed. The method produces a model of static and/or dynamic wind farm behavior. Additionally, a software configured to execute a method of modeling an equivalent wind turbine generator (WTG) system for a wind farm having a plurality of WTG units.Type: ApplicationFiled: June 18, 2020Publication date: December 24, 2020Applicant: The Governors of the University of AlbertaInventors: Sayed Ali Khajehoddin, Ahmadreza Tabesh, Navid Shabanikia
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Publication number: 20190109461Abstract: A method for controlling an inverter, and in particular a double stage inverter, for implementing a model of a synchronous generator is provided including implementing a rotor inertia using an intermediate dc-link capacitor without duplicating the emulated inertia in the controller, simulating the rotor speed based on a measured voltage of the dc-link capacitor, while allowing the voltage to change in a defined range, and mapping the changing voltage of the dc-link capacitor into the inverter as an internal frequency. A system for connecting a power generator to a power grid is also provided including a control device for an inverter, the control device implementing a model of a synchronous generator. The control device including a computer processor in electrical communication with a storage device with instructions stored thereon, that when executed on the computer processor, perform the method for controlling an inverter for implementing a model of a synchronous generator.Type: ApplicationFiled: September 26, 2018Publication date: April 11, 2019Inventors: Ali Khajehoddin, Masoud Karimi Ghartemani, Mohammad Ebrahimi
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Patent number: 9705331Abstract: Provided herein is a single phase power system controller and a method for controlling a single phase power system. The single phase power system controller comprises an error signal generator that generates an error signal from an instantaneous power reference signal and a measured instantaneous output power signal corresponding to the power delivered to a power distribution grid; and a modulator that modulates the error signal according to a trigonometric function of the grid voltage phase angle and produces a control signal for an inverter controller. In accordance with the circuits and methods provided herein, real and reactive power delivered to the grid are controlled simultaneously based on instantaneous output power feedback.Type: GrantFiled: March 12, 2014Date of Patent: July 11, 2017Assignee: SPARQ SYSTEMS INC.Inventors: Sayed Ali Khajehoddin, Masoud Karimi Ghartemani, Praveen K. Jain, Alireza Bakhshai
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Patent number: 9698665Abstract: Provided are methods and circuits for a controller for a control system, comprising first and second control loops that operate substantially independently, wherein the first control loop is an amplitude control loop and the second loop is a phase or frequency control loop. In some embodiments the amplitude control loop operates at an amplitude that is proportional to an amplitude of an input signal at a fundamental system frequency and at a selected harmonic of a fundamental system frequency; and the frequency control loop operates at a fundamental system frequency and at a selected harmonic of the fundamental system frequency. The frequency control loop may adaptable to a fundamental control system frequency or to a selected harmonic of the fundamental control system frequency. The controller may be implemented as a resonant controller and used in various ac systems, and offers high structural robustness in digital implementations.Type: GrantFiled: September 13, 2013Date of Patent: July 4, 2017Assignee: SPARQ SYSTEMS, INC.Inventors: Sayed Ali Khajehoddin, Masoud Karimi Ghartemani, Praveen K. Jain, Alireza Bakhshai
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Patent number: 9680364Abstract: Described herein are methods, systems, and apparatus for a controller for a power circuit that interfaces distributed power generation with a power distribution grid, comprising: a first portion, including a maximum power point tracker, that receives signals corresponding to the distributed power generation voltage and current, and outputs to the power circuit a signal for controlling the voltage of the distributed power generation; a second portion, including a current reference generator, a current controller, and a dc voltage controller, that receives signals corresponding to a dc voltage of the power circuit, the power distribution grid voltage and current, and the inverter current, and outputs signals for controlling the power circuit output voltage; wherein the current reference generator includes nonlinear circuit elements and generates a current reference signal from the dc voltage of the power circuit and the grid voltage and current; such that substantially harmonic-free power is injected into the pType: GrantFiled: March 26, 2014Date of Patent: June 13, 2017Assignee: SPARQ SYSTEMS INC.Inventors: Sayed Ali Khajehoddin, Masoud Karimi Ghartemani, Praveen K. Jain, Alireza Bakhshai
