scholarly journals Grid Interconnecting Solar Generation System Using Transformer Less Cascaded Seven Level Inverter

2019 ◽  
pp. 235-245
Author(s):  
Naveen Kokku
Keyword(s):  
Pulse Width Modulation ◽  
Electronic Device ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Generation System ◽  
Leakage Currents ◽  
Control Scheme ◽  
Passive Filters ◽  
Cascaded Multilevel Inverter ◽  
Sinusoidal Pulse Width Modulation

Multilevel inverter is a power electronic device that is used for high voltage and high power applications and has many advantages like, low switching stress, low total harmonic distortion (THD). Hence, the size and bulkiness of passive filters can be reduced. This paper proposes three topologies of a 7- level cascaded multilevel inverter with reduced number of switches with the 5-level cascaded multilevel inverter and 3-level inverter. The topologies consist of circuits with 9 switches for 7-level CMLI, 8 switches for the 5-level CMLI and 6 switches for the 3-level inverter. Apart from the reduction in switch count this paper also includes minimization of leakage currents and comparative analysis of levels of CMLI’s in every inverter connected to PV source. The control scheme based on Sinusoidal Pulse Width Modulation (SPWM) is adopted due to its ease of implementation. More number of levels results in reduced THD and nearly sinusoidal output. Simulation is performed using Matlab/Simulink.

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 Design of new structure of multilevel inverter based on modified absolute sinusoidal PWM technique

2021 ◽  
Vol 12 (4) ◽  
pp. 2314
Author(s):  
Asef A. Saleh ◽  
Rakan Khalil Antar ◽  
Harith Ahmed Al-Badrani
Keyword(s):  
Output Voltage ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Power Circuit ◽  
Zero Level ◽  
Multilevel Inverters ◽  
Simulink Simulation ◽  
High Output Voltage ◽  
Sinusoidal Pulse Width Modulation

The advantage of multilevel inverters is to produce high output voltage values with distortion as minimum as possible. To reduce total harmonic distortion (THD) and get an output voltage with different step levels using less power electronics switching devices, 15-level inverter is designed in this paper. Single-phase 11-switches with zero-level (ZL) and none-zero-level (NZL) inverter based on modified absolute sinusoidal pulse width modulation (MASPWM) technique is designed, modelled and built by MATLAB/Simulink. Simulation results explained that, multilevel inverter with NZL gives distortion percent less than that with ZL voltage. The THD of the inverter output voltage and current of ZL are 4% and 1%, while with NZL is 3.6% and 0.84%, respectively. These results explain the effectiveness of the suggested power circuit and MASPWM controller to get the required voltage with low THD.

Performance Estimation of Multicarrier Based Multilevel Inverter

2014 ◽  
Vol 622 ◽  
pp. 133-139
Author(s):  
Jayabal Gayathri Monicka ◽  
Venkatesan Jamuna ◽  
Kannakumar Hemalatha
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Performance Estimation ◽  
Multilevel Inverter ◽  
Total Harmonic Distortion ◽  
Modulation Technique ◽  
Cascaded Multilevel Inverter

This paper presents performance features of Symmetric and Asymmetric Cascaded Multilevel inverter. Both the Phase shifted and level shifted multicarrier pulse width modulation (MCPWM) technique are used in MLI. The best harmonic performance is improved by Level-shifted multicarrier modulations technique . The objective of this work to propose MCPWM Technique for multilevel inverter with equal and unequal DC sources. The Performances indices like Total Harmonic Distortion (THD), reduction of switches and number of DC Sources is considered. An appropriate method to achieve the MC modulation technique is also presented in this paper.

scholarly journals Comparative Study of Total Harmonic Distortion in Multilevel Inverters Based WECS

2018 ◽  
Vol 7 (3.1) ◽  
pp. 42
Author(s):  
B Kandavel ◽  
G Uvaraj ◽  
M Manikandan
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Total Harmonic Distortion ◽  
Multilevel Inverters ◽  
Wind Speeds ◽  
Harmonic Content ◽  
Multi Level ◽  
Sinusoidal Pulse Width Modulation

