Patents by Inventor Petr Korba
Petr Korba 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: 8798800Abstract: The invention provides improved control of a power transmission system having a first group of measurement units in a first geographical area providing a first set of phasors and a second group of measurement units in a second geographical area providing a second set of phasors, where the phasors in the sets are generated at the same instant in time. In this system the power control device includes a phasor aligning unit that time aligns the first and second sets of phasors and a control unit that compares each set of phasors with a corresponding phasor number threshold, determines that a first control condition is fulfilled if each phasor number threshold has been exceeded and enables the provision of a common signal if the first control condition is fulfilled. The common signal is based on the obtained phasors in the first and second sets.Type: GrantFiled: December 12, 2011Date of Patent: August 5, 2014Assignee: ABB Research Ltd.Inventors: Bertil Berggren, Petr Korba, Rajat Majumder, Swakshar Ray
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Patent number: 8497602Abstract: A method and controller are provided for the compensation of time delays in remote feedback signals in power system control. The method includes converting the time delay into a phase shift and calculating four compensation angles from the phase shift. The optimal compensation angle is determined and applied to the remote feedback signals. A technique of equipping a controller with a global clock is also disclosed.Type: GrantFiled: November 23, 2010Date of Patent: July 30, 2013Assignee: ABB Research LtdInventors: Petr Korba, Rafael Segundo, Bertil Berggren, Andrew D. Paice, Rajat Majumder
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Publication number: 20130054035Abstract: The invention provides improved control of a power transmission system having a first group of measurement units in a first geographical area providing a first set of phasors and a second group of measurement units in a second geographical area providing a second set of phasors, where the phasors in the sets are generated at the same instant in time. In this system the power control device includes a phasor aligning unit that time aligns the first and second sets of phasors and a control unit that compares each set of phasors with a corresponding phasor number threshold, determines that a first control condition is fulfilled if each phasor number threshold has been exceeded and enables the provision of a common signal if the first control condition is fulfilled. The common signal is based on the obtained phasors in the first and second sets.Type: ApplicationFiled: December 12, 2011Publication date: February 28, 2013Inventors: Bertil Berggren, Petr Korba, Rajat Majumder
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Patent number: 8170723Abstract: The present disclosure relates to power system sensitivities as computed from power flow parameters and control parameters of a Power Flow Control Device (PFC). To this end, control parameter variations are applied to or generated by a PFC, and comprise variations in a control input u, a control effort e (injected series voltage, inserted series reactance), or a control effect q (power flow, active power transfer, phase-shift, current). A power flow response measuring unit measures a variation of a power flow response such as current, active or apparent power, in a way sufficiently synchronized with the control parameter variation to allow establishing an unambiguous causal relationship or correspondence in the form of a power system sensitivity.Type: GrantFiled: April 3, 2009Date of Patent: May 1, 2012Assignee: ABB Research Ltd.Inventors: Bertil Berggren, Mats Larsson, Tord Bengtsson, Petr Korba, Alexandre Oudalov
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Patent number: 8022575Abstract: Exemplary embodiments of the present disclosure provide a method and controller for damping multimode electromagnetic oscillations in electric power systems which interconnect a plurality of generators and consumers. The controller for damping such oscillations includes a phasor measurement unit (PMU) and a power oscillation damper (POD) controller. Each oscillating mode signal is damped and then superposed to derive a control signal. A feedback controller is used to feedback the control signal to a power flow control device in the power system.Type: GrantFiled: September 16, 2009Date of Patent: September 20, 2011Assignee: ABB Research LtdInventors: Petr Korba, Mats Larsson
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Patent number: 8019484Abstract: The present disclosure is concerned with the combined voltage or power flow control and damping of electromechanical oscillations in an electric power system by Flexible AC Transmission System (FACTS) devices or High Voltage DC (HVDC) transmission devices. To this end, information about a state or operating point of the power system is generated from suitable second system signals (y2) and a control parameter (cp) of a FACTS controller is derived therefrom. The control parameter and a first system signal (y1) are used in the calculation of a control command (u) defining the settings of the FACTS device. Following a change in the state of the power system such as a change in the topology of a transmission network, poorly damped or even unstable oscillations are avoided by appropriate re-tuning of the control parameter of the damping or stabilizing equipment.Type: GrantFiled: December 7, 2007Date of Patent: September 13, 2011Assignee: ABB Research LtdInventors: Petr Korba, Alexandre Oudalov, Mats Larsson, Johan A. Lindberg, Stefan G. Thorburn
