scholarly journals Symmetrical Cascaded Switched-Capacitor Multilevel Inverter Based on Hybrid Pulse Width Modulation

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7643
Author(s):  
Lingling Cao ◽  
Jiefeng Lin ◽  
Shikai Chen ◽  
Yuanmao Ye
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Reactive Power ◽  
Input Voltage ◽  
Industrial Applications ◽  
Multilevel Inverter ◽  
Switching Frequency ◽  
Switched Capacitor ◽  
Cascaded Multilevel Inverter

Multilevel inverters have been widely used in various industrial applications such as renewable energy generation and electric vehicles. An improved circuit of symmetrical cascaded switched-capacitor multilevel inverter is proposed so that the reactive power is absorbed by its power supply instead of capacitors. Then, a special hybrid pulse width modulation strategy combing level-shifted pulse width modulation (LS-PWM) and phase-shifted pulse width modulation (PS-PWM) was developed for the inverter. With this modulation algorithm, the power between cascaded units is automatically balanced, and the voltage of the capacitor in each unit is also automatically balanced to the dc input voltage. In addition, the optimized capacitor voltage ripple makes it possible to use a smaller capacitor to produce a better output voltage waveform. Theoretical analysis, simulation and experimental results show that the equivalent switching frequency of the cascaded multilevel inverter is twice the original frequency so that the output voltage harmonics are only distributed near even multiples of the carrier frequency.

Synchronized Symmetrical Bus-Clamping PWM Strategies for Three Level Inverter: Applications to Low Switching Frequencies

2011 ◽  
Vol 12 (2) ◽  
Author(s):  
Sreenivasappa Bhupasandra Veeranna ◽  
Udaykumar R Yaragatti ◽  
Abdul R Beig
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
High Performance ◽  
Pulse Width Modulation ◽  
Industrial Applications ◽  
Voltage Source ◽  
Switching Frequency ◽  
Space Vector ◽  
Digital Implementation ◽  
Switching Losses

The digital control of three-level voltage source inverter fed high power high performance ac drives has recently become a popular in industrial applications. In order to control such drives, the pulse width modulation algorithm needs to be implemented in the controller. In this paper, synchronized symmetrical bus-clamping pulse width modulation strategies are presented. These strategies have some practical advantages such as reduced average switching frequency, easy digital implementation, reduced switching losses and improved output voltage quality compared to conventional space vector pulse width modulation strategies. The operation of three level inverter in linear region is extended to overmodulation region. The performance is analyzed in terms THD and fundamental output voltage waveforms and is compared with conventional space vector PWM strategies and found that switching losses can be minimized using bus-clamping strategy compared to conventional space vector strategy. The proposed method is implemented using Motorola Power PC 8240 processor and verified on a constant v/f induction motor drive fed from IGBT based inverter.

Performance Analysis of H-bridge and T-Bridge Multilevel Inverters for Harmonics Reduction

2018 ◽  
Vol 9 (1) ◽  
pp. 231 ◽  
Author(s):  
S. Usha ◽  
C. Subramani ◽  
A. Geetha
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Multilevel Inverter ◽  
Multilevel Inverters ◽  
Semiconductor Switches ◽  
Output Waveform ◽  
Cascaded Multilevel Inverter ◽  
Sinusoidal Pulse Width Modulation

This paper deals with the design of cascaded 11 level H- bridge inverter. It includes a comparison between the 11 level H-bridge and T-bridge multilevel inverter. The cascaded inverter of higher level is a very effective and practical solution for reduction of total harmonic distortion (THD).These cascaded multilevel inverter can be used for higher voltage applications with more stability. As the level is increased the output waveform becomes more sinusoidal in nature. The inverter is designed using multicarrier sinusoidal pulse width modulation technique for generating triggering pulses for the semiconductor switches used in the device. Through this paper it will be proved that a cascaded multilevel H-bridge topology has higher efficiency than a T-bridge inverter, as whichever source input voltage is provided since input is equal to the output voltage. In T-bridge inverter, the output obtained is half of the applied input, so efficiency is just half as compared to H-bridge. The output waveform is distorted and has higher THD.  The simulation is performed using MATLAB /Simulink 2013 software.

