The Experts below are selected from a list of 366144 Experts worldwide ranked by ideXlab platform
Ned Mohan - One of the best experts on this subject based on the ideXlab platform.
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a single stage dual active bridge based soft switched ac dc converter with open loop Power factor correction and other advanced features
IEEE Transactions on Power Electronics, 2014Co-Authors: Nathan Weise, Gysler Castelino, Kaushik Basu, Ned MohanAbstract:A dual-active-bridge-based single-stage ac/dc converter may find a wide range of emerging applications such as interfacing plug-in hybrid vehicles with the ac grid, interconnection of dc grid, etc. This type of converter can be used due to unique features such as 1) high-frequency isolation resulting in a) high Power density and b) safety and voltage matching; 2) bidirectional Power flow; 3) soft switching leading to higher efficiency. In this paper, a modulation strategy has been proposed that results in 1) open-loop Power factor correction; 2) zero current switching in the ac-side converter for all load conditions; 3) linear Power Relationship for easy control implementation; and 4) Zero voltage switching in the load side converter. The converter with the proposed control has been analyzed. Simulation and experimental results on a 1-KW prototype confirm the advantages.
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a bi directional isolated single stage dab based ac dc converter with open loop Power factor correction and other advanced features
International Conference on Industrial Technology, 2012Co-Authors: Gysler Castelino, Kaushik Basu, Nathan Weise, Ned MohanAbstract:In this paper, a control method for an AC-DC converter is proposed that simultaneously has the following features: a) galvanic isolation b) bi-directional Power flow, c) Zero Current Switching (ZCS) for the primary side switches and Zero Voltage Switching (ZVS) turn-on for the secondary side, d) linear Power Relationship for easy control implementation, e) unity Power factor with open-loop control and f) single-stage Power conversion. It is thoroughly analyzed by first assuming it to be a DC-DC converter in a push-pull topology and then extending the results to analyze an AC-DC converter. The conclusions of the analysis are confirmed by simulations.
George A Lesieutre - One of the best experts on this subject based on the ideXlab platform.
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Optimized piezoelectric energy harvesting circuit using step-down converter in discontinuous conduction mode
IEEE Transactions on Power Electronics, 2003Co-Authors: Geffrey K. Ottman, Heath Hofmann, George A LesieutreAbstract:An optimized method of harvesting vibrational energy with a piezoelectric element using a step-down DC-DC converter is presented. In this configuration, the converter regulates the Power flow from the piezoelectric element to the desired electronic load. Analysis of the converter in discontinuous current conduction mode results in an expression for the duty cycle-Power Relationship. Using parameters of the mechanical system, the piezoelectric element, and the converter; the "optimal" duty cycle can be determined where the harvested Power is maximized for the level of mechanical excitation. It is shown that, as the magnitude of the mechanical excitation increases, the optimal duty cycle becomes essentially constant, greatly simplifying the control of the step-down converter. The expression is validated with experimental data showing that the optimal duty cycle can be accurately determined and maximum energy harvesting attained. A circuit is proposed which implements this Relationship, and experimental results show that the converter increases the harvested Power by approximately 325%.
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optimized piezoelectric energy harvesting circuit using step down converter in discontinuous conduction mode
Power Electronics Specialists Conference, 2002Co-Authors: Geffrey K. Ottman, Heath Hofmann, George A LesieutreAbstract:An optimized method of harvesting vibrational energy with a piezoelectric element using a step-down DC-DC converter is presented. In this configuration, the converter regulates the Power flow from the piezoelectric element to the desired electronic load. Analysis of the converter in discontinuous current conduction mode results in an expression for the duty cycle-Power Relationship. Using parameters of the mechanical system, the piezoelectric element, and the converter an optimal duty cycle can be determined where the harvested Power is maximized for a given frequency of mechanical excitation. It is shown that, as the magnitude of the excitation increases, the optimal duty cycle becomes essentially constant, greatly simplifying the control of the step-down converter. The expression is validated with experimental data showing that the optimal duty cycle can be accurately determined and maximum energy harvesting attained. A circuit is proposed which implements this Relationship, and experimental results show that the converter increases the harvested Power by approximately 325%.
Nathan Weise - One of the best experts on this subject based on the ideXlab platform.