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Patent number: 9641099Abstract: Provided are single phase and multiple phase DC-AC inverters with soft switching, and related methods and uses. The DC-AC inverters comprise at least one voltage source inverter circuit or at least one current source inverter circuit having a DC input and an AC output including a first component at a fundamental frequency and a ripple component at a frequency higher than the fundamental frequency; wherein the ripple component is of a sufficient magnitude that the voltage source inverter circuit output current reverses polarity and allows the at least one inverter circuit to operate with zero voltage switching; or wherein the ripple component is of a sufficient magnitude that the current source inverter circuit output voltage reverses polarity and allows the at least one inverter circuit to operate with zero current switching. The circuits and methods may be used with grid-connected renewable energy sources.Type: GrantFiled: March 12, 2014Date of Patent: May 2, 2017Assignee: SPARQ SYSTEMS INC.Inventors: Vidisha Gupta, Sayed Ali Khajehoddin, Praveen K. Jain
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Patent number: 9553500Abstract: Provided is a maximum power point (MPP) tracker for a PV cell inverter, and a PV cell inverter. The MPP tracker decouples output power oscillations from the input power generation and extracts maximum available power from the PV cell. The PV cell inverter uses the MPP tracker and generates a sinusoidal output current from the MPP tracker output. The sinusoidal output current may be fed to a power distribution grid. The PV cell inverter may use a pulse width modulation technique to cancel harmonics in the sinusoidal output current. The circuits use a minimum number of components and avoid use of large electrolytic capacitors.Type: GrantFiled: February 5, 2014Date of Patent: January 24, 2017Assignee: SPARQ Systems Inc.Inventors: Ali Khajehoddin, Praveen K. Jain, Alireza Bakhshai
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Publication number: 20140268932Abstract: Provided are single phase and multiple phase DC-AC inverters with soft switching, and related methods and uses. The DC-AC inverters comprise at least one voltage source inverter circuit or at least one current source inverter circuit having a DC input and an AC output including a first component at a fundamental frequency and a ripple component at a frequency higher than the fundamental frequency; wherein the ripple component is of a sufficient magnitude that the voltage source inverter circuit output current reverses polarity and allows the at least one inverter circuit to operate with zero voltage switching; or wherein the ripple component is of a sufficient magnitude that the current source inverter circuit output voltage reverses polarity and allows the at least one inverter circuit to operate with zero current switching. The circuits and methods may be used with grid-connected renewable energy sources.Type: ApplicationFiled: March 12, 2014Publication date: September 18, 2014Inventors: Vidisha GUPTA, Sayed Ali KHAJEHODDIN, Praveen K. JAIN
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Publication number: 20140268957Abstract: Provided herein is a single phase power system controller and a method for controlling a single phase power system. The single phase power system controller comprises an error signal generator that generates an error signal from an instantaneous power reference signal and a measured instantaneous output power signal corresponding to the power delivered to a power distribution grid; and a modulator that modulates the error signal according to a trigonometric function of the grid voltage phase angle and produces a control signal for an inverter controller. In accordance with the circuits and methods provided herein, real and reactive power delivered to the grid are controlled simultaneously based on instantaneous output power feedback.Type: ApplicationFiled: March 12, 2014Publication date: September 18, 2014Applicant: SPARQ Systems Inc.Inventors: Sayed Ali Khajehoddin, Masoud Karimi Ghartemani, Praveen K. Jain, Alireza Bakhshai