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.  

scholarly journals Performance Evaluation of Cascaded and Reduced Switch Multilevel Inverter Using Modified Carrier Based PWM Technique

2020 ◽  
Vol 6 (1) ◽  
pp. 12-19
Author(s):  
Md Tariqul Islam ◽  
Md Fayzur Rahman ◽  
AA Md Monzur Ul Akhir ◽  
Zisun Ahmed
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Modulation Scheme ◽  
Switching Loss ◽  
Quality Performance ◽  
Triangular Wave ◽  
Switching Losses ◽  
Control Scheme

This paper proposes an improved harmonic distorted modified triangular carrier-based multicarrier pulse width modulation for generating the switching pulses of a multilevel inverter. This modified triangular wave consists of a triangular wave bearing a close resemblance to an ‘M’ shaped wave. The design of this carrier signal has been optimized to maintain a low level of total harmonic distortion (THD), while increasing the fundamental o/p voltage to ensure the effective DC voltage utilization. Moreover, this optimization reduces the switching losses and improve the efficiency of the power inverter. With the help of this carrier signal, High-frequency alternative phase opposition disposition pulse width modulation (APODPWM) is generated. This new control scheme has been applied to seven levels of conventional cascaded H-bridge with reduced switch multilevel inverter. The output is compared with conventional carrier-based APODPWM. The comparison is made in terms of THD, fundamental output voltages and inverter losses. To ensure quality performance, conventional carrier and modified carrier-based multicarrier PWM topologies are used for the Cascaded seven-level inverter with reduced switch seven-level inverter having a carrier frequency of 2 kHz and modulation index of 0.8-1.30. According to the simulation results, by using the proposed modulation scheme the THD and the switching loss were reduced by 9.64[%] and 4.2[%] respectively. Besides, the proposed modulation technique increases the fundamental output voltages. The total simulation process is done in MATLAB Simulink environment. GUB JOURNAL OF SCIENCE AND ENGINEERING, Vol 6(1), Dec 2019 P 12-19

scholarly journals Comparative Analysis of Carrier based techniques for Single phase Diode Clamped MLI and Hybrid inverter with reduced components

2017 ◽  
Vol 7 (3) ◽  
pp. 687
Author(s):  
Nunsavath Susheela
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Harmonic Distortion ◽  
Low Frequency ◽  
Multilevel Inverter ◽  
Voltage Balancing ◽  
Multilevel Inverters ◽  
The Comparative Study ◽  
Sinusoidal Pulse Width Modulation

<p>The multilevel inverters have highly desirable characteristics in high power high voltage applications. The multilevel inverter was started first with diode clamped multilevel inverter. Later, various configurations have been came into existence for many applications. However the multilevel inverters have some demerits such as requiring higher number of components, PWM control method is complex and capacitor voltage balancing problem. The hybrid multilevel inverter presented in this paper has superior characteristics over conventional multilevel inverters. The hybrid multilevel inverter employs fewer components and less carrier signals when compared to conventional multilevel inverters. It consists of level generation and polarity generation stages which involves high frequency and low frequency switches. The complexity and overall cost for higher output voltage levels are greatly reduced. Implementation of single phase 7-level, 9-level and 11-level diode clamped multilevel inverter and hybrid multilevel inverter has been performed using sinusoidal pulse width modulation (SPWM) strategies i.e., phase disposition (PD), alternate phase opposition disposition (APOD). Also these techniques are compared in terms of total harmonic distortion (THD) for various modulation indices and observed to be greatly improved in case of hybrid inverter when compared to diode clamped inverter. The comparative study of performance for single phase diode clamped multilevel inverter and hybrid inverter is analyzed with different loads.  Simulation is performed using MATLAB/ SIMULINK. </p>

scholarly journals A New Method of Selective Harmonic Elimination PWM for H-Bridge Cascaded Multilevel Inverter

