scholarly journals Comparative Evaluation of Wide-Range Soft-Switching PWM Full-Bridge Modular Multilevel DC–DC Converters

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 231 ◽  
Author(s):  
Jingwen Chen ◽  
Xiaofei Li ◽  
Hongshe Dang ◽  
Yong Shi

This paper discusses some wide-range soft-switching full-bridge (FB) modular multilevel dc–dc converters (MMDCs), and a comparative evaluation of these FB MMDCs is also presented. The discussed topologies have all merits belonging to conventional FB MMDCs, e.g., smaller voltage stress on the primary switches, no added primary clamping devices and modular primary structure. In addition, the primary switches in each converter can obtain zero-voltage switching (ZVS) or zero-current switching (ZCS) in a wide load range. Two presented topologies are selected as examples to discuss in detail. The proposed FB MMDCs are assessed and evaluated based on performance, components and topology structure indices, such as soft switching characteristics, current stress, power loss distribution, number of added devices, complexity of structure and added cost. Experimental results are also included to verify the feasibility and advantages of the new topologies.

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.


10.14311/1153 ◽  
2010 ◽  
Vol 50 (1) ◽  
Author(s):  
Z. Pfof ◽  
P. Vaculík

This paper describes the basic properties of ultracapacitors and a converter for ultracapacitors with application zero-voltage switching (ZVS). Because of the very high efficiency of the ultracapacitor, the efficiency of the converter for ultracapacitors also has to be high; otherwise, the converter reduces efficiency of the whole drive unit. Further, the paper describes the drive unit concept for the CityEl electric vehicle, with the use of ultracapacitors in cooperation with a fuel cell. This co-operation with ultracapacitors is useful for the supply unit as a fuel cell, which cannot deliver peak power in dynamic conditions while maintaining its nominal efficiency. However, this poses no problems for ultracapacitors.There is also a description of the basic principles of soft switching using zero-voltage and zero-current switching together with a comparison of the power losses between hard and soft switching. 


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5448
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Jenn-Jong Shieh

A soft switching boost converter, with a small number of components and constant frequency control, is proposed herein by using the quasi-resonance method and the zero-voltage-transition method, realizing (1) the zero-voltage switching during the switch-on transient of the main switch, (2) the zero-current switching during the switch-off transient of the main switch, (3) the zero-current switching during the switch-on transient of the auxiliary switch, and (4) the zero-current switching during the switch-off transient of the auxiliary switch. Accordingly, the corresponding efficiency can be improved. The feasibility and effectiveness of the proposed structure are validated by the field programmable gate array (FPGA).


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 ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5290
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Jenn-Jong Shieh

A non-isolated buck converter, together with resonance and zero voltage transition to achieve zero voltage switching (ZVS) and zero current switching (ZCS), is presented herein to upgrade the conversion efficiency. In this circuit, the main switch and the auxiliary switch are connected to the common ground so as to make the two switches easily driven. Furthermore, these two switches take time division multiplexing operation. In addition, the pulse width modulation (PWM) control technique is utilized so as to render the output inductor and capacitor easily designed. In this paper, the theoretical derivation is first introduced, and secondly, some experimental results are provided to demonstrate the effectiveness of the proposed topology.


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