The Experts below are selected from a list of 68892 Experts worldwide ranked by ideXlab platform
Wu Chen - One of the best experts on this subject based on the ideXlab platform.
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a resonant zvzcs dc dc converter with two uneven transformers for an mvdc collection system of offshore wind farms
IEEE Transactions on Industrial Electronics, 2017Co-Authors: Liangcai Shu, Wu Chen, Guangfu Ning, Wu Cao, Jun Mei, Jianfeng Zhao, Chun LiuAbstract:A resonant zero-voltage and zero-current-switching (ZVZCS) dc–dc converter is proposed in this paper for a medium-voltage dc collection system of offshore wind farms. The resonant converter is composed of two full-bridge cells sharing a bridge leg, two transformers with uneven power ratings and different functions, whose secondary windings are connected in series and a voltage-doubler rectifier. The converter operates in discontinuous current mode and can achieve zero-current switching for four main power switches and rectifier diodes over the whole load range. The two auxiliary switches with small forward current can be turned on with ZVZCS, and turned off with zero-voltage switching. Hence, the switching loss can be reduced and efficiency is improved. The Operation Principle of the converter is analyzed and design rules of main parameters are presented. The influences of the turn ratios of auxiliary transformer and resonant capacitance on the peak and switching-off currents are discussed in detail. Furthermore, a model is built in PLECS and simulation results are given. A 150–1500 V/2 kW prototype is established and tested to verify the Operation Principle and design rules.
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A Hybrid ZVZCS Dual-Transformer-Based Full-Bridge Converter Operating in DCM for MVDC Grids
IEEE Transactions on Power Electronics, 2017Co-Authors: Guangfu Ning, Wu Chen, Liangcai Shu, Xiaohui QuAbstract:High-power dc-dc converter is the essential component for connecting the renewable energy sources to medium-voltage dc (MVDC) grids. In this paper, a novel zero-voltage zero-current switching converter with two full-bridge cells sharing a bridge leg and connecting the secondary windings of two transformers in series is proposed for MVDC applications. One big feature of the proposed converter is that the required inductance used for energy transmission is reduced remarkably and even can be embedded in the transformer in some cases. Special but simple control strategy adopted by the converter makes it work in discontinuous current mode, which can realize zero-current switching for the main switches and rectifier diodes in the whole load range. Meanwhile, the auxiliary switches with small current rating can realize zero-voltage switching naturally. Hence, the switching loss is reduced, which is very important for high-power applications. The effects of the turns ratio of auxiliary transformer on the total loss and needed inductance are comprehensively analyzed and proved. With a detailed parameters design procedure, a simulation model is established in the software PLECS and the Operation Principle of the converter is verified. A 120 V-1200 V/1 kW prototype was built to validate the Operation Principle of the proposed converter.
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a step up resonant converter for grid connected renewable energy sources
IEEE Transactions on Power Electronics, 2015Co-Authors: Wu Chen, Liangzhong Yao, Wei JiangAbstract:With the rapid development of large-scale renewable energy sources and HVDC grid, it is a promising option to connect the renewable energy sources to the HVDC grid with a pure dc system, in which high-power high-voltage step-up dc–dc converters are the key equipment to transmit the electrical energy. This paper proposes a resonant converter which is suitable for grid-connected renewable energy sources. The converter can achieve high voltage gain using an LC parallel resonant tank. It is characterized by zero-voltage-switching (ZVS) turn-on and nearly ZVS turn-off of main switches as well as zero-current-switching turn-off of rectifier diodes; moreover, the equivalent voltage stress of the semiconductor devices is lower than other resonant step-up converters. The Operation Principle of the converter and its resonant parameter selection is presented in this paper. The Operation Principle of the proposed converter has been successfully verified by simulation and experimental results.
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a novel zero voltage switching pwm full bridge converter
IEEE Transactions on Power Electronics, 2008Co-Authors: Wu Chen, Xinbo Ruan, Rongrong ZhangAbstract:Introducing resonant inductance and clamping diodes into the full-bridge converter can eliminate the voltage oscillation across the rectifier diodes and increase the load range for zero-voltage-switching (ZVS) achievement. The resonant inductance is shorted and its current keeps constant when the clamping diode is conducting, and the clamping diode is hard turned-off, causing significant reverse recovery loss if the output filter inductance is relatively larger. This paper improves the full-bridge converter by introducing a reset winding in series with the resonant inductance to make the clamping diode current decay rapidly when it conducts. The reset winding not only reduces the conduction losses, but also makes the clamping diodes naturally turn-off and avoids the reverse recovery. The Operation Principle of the proposed converter is analyzed. The design of the turns ratio of transformer is discussed. A 1 kW prototype converter is built to verify the Operation Principle and the experimental results are also demonstrated.
