Investigation of Switching Sequences on a Generalized SVPWM Algorithm for Multilevel Inverters

2018 ◽  
Vol 28 (02) ◽  
pp. 1950036 ◽  
Author(s):  
B. Hemanth Kumar ◽  
Makarand M. Lokhande

This paper investigates the various switching sequences on a generalized 60[Formula: see text] distributed coordinate system-based space vector pulse width modulation (SVPWM) algorithm for multilevel inverters. The main focus of this work is to improve the inverter output voltage profile by taking advantage of the redundancy inverter switching states. With the help of SVPWM algorithm, the three nearest vectors have to find out the synthesis of the [Formula: see text] location and then by applying the various optimum switching sequences, the inverter produces less harmonic content in the output voltage compared to the conventional switching sequence. All the switching sequence designs are developed with the help of minimum change detector (MCD) by using switching redundancies in order to reduce inverter switching loss. Simulation results to analyze various sequences on the general SVPWM algorithm are presented in the seven-level cascaded H-bridge (CHB) inverter. To validate the results, hardware results are presented on the seven-level CHB inverter.

Author(s):  
Hashim Hasabelrasul ◽  
Xiangwu Yan

<p>One of the preferred choices of electronic power conversion for high power applications are multilevel inverters topologies finding increased attention in industry. Cascaded H-Bridge multilevel inverter is one of these topologies reaching the higher output voltage, power level and higher reliability due to its modular topology. Level Shifted Carrier Pulse Width Modulation (LSCPWM) and Phase Shifted Carrier Pulse Width Modulation are used generally for switching cascaded H-bridge (CHB) multilevel inverters. This paper compares LSCPWM and PSCPWM in terms of total harmonics distortion (THD) and output voltage among inverter cells. Simulation for 21-level CHB inverter is carried out in MATLAB/SIMULINK and simulation results are presented.</p>


2021 ◽  
Vol 309 ◽  
pp. 01120
Author(s):  
Sameera Shaik ◽  
Suresh Kumar Tummala ◽  
D Srinivasa Rao

Nowadays, the multilevel inverter has gained huge attention and has become more popularized in high voltage and high-power applications with low harmonics. As the number of output voltage increases, the harmonic content of the output voltage waveform decreases. In this paper, a comparison of cascaded H-bridge and cross-switched multilevel inverters for 7, 9, 15, 21 levels will be carried out. The different control techniques that will be used for carrying out comparisons are space vector pulse width modulation (SPVPWM), sinusoidal pulse width modulation (SPWM), and third harmonic injection pulse width modulation (THI-PWM) respectively. Here, the seven-level inverter is discussed mainly and can be extended to any number of levels.


Author(s):  
R. Palanisamy ◽  
A. Velu ◽  
K. Selvakumar ◽  
D. Karthikeyan ◽  
D. Selvabharathi ◽  
...  

This paper deals the implementation of 3-level output voltage using dual 2-level inverter with control of sub-region based Space Vector Modulation (SR-SVM). Switching loss and voltage stress are the most important issues in multilevel inverters, for keep away from these problems dual inverter system executed. Using this proposed system, the conventional 3-level inverter voltage vectors and switching vectors can be located. In neutral point clamped multilevel inverter, it carries more load current fluctuations due to the DC link capacitors and it requires large capacitors. Based on the sub-region SVM used to control IGBT switches placed in the dual inverter system. The proposed system improves the output voltage with reduced harmonic content with improved dc voltage utilisation. The simulation and hardware results are verified using matlab/simulink and dsPIC microcontroller.


Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 263
Author(s):  
Manyuan Ye ◽  
Wei Ren ◽  
Qiwen Wei ◽  
Guizhi Song ◽  
Zhilin Miao

Asymmetric Cascaded H-bridge (ACHB) level inverters can output more voltage waveforms with fewer cascaded units while ensuring the quality of output voltage waveforms, so they have attracted more and more attention. Taking the topology of Type-III asymmetric CHB multilevel inverters as the research object, a Modified Hybrid Frequency Pulse Width Modulation (MHF-PWM) strategy is proposed in this paper. This modulation strategy overcomes the local overshoot of low-voltage unit in the presence of traditional Hybrid Frequency Pulse Width Modulation (HF-PWM), thus completely eliminating the low frequency harmonics in the output voltage waveform of Type-III ACHB nine-level inverters, and the Total Harmonic Distortion (THD) of output line voltage of the modulation strategy is lower than that of PS-PWM strategy in the whole modulation degree, which effectively improves the quality waveform of the output line voltage. At the same time, the strategy can also improve the problems of current backflow and energy feedback caused by the high-voltage unit pouring current to the low-voltage unit, thereby reducing the imbalance of the output power of the high-voltage and low-voltage units. Finally, the Matlab/Simulink simulation model and experimental platform are established to verify the validity and practicality of the modulation strategy.