2019 ◽  
Vol 9 (1) ◽  
pp. 6168-6175
Keyword(s):  
Degrees Of Freedom ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Voltage Range ◽  
Harmonic Elimination ◽  
Selective Harmonic Elimination ◽  
Cascaded Multilevel Inverter ◽  
Operating Points

The quality of power of the cascaded H-bridge multilevel inverter is affected due to harmonics. In this paper, a Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) method including controllable DC link voltage is introduced for the multilevel inverter. Novel mathematical modeling of SHE-PWM is established concerning the DC link voltage. Compared to ordinary selective harmonic elimination, the proposed method has an increased number of degrees of freedom because of its variable DC link voltage. On the other hand, the selective harmonic elimination utilizes constant DC link voltage. In the proposed scheme, the nonlinear equations are solved only once in the entire voltage range. As a result, the computational burden will decrease. Also, the Total Harmonic Distortion (THD) of the output voltage remains constant for various values of the operating points. The simulation is performed using Matlab Simulink and the comparison is performed with the conventional PWM method. It is intended that the proposed SHE-PWM based cascaded H-bridge multilevel inverter provides better performance in terms of lower-order harmonics and less THD compares to conventional PWM method.

Multicarrier-SPWM Based Novel 7-Level Inverter Topology with Photovoltaic System

2017 ◽  
Vol 8 (2) ◽  
pp. 826
Author(s):  
R. Palanisamy ◽  
V. Sinmayee ◽  
K. Selvakumar ◽  
K. Vijayakumar
Keyword(s):  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Photovoltaic System ◽  
Pv System ◽  
Switching Losses ◽  
Common Mode Voltage ◽  
Voltage Stress ◽  
Inverter Topology ◽  
Sinusoidal Pulse Width Modulation

<p>In this paper a novel 5 switch seven level DC-AC inverter is being proposed. The proposed multilevel inverter uses reduced number of switches as compared to the switches used in the conventional multilevel inverter. The inverter has been designed to generate a 7 level AC output using 5 switches. The voltage stress on each of the switches as well as the switching losses is found to be less, minimized common mode voltage (CMV) level and reduced total harmonic distortion. The proposed 7-level inverter topology has four dc sources, which is energized through the PV system. Proposed inverter is controlled with help of multicarrier sinusoidal pulse width modulation (MCSPWM).The simulation and hardware results were verified using matlab simulink and dspic microcontroller respectively.</p>

scholarly journals Sinusoidal Pulse Width Modulation Based Speed Control of Induction Motor using Fifteen Level Diode Clamped Multilevel Inverter

2020 ◽  
Vol 9 (4) ◽  
pp. 2340-2345
Keyword(s):  
Induction Motor ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Speed Control ◽  
Multilevel Inverter ◽  
Motor Speed ◽  
Sine Curve ◽  
Driver Performance ◽  
Multi Level ◽  
Sinusoidal Pulse Width Modulation

The main purpose of this work is to use a fifteenstage diode clamped multi-level inverter that is able to control the speed of an induction motor. To get reduced synchronization and high quality sine curve output voltage. The proposed plan for the diode clamped multilevel inverter is controlled using multicarrier SPWM control. An open circle speed control can be accomplished by utilizing the V/ƒ strategy. This strategy can be executed by changing the recurrence utilized in the three-stage induction motor at the stock voltage and the consistent rate. The proposed system, which results in a poor driver performance, is a useful alternative to the conventional method with high transient losses. Simulation depicts an improved drive performance by reducing the Total Harmonic Distortion resulting from the simulation and effectively controlling the motor speed.

Multi Carrier based Multilevel Inverter with Minimal Harmonic Distortion

2015 ◽  
Vol 6 (2) ◽  
pp. 356 ◽  
Author(s):  
V.Jamuna Venkatesan ◽  
Gayathrimonicka Subarnan
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Multicarrier Modulation ◽  
Multilevel Inverter ◽  
Total Harmonic Distortion ◽  
Multilevel Inverters ◽  
Cascaded Multilevel Inverter

<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>

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