scholarly journals Design buck converter with variable switching frequency by using matlab simulink simulation

2020 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Norazila Binti Md Posdzi ◽  
Norsa’adah Binti Mahmor ◽  
Rasidah Binti Abdul Rani

This paper presents the design of a buck converter circuit with different input switching frequency by using Matlab Simulink software. This study focuses on defining the suitable value of the inductor and capacitor to be used in the buck converter with 100VDC supply input, where the input switching frequency is use 5kHz and 25kHz. This is because the input switching frequency of a buck converter affects many aspects of circuit functionality. This design of the circuit used 20% of the duty cycle, and inductor value is 25% of Lmin to ensure the operation is in continuous current mode. The evaluation of inductor current and switching frequency used in the circuit and parameters for this analysis based on the output voltage, inductor voltage and inductor current waveform. The design of the circuit verified by simulation and results compared with the theoretical. In addition, the appropriate input switching frequency between 5kHz and 25kHz has been determined in order to use in the buck converter circuit for 100Ω resistive load.

2020 ◽  
Vol 10 (4) ◽  
pp. 39
Author(s):  
Maziar Rastmanesh ◽  
Ezz El-Masry ◽  
Kamal El-Sankary

Photo-voltaic (PV) power harvest can have decent efficiency when dealing with high power. When operating with a DC–DC boost converter during the low-power harvest, its efficiency and output voltage are degraded due to excessive losses in the converter components. The objective of this paper is to present a systematic approach to designing an efficient low-power photo-voltaic harvesting topology with an improved efficiency and output voltage. The proposed topology uses a boost converter with and extra inductor in recycled and synchro-recycled techniques in continuous current mode (CCM). By exploiting the non-linearity of the PV cell, it reduces the power loss and using the current stored in the second inductor, it enhances the output voltage and output power simultaneously. Further, by utilizing the Metal Oxide Silicon Field Effect Transistor’s (MOSFET) body diode as a switch, it maintains a minimum hardware, and introduces a negligible impact on the reliability. The test results of the proposed boost converters show that it achieves a decent power and output voltage. Theoretical and experimental results of the proposed topologies with a tested prototype are presented along with a strategy to maximize power and voltage conversion efficiencies and output voltage.


In order to analyze the bifurcation and chaos of Superbuck converter in Continuous Current Mode (CCM), a new method of time-frequency diagram based on Wigner-Ville distribution is proposed. The method is used to analyze the variation of the energy component of the output voltage with frequency and time. It reveals that the Superbuck converter exhibits period-1 bifurcation, period-2 bifurcation, period-4 bifurcation and chaos under different reference current. The results of the time-frequency diagram are consistent with the results of the bifurcation diagram, time-domain diagram, phase diagram and Poincare section. It proves that the method can deeply understand the nature of bifurcation and chaos in Superbuck converter, and it provides a new way to analyze the nonlinear phenomena of DC-DC converter


2003 ◽  
Vol 13 (03) ◽  
pp. 713-722 ◽  
Author(s):  
CARLES BATLLE ◽  
IMMA MASSANA ◽  
ALICIA MIRALLES

Using the QR decomposition of the tangent map, we explicitly write the differential equations satisfied by the Lyapunov exponents of a two-dimensional bilinear system, and specialize them to the buck converter in continuous current mode. These equations are solved numerically for an arbitrary value of the bifurcation parameter, and analytically for periodic orbits, recovering for the later results already known from the computation of Floquet exponents.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1131 ◽  
Author(s):  
Mauricio Dalla Vecchia ◽  
Giel Van den Broeck ◽  
Simon Ravyts ◽  
Johan Driesen

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.


Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1540
Author(s):  
Longkun Lai ◽  
Ronghua Zhang ◽  
Kui Cheng ◽  
Zhiying Xia ◽  
Chun Wei ◽  
...  

Integration is a key way to improve the switching frequency and power density for a DC-DC converter. A monolithic integrated GaN based DC-DC buck converter is realized by using a gate driver and a half-bridge power stage. The gate driver is composed of three stages (amplitude amplifier stage, level shifting stage and resistive-load amplifier stage) to amplify and modulate the driver control signal, i.e., CML (current mode logic) level of which the swing is from 1.1 to 1.8 V meaning that there is no need for an additional buffer or preamplifier for the control signal. The gate driver can provide sufficient driving capability for the power stage and improve the power density efficiently. The proposed GaN based DC-DC buck converter is implemented in the 0.25 μm depletion mode GaN-on-SiC process with a chip area of 1.7 mm × 1.3 mm, which is capable of operating at high switching frequency up to 200 MHz and possesses high power density up to 1 W/mm2 at 15 V output voltage. To the authors’ knowledge, this is the highest power density for GaN based DC-DC converter at the hundreds of megahertz range.


2016 ◽  
Vol 9 (4) ◽  
pp. 710-718 ◽  
Author(s):  
Federico Martin Ibanez ◽  
Jose Martin Echeverria ◽  
Daniel Astigarraga ◽  
Luis Fontan

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