scholarly journals Correction of errors and harmonic distortion in pulse-width modulation of digital signals

Author(s):  
Francisco Colodro ◽  
Juana María Martínez-Heredia ◽  
José Luis Mora ◽  
Antonio Torralba
Author(s):  
N. Susheela ◽  
P. Satish Kumar

<p>The popularity of multilevel inverters have increasing over the years in various applications without use of a transformer and has many benefits. This work presents the performance and comparative analysis of single phase diode clamped multilevel inverter and a hybrid inverter with reduced number of components. As there are some drawbacks of diode clamped multilevel inverter such as requiring higher number of components, PWM control method is complex and capacitor voltage balancing problem, an implementation of hybrid inverter that requires fewer components and less carrier signals when compared to conventional multilevel inverters is discussed. The performance of single phase diode clamped multilevel inverter and hybrid multilevel inverter for seven, nine and eleven levels is performed using phase disposition, alternate phase opposition disposition sinusoidal pulse width modulation techniques. Both the multilevel inverter are implemented for the above mentioned multicarrier based Pulse Width Modulation methods for R and R-L loads.  The total harmonic distortion is evaluated at various modulation indices. The analysis of the multilevel inverters is done by simulation in matlab / simulink environment.</p>


Author(s):  
Jalla Sowndarya ◽  
M. Shekar ◽  
N. V. Vinay Kumar

To generate the required reference vector than triangle comparison based PWM techniques for three-level inverters the space vector based PWM (SVPWM) strategies contain broader choice of switching sequences. This space vector based PWM technique involves in various steps. These steps are computationally exhaustive. The SVPWM has been used in three phase inverter control system. The center-aligned PWM is the most effective way for the Microprocessor Control Unit implementation of the SVPWM, because it can easily generate the center aligned PWM of the multilevel inverters for generation of the signal of space vector pulse width modulation (SVPWM), this concept brings out the method. The inverter leg switching times are generated by this algorithm and middle vector switching times are centered in a sampled interval. The proposed algorithm does not require any sector identification. And it reduces the computational time as a result. The adjacent voltage space vectors are forming the small triangles it is called sectors. Multilevel converters can meet the increasing demand of power ratings and power quality associated with reduced harmonic distortion and lower electromagnetic interference. Furthermore to optimize switching waveforms, space vector pulse-width modulation algorithms offer great flexibility among them. Finally the results are verified through MATLAB/SIMULINK


Author(s):  
Adireddy Ramesh, ◽  
O. Chandra Sekhar ◽  
M. Siva Kumar

<p>Penetration of multilevel inverters (MLI) in to high power and medium voltage application has been increasing because of its advantages. The conventional two levels inverter has high harmonic distortion which gives poor power quality. Lot of topologies has been developed to overcome the drawbacks of a two level inverter. These topologies include more number of switching devices which increases the design complexity and cost. The optimum design of inverter requires less number of switches with better quality in waveform. In this paper, a symmetrical five level and seven levels inverter configuration with simplified pulse width modulation technique is proposed. This proposed inverter requires less switches, less protection circuits along with low cost and size. The analysis of the inverter circuits is done by using Matlab/Simulink software. The synthesized staircase wave form is shown and total harmonic distortion (THD) is also measured.</p>


2021 ◽  
Author(s):  
Bolisetti Kavya Santhoshi ◽  
Kuppusamy Mohanasundaram ◽  
Vishnu Kumar Kaliappan ◽  
Ravishankar Sathyamurthy

Abstract The work proposed in this paper focuses on providing an effective solution to shortage of power in rural areas with an effective technique implemented in an economically feasible way. The traditional Inverters used for either residential or commercial purposes consume electrical energy from the grid to fulfill the charging and discharging of the battery, which may lead to overloading. The shortcomings of the traditional inverters such as Non-Renewable nature of power sources, increased cost of manufacturing, and multi-stage conversion complexity, are considered by the researchers for improvement. As a result, an attempt has been made to provide a cost effective renewable energy system with single stage topology for AC power applications. Single stage power conversion with allowed shoot through state is used here to avoid additional components and reduce the switching losses. Unlike the traditional inverters, the Quasi Impedance Source Inverter that is brought forward can be utilized as a Standalone system or a capable backup at the time of power outages. Sinusoidal pulse width modulation (SPWM) is applied to attain reduced harmonics which are measured by observing the harmonic pattern in Total Harmonic Distortion (THD) curve. The lab results obtained through MATLAB simulation confirm the noteworthy diminution of THD level in the proposed system compared to the reported one. Usage of Photovoltaic (PV) Panel to tap energy with reduced stochastic fluctuations due to high filtering capacity of the proposed circuit, eliminating the need of additional filters, is the uniqueness of this technique.


Author(s):  
N. Murali ◽  
V. Balaji

<span>This paper presents the performance enhancement of capacitor run induction motor by pulse width modulated AC chopper.The phase angle control faces severe shortfall in the performance improvement for larger triggering angles. In this paper the comparison of phase angle control and sinusoidal pulse width modulation technique is encountered for effective speed control of single phase capacitor run induction motor. The necessary parameters are taken into considerations are higher efficiency, lesser total harmonic distortion and high input power factor. The results are compared by using the simulations using matlab Simulink environment. The validation of result in hardware is implemented using Field programmable gate array for sinusoidal pulse width modulation technique.</span>


Author(s):  
N. Murali ◽  
V. Balaji

<span>This paper presents the performance enhancement of capacitor run induction motor by pulse width modulated AC chopper.The phase angle control faces severe shortfall in the performance improvement for larger triggering angles. In this paper the comparison of phase angle control and sinusoidal pulse width modulation technique is encountered for effective speed control of single phase capacitor run induction motor. The necessary parameters are taken into considerations are higher efficiency, lesser total harmonic distortion and high input power factor. The results are compared by using the simulations using matlab Simulink environment. The validation of result in hardware is implemented using Field programmable gate array for sinusoidal pulse width modulation technique.</span>


2014 ◽  
Vol 622 ◽  
pp. 133-139
Author(s):  
Jayabal Gayathri Monicka ◽  
Venkatesan Jamuna ◽  
Kannakumar Hemalatha

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.


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