scholarly journals THD Analysis of a Seven, Nine, and Eleven Level Cascaded H-Bridge Multilevel Inverter for Different Loads

2020 ◽  
Vol 14 (4) ◽  
pp. 514-523
Author(s):  
Manoj Kumar Sahu ◽  
Madhusmita Biswal ◽  
Jagan Mohana Rao Malla

A multilevel inverter is implemented for generating the required staircase AC voltage of output from various steps of voltages of DC sources. The multilevel inverter gives a better harmonic spectrum and a compatible quality of output. This article delves into an analytical analysis of the total harmonic distortion (THD) of different multilevel inverters which employ a multicarrier PWM technique. This technique is implemented for operating the switches at their respective angle of conduction. This paper deals with various cascaded H-Bridge multilevel inverters (CMI) with various loads that are modelled by implementing the MATLAB/Simulink platform. The output gives a better result of the proposed model in terms that it is helpful towards reducing the THD and the losses of switching.

2017 ◽  
Vol 7 (1.5) ◽  
pp. 209
Author(s):  
B.Vijaya Krishna ◽  
B. Venkata Prashanth ◽  
P. Sujatha

Multilevel Inverters (MLI) have very good features when compared to Inverters. But using more switches in the conventional configuration will reduce its application in a wider range. For that reason a modified 7-level MLI Topology is presented. This new topology consists of less number of switches that can be reduced to the maximum extent and a separate gate trigger circuit. This will reduce the switching losses, reduce the size of the multilevel inverter, and cost of installation. This new topology can be used in Electrical drives and renewable energy applications. Performance of the new MLI is tested via. Total harmonic distortion. This construction structure of this multilevel inverter topology can also be increased for 9-level, 11-level and so on and simulated by the use of MATLAB/SIMULINK. A separate Carrier Based PWM Technique is used for the pulse generation in this configuration.


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.


2017 ◽  
Vol 5 (1) ◽  
pp. 91-118 ◽  
Author(s):  
Lucky Pradigta Setiya Raharja ◽  
Ony Asrarul Q. ◽  
Zainal Arief ◽  
Novie Ayub Windarko

In this research, modified PWM has been applied to the multilevel inverter (MLI) single-phase three-level diode clamp full bridge. Modified PWM is performed to produce minimum Total Harmonic Distortion (THD) the voltage because the quality of the good voltage is indicated by small THD. The THD indicates the quality of AC voltage source. The THD standard by the IEEE STD 519-1992 Harmonic Voltage Limits is 5% and the Pacific Corp standard is 8%, if the THD value is greater than the THD standard it can cause the electronic load to be damaged due to the damaged waveform. Modified PWM is applied by adding a 50 Hz sinusoidal reference signal with a sinusoidal signal which has a certain amplitude, frequency and phase shift angle. The frequency of the adder signal is the frequency at which the value of the individual harmonic voltage appears (n harmonic). To get maximum result, optimization using Genetic Algorithm (GA) method to determinate amplitude & phase shift angle done. The result of implementation hardware with modified PWM shows smaller THD voltage compared to the THD voltage with Sinusoidal Pulse Width Modulation (SPWM) switching up to 0.19 or decrease 65,51 % for modified PWM of harmonic injection n = 7 with GA optimization ma= 0.8 (A=0.0936 and ø = 0 rad) and up to 0.08 or decrease 12,30 % for modified PWM of harmonic injection n = 22 with GA optimization ma = 0.4 (A=0.1221 and ø = 0 rad).


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.  


Author(s):  
Jayesh B. Patil

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Arbi Khlifi

Use of multilevel inverters with induction machines has become popular in most energy conversion and management systems. The present paper discusses the behavior of the dual stator-winding induction machine (DSIM) for the power source, which is a power supply with Neutral Point Clamped (NPC). Multilevel inverter with PWM technique control is analyzed. The DSIM control is obtained by the PWM technique to multicarrier PWM technique and after a comparative study of various characteristics of the DSIM taking into account the different electrical offsets between the two stars (0°, 30°, 60°). The gap between the two stars was considered, and it is impacted on torque and rates harmonic distortion of circulation currents.


2012 ◽  
Vol 229-231 ◽  
pp. 2380-2384
Author(s):  
Bing Yi Wang ◽  
Shuang Zhai ◽  
Xiao Qian Zhu

In order to improve the quality of cascade multilevel inverter’s output voltage, this paper introduces an optimization harmonic elimination control technique. The harmonic of cascade multilevel inverter is controlled by the switch angels of inverter units. Through this technique, switch angels eliminate the low and middle frequency harmonic compositions and at the same time make total harmonic distortion rate of cascade multilevel inverter low are found. The correctness and accuracy of optimization harmonic elimination control technique are validated by simulation and experiment model.


Author(s):  
Arun V. ◽  
Prabaharan N.

This paper presents the Asymmetrical multilevel inverter with 1:3 voltage propagation. Switching pulse for Asymmetrical multilevel inverter are generated using embedded controller in m-file using MATLAB. The Asymmetrical multilevel inverter with 1:3 voltage propagation can produce high quality output voltage with less number of switches and voltage sources compare to conventional multilevel inverters. Contrasting other switching schemes, the proposed Switching scheme significantly reduces the Total Harmonic Distortion (THD) and minimize switching losses and reduces the complexity. To evaluate the developed scheme, simulations are carried out through MATLAB and real time implementations are done through microcontroller ARM Cortex™-M0 Core. The simulation and hardware results are presented.


Author(s):  
V.Jamuna Venkatesan ◽  
Gayathrimonicka Subarnan

<p>This paper presents performance features of Asymmetric Cascaded Multilevel inverter. Multilevel inverters are commonly modulated by using multicarrier pulse width modulation (MCPWM) techniques such as phase-shifted multicarrier modulation and level-shifted multicarrier modulation. Amongst these level-shifted multicarrier modulations technique produces the best harmonic performance. This work studies about multilevel inverter with unequal DC sources using level shifting MCPWM technique. The Performances indices like Total Harmonic Distortion (THD), reduction of switches and number of DC Sources are considered. A procedure to achieve the appropriate level shifting is also presented is this paper.</p>


2016 ◽  
Vol 78 (5-8) ◽  
Author(s):  
N.S.M. Nazar ◽  
S. Thanakodi ◽  
N.A. Othman ◽  
H.D.M. Hidzir ◽  
M.S. Mat

It has been accepted that conventional inverters have limitation dealing with high voltage and high power applications. Lately, multilevel inverters are popular for high power applications due to its improved harmonic profile and increased power ratings. There are various literatures regarding topology and control techniques of multilevel inverters. This paper presents the performance of two Flying Capacitor Multilevel Inverter (FCMI) topologies particularly a 3-level and 5-level multilevel inverters. Besides that, concept of the topologies and its modulation techniques were described. Sinusoidal pulse width modulation (SPWM) techniques were utilized in this paper as the topologies control strategy. Two control parameters, namely the amplitude modulation index, ma and the frequency modulation index, mfwere varied in order to control the output voltage of the inverters. The model and simulation study were carried out using Matlab/Simulink software. Analyses on the performance of the two topologies were based on the fundamental voltage, output voltage waveform, output harmonic spectrum and total harmonic distortion (THD). It’s found that the five level FCMI have shown better performance in terms of THD compared to the three level FCMI in all conditions of varied ma and mf. Based on the study also, five level FCMI shows a better voltage output waveform; close to a sinusoidal waveform compared to the three level FCMI.


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