scholarly journals Multilevel level single phase inverter implementation for reduced harmonic contents

Author(s):  
Taha Ahmed Hussein

<p>Selective harmonic elimination technique SHE is adopted in this work to reduce the harmonic contents in single phase cascaded multilevel inverter. The firing instants for the electronic switches MOSFETs in the inverter are calculated off line for five level to thirteen level inverter. An Arduino microcontroller is programmed to cope with different topologies of the multilevel inverter. The implemented multi-level (MLI) inverter results are compared with Simulink simulation program and are found very close to each other. SHE technique works at system frequency (50 Hz or 60 Hz) and the switching losses are very small. The sinusoidal pulse width modulation SPWM requires a carrier frequency not less 20 times the system frequency so SHE approach is found to be superior compared with SPWM. Also, SHE technique shows significant reduction in THD as the number of levels increased. Results for the output voltages and currents along with their frequency spectrum are shown and compared with traditional SPWM.</p>

2021 ◽  
Author(s):  
Baharuddin Ismail ◽  
Muzamir Isa ◽  
M. Z. Aikhsan ◽  
M. N. K. H. Rohani ◽  
C. L. Wooi ◽  
...  

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.


Author(s):  
Rabiya Rasheed ◽  
K. K. Saju ◽  
V. Bindu

AbstractNumerical simulation for calculation of losses of a new cascaded multilevel inverter (MLI) topology depending upon a bi-directional-blocking-bidirectional–conducting-switch is summarized in this paper. The numerical circuit simulation is performed in PSIM software by utilizing thermal models of power electronic switches. Calculation of conduction and switching losses of a 73 W inverter by relying on data sheet values has also been made. A comparison of efficiency of 73 W inverter using numerical simulation as well as analytical calculation has also been made. The new proposed inverter is a compound of both unidirectional as well as bidirectional power electronic switches challenging the attempt to reduce device count of the cascaded MLI.


Author(s):  
Mohammed Rasheed ◽  
Rosli Omar ◽  
Marizan Sulaiman ◽  
Wahidah Abd Halim

<span>In this paper, modified multilevel inverter, via addition of an auxiliary bidirectional switch, based on Newton Raphson (NR) and Particle Swarm Optimization (PSO) techniques is presented. The NR and PSO techniques were employed for selective harmonics elimination (SHE) solution in a modified Cascaded H Bridge Multilevel inverter (CHB-MLI). The Selective Harmonic Elimination Pulse-Width Modulation (SHE-PWM) is a powerful technique for harmonic minimization in multilevel inverter. The NR and PSO techniques were used to determine the switching angles by solving the non-linear equations of the output voltage waveform of the modified CHB-MLI in order to control the fundamental component and eliminate some low order harmonics. The proposed NR and PSO techniques are capable to minimize the Total Harmonic Distortion (THD) of the output voltage of the modified inverter within allowable limits. This paper aims to modeling and simulation by MATLAB of the modified topology of the CHB-MLI for a single-phase prototype for 13-levels. The inverter offers less THD and greater efficiency using PSO control algorithm compared with the NR algorithm. <br https://server9.kproxy.com/servlet/redirect.srv/sruj/snbzofspy/skvyzff/p1/> The performance of the proposed controllers based on NR and PSO techniques is verified through simulation.</span>


2018 ◽  
Author(s):  
Asnil ◽  
krismadinata ◽  
Irma Husnaini ◽  
Syahril

This paper recounts an approach to optrmize the switching angles or single-phase live-level cascaded H-bridgc multilevel inverter. Optimized Harmonic Elimination Stepped Waveform (OHESW) technique was engaged to enhance the output waveform quality. Newtcn-Raphson method is employed to determine the switching angles for the inverter which eliminates specified higher order harmonics while maintaining the required fundamental voltage. Computation resulting from the optimized switching angle was simulated Its results indicated the proposed method's effectiveness


Recently the use of high power Voltage Source Inverter is increased but the problem of harmonic and switching losses in inverter are also increased because of the use of power electronic switches, which are used for fast and efficient operation. In this paper, for eliminating the harmonics presented in H Bridge inverter during switching operation of the power electronic switches the Selective Harmonic Elimination Pulse Width Modulation (SHEPWM) Technique is used. For H-Bridge operation specific switching angles are calculated by solving nonlinear equation using Newton Raphson method. The result of H-bridge single phase inverter are implemented on hardware with and without SHEPWM technique for eliminated specific 3 rd,5th,7th,9th,11th,13th voltage harmonics are obtained. Comparison of harmonic analysis of H bridge inverter with and without SHEPWM technique is done. In this paper Modulation index (m) is varied to control output voltage amplitude and the results are observed for maximum modulation index.


2018 ◽  
Vol 7 (2.24) ◽  
pp. 55
Author(s):  
Anuja Prashant Diwan ◽  
N Booma Nagarajan ◽  
T Murugan ◽  
S Ashrafudeen ◽  
G J. Jenito Paul

In this paper, single phase nine level cascaded multilevel inverter using trinary voltage source is described. Normally for getting nine level MLI output, four H-Bridges are required. But in proposed method, nine level output is achieved by using two H-Bridges only. Performance of Multilevel inverter is improved by using modular switching pattern. This method reduces the number of switches to the half and thus reduces switching losses. Since the number of levels at the output voltage is increased, Total Harmonic Distortion (THD) gets reduced significantly. This presents simple configuration is simple and can be controlled easily. MATLAB-SIMULINK is used to validate the results of proposed technic, simulation is carried out using. The proposed method has been exhaustively compared with classical cascaded H-Bridge topology. 


Author(s):  
Hussain Attia ◽  
Hang Seng Che ◽  
Tan Kheng Suan Freddy ◽  
Ahmad Elkhateb

The single phase inverter performance through the unipolar and bipolar strategies has been previously analyzed based on the constant switching frequency pulse width modulation (CSFPWM). However, the confined band variable switching frequency PWM (CB-VSFPWM) is currently proposed as a new variable switching frequency PWM technique through unipolar strategy to facilitate the design of high order filter, to reduce the switching losses, and to reduce the current total harmonics distortion (THD) as well. To evaluate the performance of a single phase inverter based on the CBVSFPWM through bipolar strategy, this paper presents a comparative study of the CB-VSFPWM based inverter performance using the unipolar PWM and the bipolar PWM strategies. The study adopts MATLAB/Simulink to simulate the inverter and to analyze the simulation results in terms of harmonics spectrum, total harmonic distortion (THD), and fundamental components. The analysis of the study results gives an indication about the appropriate type of CB-VSFPWM strategy (unipolar PWM or bipolar PWM) to guarantee the desired performance of the connected inverter in terms of the electrical grid standards like THD, and harmonics spectrum of the inverter current.


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