Novel modulation method of a three-level isolated full-bridge LLC resonant DC-DC converter for wide-output voltage application

Author(s):  
Francisco Canales ◽  
Tin Ho Li ◽  
Daniel Aggeler
2018 ◽  
Vol 7 (3) ◽  
pp. 1059
Author(s):  
Mustafa Fawzi Mohammed ◽  
Ali Husain Ahmad ◽  
AbdulRahim Thiab Humod

The most concerns in the inverter's design are about, how to make the output voltage of the inverter sinusoidal at the desired fundamental frequency with low total harmonic distortion (THD). This paper presents a design and implementation of single-phase five-level inverter which is powered by single dc source and based on T-type multi-level inverters construction. The proposed inverter is built mainly by six IGBTs and two diodes. The used modulation technique is based on using two triangular carriers at 2000 Hz frequency and shifted by phase opposition disposition (POD) method. The carriers are made slightly unbalanced with their amplitudes. The over-modulation method is also introduced in the design to get the lowest possible THD effect without using filters. The inverter is simulated by MATLAB SIMULINK, implemented practically, and tested with the help of LabVIEW software.  


2020 ◽  
Vol 8 (5) ◽  
pp. 5180-5185

Paper Setup must be in A4 size with Margin: Top In the present paper multi carrier sinusoidal modulation technique which is an efficient method of producing control signals is used for a symmetrical inverter with several levels in cascade H Bridge is discussed. The Cascaded H-Bridge performance output levels depend on the DC voltage sources used at the input side. With the help of two DC voltage sources, five level output can be obtained whereas three sources gives levels of seven in output voltage. In this paper, multi-carrier SPWM switching is obtained for switching of multilevel inverter based switches. Two signals are used in this switching method, among which one of the signals is reference which is a low frequency sinusoidal signal and the one is a carrier signal. In case of sinusoidal PWM method of modulation technique, the reference signal is a sinusoidal one and triangular signal can be used as a carrier signal. These types of inverters have the ability to generate inverted output voltage with an efficient harmonic spectrum and reliable output results. This document provides switching signal for H-bridge inverter structure which can improve harmonic performance. The 5-level multilevel inverter is simulated for traditional carrier-based pulse-width modulation (PWM) phase change carrier techniques. The total harmonic performance of the output voltages is analyzed for the two PWM control methods. The performance of the symmetrical PWM CHB is simulated using MATLAB-SIMULINK model. Model results show that THD can be minimized to a limit with level shifted modulation method of the sinusoidal pulse width. The results from the simulations show that the quality of the waveform of the output voltage improves with less loss and with a lower THD.


Author(s):  
Laith M. Akram Alsaqal ◽  
Ahmed M. T. Ibraheem Alnaib ◽  
Omar Talal Mahmood

There are various types of Multilevel Converters (MCs) in addition to various types of modulation techniques for these types of MCs; the challenges in selecting the best one of them with regard to the amount of the required of components, and its harmonics content. So, a comparison study among these types has been done in this paper. For comparison study, the simulation of seven level of two popular topologies of MCs: Neutral Point Clamped (NPC) converter, and Cascaded-MCs were carried out with Matlab/Simulink software program. These converters are used to drive a single phase capacitor start motor drive. Multicarrier modulation control techniques are used for controlling the MCs; these techniques involve two main type: Level Shifted Carrier (LSC), and Phase Shifted Carrier (PSC). The comparison is made with respect to the performance factors as, the amplitude of  the Total Harmonic Distortion (THD), and the DC-bus utilization performance which measured by Root Mean Square of the output voltage Vrms at variable modulation indices and variable carrier frequency. Based on simulation results it's found, that the cascaded-MC with PSC modulation method gives best results, in addition to the Alternative Phase Opposition Disposition APOD-LSC modulation technique (with even number of modulation frequency) generate the output voltage with a lower harmonic content compared with the other techniques.