2016 ◽  
Vol 25 (09) ◽  
pp. 1650108 ◽  
Author(s):  
P. Karuppusamy ◽  
G. Vijayakumar ◽  
S. Sathishkumar

This paper presents a photovoltaic (PV) system to convert the solar energy into electrical energy. DC power from PV system is converted into AC power using multilevel inverters. Cascaded H-bridge (CHB) inverter and diode clamped inverter (DCI) are used to convert variable DC power into sinusoidal AC power. Harmonic content is the important part to improve the efficiency of the inverter. Harmonics of CHB inverter and DCI are simulated and analyzed with different pulse width modulation (PWM) techniques.


Author(s):  
Piyush L. Kamani ◽  
Mahmadasraf A. Mulla

AbstractThis paper presents a univariate equation-based selective harmonic elimination-pulse-width modulation (USHE-PWM) method for cascaded H-bridge (CHB) multilevel inverters (MLIs). Using equal-area criteria, the selection of voltage rating of dc-links have been done. The output voltage is controlled by inserting switching notch at the centre of each level of output voltage. Instead of conventional transcendental SHE-PWM equations, all these calculations are accomplished using univariate equations. This simplifies the real-time implementation of the proposed method greatly, even for the MLI with a large number of levels. The USHE-PWM method can eliminate more harmonics compared with the conventional SHE-PWM methods. While controlling the output voltage, the harmonic pattern remains unaffected. The validity of the proposed method is confirmed by the simulation and experimental studies.


2018 ◽  
Vol 7 (3.1) ◽  
pp. 42
Author(s):  
B Kandavel ◽  
G Uvaraj ◽  
M Manikandan

This paper presents comparative study of Total Harmonic Distortion (THD) and its individual harmonic contents without grid and with grid for Diode clamped multi level inverter (DCMLI) and Flying capacitor clamped multilevel inverter (FCMLI) based Doubly Fed Induction Generator (DFIG) employing PI and Fuzzy logic controller (FLC). Simple method to control for a variable speed wind energy conversion system with a DFIG is connected to the grid through a diode rectifier and a diode clamped multilevel inverter (DCMLI). The DC-link voltage is controlled through a DC-DC boost converter to keep the DC voltage at constant value. Inverter is controlled by sinusoidal pulse width modulation technique, which supplies power to the grid. The THD and its harmonic content are studied for different wind speeds. DFIG fed flying capacitor multi level inverter (FCMLI) based WECS connected to load as well as grid. FCMLI is controlled through sinusoidal pulse width modulation. Voltage and current harmonics are studied. The results of both multilevel inverters are compared. It shows that the level of harmonic content of two types of multilevel inverters working at different wind speeds indicates that Total Harmonic Distortion (THD) for DCMLI has given best results.  


2014 ◽  
Vol 556-562 ◽  
pp. 1939-1944
Author(s):  
Zuo Ming Liu ◽  
Zi Qiang Xi ◽  
Chen Guang Yu

First of all, this paper speculates that the essence of the space vector pulse width modulation (SVPWM) is the injection of some kind of zero sequence component through the theoretical analysis. Increasing the range of output voltage and reducing the switching loss are the optimization it can realize, the essential realization method is implemented by changing the placement of zero space vector. Then the method is applied to the cascade multilevel carrier modulation. The main work of this paper is to analyze the relation between SVPWM and the carrier PWM in the two level converter, then add the discrete modulation into the cascade multilevel carrier modulation to verify that the space vector modulation can be realized in cascade multilevel and can get similar results with the two level.


Author(s):  
Chinnapettai Ramalingam Balamurugan ◽  
S.P. Natarajan ◽  
T.S. Anandhi ◽  
R. Bensaraj

<p class="JESTECAbstract">This paper presents the comparison of various multicarrier Pulse Width Modulation (PWM) techniques for the Cascaded Hybrid Multi Level Inverter (CHBMLI). Due to switch combination redundancies, there are certain degrees of freedom to generate the five level AC output voltage. This paper presents the use of Control Freedom Degree (CFD) combination. The effectiveness of the PWM strategies developed using CFD are demonstrated by simulation and experimentation.  The simulation results indicate that the chosen five level inverter triggered by the developed Phase Disposition(PD), Phase Opposition and Disposition(POD), Alternate Phase Opposition and Disposition (APOD), Carrier Overlapping (CO), Phase Shift (PS) and Variable Frequency (VF)<strong> </strong>PWM strategies developed are implemented in real time using FPGA. The simulation and experimental outputs closely match with each other validating the strategies presented.</p>


2018 ◽  
Vol 15 (2) ◽  
pp. 417-422
Author(s):  
P. Tamilvani ◽  
K. R. Valluvan

The Extended Phase Opposition Disposition PWM (EPODPWM) technique has been applied in the two-level inverters successfully, but it is impossible to apply directly the EPODPWM technique to multilevel inverters. This paper proposes two kinds of EPODPWM techniques suitable for a cascaded multilevel inverter, analyzes the control strategy with the EPODPWM and obtains the design of its parameters. The simulation results show the proposed EPODPWM methods can get high magnitudes of the output fundamental frequency component, low total harmonic distortion and simpler digital implementation.


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