scholarly journals Power Quality Improvement in Modular Multilevel Inverter Using for Different Multicarrier PWM

2021 ◽  
Vol 5 (2) ◽  
pp. 19-27
Author(s):  
Thenmalar Kaliannan ◽  
Johny Renoald Albert ◽  
D. Muhamadha Begam ◽  
P. Madhumathi
Keyword(s):  
Power Quality ◽  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Analog Circuit ◽  
Reactive Power ◽  
Pso Algorithm ◽  
Multilevel Inverter ◽  
Modulation Scheme ◽  
Non Linear Load

Pulse width modulation (PWM) is a powerful technique employed in analog circuit convert with a microprocessor based digital output. Besides, Pseudo Random Multi Carrier (PRMC) involves in two random PWM strategies to minimize the harmonic order for 9- level cascaded multilevel H-bridge (CHB) inverter and 9-level Modular Multilevel inverter are introduced. The design mainly focuses on the (Pulse Width Modulation) PWM method, in which two nearest voltage levels are approached in estimated output voltage prediction based on the Partial swarm optimization (PSO) algorithm, and it conveys a random variation in the pulse position of output by Pseudo Random Multi Carrier- Pulse Width Modulation (PRMC-PWM). The CHB and the Modular inverters generate low distortion output by using PMRC. The simulation and prototype circuit are developed for the nine level output using sixteen switches and ten with Resistive-Inductive (R-L) load variation condition. The power quality is improved in CHB and Modular inverter (MoI) with minimized harmonics in various modulation index (MI) as varied from 0.1 up to 0.8. The circuit is designed by using a Field Programmable Gate Array (FPGA), Implementing a PSO algorithm for both CHB, and MoI are proposed. The comparisons of results are verified with lower order harmonics and find the best switching angle across the MLI switches. Modular inverter furthermore investigates with PRMC, Random Nearest level (RNL) modulation scheme are presented, and the proposed circuit is along with the respective degree of the output voltage were synthesized in non-linear load by the development of reactive power across a motor load.

scholarly journals STATCOM based Multilevel Inverter Modelling and Simulation

2019 ◽  
Vol 8 (2) ◽  
pp. 4575-4578
Keyword(s):  
Energy Storage ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Reactive Power ◽  
Modelling And Simulation ◽  
Multilevel Inverter ◽  
Modulation Technique ◽  
System A ◽  
Bridge Type ◽  
Cascaded Multilevel Inverter

The desired reactive power can be provide by exchanging the instantaneous reactive power among the system. A cascaded multilevel inverter type STATCOM is implemented with an isolate DC energy storage. To generate gate pulses for cascaded H-bridge type of multilevel inverter a Level shifted pulse-width modulation technique is employed which reduces harmonics and also the voltage at the output can be maintained. This topology for applying STATCOM together with ANN controller for injecting reactive power gives effective results.

scholarly journals Multilevel inverter with MPWM-LFT switching strategy for voltage THD minimization

2019 ◽  
Vol 10 (3) ◽  
pp. 1461
Author(s):  
M. H. Yatim ◽  
A. Ponniran ◽  
A. N. Kasiran
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Total Harmonic Distortion ◽  
Switching Frequency ◽  
Switching Strategy ◽  
Circuit Structure ◽  
Switching Strategies

<span>This paper presents a proposed modified pulse width modulation – low frequency triangular (MPWM-LFT) switching strategy for minimization of voltage THD with implementation of asymmetric multilevel inverter (AMLI) topology on the reduced number of switching devices (RNSD) circuit structure. Principally, MPWM-LFT able to produce optimum angle of the output voltage level in order to minimize total harmonic distortion (THD). In this study, 5-level reduced number of switching devices circuit structure is selected as a circuit configuration for asymmetric (7-level structure) multilevel inverter. For switching strategy, MPWM used low switching frequency in producing signal and needs higher output voltage levels to achieve low total harmonic distortion. In contrast, sinusoidal pulse width modulation used high switching frequency in order to minimize total harmonic distortion. By optimizing angle at the output voltage using MPWM-LFT switching strategy, the voltage THD is lower as compared to MPWM and SPWM switching strategies. MPWM-LFT switching strategy obtains 11.6% of voltage THD for the 7-level asymmetric topology as compared to MPWM and SPWM switching strategies with the voltage THD are 21.5% and 17.5% respectively from the experimental works.</span>

