The Experts below are selected from a list of 120102 Experts worldwide ranked by ideXlab platform
Takao Hirasa - One of the best experts on this subject based on the ideXlab platform.
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loss minimization control of permanent magnet synchronous motor drives
IEEE Transactions on Industrial Electronics, 1994Co-Authors: S Morimoto, Y Tong, Y Takeda, Takao HirasaAbstract:This paper aims to improve efficiency in permanent magnet synchronous (PM) motor drives. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature Current Vector. The control algorithm of the Current Vector minimizing the electrical loss is proposed and the optimal Current Vector can be decided according to the operating speed and the load conditions. The proposed control algorithm is applied to the experimental PM motor drive system, in which one digital signal processor is employed to execute the control algorithms, and several drive tests are carried out. The operating characteristics controlled by the loss minimization control algorithm are examined in detail by computer simulations and experimental results. >
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variable speed drive system of interior permanent magnet synchronous motors for constant power operation
Power Conversion Conference, 1993Co-Authors: Shigeo Morimoto, Masayuki Sanada, Yoji Takeda, T Ueno, Takao HirasaAbstract:Interior permanent magnet synchronous (IPM) motors can be applied to applications requiring constant power operation by means of the flux weakening control. The Current Vector control algorithm of IPM motors for constant power operation over the base speed is proposed. As the available voltage controlling the armature Current Vector is small in the flux weakening constant power region, the Current Vector sometimes becomes uncontrollable in transient operations because of the Current regulator saturation. The high performance Current regulator is also proposed to improve the Current responses in the flux weakening region, which includes the decoupling Current controller and the voltage command compensator. The control performances are confirmed by several drive tests with respect to the prototype IPM motor. >
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servo drive system and control characteristics of salient pole permanent magnet synchronous motor
IEEE Transactions on Industry Applications, 1993Co-Authors: S Morimoto, Yoji Takeda, Y Tong, K Hatanaka, Takao HirasaAbstract:Permanent magnet (PM) synchronous motors fed by PWM inverters are considered. PM motors sometimes have a saliency, in which the q-axis inductance is larger than the d-axis inductance. A high-performance servomotor drive system for a salient-pole PM motor is described. An armature Current Vector is actively controlled according to load conditions in order to use a reluctance torque effectively, and, as a result, a large torque can be produced. The control algorithm for the armature Current Vector is described, taking the demagnetization of the PM and the magnetic saturation into account. Characteristics such as torque, power factor, efficiency, power capability, transient responses, etc. are examined in detail by computer simulations and experimentally. >
Lopez Dekker J.f. - One of the best experts on this subject based on the ideXlab platform.
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DopSCA, Scatterometer-based Simultaneous Ocean Vector Current and Wind Estimation
IEEE, 2018Co-Authors: Hoogeboom P., Ad Stoffelen, Lopez Dekker J.f.Abstract:Satellite wind scatterometers like the MetOp SG (Second Generation) SCA of Eumetsat are not designed to measure ocean Currents, yet if they could, it would improve the wind Vector product and provide important additional information to the oceanographic community for various applications. Previous publications showed this possibility, but only with modifications to the system. In this paper the possibilities of measuring the ocean Current Vector simultaneously with the wind Vector without modifications to the SCA system, are investigated through simulation studies. The measurement principle relies on phase change in a pulse pair measurement. The results indicate that it should be possible with SCA to measure the ocean Current Vector simultaneously with the wind with an accuracy of better than 1 m/s on a 50 x 50 km grid
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DopSCA, Scatterometer-based Simultaneous Ocean Vector Current and Wind Estimation
'Institute of Electrical and Electronics Engineers (IEEE)', 2018Co-Authors: Hoogeboom P., Ad Stoffelen, Lopez Dekker J.f.Abstract:Satellite wind scatterometers like the MetOp SG (Second Generation) SCA of Eumetsat are not designed to measure ocean Currents, yet if they could, it would improve the wind Vector product and provide important additional information to the oceanographic community for various applications. Previous publications showed this possibility, but only with modifications to the system. In this paper the possibilities of measuring the ocean Current Vector simultaneously with the wind Vector without modifications to the SCA system, are investigated through simulation studies. The measurement principle relies on phase change in a pulse pair measurement. The results indicate that it should be possible with SCA to measure the ocean Current Vector simultaneously with the wind with an accuracy of better than 1 m/s on a 50 x 50 km grid.Atmospheric Remote SensingMathematical Geodesy and Positionin
Timothy A. Haskew - One of the best experts on this subject based on the ideXlab platform.