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Publication number: 20140204633Abstract: Described herein are methods, systems, and apparatus for a controller for a power circuit that interfaces distributed power generation with a power distribution grid, comprising: a first portion, including a maximum power point tracker, that receives signals corresponding to the distributed power generation voltage and current, and outputs to the power circuit a signal for controlling the voltage of the distributed power generation; a second portion, including a current reference generator, a current controller, and a dc voltage controller, that receives signals corresponding to a dc voltage of the power circuit, the power distribution grid voltage and current, and the inverter current, and outputs signals for controlling the power circuit output voltage; wherein the current reference generator includes nonlinear circuit elements and generates a current reference signal from the dc voltage of the power circuit and the grid voltage and current; such that substantially harmonic-free power is injected into the pType: ApplicationFiled: March 26, 2014Publication date: July 24, 2014Applicant: Sparq Systems Inc.Inventors: Sayed Ali KHAJEHODDIN, Masoud Karimi GHARTEMANI, Praveen K. JAIN, Alireza BAKHSHAI
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Publication number: 20140192568Abstract: Provided is a maximum power point (MPP) tracker for a PV cell inverter, and a PV cell inverter. The MPP tracker decouples output power oscillations from the input power generation and extracts maximum available power from the PV cell. The PV cell inverter uses the MPP tracker and generates a sinusoidal output current from the MPP tracker output. The sinusoidal output current may be fed to a power distribution grid. The PV cell inverter may use a pulse width modulation technique to cancel harmonics in the sinusoidal output current. The circuits use a minimum number of components and avoid use of large electrolytic capacitors.Type: ApplicationFiled: February 5, 2014Publication date: July 10, 2014Applicant: SPARQ Systems Inc.Inventors: Ali Khajehoddin, Praveen K. Jain, Alireza Bakhshai
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Patent number: 8688287Abstract: Described herein are methods, systems, and apparatus for a controller for a power circuit that interfaces distributed power generation with a power distribution grid, comprising: a first portion, including a maximum power point tracker, that receives signals corresponding to the distributed power generation voltage and current, and outputs to the power circuit a signal for controlling the voltage of the distributed power generation; a second portion, including a current reference generator, a current controller, and a dc voltage controller, that receives signals corresponding to a dc voltage of the power circuit, the power distribution grid voltage and current, and the inverter current, and outputs signals for controlling the power circuit output voltage; wherein the current reference generator includes nonlinear circuit elements and generates a current reference signal from the dc voltage of the power circuit and the grid voltage and current; such that substantially harmonic-free power is injected into the pType: GrantFiled: September 17, 2010Date of Patent: April 1, 2014Assignee: Sparq Systems Inc.Inventors: Sayed Ali Khajehoddin, Masoud Karimi Ghartemani, Praveen Jain, Alireza Bakhshai
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Publication number: 20140078780Abstract: Provided are methods and circuits for a controller for a control system, comprising first and second control loops that operate substantially independently, wherein the first control loop is an amplitude control loop and the second loop is a phase or frequency control loop. In some embodiments the amplitude control loop operates at an amplitude that is proportional to an amplitude of an input signal at a fundamental system frequency and at a selected harmonic of a fundamental system frequency; and the frequency control loop operates at a fundamental system frequency and at a selected harmonic of the fundamental system frequency. The frequency control loop may adaptable to a fundamental control system frequency or to a selected harmonic of the fundamental control system frequency. The controller may be implemented as a resonant controller and used in various ac systems, and offers high structural robustness in digital implementations.Type: ApplicationFiled: September 13, 2013Publication date: March 20, 2014Applicant: Sparq Systems Inc.Inventors: Sayed Ali KHAJEHODDIN, Masoud KARIMI GHARTEMANI, Praveen K. JAIN, Alireza BAKHSHAI
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Patent number: 8670249Abstract: Provided is a maximum power point (MPP) tracker for a PV cell inverter, and a PV cell inverter. The MPP tracker decouples output power oscillations from the input power generation and extracts maximum available power from the PV cell. The PV cell inverter uses the MPP tracker and generates a sinusoidal output current from the MPP tracker output. The sinusoidal output current may be fed to a power distribution grid. The PV cell inverter may use a pulse width modulation technique to cancel harmonics in the sinusoidal output current. The circuits use a minimum number of components and avoid use of large electrolytic capacitors.Type: GrantFiled: February 19, 2010Date of Patent: March 11, 2014Assignee: SPARQ Systems Inc.Inventors: Sayed Ali Khajehoddin, Praveen Jain, Alireza Bakhshai