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a novel zero voltage switching pwm full bridge converter
Power Electronics Specialists Conference, 2007Co-Authors: Wu Chen, Xinbo Ruan, Rongrong ZhangAbstract:Introducing resonant inductance and clamping diodes into the full-bridge converter can eliminate the voltage oscillation across the rectifier diodes and increase the load range for zero- voltage-switching (ZVS) achievement. The resonant inductance is shorted and its current keeps constant when the clamping diode is conducting, and the clamping diodes are hard turned-off and cause significant reverse recovery loss if the output filter inductance is relatively larger. This paper improves the full-bridge converter by introducing a reset winding in series with the resonant inductance to make the clamping diode current decay rapidly when it conducts. The reset winding not only reduces the conduction losses, but also makes the clamping diodes naturally turn-off and avoids the reverse recovery. The Operation Principle of the proposed converter is analyzed. The design of the turns ratio of transformer is discussed. A 1kW prototype converter is built to verify the Operation Principle and the experimental results are also demonstrated.
Marc Linder - One of the best experts on this subject based on the ideXlab platform.
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heat transformation based on cacl2 h2o part b open Operation Principle
Applied Thermal Engineering, 2016Co-Authors: Martin Bouche, Margarethe Richter, Marc LinderAbstract:Abstract In order to increase the efficiency of industrial processes by means of thermal energy storage and upgrade of waste heat in a temperature range of 100–200 °C thermochemical systems are a promising option. The working pair CaCl2/H2O has been identified as suitable reference system due to the possibility to store thermal energy and perform an upgrade of thermal energy at the same time. As working Principle an open mode with air as purge gas is investigated in this work. Thus, an Operation at ambient pressure level as well as a less complex experimental setup can be realized. Therefore, a test facility has been set up for experimental investigation of the thermochemical system focusing on dehydration reaction. First, various reactor modifications are examined with respect to influence the pressure drop of the reactor containing the CaCl2. It was shown that by the insertion of gas channels made of fine metal mesh a reduction of the pressure drop by factor 6 is possible in comparison to the unmodified fixed bed. Additionally, parametric studies have been carried out regarding the variation of charging temperature and volume rate of air. In order to obtain a high temperature lift in the heat transformation process, low thermal charging temperatures are targeted.
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heat transformation based on cacl2 h2o part a closed Operation Principle
Applied Thermal Engineering, 2016Co-Authors: Margarethe Richter, Martin Bouche, Marc LinderAbstract:Abstract Thermochemical systems based on gas–solid-reactions enable both storage of thermal energy and its thermal upgrade by heat transformation. Thus, they are an interesting and promising option in order to reutilize industrial waste heat and reduce primary energy consumption. In this publication an experimental analysis of the reaction system calcium chloride and water vapor is presented. The endothermic dehydration reaction is used in order to charge the storage at 130 °C while the reverse reaction leads to a discharging at 165 °C. Thus, a thermal upgrade by 35 K could be demonstrated and main limitations by heat and mass transfer were analyzed. Whereas this part focusses on a closed Operation Principle, the associated part B deals with the open Operation utilizing air as purge gas.
Rongrong Zhang - One of the best experts on this subject based on the ideXlab platform.
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a novel zero voltage switching pwm full bridge converter
IEEE Transactions on Power Electronics, 2008Co-Authors: Wu Chen, Xinbo Ruan, Rongrong ZhangAbstract:Introducing resonant inductance and clamping diodes into the full-bridge converter can eliminate the voltage oscillation across the rectifier diodes and increase the load range for zero-voltage-switching (ZVS) achievement. The resonant inductance is shorted and its current keeps constant when the clamping diode is conducting, and the clamping diode is hard turned-off, causing significant reverse recovery loss if the output filter inductance is relatively larger. This paper improves the full-bridge converter by introducing a reset winding in series with the resonant inductance to make the clamping diode current decay rapidly when it conducts. The reset winding not only reduces the conduction losses, but also makes the clamping diodes naturally turn-off and avoids the reverse recovery. The Operation Principle of the proposed converter is analyzed. The design of the turns ratio of transformer is discussed. A 1 kW prototype converter is built to verify the Operation Principle and the experimental results are also demonstrated.
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a novel zero voltage switching pwm full bridge converter
Power Electronics Specialists Conference, 2007Co-Authors: Wu Chen, Xinbo Ruan, Rongrong ZhangAbstract:Introducing resonant inductance and clamping diodes into the full-bridge converter can eliminate the voltage oscillation across the rectifier diodes and increase the load range for zero- voltage-switching (ZVS) achievement. The resonant inductance is shorted and its current keeps constant when the clamping diode is conducting, and the clamping diodes are hard turned-off and cause significant reverse recovery loss if the output filter inductance is relatively larger. This paper improves the full-bridge converter by introducing a reset winding in series with the resonant inductance to make the clamping diode current decay rapidly when it conducts. The reset winding not only reduces the conduction losses, but also makes the clamping diodes naturally turn-off and avoids the reverse recovery. The Operation Principle of the proposed converter is analyzed. The design of the turns ratio of transformer is discussed. A 1kW prototype converter is built to verify the Operation Principle and the experimental results are also demonstrated.
Xinbo Ruan - One of the best experts on this subject based on the ideXlab platform.