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a single stage dual active bridge based soft switched ac dc converter with open loop Power factor correction and other advanced features
IEEE Transactions on Power Electronics, 2014Co-Authors: Nathan Weise, Gysler Castelino, Kaushik Basu, Ned MohanAbstract:A dual-active-bridge-based single-stage ac/dc converter may find a wide range of emerging applications such as interfacing plug-in hybrid vehicles with the ac grid, interconnection of dc grid, etc. This type of converter can be used due to unique features such as 1) high-frequency isolation resulting in a) high Power density and b) safety and voltage matching; 2) bidirectional Power flow; 3) soft switching leading to higher efficiency. In this paper, a modulation strategy has been proposed that results in 1) open-loop Power factor correction; 2) zero current switching in the ac-side converter for all load conditions; 3) linear Power Relationship for easy control implementation; and 4) Zero voltage switching in the load side converter. The converter with the proposed control has been analyzed. Simulation and experimental results on a 1-KW prototype confirm the advantages.
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a bi directional isolated single stage dab based ac dc converter with open loop Power factor correction and other advanced features
International Conference on Industrial Technology, 2012Co-Authors: Gysler Castelino, Kaushik Basu, Nathan Weise, Ned MohanAbstract:In this paper, a control method for an AC-DC converter is proposed that simultaneously has the following features: a) galvanic isolation b) bi-directional Power flow, c) Zero Current Switching (ZCS) for the primary side switches and Zero Voltage Switching (ZVS) turn-on for the secondary side, d) linear Power Relationship for easy control implementation, e) unity Power factor with open-loop control and f) single-stage Power conversion. It is thoroughly analyzed by first assuming it to be a DC-DC converter in a push-pull topology and then extending the results to analyze an AC-DC converter. The conclusions of the analysis are confirmed by simulations.
Geffrey K. Ottman - One of the best experts on this subject based on the ideXlab platform.
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Optimized piezoelectric energy harvesting circuit using step-down converter in discontinuous conduction mode
IEEE Transactions on Power Electronics, 2003Co-Authors: Geffrey K. Ottman, Heath Hofmann, George A LesieutreAbstract:An optimized method of harvesting vibrational energy with a piezoelectric element using a step-down DC-DC converter is presented. In this configuration, the converter regulates the Power flow from the piezoelectric element to the desired electronic load. Analysis of the converter in discontinuous current conduction mode results in an expression for the duty cycle-Power Relationship. Using parameters of the mechanical system, the piezoelectric element, and the converter; the "optimal" duty cycle can be determined where the harvested Power is maximized for the level of mechanical excitation. It is shown that, as the magnitude of the mechanical excitation increases, the optimal duty cycle becomes essentially constant, greatly simplifying the control of the step-down converter. The expression is validated with experimental data showing that the optimal duty cycle can be accurately determined and maximum energy harvesting attained. A circuit is proposed which implements this Relationship, and experimental results show that the converter increases the harvested Power by approximately 325%.
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optimized piezoelectric energy harvesting circuit using step down converter in discontinuous conduction mode
Power Electronics Specialists Conference, 2002Co-Authors: Geffrey K. Ottman, Heath Hofmann, George A LesieutreAbstract:An optimized method of harvesting vibrational energy with a piezoelectric element using a step-down DC-DC converter is presented. In this configuration, the converter regulates the Power flow from the piezoelectric element to the desired electronic load. Analysis of the converter in discontinuous current conduction mode results in an expression for the duty cycle-Power Relationship. Using parameters of the mechanical system, the piezoelectric element, and the converter an optimal duty cycle can be determined where the harvested Power is maximized for a given frequency of mechanical excitation. It is shown that, as the magnitude of the excitation increases, the optimal duty cycle becomes essentially constant, greatly simplifying the control of the step-down converter. The expression is validated with experimental data showing that the optimal duty cycle can be accurately determined and maximum energy harvesting attained. A circuit is proposed which implements this Relationship, and experimental results show that the converter increases the harvested Power by approximately 325%.
Robert L Yuan - One of the best experts on this subject based on the ideXlab platform.
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experimental Relationship between splitting tensile strength and compressive strength of gfrc and pfrc
Cement and Concrete Research, 2005Co-Authors: Yeol Choi, Robert L YuanAbstract:Abstract This paper describes an experimental investigation into the Relationship between the splitting tensile strength and compressive strength of glass fiber reinforced concrete (GFRC) and polypropylene fiber reinforced concrete (PFRC). The splitting tensile strength and compressive strength of GFRC and PFRC at 7, 28 and 90 days are used. Test results indicate that the addition of glass and polypropylene fibers to concrete increased the splitting tensile strength of concrete by approximately 20–50%, and the splitting tensile strength of GFRC and PFRC ranged from 9% to 13% of its compressive strength. Based on this investigation, a simple 0.5 Power Relationship between the splitting tensile strength and the compressive strength was derived for estimating the tensile strength of GFRC and PFRC.