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Patent number: 8612058Abstract: A maximum power point tracking method and system for use with a power generator comprises sampling instantaneous output voltage and current of the power generator at a first instant in time and at a second instant in time to obtain first and second power samples, generating a reference voltage or current signal from a difference of the first and second power samples; comparing the reference voltage or current to the instantaneous power generator voltage or current and generating at least one gating signal; and repeating so as to minimize the difference of the first and second power samples; wherein the gating signal affects magnitude of the output voltage and current of the power generator; wherein the maximum power point is tracked when the difference signal is minimized. The power generator may be at least one photovoltaic cell, wind turbine, or fuel cell.Type: GrantFiled: April 26, 2011Date of Patent: December 17, 2013Assignee: SPARQ Systems Inc.Inventors: Sayed Ali Khajehoddin, Praveen K. Jain, Alireza Bakhshai
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Patent number: 8467200Abstract: Provided are methods, circuits, and systems for obtaining power from a power generator such as a photovoltaic cell or a fuel cell. The methods, circuits, and systems comprise converting substantially DC output power from the power generator into a high frequency AC voltage while rejecting or minimizing oscillations in the output power from the power generator; converting the high frequency AC voltage into a high frequency substantially sinusoidal voltage or current; and converting the high frequency substantially sinusoidal AC voltage or current into (i) a DC voltage or current, and (ii) a low frequency substantially sinusoidal AC voltage or current; wherein the high frequency substantially sinusoidal AC voltage or current is isolated from the DC voltage or current or the low frequency substantially sinusoidal AC voltage or current.Type: GrantFiled: April 26, 2011Date of Patent: June 18, 2013Assignee: Queen's University at KingstonInventors: Shangzhi Pan, Sayed Ali Khajehoddin, Praveen K. Jain, Alireza Bakhshai
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Publication number: 20110261593Abstract: Provided are methods, circuits, and systems for obtaining power from a power generator such as a photovoltaic cell or a fuel cell. The methods, circuits, and systems comprise converting substantially DC output power from the power generator into a high frequency AC voltage while rejecting or minimizing oscillations in the output power from the power generator; converting the high frequency AC voltage into a high frequency substantially sinusoidal voltage or current; and converting the high frequency substantially sinusoidal AC voltage or current into (i) a DC voltage or current, and (ii) a low frequency substantially sinusoidal AC voltage or current; wherein the high frequency substantially sinusoidal AC voltage or current is isolated from the DC voltage or current or the low frequency substantially sinusoidal AC voltage or current.Type: ApplicationFiled: April 26, 2011Publication date: October 27, 2011Inventors: Shangzhi Pan, Sayed Ali Khajehoddin, Praveen K. Jain, Alireza Bakhshai
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Publication number: 20110264288Abstract: A maximum power point tracking method and system for use with a power generator comprises sampling instantaneous output voltage and current of the power generator at a first instant in time and at a second instant in time to obtain first and second power samples, generating a reference voltage or current signal from a difference of the first and second power samples; comparing the reference voltage or current to the instantaneous power generator voltage or current and generating at least one gating signal; and repeating so as to minimize the difference of the first and second power samples; wherein the gating signal affects magnitude of the output voltage and current of the power generator; wherein the maximum power point is tracked when the difference signal is minimized. The power generator may be at least one photovoltaic cell, wind turbine, or fuel cell.Type: ApplicationFiled: April 26, 2011Publication date: October 27, 2011Inventors: Sayed Ali KHAJEHODDIN, Praveen K. Jain, Alireza Bakhshai