scholarly journals Efficiency of Synchronous and Asynchronous Buck-Converter at Low Output Current.

2019 ◽  
Vol 27 (2) ◽  
pp. 194-206
Author(s):  
Ismael Khaleel Murad
Keyword(s):  
Duty Cycle ◽  
Buck Converter ◽  
Voltage Regulator ◽  
Switching Frequency ◽  
Output Current ◽  
Load Current ◽  
Small Load ◽  
Step Down ◽  
Conduction Mode ◽  
Continuous Conduction Mode

In this paper both synchronous and asynchronous buck-converter were designed to work in continuous conduction mode “CCM” and to deliver small load current. Then the two topologies were tested in terms of efficiency at small load current by use of  different values of switching frequencies (range from 150 KHz to 1MHz) and three separated values of duty-cycle (0.4, 0.6 and 0.8).   Obtained results turns out that efficiency of both synchronous and asynchronous buck-converter “switching step-down voltage regulator” responds in a negative manner to the increase in the switching frequency. However, this impact is being stronger in synchronous topology because of magnifying effect of losses related to switching frequency compared to those related to conduction when working at small load currents; this behavior makes obtained efficiency of both topologies in convergent levels when they operated to deliver small output current especially when working with higher switching frequencies. Larger duty-cycle can rise up the efficiency of both topologies.

scholarly journals Voltage Control for DC-DC Converters

2018 ◽  
Author(s):  
Usman Rahat ◽  
Abdul Basit ◽  
Muhammad Salman
Keyword(s):  
Operational Amplifier ◽  
Output Voltage ◽  
Control Method ◽  
Voltage Control ◽  
Feedback System ◽  
Buck Converter ◽  
Load Current ◽  
Cuk Converter ◽  
Conduction Mode ◽  
Continuous Conduction Mode

In this paper, we discuss voltage control method for buck converter operating in continuous conduction mode (CCM) using analog feedback system. The aim of this work is to control the output voltage of a buck converter during the variation in load current. This is obtained using analog feedback made with operational amplifier (Opamp). However, the same technique can be applied to other DC-DC converters (e.g boost, buck-boost, cuk converter, etc) in CCM mode, but for the purpose of analysis buck converter is chosen as an example.

scholarly journals Novel Step-Down DC–DC Converters Based on the Inductor–Diode and Inductor–Capacitor–Diode Structures in a Two-Stage Buck Converter

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1131 ◽  
Author(s):  
Mauricio Dalla Vecchia ◽  
Giel Van den Broeck ◽  
Simon Ravyts ◽  
Johan Driesen
Keyword(s):  
Output Voltage ◽  
Buck Converter ◽  
Switching Frequency ◽  
Two Stage ◽  
Voltage Level ◽  
Multiple Strategies ◽  
Power Electronics Converters ◽  
Load Demand ◽  
Duty Cycles ◽  
Step Down

This paper explores and presents the application of the Inductor–Diode and Inductor-Capacitor-Diode structures in a DC–DC step-down configuration for systems that require voltage adjustments. DC micro/picogrids are becoming more popular nowadays and the study of power electronics converters to supply the load demand in different voltage levels is required. Multiple strategies to step-down voltages are proposed based on different approaches, e.g., high-frequency transformer and voltage multiplier/divider cells. The key question that motivates the research is the investigation of the aforementioned Inductor–Diode and Inductor–Capacitor–Diode, current multiplier/divider cells, in a step-down application. The two-stage buck converter is used as a study case to achieve the output voltage required. To extend the intermediate voltage level flexibility in the two-stage buck converter, a second switch was implemented replacing a diode, which gives an extra degree-of-freedom for the topology. Based on this modification, three regions of operation are theoretically defined, depending on the operational duty cycles δ2 and δ1 of switches S2 and S1. The intermediate and output voltage levels are defined based on the choice of the region of operation and are mapped herein, summarizing the possible voltage levels achieved by each configuration. The paper presents the theoretical analysis, simulation, implementation and experimental validation of a converter with the following specifications; 48 V/12 V input-to-output voltage, different intermediate voltage levels, 100 W power rating, and switching frequency of 300 kHz. Comparisons between mathematical, simulation, and experimental results are made with the objective of validating the statements herein introduced.

