Multi-carrier Based Pulse Width Modulation Research Articles

Modeling and Analysis of Asymmetrical Modified Hybrid Thirty One Level Inverter with Reduced THD

This paper proposes a 1Φ 31 level inverter using minimum number of switching devices and improved THD level. Multi Carrier based Pulse Width-Modulation (MC-PWM) control method is used to control MOSFET switches in input and load side. In this paper a modified hybrid asymmetrical multilevel inverter using eight numbers of switching devices driven by the multicarrier modulation technique is proposed. This inverter produces thirty one levels at output from four different dc voltage sources. Also THD level is taken into consideration to maintain the power quality. The proposed 31 level inverter is verified through MATLAB simulink.

Performance Evaluation of Multi-Carrier Based SPWM Technique for Three Phase Three level FCMLI

In this paper, the flying capacitor multi level inverter is simulated for various multi-carrier based pulse width modulation technique and some of the interesting characteristics of THD and harmonics are revealed. Sinusoidal wave is used as reference wave. The harmonics in the output voltage is observed for various techniques like pulse width modulation. The THD and harmonics of the chosen FCMLI is analyzed through matlab – simulink based simulation, and it is found that Phase Disposition Pulse Width Modulation has a better performance.

Performance Evaluation of Multi-carrier PWM Techniques: PD, POD and APOD

In industrial applications, modulation strategies play a significant role to provide the effective voltage generation at the outputs of inverter structures. Also, the modulation strategies are important to generate output voltages with lower harmonic distortions. For this purpose, there are several modulation techniques to produce stepped voltage waveforms by reducing harmonics for high voltage levels. Therefore, this work introduces the comparative study of multi-carrier based pulse width modulation (PWM) methods used in high power rated inverters. In this regard, phase disposition (PD), phase opposition disposition (POD) and alternative phase opposition disposition (APOD) PWM strategies are tested in five-level cascaded H-bridge inverter. The performance consequences are received for different carrier frequencies, and total harmonic distortions are evaluated for tested methods. The results show that total harmonic distortion in APOD-PWM controlled inverter is less than other methods. In addition, total harmonic distortion values are performed for frequency values, which are from 0.5 kHz to 4 kHz.

Performance evaluation and comparison of diode clamped multilevel inverter and hybrid inverter based on PD and APOD modulation techniques

<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>

Novel Neural Control of Single-Phase Grid-Tied Multilevel Inverters for Better Harmonics Reduction

A single-phase Cascaded H-Bridge (CHB) grid-tied multilevel inverter is introduced with a detailed discussion of the proposed novel neural controller for better efficiency and power quality in the integration of renewable sources. An LCL (inductor-capacitor-inductor) filter is used in the multilevel inverter system to achieve better harmonic attenuation. The proposed Neural Network (NN) controller performs the inner current control and tracks the references generated from the outer loop to satisfy the requirements of voltage or power control. Two multicarrier-based Pulse Width Modulation (PWM) techniques (phase-shifted modulation and level-shifted modulation) are adopted in the development of the simulation model to drive the multilevel inverter system for the evaluation of the neural control technique. Simulations are carried out to demonstrate the effectiveness and efficient outcomes of the proposed neural network controller for grid-tied multilevel inverters. The advantages of the proposed neural control include a faster response speed and fewer oscillations compared with the conventional Proportional Integral (PI) controller based vector control strategy. In particular, the neural network control technique provides better harmonics reduction ability.

Parallel Connected VSI Inverter using Multi-carrier based Sinusoidal PWM Technique

This paper explains the simulation and modelling of Parallel operation of VSI inverter using multi-carrier based PWM technique. By this proposed method three level inverter output voltages generated instead of using multilevel inverter or two level dual VSI inverter. This system employs single dc voltage source, which gives supply to both VSI inverter by using parallel connection. The multi-carrier based pulse width modulation technique affianced to control the inverter power switches. The proposed system offers improved output voltage, better current control and reduced harmonic distortion. The simulation results of this proposed system was verified using matlab/simulink.

Hybrid Control Strategy for BCD Topology Based Modular Multilevel Inverter

In this paper, a Binary Coded Decimal (BCD) topology of modular multilevel inverter with reduced component count is proposed. For the control of this inverter, hybrid control strategy is used. The proposed modular multilevel inverter uses asymmetrical dc sources and reduced number of switches topology. This hybrid modulation technique uses the multicarrier based Pulse Width Modulation (PWM) and the fundamental frequency modulation strategy. The hybrid modulation algorithm is implemented with “NUC140” micro-controller. In comparison with the conventional and some of the recently reported inverter topologies, the proposed inverter topology is able to generate high number of voltage levels in the output by using minimum number of components such as dc sources, power switches and driver circuits. This inverter offers significant performance with less number of components. The feasibility of the proposed topology is confirmed by simulation and experimental results.