Asymmetrical Cascaded Multi Level Inverter Using Control Freedom Pulse Width Modulation Techniques

2016 ◽  
Vol 7 (3) ◽  
pp. 854
Author(s):  
Periyaazhagar D ◽  
Irusapparajan G
Keyword(s):  
Pulse Width ◽  
Degrees Of Freedom ◽  
Pulse Width Modulation ◽  
Multilevel Inverter ◽  
Switching Frequency ◽  
Three Phase ◽  
Modulation Techniques ◽  
Multi Level ◽  
Cascaded Multilevel Inverter ◽  
Sinusoidal Pulse Width Modulation

In this paer, the suggested topologies are gained by cascading a full bridge inverter with dissimilar DC sources. This topology has a several new patterns adopting the fixed switching frequency, multicarrier control freedom degree with mixture conceptions are established and simulated for the preferred three-phase cascaded multilevel inverter. In outstanding switching arrangement terminations, there are convinced degrees of freedom to produce the nine level AC output voltages with terminated switching positions for producing altered output voltages. These investigations focus on asymmetrical cascaded multilevel inverter engaging with carrier overlapping pulse width modulation (PWM) topologies. These topologies offer less amount of harmonics present in the output voltage and superior root mean square (RMS) values of the output voltages associated with the traditional sinusoidal pulse width modulation. This research studies carries with it MATLAB/SIMULINK based simulation and experimental results obtained using appropriated prototype to prove the validity of the proposed concept.

Investigation on Harmonic Spreading Effect of Conventional and Innovative Multi-Level Inverter Control Strategies

2014 ◽  
Vol 626 ◽  
pp. 141-149 ◽  
Author(s):  
Shibu J.V. Bright ◽  
V. Suba ◽  
S. Ramkumar ◽  
S. Jeevananthan
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Acoustic Noise ◽  
Multilevel Inverter ◽  
Superior Performance ◽  
Voltage Source ◽  
Switching Frequency ◽  
Spreading Effect ◽  
Harmonic Injection

The pulse width modulation (PWM) strategy employed in the voltage source inverter (VSI) not only control the magnitude of the output voltage but also the quality. Performance evaluations of such strategies are done in terms of fundamental voltage, total harmonic distortion (THD), switching losses etc. (primary indices) and also in terms of acoustic noise, electromagnetic interference (EMI), harmonic spread factor, distribution of harmonic power etc. (secondary indices). Multilevel inverter (MLI) has become unanimous choice in medium and high power applications due to their superior performance compared to three level inverters. The conventional Sub-Harmonic PWM (SHPWM) scheme and its variations offer the output voltage spectrum with high intensity harmonic components around the switching frequency; it will end with cluster harmonic with high acoustic noise. The first objective of this paper is to investigate harmonic spreading effects of existing multilevel inverter (MLI) strategies. Secondly the developing innovative PWM strategies for MLIs based on modified reference and carrier functions, which were proved for superior the primary indices at three-level VSI. Thorough simulation study of Pulse width modulation strategies such as SHPWM, inverted sine carrier PWM, MWM PWM, third harmonic injection PWM, triplen harmonic injection PWM, analog space vector PWM, trapezoidal PWM and discontinuous PWM for a cascaded multilevel inverter, are presented with results of primary and secondary indices. Hence, the PWM strategies of MLI are evaluated for harmonic spreading effect first time and a guide line for a beginner to select the PWM scheme for MLI fed drive systems is stenciled.

Selective harmonic elimination pulse width modulation for three-phase cascaded multilevel inverter

2021 ◽  
Author(s):  
Baharuddin Ismail ◽  
Muzamir Isa ◽  
M. Z. Aikhsan ◽  
M. N. K. H. Rohani ◽  
C. L. Wooi ◽  
...  
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Multilevel Inverter ◽  
Harmonic Elimination ◽  
Three Phase ◽  
Selective Harmonic Elimination ◽  
Cascaded Multilevel Inverter
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