The Experts below are selected from a list of 2931 Experts worldwide ranked by ideXlab platform
Henry Shuhung Chung - One of the best experts on this subject based on the ideXlab platform.
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Optimal operation of coreless pcb transformer isolated gate drive circuits with wide switching frequency range
IEEE Transactions on Power Electronics, 1999Co-Authors: Sydney C W Tang, Henry Shuhung ChungAbstract:Gate drive circuits for power MOSFETs and insulated gate bipolar transistors (IGBTs) often require electrical isolation. Coreless printed circuit board (PCB) transformers have been shown to have desirable characteristics from a few hundreds of hertz to a few megahertz and can be used for both power and signal transfer at low-power level. At low Operating frequency, the magnetizing inductance has such low impedance that the driving power requirement could become excessive. This paper describes the use of a coreless PCB transformer for isolated gate drive circuits over a wide-frequency range. Based on a resonance concept, the Optimal Operating Condition that minimizes the power consumption of the gate drive circuits is developed and verified with experiments. The coreless PCB transformer demonstrated here confirms a fundamental concept that the size and volume of a magnetic core could approach zero and become zero if the Operating frequency is sufficiently high. Coreless PCB transformers do not require the manual winding procedure and thus simplify the manufacturing process of transformer-isolated gate drive circuits and low-power converters. Their sizes can be much smaller than those of typical core-based pulse transformers. The electrical isolation of a PCB is much higher than that of an optocoupler.
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Optimal operation of coreless pcb transformer isolated gate drive circuits with wide switching frequency range
Applied Power Electronics Conference, 1999Co-Authors: S Y R Hui, Sydney C W Tang, Henry Shuhung ChungAbstract:Gate drive circuits for power MOSFETs and IGBTs often require electrical isolation. Coreless printed-circuit-board (PCB) transformers have been shown to have desirable characteristics from a few hundreds of Hertz to a few Mega-Hertz and can be used for both power and signal transfer at low-power level. At low Operating frequency, the magnetizing inductance has such low impedance that the driving power requirement could become excessive. This paper describes the use of coreless PCB transformer for isolated gate drive circuits over a wide frequency range. Based on a resonance concept, the Optimal-Operating Condition that minimizes the power consumption of the gate drive circuits is developed and verified with experiments. Coreless PCB transformers do not require the manual winding procedure and thus simplifies the manufacturing process of transformer isolated gate drive circuits and low-power converters. Their sizes can be much smaller than those of typical core-based pulse transformers. The electrical isolation of PCB (typically from 15 kV to 40 kV) is much higher than that of an optocoupler (typically 2.5 kV).
Robert J Braun - One of the best experts on this subject based on the ideXlab platform.
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novel electrical energy storage system based on reversible solid oxide cells system design and Operating Conditions
Journal of Power Sources, 2015Co-Authors: Christopher H Wendel, Pejman Kazempoor, Robert J BraunAbstract:Abstract Electrical energy storage (EES) is an important component of the future electric grid. Given that no other widely available technology meets all the EES requirements, reversible (or regenerative) solid oxide cells (ReSOCs) working in both fuel cell (power producing) and electrolysis (fuel producing) modes are envisioned as a technology capable of providing highly efficient and cost-effective EES. However, there are still many challenges and questions from cell materials development to system level operation of ReSOCs that should be addressed before widespread application. This paper presents a novel system based on ReSOCs that employ a thermal management strategy of promoting exothermic methanation within the ReSOC cell-stack to provide thermal energy for the endothermic steam/CO 2 electrolysis reactions during charging mode (fuel producing). This approach also serves to enhance the energy density of the stored gases. Modeling and parametric analysis of an energy storage concept is performed using a physically based ReSOC stack model coupled with thermodynamic system component models. Results indicate that roundtrip efficiencies greater than 70% can be achieved at intermediate stack temperature (680 °C) and elevated stack pressure (20 bar). The Optimal Operating Condition arises from a tradeoff between stack efficiency and auxiliary power requirements from balance of plant hardware.
Fathollah Pourfayaz - One of the best experts on this subject based on the ideXlab platform.