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optimal and direct Current Vector control of direct driven pmsg wind turbines
IEEE Transactions on Power Electronics, 2012Co-Authors: Timothy A. Haskew, Richard P Swatloski, W GathingsAbstract:With the advances of power electronic technology, direct-driven permanent magnet synchronous generators (PMSGs) have increasingly drawn the interest of wind turbine manufacturers. At the present time, a commercial PMSG wind turbine primarily makes use of a passive rectifier followed by an insulated gate bipolar transistor (IGBT) inverter. Although a PMSG wind turbine with two back-to-back voltage source IGBT converters is considered more efficient, it has not been widely adopted by the wind power industry. This paper investigates both the conventional and a novel Vector control mechanism for a PMSG wind turbine that has two side-by-side voltage source pulsewidth modulation converters. The proposed approach is based on a direct-Current Vector control mechanism for control of both machine- and grid-side converters of a PMSG wind turbine. Then, an optimal control strategy is developed for integrated control of PMSG maximum power extraction, reactive power, and grid voltage support controls. A transient system simulation using SimPowerSystem is built to investigate the performance of the conventional and proposed control techniques for the PMSG wind turbine under steady and gusty wind conditions. This paper shows that when using the direct-Current Vector control structure, a PMSG system has excellent performance in various aspects.
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control of dfig wind turbine with direct Current Vector control configuration
IEEE Transactions on Sustainable Energy, 2012Co-Authors: Shuhui Li, Timothy A. Haskew, K A Williams, Richard P SwatloskiAbstract:The doubly-fed induction generator (DFIG) wind turbine is a variable speed wind turbine widely used in the modern wind power industry. At present, commercial DFIG wind turbines primarily make use of the technology that was developed a decade ago. But, it is found in this paper that there is a limitation in the conventional Vector control technique. This paper presents a direct-Current Vector control method in a DFIG wind turbine, based on which an integrated control strategy is developed for wind energy extraction, reactive power, and grid voltage support controls of the wind turbine. A transient simulation system using SimPowerSystem is built to validate the effectiveness of the proposed control method. The conventional control approach is compared with the proposed control technique for DFIG wind turbine control under both steady and gust wind conditions. The paper shows that under the dc Vector control configuration, a DFIG system has a superior performance in various aspects.
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direct Current Vector control of three phase grid connected rectifier inverter
Electric Power Systems Research, 2011Co-Authors: Shuhui Li, Yangki Hong, Timothy A. Haskew, Ling XuAbstract:Abstract The three-phase grid-connected converter is widely used in renewable and electric power system applications. Traditionally, control of the three-phase grid-connected converter is based on the standard decoupled d – q Vector control mechanism. Nevertheless, the study of this paper shows that there is a limitation in the conventional standard Vector control method. Some of the limitations have also been found recently by other researchers. To overcome the shortage of the conventional Vector control technique, this paper proposes a new direct-Current d – q Vector control mechanism in a nested-loop control structure, based on which an optimal control strategy is developed in a nonlinear programming formulation. The behaviors of both the conventional and proposed control methods are compared and evaluated in simulation and laboratory hardware experiment environments, both of which demonstrates that the proposed approach is effective for grid-connected power converter control in a wide system conditions while the conventional standard Vector control approach may behave improperly especially when the converter operates beyond its PWM saturation limit.