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Patent number: 7973427Abstract: The disclosure relates to a converter control unit or power system stabilizing unit for counteracting oscillations in electric power systems that is equipped and employed to provide and processes information for system-wide monitoring, protection, control and metering. It comprises means for synchronized (e.g. via GPS or another absolute/global time reference) sampling of voltages and/or currents, means for down-sampling in order to decrease the number of samples, and means for calculating phasors, i.e. time stamped amplitude and phase angle of the voltages and/or currents.Type: GrantFiled: August 29, 2008Date of Patent: July 5, 2011Assignee: ABB Research LtdInventors: Petr Korba, Rudolf Wieser, Srinivas Ponnaluri, Mats Larsson, Alexandre Oudalov, Jose Taborda, Peter Steimer
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Publication number: 20110126038Abstract: A method and controller are provided for the compensation of time delays in remote feedback signals in power system control. The method includes converting the time delay into a phase shift and calculating four compensation angles from the phase shift. The optimal compensation angle is determined and applied to the remote feedback signals. A technique of equipping a controller with a global clock is also disclosed.Type: ApplicationFiled: November 23, 2010Publication date: May 26, 2011Applicant: ABB RESEARCH LTDInventors: Petr KORBA, Rafael SEGUNDO, Bertil BERGGREN, Andrew D. PAICE, Rajat MAJUMDER
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Patent number: 7912589Abstract: The present disclosure relates to monitoring of electromechanical oscillations in electric power systems, and their identification by an adaptive algorithm based on a repeatedly measured and evaluated signal. In order for an estimation of parameters of a model of the power system to reasonably converge, proper initialization of the recursive calculation is required, including the definition of tuning parameters constraining the model and the calculation. Initialization for a second signal to be exploited can then be simplified by copying the set of tuning parameters tuned previously for a different signal. A conditioning gain multiplying the second signal establishes compatibility between the different signals, and a signal pre-filter in turn discards contributions beyond a frequency band comprising typical electromagnetic oscillations.Type: GrantFiled: April 29, 2008Date of Patent: March 22, 2011Assignee: ABB Research LtdInventors: Petr Korba, Marek Zima, Mats Larsson
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Publication number: 20100094477Abstract: The present disclosure relates to power system sensitivities as computed from power flow parameters and control parameters of a Power Flow Control Device (PFC). To this end, control parameter variations are applied to or generated by a PFC, and comprise variations in a control input u, a control effort e (injected series voltage, inserted series reactance), or a control effect q (power flow, active power transfer, phase-shift, current). A power flow response measuring unit measures a variation of a power flow response such as current, active or apparent power, in a way sufficiently synchronized with the control parameter variation to allow establishing an unambiguous causal relationship or correspondence in the form of a power system sensitivity.Type: ApplicationFiled: April 3, 2009Publication date: April 15, 2010Applicant: ABB Research LtdInventors: Bertil Berggren, Mats Larsson, Tord Bengtsson, Petr Korba, Alexandre Oudalov
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Publication number: 20100023179Abstract: Exemplary embodiments of the present disclosure provide a method and controller for damping multimode electromagnetic oscillations in electric power systems which interconnect a plurality of generators and consumers. The controller for damping such oscillations includes a phasor measurement unit (PMU) and a power oscillation damper (POD) controller. Each oscillating mode signal is damped and then superposed to derive a control signal. A feedback controller is used to feedback the control signal to a power flow control device in the power system.Type: ApplicationFiled: September 16, 2009Publication date: January 28, 2010Applicant: ABB Research LtdInventors: Petr KORBA, Mats Larsson
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Publication number: 20090216472Abstract: A relationship between a temperature TI of a power line or power transmission conductor, an electrical quantity of the power line such as a current I or power flow P through the power line, as well as meteorological quantities or ambient conditions of the power line such as wind speed W, wind direction, humidity, solar radiation S and ambient temperature Ta, is established in the form of a thermal model of the power line. Values of the aforementioned quantities or variables are continuously measured, and the collected values of the quantities are evaluated in order to update model parameters of the thermal model during operation of the power line. In one example, an average temperature representative of the entire line is determined via two Phasor Measurement Units (PMU) 11, 11? providing synchronized phasor values from two ends of the power line. An ohmic resistance of the power line is computed from the phasor values, from which in turn the average line temperature can be derived.Type: ApplicationFiled: February 10, 2009Publication date: August 27, 2009Applicant: ABB Research LtdInventors: Marek Zima, Petr Korba, Albert Leirbukt, Mats Larsson
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Publication number: 20090079267Abstract: The disclosure relates to a converter control unit or power system stabilizing unit for counteracting oscillations in electric power systems that is equipped and employed to provide and processes information for system-wide monitoring, protection, control and metering. It comprises means for synchronized (e.g. via GPS or another absolute/global time reference) sampling of voltages and/or currents, means for down-sampling in order to decrease the number of samples, and means for calculating phasors, i.e. time stamped amplitude and phase angle of the voltages and/or currents.Type: ApplicationFiled: August 29, 2008Publication date: March 26, 2009Applicant: ABB Research LtdInventors: Petr Korba, Rudolf Wieser, Srinivas Ponnaluri, Mats Larsson, Alexandre Oudalov, Jose Taborda, Peter Steimer