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Introducing an integrated chemical looping hydrogen production, inherent carbon capture and solid oxide fuel cell biomass fueled power plant process configuration
Energy Conversion and Management, 2016Co-Authors: Mahsa Aghaie, Mehdi Mehrpooya, Fathollah PourfayazAbstract:A novel integrated system is proposed which combines biomass gasification, chemical looping combustion, solid oxide fuel cell system and a steam power cycle. Sensitivity analysis is done for effective parameters to analyze the performance of the integrated system and investigation of the Optimal Operating Condition. Because of some restrictions in the integrated system experiments, a chemical process simulator is used for analysis of the hybrid system. Products of this process are high-purity hydrogen and electrical power which are produced by chemical looping and solid oxide fuel cell (and a power cycle) respectively. The net efficiency of the system reaches to 55.8% with 100% carbon dioxide capture. Solid oxide fuel cell operates at 850 °C and 12 bar. Chemical looping system uses Calcium oxide metal oxide as oxygen carrier. Also carbonator, calcinator and hydrator reactors Operating temperature are 800 °C 850 °C and 650 °C respectively.
Sydney C W Tang - One of the best experts on this subject based on the ideXlab platform.
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Optimal operation of coreless pcb transformer isolated gate drive circuits with wide switching frequency range
IEEE Transactions on Power Electronics, 1999Co-Authors: Sydney C W Tang, Henry Shuhung ChungAbstract:Gate drive circuits for power MOSFETs and insulated gate bipolar transistors (IGBTs) often require electrical isolation. Coreless printed circuit board (PCB) transformers have been shown to have desirable characteristics from a few hundreds of hertz to a few megahertz and can be used for both power and signal transfer at low-power level. At low Operating frequency, the magnetizing inductance has such low impedance that the driving power requirement could become excessive. This paper describes the use of a coreless PCB transformer for isolated gate drive circuits over a wide-frequency range. Based on a resonance concept, the Optimal Operating Condition that minimizes the power consumption of the gate drive circuits is developed and verified with experiments. The coreless PCB transformer demonstrated here confirms a fundamental concept that the size and volume of a magnetic core could approach zero and become zero if the Operating frequency is sufficiently high. Coreless PCB transformers do not require the manual winding procedure and thus simplify the manufacturing process of transformer-isolated gate drive circuits and low-power converters. Their sizes can be much smaller than those of typical core-based pulse transformers. The electrical isolation of a PCB is much higher than that of an optocoupler.
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Optimal operation of coreless pcb transformer isolated gate drive circuits with wide switching frequency range
Applied Power Electronics Conference, 1999Co-Authors: S Y R Hui, Sydney C W Tang, Henry Shuhung ChungAbstract:Gate drive circuits for power MOSFETs and IGBTs often require electrical isolation. Coreless printed-circuit-board (PCB) transformers have been shown to have desirable characteristics from a few hundreds of Hertz to a few Mega-Hertz and can be used for both power and signal transfer at low-power level. At low Operating frequency, the magnetizing inductance has such low impedance that the driving power requirement could become excessive. This paper describes the use of coreless PCB transformer for isolated gate drive circuits over a wide frequency range. Based on a resonance concept, the Optimal-Operating Condition that minimizes the power consumption of the gate drive circuits is developed and verified with experiments. Coreless PCB transformers do not require the manual winding procedure and thus simplifies the manufacturing process of transformer isolated gate drive circuits and low-power converters. Their sizes can be much smaller than those of typical core-based pulse transformers. The electrical isolation of PCB (typically from 15 kV to 40 kV) is much higher than that of an optocoupler (typically 2.5 kV).
Tetsuo Kawagoe - One of the best experts on this subject based on the ideXlab platform.
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Study on continuous ice slurry formation using functional fluid for ice storage - Discussion of Optimal Operating Conditions
International Journal of Refrigeration, 2006Co-Authors: K. Matsumoto, Yutaka Suzuki, Yoshiyuki Teraoka, Masashi Okada, Tetsuo KawagoeAbstract:A functional fluid was made by adding a small amount of additive to a water-silicone-oil mixture with 90 vol% water content, and the functional fluid was transformed into an ice slurry by cooling while stirring. The new ice formation system, which authors proposed for ice storage based on the results of previous studies, demonstrated that the ice slurry could be formed continuously for 10 h. In the current paper, experiments were carried out, varying Operating Conditions, and an Optimal Operating Condition was determined to improve performance of the present system still more. From the experimental results, the Conditions necessary to increase the amount of recovery ice were clarified. The time-dependencies of the shape and size of formed ice particles were also shown. Moreover, the reason why the freezing temperature of the functional fluid rose due to repetition of ice formation was clarified, and its measure was discussed. The present study then found that it was possible to form and recover a larger amount of ice than in previous attempts, given the rise in freezing temperature. ?? 2006 Elsevier Ltd and IIR.