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control of hvdc light system using conventional and direct Current Vector control approaches
IEEE Transactions on Power Electronics, 2010Co-Authors: Timothy A. HaskewAbstract:With the advance of power electronic technology, the application of HVdc light systems based on voltage-source insulated gate bipolar transistor (IGBT) converters has increased rapidly in renewable, microgrid, and electric power systems. This paper proposes an optimal control strategy for an HVdc light system using a direct Current Vector control mechanism. The proposed approach is compared with the traditional Vector control method for different HVdc control requirements, such as active power, reactive power, and grid voltage support control. A limitation of the conventional control mechanism is analyzed through a theoretical study and computer simulation. Closed-loop control evaluation demonstrates that the proposed approach works well for HVdc light system control both within and beyond the physical constraints of the system, such as rated power and saturation of pulse width modulation (PWM). The evaluation also shows that the conventional control technique could result in over voltage and system oscillation, especially when the controller operates beyond the PWM saturation limit.
Adriano Camps - One of the best experts on this subject based on the ideXlab platform.
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dual beam interferometry for ocean surface Current Vector mapping
IEEE Transactions on Geoscience and Remote Sensing, 2001Co-Authors: Stephen J Frasier, Adriano CampsAbstract:The recent use of along-track interferometry (ATI) in synthetic aperture radar (SAR) has shown promise for synoptic measurement of ocean surface Currents. ATI-SARs have been used to estimate wave fields, Currents, and Current features. This paper describes and analyzes a dual-beam along-track interferometer to provide spatially resolved Vector surface velocity estimates with a single pass of an aircraft. The design employs a pair of interferometer beams, one squinted forward and one squinted aft. Each interferometric phase is sensitive to the component of surface Doppler velocity in the direction of the beam. Therefore, a proper combination of these measurements provides a Vector surface velocity estimate in one pass of the aircraft. The authors find that precise measurements dictate widely spaced beams and that the spatial resolution for the squinted SAR is essentially identical to the sidelooking case. Practical instrument design issues are discussed, and an airborne system Currently in development is described. Through computer simulation, they observe the azimuthal displacement of interferometric phases by moving surfaces identical to those of conventional SAR and find that such displacement can bias the estimated surface velocity.
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dual beam interferometry for ocean surface Current Vector mapping
IEEE Transactions on Geoscience and Remote Sensing, 2001Co-Authors: Stephen J Frasier, Adriano CampsAbstract:The recent use of along-track interferometry (ATI) in synthetic aperture radar (SAR) has shown promise for synoptic measurement of ocean surface Currents. ATI-SARs have been used to estimate wave fields, Currents, and Current features. This paper describes and analyzes a dual-beam along-track interferometer to provide spatially resolved Vector surface velocity estimates with a single pass of an aircraft. The design employs a pair of interferometer beams, one squinted forward and one squinted aft. Each interferometric phase is sensitive to the component of surface Doppler velocity in the direction of the beam. Therefore, a proper combination of these measurements provides a Vector surface velocity estimate in one pass of the aircraft. The authors find that precise measurements dictate widely spaced beams and that the spatial resolution for the squinted SAR is essentially identical to the sidelooking case. Practical instrument design issues are discussed, and an airborne system Currently in development is described. Through computer simulation, they observe the azimuthal displacement of interferometric phases by moving surfaces identical to those of conventional SAR and find that such displacement can bias the estimated surface velocity.
Teresa Orlowska-kowalska - One of the best experts on this subject based on the ideXlab platform.
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Optimum Trajectory Control of the Current Vector of a Nonsalient-Pole PMSM in the Field-Weakening Region
IEEE Transactions on Industrial Electronics, 2012Co-Authors: R. Nalepa, Teresa Orlowska-kowalskaAbstract:Industry-proven field-weakening solutions for nonsalient-pole permanent-magnet synchronous motor drives are presented in this paper. The core algorithm relies on direct symbolic equations. The equations take into account the stator resistance and reveal its effect on overall algorithm quality. They establish a foundation for an offline calculated lookup table which secures effective d-axis Current reference over entire field-weakening region. The table has been proven on its own and in combination with a PI compensator. Usage recommendations are given in this paper. Functionality of the proposed solutions has been investigated theoretically and in practice. The investigation has been carried out in the presence of motor magnetic saturation and parameter tolerance, taking into account the change of operating temperature. The results and analysis method are included in this paper.
