Staircase modulation of modular multilevel converters with minimal total harmonic distortion and maximal number of output voltage levels

2016 ◽  
Author(s):  
Sufei Li ◽  
Yi Deng ◽  
Ronald G. Harley
Keyword(s):  
Output Voltage ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Multilevel Converters ◽  
Modular Multilevel Converters

scholarly journals WIDE RANGE MODULATION INDEXES FEATURED CARRIER-BASED PWM STEPPED WAVEFORM FOR HALF-BRIDGE MODULAR MULTILEVEL CONVERTERS

2018 ◽  
Vol 19 (2) ◽  
pp. 43-53
Author(s):  
Majdee Tohtayong ◽  
Sheroz Khan ◽  
MASHKURI BIN YAACOB ◽  
Siti Hajar Yusoff ◽  
NUR SHAHIDA BINTI MIDI ◽  
...  
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Modulation Index ◽  
Output Current ◽  
Multilevel Converters ◽  
Voltage Output ◽  
Wide Range ◽  
Modular Multilevel Converters ◽  
Modulation Region

ABSTRACT: This paper presents simulation results of the influence of wide range modulation index values ( ) in carrier-based PWM strategy for application in generating the stepped waveform. The waveform is tested for application in single-phase half-bridge modular multilevel converters (MMCs) topology. The results presented in this paper include a variation of the fundamental component (50 Hz) in the voltage output.  It also studies total harmonic distortion of the output voltage (THDv) and the output current (THDi) when the modulation index is changed over the linear-modulation region, 0 < < 1. It also explores the effect of a modulation index greater than 1. Moreover, different output voltage shapes, as a consequence of varied  on MMCs, are also illustrated for showing the effect of varying the value of on sub-module of MMCs. ABSTRAK: Kajian ini berkenaan tentang pengaruh simulasi terhadap pelbagai nilai indeks ( ) berasaskan strategi PWM bagi menghasilkan bentuk gelombang bertingkat. Bentuk gelombang ini diuji untuk aplikasi topologi MMCs. Keputusan menunjukkan variasi pada komponen asas (50Hz) pada voltan akhir. Keputusan menunjukkan jumlah penyelarasan harmonik voltan akhir (THDv) dan arus (THDv) apabila indeks modulasi telah ditukar pada had modulasi linear, 0 < < 1. Ia juga membincangkan tentang kesan indeks modulasi lebih daripada 1. Selain itu, bentuk voltan akhir yang berbeza mengikut perubahan nilai   pada MMCs juga dilampirkan bagi menunjukkan kesan perbezaan nilai    pada sub-modul MMCs.

scholarly journals An analytical technique to obtain higher-order approximate periods for nonlinear oscillator

2018 ◽  
Vol 19 (2) ◽  
pp. 182-191 ◽  
Author(s):  
Md Sazzad Hossien Chowdhury ◽  
Md. Alal Hosen ◽  
MOHAMMAD YEAKUB ALI ◽  
AHMAD FARIS ISMAIL
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Modulation Index ◽  
Multilevel Converters ◽  
Analytical Technique ◽  
Voltage Output ◽  
Wide Range ◽  
Modular Multilevel Converters ◽  
Modulation Region