scholarly journals Interleaved DC-DC Converter with Discrete Duty Cycle and Open Loop Control

2016 ◽  
Vol 53 (4) ◽  
pp. 14-21
Author(s):  
K. Kroics ◽  
A. Sokolovs
Keyword(s):  
Duty Cycle ◽  
Control Algorithm ◽  
Open Loop ◽  
Current Loop ◽  
Open Loop Control ◽  
Output Current ◽  
Loop Control ◽  
Control Principle ◽  
Conduction Mode ◽  
Current Ripple

Abstract The authors present the control principle of the multiphase interleaved DC-DC converter that can be used to vastly reduce output current ripple of the converter. The control algorithm can be easily implemented by using microcontroller without current loop in each phase. The converter works in discontinuous conduction mode (DCM) but close to boundary conduction mode (BCM). The DC-DC converter with such a control algorithm is useful in applications that do not require precise current adjustment. The prototype of the converter has been built. The experimental results of the current ripple are presented in the paper.

scholarly journals Low-frequency oscillation of continuous conduction mode buck converter with pulse skipped modulation

2014 ◽  
Vol 63 (19) ◽  
pp. 198401
Author(s):  
Zhong Shu ◽  
Sha Jin ◽  
Xu Jian-Ping ◽  
Xu Li-Jun ◽  
Zhou Guo-Hua
Keyword(s):  
Low Frequency ◽  
Buck Converter ◽  
Frequency Oscillation ◽  
Low Frequency Oscillation ◽  
Conduction Mode ◽  
Continuous Conduction Mode

SIMULATION MEASUREMENT OF CONDUCTIVE INTERFERENCE

2021 ◽  
Author(s):  
А.М. САЖНЕВ ◽  
Л.Г. РОГУЛИНА
Keyword(s):  
Output Voltage ◽  
Electronic Device ◽  
Switching Frequency ◽  
Output Current ◽  
Voltage Converter ◽  
Software Environment ◽  
Load Current ◽  
Frequency Dependences

Разработана модель имитационных испытаний электронного устройства в современной программной среде на основе отечественных компонентов. Проведены имитационные испытания конвертора напряжения на 24 В с выходным током 1,4 А, частотой коммутации 20 кГц и выпрямительного устройства с выходным напряжением 48 В, током нагрузки 28 А. Получены частотные зависимости уровней кондуктивных помех и выполнена их оценка на соответствие нормам. A model of simulation tests of an electronic device in a modern software environment based on domestic components has been developed. Simulation tests of a 24 V voltage converter with an output current of 1.4 A, a switching frequency of 20 kHz, and a rectifier device with an output voltage of 48 V, a load current of 28 A were carried out. The frequency dependences of conductive interference levels were obtained and their compliance with the standards was evaluated.

scholarly journals Improvement in Voltage Gain of Interleaved High Step-Down Converter

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1019
Author(s):  
Kuo-Ing Hwu ◽  
Jenn-Jong Shieh ◽  
Hsiang-Hao Tu
Keyword(s):  
Output Power ◽  
Duty Cycle ◽  
Voltage Gain ◽  
Output Current ◽  
Elapsed Time ◽  
Basic Operating ◽  
Step Down ◽  
High Output

An interleaved high step-down converter is presented herein, which utilized a diode-capacitor module so as to make the step-down voltage gain under the same duty cycle as well as the voltage stresses on switches and diodes relatively low as compared with the existing circuits. Also, under the same voltage gain, the proposed circuit had a relatively large duty cycle, making the elapsed time per cycle for the connection between the input and the output enlarged, and hence the controller was not interrupted by noises. This converter can be used in low-output-power high-output-current applications. In this study, the basic operating principles of the proposed converter were firstly described and analyzed, and finally, its effectiveness was demonstrated by experiment.

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