http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

The authors discuss high-voltage power conversion. Conventional series connection and three-level voltage source inverter techniques are reviewed and compared. A novel versatile multilevel commutation cell is introduced: it is shown that this topology is safer and more simple to control, and delivers purer output waveforms. The authors show how this technique can be applied to either choppers or voltage-source inverters and generalized to any number of switches.<<ETX>>

Multi-level conversion : high voltage choppers and voltage-source inverters

Multilevel inverters (MLIs) are being used in wide range of power electronic applications. These converters have attracted a lot of attention during recent years and exist in different topologies with similar basic concepts. This paper presents five main submodules (SMs) to be used as the basic structures of MLIs. The paper reviews the common MLI topologies from the structural point of view. The topologies are divided into the different SMs to show conventional MLI configurations and future topologies that can be created from the main SMs. A comparative study between different topologies is performed in detail. The MLIs are categorized and investigated with from different perspectives such as the number of components, the ability to create inherent negative voltage, working in regeneration mode and using single dc source.

A General Review of Multilevel Inverters Based on Main Submodules: Structural Point of View

Recently multilevel inverters (MLI) have attracted more attention in research and industry, as they are changing into a viable technology for several applications. The concept of MLI was introduced for high power and high/medium voltage applications as they can provide an effective interface with renewable energy sources. Developing of reduced switch MLI topology has been a rapid research topic since the past decade, which has not been reviewed so far. Therefore, this review article focuses on the different reduced switch MLI topologies under three categories such as symmetric, asymmetric and hybrid configurations. The important knowledge on these topologies is carefully tabulated based on the three categories in the comparison tables to understand the essential parameters of the MLI topologies. These configurations are not only generating higher voltage levels to improve the power quality but also to reduce the passive filter requirements. Also, this review includes a detailed perspective of various modulation techniques and control strategies for MLI topologies. In addition to that, the different performance parameters of MLI and its calculation methods are discussed with appropriate mathematical expression. This review will help in the selection of appropriate MLI topology for FACTS, motor drives and renewable applications.

A comprehensive review on reduced switch multilevel inverter topologies, modulation techniques and applications

Provided is an electric power converter. A First and second series circuits of switching devices and a series circuit of capacitors are connected in parallel. Between the connection point in the first series circuit of switching devices and the connection point in the series circuit of capacitors, a first bidirectional switch is connected and, between the connection point in the second series circuit of switching devices and the connection point in the series circuit of capacitors, a second bidirectional switch is connected. The connection point in the first series circuit of switching devices is connected through a reactor to an input-output common connection line connected to one end of an AC power supply and the other end of the AC power supply is connected to the connection point in the series circuit of capacitors.

Electric power converter

A new series parallel switched multilevel dc-link inverter topology

A new dual bridge multilevel dc-link inverter topology

A new single-phase H-bridge multilevel inverter (MLI) topology constructed using auxiliary reverse-connected voltage sources along with a hybrid pulse width modulation (PWM) strategy is proposed, to extract a variable frequency variable amplitude output voltage. The principle eschews an astute philosophy to employ PWM approach only for a particular H-bridge that serves to produce the desired level while the remaining add-on modules function with the theory of fundamental switching. It involves the use of reduced number of switching devices for a specific number of output voltage levels in comparison with conventional MLIs. The design of the hybrid PWM suitable to power the appropriate switches add strength to its formulation in the sense it requires only either addition or subtraction to generate the square wave modulated pulses for the power devices in the other units other than that responsible for offering the preferred level of output voltage. The MATLAB R2010b-based simulated performance adequately validated through experimental results foresee the emergence of a new variety of MLIs and forge a different dimension for inverter interfaces in power control applications.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-pel.2013.0606

Cross-switched multilevel inverter using auxiliary reverse-connected voltage sources

The Selective Harmonic Elimination Pulse-Width Modulation (SHE-PWM) has been an inclusive research area in the field of Power Converters. This technique offers a tight control of the harmonic spectrum of a given voltage waveform generated by a power electronic converter along with a low number of switching transitions. It involves the solution of non-linear transcendental equation sets representing the relation between the amplitude of the fundamental wave, harmonic components and the switching angles. This paper reports solutions to the Selective Harmonic Elimination (SHE) method based on novel usage of Artificial Intelligence (AI) technique such as Genetic algorithm (GA) for single-phase unipolar waveform. This paper uses Matlab GA Toolbox to generate the gate pulse pattern to eliminate the required order of harmonics at any demanded fundamental output voltage.

GA based optimization and critical evaluation SHE methods for three-level inverter

The paper unleashes a new idea to arrive at reduced switch count topological structures configured in the form of a matrix for a cascaded Multi level inverter (CMLI). The theory encircles to minimize the number of switches involved in the conduction path and there from acclaim reduced input current distortion, lower switching losses and electromagnetic interference. The focus extends to standardize the number of power devices required for reaching different levels of output voltage from the same architecture. It includes appropriate pulse width modulation (PWM) strategy to generate firing pulses and ensure the desired operation of the power modules. The investigative study carries with it MATLAB based simulation and experimental results obtained using suitable prototypes to illustrate the viability of the proposed concept. The promising nature of the performance projects a new dimension in the use of single phase MLIs for renewable energy related applications.

http://www.koreascience.or.kr:80/article/JAKO201525961695086.pdf

S. Thamizharasan

Papers

A new series parallel switched multilevel dc-link inverter topology

A new dual bridge multilevel dc-link inverter topology

Cross-switched multilevel inverter using auxiliary reverse-connected voltage sources

GA based optimization and critical evaluation SHE methods for three-level inverter

A New Cascaded Multilevel Inverter Topology with Voltage Sources Arranged in Matrix Structure