ABSTRACT: This paper presents simulation results of the influence of wide range modulation index values ( ) in carrier-based PWM strategy for application in generating the stepped waveform. The waveform is tested for application in single-phase half-bridge modular multilevel converters (MMCs) topology. The results presented in this paper include a variation of the fundamental component (50 Hz) in the voltage output.  It also studies total harmonic distortion of the output voltage (THDv) and the output current (THDi) when the modulation index is changed over the linear-modulation region, 0 < < 1. It also explores the effect of a modulation index greater than 1. Moreover, different output voltage shapes, as a consequence of varied on MMCs, are also illustrated for showing the effect of varying the value of on sub-module of MMCs. ABSTRAK: Penulisan ini berkenan simulasi pengaruh pelbagai nilai indeks modulasi     ( ) dalam strategi PWM berasaskan aplikasi dalam menghasilkan bentuk gelombang yang bertingkat. Bentuk gelombang ini diuji untuk aplikasi dalam topologi MMCs. Penilaian dan hasil dari artikle ini termasuk variasi komponen asas (50 Hz) dalam voltan keluar. Ia juga meneliti jumlah penyelarasan harmonik voltan keluar (THDv) dan arus keluaran (THDi) apabila indeks modulasi ditukar dalam rantau modulasi linear, 0 < <1. Ia juga meneroka kesan indeks modulasi lebih daripada 1. Selain itu, bentuk voltan keluar yang berbeza sebagai akibat dari pelbagai  pada MMCs juga digambarkan untuk menunjukkan kesan berbeza-beza nilai  pada sub-modul MMCs.

scholarly journals Harmonics reduction of a five-level inverter by unbalanced carriers and over-modulation techniques

2018 ◽  
Vol 7 (3) ◽  
pp. 1059
Author(s):  
Mustafa Fawzi Mohammed ◽  
Ali Husain Ahmad ◽  
AbdulRahim Thiab Humod
Keyword(s):  
Fundamental Frequency ◽  
Output Voltage ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Modulation Method ◽  
Labview Software ◽  
Design And Implementation ◽  
Modulation Techniques ◽  
Multi Level

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.  

scholarly journals Multicarrier PWM Strategies for Hybrid Symmetrical Multilevel Inverter with Reduced Switch Count

2020 ◽  
Vol 9 (5) ◽  
pp. 860-866
Keyword(s):  
Electromagnetic Interference ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Total Harmonic Distortion ◽  
Switching Frequency ◽  
Third Harmonic ◽  
Multilevel Inverters ◽  
High Switching Frequency

Multilevel inverters are widely used for high power and high voltage applications. The performance of multilevel inverters are superior to conventional two level inverters in terms of reduced total harmonic distortion, higher dc link voltages, lower electromagnetic interference and increased quality in the output voltage waveform. This paper presents a single phase hybrid eleven level multilevel inverter topology with reduced switch count to compensate the above mentioned disadvantages. This paper also presents various high switching frequency based multi carrier pulse width modulation strategies such as Phase Disposition PWM Strategy (PDPWM), Phase Opposition and Disposition PWM Strategy (PODPWM), Alternate Phase opposition Disposition PWM (APODPWM), Carrier Overlapping PWM (COPWM), Variable frequency carrier PWM (VFPWM), Third Harmonic Injection PWM (TFIPWM) applied to the proposed eleven level multilevel inverter and is analyzed for RL load. FFT analysis is carried out and total harmonic distortion, fundamental output voltage are calculated. Simulation is carried out in MATLAB/SMULINK.

scholarly journals Comparison of multiple modulation techniques for various topologies of multilevel converters for single phase AC motor drive

2019 ◽  
Vol 10 (2) ◽  
pp. 662
Author(s):  
Laith M. Akram Alsaqal ◽  
Ahmed M. T. Ibraheem Alnaib ◽  
Omar Talal Mahmood
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Modulation Frequency ◽  
Harmonic Distortion ◽  
Modulation Method ◽  
Motor Drive ◽  
Comparison Study ◽  
Multilevel Converters ◽  
Performance Factors ◽  
Modulation Techniques

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.