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Publication number: 20080281437Abstract: The present disclosure relates to monitoring of electromechanical oscillations in electric power systems, and their identification by an adaptive algorithm based on a repeatedly measured and evaluated signal. In order for an estimation of parameters of a model of the power system to reasonably converge, proper initialization of the recursive calculation is required, including the definition of tuning parameters constraining the model and the calculation. Initialization for a second signal to be exploited can then be simplified by copying the set of tuning parameters tuned previously for a different signal. A conditioning gain multiplying the second signal establishes compatibility between the different signals, and a signal pre-filter in turn discards contributions beyond a frequency band comprising typical electromagnetic oscillations.Type: ApplicationFiled: April 29, 2008Publication date: November 13, 2008Applicant: ABB Research LtdInventors: Petr Korba, Marek Zima, Mats Larsson
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Publication number: 20080177425Abstract: The present disclosure is concerned with the combined voltage or power flow control and damping of electromechanical oscillations in an electric power system by Flexible AC Transmission System (FACTS) devices or High Voltage DC (HVDC) transmission devices. To this end, information about a state or operating point of the power system is generated from suitable second system signals (y2) and a control parameter (cp) of a FACTS controller is derived therefrom. The control parameter and a first system signal (y1) are used in the calculation of a control command (u) defining the settings of the FACTS device. Following a change in the state of the power system such as a change in the topology of a transmission network, poorly damped or even unstable oscillations are avoided by appropriate re-tuning of the control parameter of the damping or stabilizing equipment.Type: ApplicationFiled: December 7, 2007Publication date: July 24, 2008Applicant: ABB Research LtdInventors: Petr Korba, Alexandre Oudalov, Mats Larsson, Johan A. Lindberg, Stefan G. Thorburn
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Publication number: 20070038396Abstract: A relationship between a temperature Tl of a power line or power transmission conductor 10, an electrical quantity of the power line such as a current l or power flow P through the power line, as well as meteorological quantities or ambient conditions of the power line such as wind speed W, wind direction, humidity, solar radiation S and ambient temperature Ta, is established in the form of a thermal model of the power line. Values of the aforementioned quantities or variables are continuously measured, and the collected values of the quantities are evaluated in order to update model parameters of the thermal model during operation of the power line. In an exemplary embodiment, an average temperature representative of the entire line is determined via two phasor measurement units (PMU) 11, 11? providing synchronized phasor values from two ends of the power line. An ohmic resistance of the power line can be computed from the phasor values, from which in turn the average line temperature can be derived.Type: ApplicationFiled: August 14, 2006Publication date: February 15, 2007Applicant: ABB Schweiz AGInventors: Marek Zima, Petr Korba, Albert Leirbukt, Mats Larsson
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Patent number: 7149637Abstract: The detection of electromechanical oscillations in power systems and the estimation of their frequency and damping parameters are based on a linear time-varying model. The parameters of the linear model are on-line adapted by means of Kalman filtering techniques to optimally approximate the measured signal representing the behavior of the power system based on a quadratic criterion. The estimated model parameters are then the basis for the calculation of parameters of the oscillations. Adaptive algorithms are based on a recursive calculation of the estimated parameter vector for each time-step based on the new value of the measured signal and the old values of the estimated parameters.Type: GrantFiled: June 18, 2004Date of Patent: December 12, 2006Assignee: ABB Research LtdInventors: Petr Korba, Mats Larsson, Christian Rehtanz
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Publication number: 20050187726Abstract: The detection of electromechanical oscillations in power systems and the estimation of their parameters (frequency ƒ and damping ?) is based on a linear time-varying model. The parameters of the linear model are on-line adapted by means of Kalman filtering techniques to approximate the measured signal y (representing the behaviour of the power system) optimally in the sense of a quadratic criterion. The estimated model parameters are then the basis for the calculation of parameters of the oscillations. Adaptive algorithms are based on a recursive calculation of the estimated parameter vector for each time-step based on the new value of the measured signal and the old values of the estimated parameters. As opposed to the collection of data over a time window and then performing the parameter identification at once, any change in the system can thus be detected much faster.Type: ApplicationFiled: June 18, 2004Publication date: August 25, 2005Applicant: ABB Research Ltd.Inventors: Petr Korba, Mats Larsson, Christian Rehtanz