Motor performance and life is decreased due to presence of harmonic in the output voltage. Many inverter topologies were proposed for industrial drives application. PV based three phase asymmetrical cascade nine level inverter fed induction motor is proposed in this article. The proposed circuit has one dc source derived from PV with MPPT and nine level inverter with reduced components. The PV output voltage is regulated with help of boost converter using MPPT algorithm. The proposed inverter has unequal voltage source 1:2:4 ratios. The fundamental frequency modulation method is used for control the inverter output voltage. The proposed multi level inverter has less switching device and diode compare than other multilevel inverter topology. The circuit is modified further by replacing switching device with diode in the source section for reducing switching count; as a result, the control algorithm and driver circuit complexity are reduced further. The circuit performance is verified with help of simulation results


2015 ◽  
Vol 7 (3) ◽  
pp. 357-360 ◽  
Author(s):  
Tadas Lipinskis ◽  
Valerijus Zlosnikas

Multiphase AC machines are more reliable that three phase machines due to their ability to work when one or more phases fail. Also multiphase machines have higher starting torque, which enables them to start with heavier loads. Inverters are used to supply power and control parameters of an AC machine. In this paper a six phase inverter with a symmetrical star connected load with a single neutral is discussed. When the inverter's output voltage is formed by space vector pulse width modulation method, a high frequency harmonics appear in the output voltage, which increases power losses. The purpose of this work is to investigate what type of effect on output voltage harmonics has the sequence of space vectors in the switching table. Two methods of creating a switching table are presented in this paper, and two switching tables are created. Inverter's operation with both switching tables is simulated in Matlab/Simulink environment. Result analysis shows that changing the switching vector sequence in the switching table has an effect on output voltage harmonics of frequency around inverter's switching frequency. Daugiafaziai elektros varikliai yra patikimesni nei trifaziai dėl jų galimybės veikti dingus vienai ar daugiau fazių. Taip pat daugiafazių variklių startinis sukimo momentas yra didesnis, todėl šie varikliai gali pradėti veikti esant didesnei apkrovai. Daugiafaziams varikliams energijai tiekti ir valdyti naudojami dažnio keitikliai. Darbe nagrinėjamas šešių fazių dažnio keitiklis, apkrautas žvaigždės jungimo simetrine apkrova su viena neutrale. Formuojant įtampą erdvinių vektorių impulsų skvarbos moduliacijos metodu, keitiklio išėjimo įtampoje dėl raktų junginėjimo atsiranda komutavimo triukšmų, kurie sukelia energijos nuostolių. Darbo tikslas yra ištirti erdvinių vektorių perjungimo tvarkos įtaką išėjimo įtampos harmonikoms. Darbe tiriami komutavimo triukšmai esant dvejopiems erdvinio vektoriaus perjungimo tvarkos atvejams. Tyrimams naudoti Matlab/Simulink modeliai.


2021 ◽  
Vol 25 (1) ◽  
pp. 31-36
Author(s):  
Rim Feyrouz Abdelgoui ◽  
◽  
Rachid Taleb ◽  
Abderrahim Bentaallah ◽  
Fayçal Chabni ◽  
...  

This study presents the application of differential evolution algorithm to compute optimal switching angles for a single-phase nine-level inverter to improve the output voltage quality. The topology of the proposed inverter in this article is a simple cascade converter composed of two H-bridge cells with non-equal DC voltage sources in order to generate multiple voltage levels. Selective harmonic elimination pulse width modulation strategy is used to improve the generated AC output voltage waveform. The differential evolution optimization algorithm is used to solve non-linear transcendental equations necessary for the (SHPWM). Computational results obtained from computer simulations presented a good agreement with the theoretical predictions. A laboratory prototype based on STM32F407 microcontroller was built in order to validate the simulation results. The experimental results show the effectiveness of the proposed modulation method.


Foristek ◽  
2019 ◽  
Vol 9 (2) ◽  
Author(s):  
Agus Mahendra ◽  
Sapril Sapril ◽  
Maryantho Masarrang

Flyback Converter is an electronic circuit that can increase the output voltage value, the voltage value can be adjusted by changing the value of the duty cycle. This Flyback Converter will be controlled by the Pulse Width Modulation method as the output voltage setting and this research is equipped with a feedback function as monitoring and control of Input Pulse Width Modulation. This designed flyback converter aims to provide an isolated power supply as a power source for Brushless Direct Current Motor drivers, and this research was conducted to analyze how much power the flyback converter can produce to be able to supply Brushless Direct Current Motor drivers. The results of the analysis obtained in the research Design of flyback converter for power supply of BLDC (Brushless Direct Current) motor driver that is flyback converter is given an input voltage of 31 VDC and output voltage of 15 VDC, rheostat load with a capacity of 39 Ohm, a frequency of 31 KHz in the form of a box wave duty cycle reaches 70%. Flyback converter designed to produce maximum power of 49.6 watts on 70% duty cycle testing.


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