Enhanced frequency shift carrier modulation for H-bridge multilevel converter to conquer the impact of instability in deputize condenser voltage

2018 ◽  
Vol 57 (2) ◽  
pp. 164-174
Author(s):  
Yuvaraja T ◽  
KA Ramesh Kumar
Keyword(s):  
Frequency Shift ◽  
High Power ◽  
Output Voltage ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Multilevel Converter ◽  
Control Scheme ◽  
Capacitor Voltage ◽  
Nonlinear Compensation ◽  
The Impact

H-bridge multilevel converter is the most challenging topology from nominal to high power applications. However, when the energy is exchanged between AC side and DC side or vice versa, the fluctuation in the capacitor used in deputize unit is unavoidable. The fluctuation in the deputize unit is due to the increase in the total harmonic distortion by the capacitor in the output voltages. This total harmonic distortion is evaded by exploring the deputize unit capacitor voltage mathematically. This paper proposes the enhanced frequency shift carrier modulation in H-bridge multilevel converter to suppress the influence of fluctuation in deputize unit capacitor voltages. Enhanced frequency shift carrier modulation is considered for nonlinear compensation. The principal results of using this enhanced frequency shift carrier modulation improvise the total harmonic distortion in the output voltage of H-bridge multilevel converter. Simulation and experimental results are done using MATLAB/SIMULINK to verify the effectiveness of the proposed control scheme.

scholarly journals Symmetrical and Asymmetrical Multilevel Inverter Structures with Reduced Number of Switching Devices

2018 ◽  
Vol 11 (1) ◽  
pp. 144 ◽  
Author(s):  
M. H. Yatim ◽  
A. Ponniran ◽  
M. A. Zaini ◽  
M. S. Shaili ◽  
N. A. S. Ngamidun ◽  
...  
Keyword(s):  
Stress Reduction ◽  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Total Harmonic Distortion ◽  
Multilevel Structure ◽  
Distortion Reduction ◽  
Switching Devices

The purpose of this study is to analyze the operation and design of symmetrical and asymmetrical multilevel inverter structures with reduced number of switching devices. In this study, the term of conventional inverter is defined as a single cascaded inverter. Specifically, the inverter operates in three complete loops and only produces 2-level and 3-level of output voltages. Usually, cascaded structure suffers from the high total harmonic distortion. Thus, by considering multilevel structure of inverter, low total harmonic distortion reduction and voltage stress reduction on switching devices can be archived. Sinusoidal pulse width modulation and modified square pulse width modulation are used as modulation techniques in switching schemes of the designed multilevel inverters. The findings indicate that, the designed multilevel structure cause low total harmonics distortion at the output voltage. Furthermore, the asymmetrical structure is producing the same output voltage levels with reduced number of switching devices compared to the symmetrical structure is experimentally confirmed. The findings show that the total harmonic distortion for 7-level (symmetrical) and 9-level (asymmetrical) are 16.45% and 15.22%, respectively.

scholarly journals Compare the Symmetric Hybridized Cascaded MLI with 17 levels with the Asymmetric Switched Capacitor MLI Topologies for Dynamic Loading

2021 ◽  
Vol 9 (VII) ◽  
pp. 1951-1958
Author(s):  
Jayesh B. Patil
Keyword(s):  
Renewable Energy ◽  
Dynamic Loading ◽  
Output Voltage ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Total Harmonic Distortion ◽  
Switched Capacitor ◽  
Matlab Simulink ◽  
Energy Applications ◽  
Load Disturbance

This article builds a symmetric hybridized cascaded a switching capacitor unit in a multilayer inverter and compares it to For 17 level inverters, A switched capacitor unit is utilized with an asymmetric multilevel inverter. In the symmetric hybridized multilevel inverter design, a In the midst of a dual-input dc source, there is a bi-directional switch is utilized to create a modified H-bridge inverter with a five-level output voltage instead of three. In the proposed scenario, In an asymmetric multilevel inverter, the switched capacitor unit substitutes the dc sources. which enlarges By a factor of two, The output voltage has been increased. and the voltage levels at the loads are increased by a factor of two. MATLAB-SIMULINK was used to verify the suggested topology using the staircase modulation approach. The findings show that multilayer inverter topologies with low total harmonic distortion, fewer switches, With greater levels of output voltage are better stable during load disturbance circumstances, making them ideal for renewable energy applications.

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