scholarly journals Operation of Current-fed Dual Active Bridge DC-DC Converters for Microgrid

2019 ◽  
Vol 8 (2) ◽  
pp. 3167-3175

Dual Active Bridge (DAB) is an isolated bidirectional DC-DC converter, which comprises two full bridge converterslinked through a high frequency transformer. It haslow stresses and permits high frequency performance because of the soft-switching. All the switches in the converter achieves the turn ON & OFF during Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) to minimize switching loss. Generally, DAB is classified as two types, namely, voltage-fed and current-fed variants. At light load conditions, soft-switching is not realized in case of voltage-fed DAB topologies. The application of current-fed DAB converters is to reduce the losses at the time of switching under light load conditions and improves the efficiency. This paper describes the various topologies of voltage-fed and current-fed DAB used for different applications in microgrid and fuel cell energy generation system by using the simulation. The performance of voltage-fed and current-fed DAB with snubber-less converters are also demonstrated and their effectiveness are validated

2012 ◽  
Vol 263-266 ◽  
pp. 43-47
Author(s):  
Fang Yang ◽  
Zhao Hui Liu ◽  
Jian Wei Zhang

This paper discusses the topology requirements of the small power photovoltaic grid-connected inverter,and introduces several typical topologies,moreover,points out the advantages and disadvantages,efficiency and applicable occasions of the various topologies. In this paper,a single-phase full-bridge grid-connected inverter topology(DC/AC) is designed. The soft-switching technology is employed on the topology for reducing switching loss. The topology can realizes zero voltage switching when the main switch turns on and turns off and zero current switching when auxiliary switch and the power diode turns on and turns off.The converter has higher efficiency than other topologies.


2012 ◽  
Vol 424-425 ◽  
pp. 1024-1027 ◽  
Author(s):  
Hyun Lark Do

A non-isolated high step-up DC-DC converter with a coupled inductor is proposed in this paper. The proposed converter provides high voltage gain and soft-switching operation of all semiconductor devices. A voltage doubler and a coupled inductor increase the voltage gain. Zero-voltage-switching (ZVS) of all switches and zero-current-switching (ZCS) of all diodes are achieved. Also, the voltages across the semiconductor devices are effectively clamped. Due to the soft-switching operation of all switching devices, the switching loss is significantly reduced and the high efficiency is obtained. The feasibility and performance of the proposed converter were verified on an experimental prototype


The conventional Bidirectional Full-bridge dc -dc converter is inefficient and may not be practical for the low power applications. This paper specifies an efficient DC-DC Converter that avoids power losses by using soft switching techniques like Zero Voltage Switching and Zero Current switching. The soft switching of Bidirectional Full-bridge DC-DC Converter operates as a buck converter when the power is positive and as a boost converter when the power flow is negative. Applications of soft switching Bidirectional Full-bridge DC-DC Converter are uninterrupted power supplies (UPS), distribution Systems, battery charger circuits, telecom power supplies, computer power systems. Detailed analysis of the converter is carried out in buck mode to obtain relations between the power circuit parameters. Based on the analysis, control schemes are described to operate the converter. The proposed full bridge DC-DC converter is simulated in Buck mode using MATLAB /SIMULINK.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1119 ◽  
Author(s):  
Chun-Wei Lin ◽  
Chang-Yi Peng ◽  
Huang-Jen Chiu

A novel three-phase power-factor-correction (PFC) rectifier with zero-voltage-switching (ZVS) in six main switches and zero-current-switching (ZCS) in the auxiliary switch is proposed, analyzed, and experimentally verified. The main feature of the proposed auxiliary circuit is used to reduce the switching loss when the six main switches are turned on and the one auxiliary switch is turned off. In this paper, a detailed operating analysis of the proposed circuit is given. Modeling and analysis are verified by experimental results based on a three-phase 7 kW rectifier. The soft-switched PFC rectifier shows an improvement in efficiency of 2.25% compared to its hard-switched counterpart at 220 V under full load.


2020 ◽  
Vol 10 (6) ◽  
pp. 2167
Author(s):  
Yong-Nong Chang ◽  
Hung-Liang Cheng ◽  
Hau-Chen Yen ◽  
Chien-Hsuan Chang ◽  
Wei-Di Huang

This study presents a dc/dc converter featuring soft-switching characteristic, high conversion efficiency, and high step-up ratio. The proposed circuit is composed of two parallel-connected boost converters. Only one coupled inductor is used to replace inductors of the boost converters which are interleaved operated at discontinuous-conduction mode (DCM). The current ripples at the input and the output terminals are reduced due to the interleaved operation. By freewheeling the current of the coupled inductor to discharge the stored electric charges in the parasitic capacitors of the active switches, both active switches can fulfill zero-voltage switching on (ZVS). Owing to DCM operation, the freewheeling diodes can fulfill zero-current switching off (ZCS). Therefore, the power conversion efficiency is improved. The operation principle for each operation mode is analyzed in detail and design equations for the component parameters are provided in this report. Finally, a prototype 200 W 48–400 V converter was implemented and measured to demonstrate the effectiveness of the proposed circuit.


2015 ◽  
Vol 16 (4) ◽  
pp. 331-337 ◽  
Author(s):  
S. Raghavendran ◽  
B. Chitti Babu ◽  
Luigi Piegari

Abstract This paper investigates a modified simple soft switching dc-dc converter for low power applications. This simple topology uses an auxiliary switch, an inductor and a capacitor to operate the converter without switching losses. The efficiency of the converter is improved by transferring the energy that would be dissipated during the switching to the load. The main switch turns-on with zero current switching (ZCS) and turns-off with zero voltage switching (ZVS), while the auxiliary switch turns-on and turns-off with zero voltage switching (ZVS). The detailed theoretical analysis and the design equations are described. In addition to that, the analysis of proposed converter is demonstrated by both simulation and experimental results for effectiveness of the study.


In this paper, the design and evaluation of isolated soft switching current LCC-T Resonant DC-DC Converter for PV/Fuel cell applications. For the front end inverter switches, zero voltage switching (ZVS) is used for conversion. For voltage double diodes, Zero-Current Switching (ZCS) is used. Earlier, DC-DC converter provides high harmonic currents, so to overcome that, proposed converter is introduced. The proposed converter will improve the content of harmonic current based on the input variations and wide load. To get the required output voltage, transformer ration will be reduced. Because of the, for PV/ Fuel cell applications have better foot Print and high potential. The proposed converter operates in two modes mainly; they are constant frequency mode and constant duty cycle mode. These modes mainly depend on the load demand. At last from results it can observe that gives satisfying proposed theory.


Author(s):  
Riz Rifai O. Sasue ◽  
Eka Firmansyah ◽  
Suharyanto Suharyanto

Interleaved boost converter gives good conversion efficiency due to its zero-current switching capability when operating in discontinuous conduction mode while keeping its input-output ripple current low. However, operating this kind of converter at interleaved operation for all the time gives poor efficiency under light-load condition. In this paper, an automatic operation region selector switch based on detection of the continuous or discontinuous current mode is proposed. With this switch, during the light-load condition, only one converter is activated, while during full-load condition both converters will be activated. The simulation results using LTspice software show that the proposed boost converter has a better efficiency compared to the conventional boost converter with efficiency range of 84.6 % to 95.32 % under various load conditions.


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