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a novel zero voltage switching pwm full bridge converter
IEEE Transactions on Power Electronics, 2008Co-Authors: Wu Chen, Xinbo Ruan, Rongrong ZhangAbstract:Introducing resonant inductance and clamping diodes into the full-bridge converter can eliminate the voltage oscillation across the rectifier diodes and increase the load range for zero-voltage-switching (ZVS) achievement. The resonant inductance is shorted and its current keeps constant when the clamping diode is conducting, and the clamping diode is hard turned-off, causing significant reverse recovery loss if the output filter inductance is relatively larger. This paper improves the full-bridge converter by introducing a reset winding in series with the resonant inductance to make the clamping diode current decay rapidly when it conducts. The reset winding not only reduces the conduction losses, but also makes the clamping diodes naturally turn-off and avoids the reverse recovery. The Operation Principle of the proposed converter is analyzed. The design of the turns ratio of transformer is discussed. A 1 kW prototype converter is built to verify the Operation Principle and the experimental results are also demonstrated.
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a novel zero voltage switching pwm full bridge converter
Power Electronics Specialists Conference, 2007Co-Authors: Wu Chen, Xinbo Ruan, Rongrong ZhangAbstract:Introducing resonant inductance and clamping diodes into the full-bridge converter can eliminate the voltage oscillation across the rectifier diodes and increase the load range for zero- voltage-switching (ZVS) achievement. The resonant inductance is shorted and its current keeps constant when the clamping diode is conducting, and the clamping diodes are hard turned-off and cause significant reverse recovery loss if the output filter inductance is relatively larger. This paper improves the full-bridge converter by introducing a reset winding in series with the resonant inductance to make the clamping diode current decay rapidly when it conducts. The reset winding not only reduces the conduction losses, but also makes the clamping diodes naturally turn-off and avoids the reverse recovery. The Operation Principle of the proposed converter is analyzed. The design of the turns ratio of transformer is discussed. A 1kW prototype converter is built to verify the Operation Principle and the experimental results are also demonstrated.
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three level bi directional converter a novel dc dc converter suitable for fuel cell power system
Power Electronics Specialists Conference, 2006Co-Authors: Mengxiong Yang, Xinbo RuanAbstract:A novel three-level bidirectional converter is proposed in this paper. Compared with the traditional bi-directional converter, the voltage stress on the switch of the proposed converter is just half of the voltage on the high voltage side. The inductor of three-level bi-directional converter also can be reduced significantly, so the dynamic response can be improved. Therefore, it is very suitable for fuel cell power systems. This paper also illustrates the Operation Principle and implementation of the control circuit. A 1kW prototype converter is built to verify the theoretical analysis.
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a novel double phase shift control scheme for full bridge three level converter
Applied Power Electronics Conference, 2005Co-Authors: Zhiling Zhang, Xinbo RuanAbstract:A novel "double phase-shift (DPS)" control for full-bridge (FB) three-level (TL) converter is proposed, which improves efficiency by reducing losses of switches' body diodes meanwhile maintains the converter's original advantages without adding additional components compared with "chopping plus phase-shift (CPS)" control. The Operation Principle is verified on 3 kW, 100 kHz prototype
Martin Bouche - One of the best experts on this subject based on the ideXlab platform.
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heat transformation based on cacl2 h2o part b open Operation Principle
Applied Thermal Engineering, 2016Co-Authors: Martin Bouche, Margarethe Richter, Marc LinderAbstract:Abstract In order to increase the efficiency of industrial processes by means of thermal energy storage and upgrade of waste heat in a temperature range of 100–200 °C thermochemical systems are a promising option. The working pair CaCl2/H2O has been identified as suitable reference system due to the possibility to store thermal energy and perform an upgrade of thermal energy at the same time. As working Principle an open mode with air as purge gas is investigated in this work. Thus, an Operation at ambient pressure level as well as a less complex experimental setup can be realized. Therefore, a test facility has been set up for experimental investigation of the thermochemical system focusing on dehydration reaction. First, various reactor modifications are examined with respect to influence the pressure drop of the reactor containing the CaCl2. It was shown that by the insertion of gas channels made of fine metal mesh a reduction of the pressure drop by factor 6 is possible in comparison to the unmodified fixed bed. Additionally, parametric studies have been carried out regarding the variation of charging temperature and volume rate of air. In order to obtain a high temperature lift in the heat transformation process, low thermal charging temperatures are targeted.
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heat transformation based on cacl2 h2o part a closed Operation Principle
Applied Thermal Engineering, 2016Co-Authors: Margarethe Richter, Martin Bouche, Marc LinderAbstract:Abstract Thermochemical systems based on gas–solid-reactions enable both storage of thermal energy and its thermal upgrade by heat transformation. Thus, they are an interesting and promising option in order to reutilize industrial waste heat and reduce primary energy consumption. In this publication an experimental analysis of the reaction system calcium chloride and water vapor is presented. The endothermic dehydration reaction is used in order to charge the storage at 130 °C while the reverse reaction leads to a discharging at 165 °C. Thus, a thermal upgrade by 35 K could be demonstrated and main limitations by heat and mass transfer were analyzed. Whereas this part focusses on a closed Operation Principle, the associated part B deals with the open Operation utilizing air as purge gas.
