Review on Single-DC-Source Multilevel Inverters: Topologies, Challenges, Industrial Applications, and Recommendations

At present, renewable energies represent 25% of the global power generation capacity. The increase in clean energy facilities is mainly due to the high levels of pollution generated by the burning of fossil fuels to satisfy the growing electricity demand. The global capacity of generating electricity from solar energy has experienced a significant increase, reaching 505 GW in 2018. Today, multilevel inverters are used in PV systems to convert direct current into alternating current. However, the use of multilevel inverters in renewable energies applications presents different challenges; for example, grid-connected systems use a transformer to avoid the presence of leakage currents. The grid-connected systems must meet at least two international standards analyzed in this work: VDE 0126-1-1 and VDE-AR-N 4105, which establish a maximum leakage current of 300 mA and harmonic distortion maximum of 5%. Previously, DC/AC converters have been studied in different industrial applications. The state-of-the-art presented in the work is due to the growing need for a greater use of clean energy and the use of inverters as an interface between these technologies and the grid. Also, the paper presents a comparative analysis of the main multilevel inverter voltage-source topologies used in transformerless PV systems. In each scheme, the advantages and disadvantages are presented, as well as the main challenges. In addition, current trends in grid-connected systems using these schemes are discussed. Finally, a comparative table based on input voltage, switching frequency, output levels, control strategy used, efficiency, and leakage current is shown.

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A State of the Art of the Multilevel Inverters with Reduced Count Components

Electronics ◽

10.3390/electronics9111924 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1924

Author(s):

Alaaeldien Hassan ◽

Xu Yang ◽

Wenjie Chen ◽

Mohamad Abou Houran

Keyword(s):

High Efficiency ◽

Low Cost ◽

Academic Research ◽

Industrial Applications ◽

Research Field ◽

Optimum Number ◽

Multilevel Inverters ◽

Pros And Cons ◽

Long Lifetime ◽

Switching Devices

Multilevel inverters (MLIs) have become a trend in the field of DC/AC inverters and one of the main requirements in many of the industrial applications. MLIs spread in the academic research field and replaced the conventional inverters due to the several advantages that these topologies presented over the conventional inverters, as follows. (1) Operate with a high number of steps in the output voltage waveform, which helps in reducing the level of harmonics and presents fine and clear waveforms; furthermore, reduce the voltage stress on the switching devices and gives it a long lifetime and more reliability. (2) MLIs have a low rating of the switching devices, which has a noticeable role in reducing the system cost. (3) MLIs can be operated at both higher and lower switching frequencies, which reduces the level of power losses and enhances the overall efficiency. The main problem that faces the researchers in the multilevel inverters field is to design a topology that uses the optimum number of components to ensure the low cost and obtain a high efficiency. This paper presents a description of different topologies of MLIs that were investigated in the last two decades to show the pros and cons of each topology. Also a set of performance parameters that were used to measure the effectiveness of the MLI topologies have been discussed.

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Experimental Validation for A Nine-Switched 3-phase Multilevel Inverter (MLI) With a Photovoltaic (PV) Source of Array

Journal of Physics Conference Series ◽

10.1088/1742-6596/2089/1/012021 ◽

2021 ◽

Vol 2089 (1) ◽

pp. 012021

Author(s):

Praveen Kumar Nalli ◽

Kalyan Sagar Kadali ◽

Ramu Bhukya ◽

V. Rajeswari ◽

Durga Prasad Garapati

Keyword(s):

Industrial Applications ◽

Multilevel Inverter ◽

Solar Photovoltaic ◽

Solar Pv ◽

Photovoltaic Panel ◽

Multilevel Inverters ◽

Semiconductor Switches ◽

Experimental Implementation ◽

Three Phase ◽

Input Side

Abstract Now-a-days Usage of Multilevel Inverters application is very wide in the industrial applications. Keeping in view of industrial applications, a multi-level inverter with a solar PV array is designed in this paper to deliver power to the Alternating Current based load. A step-up converter is used at the input side of the three-phase multilevel inverter, which delivers the energy for the three-phase load, to regulate the output voltage of the solar Photovoltaic panel. The multilevel inverter utilizes 9 switching devices with five level sources in accordance to the usage of the level of sources in recent topologies. However, the advantage of this topology is that it uses fewer semiconductor switches than current topologies. Eventually, the paper includes the results of the modelling in the MATLAB and the experimental implementation of the proposed topology.

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Critical Failure Mechanisms in Isolated Three-phase Multilevel Inverters Design

10.36227/techrxiv.14794842.v1 ◽

2021 ◽

Author(s):

Juan Carlos Iglesias-Rojas

Keyword(s):

Fault Tolerant ◽

Short Circuit ◽

Failure Mechanisms ◽

Low Frequency ◽

Industrial Applications ◽

Control Signal ◽

Design Stage ◽

Inrush Current ◽

Inductive Load ◽

Multilevel Inverters

<div>Isolated multilevel inverters are widely used in renewable energy systems and industrial applications. Isolated IGBT topologies exploit the usage of low-frequency transformers that improve robustness and reliability. However, critical failure mechanisms should be considered at the design stage to ensure proper performance. This paper describes these critical failure mechanisms, such as short circuit, cross-conduction, IGBT high inductive load avalanche, IGBT second turn-on, VS-undershoot, transformer inrush current, IGBT thermal runaway, and cable switching interference. Furthermore, this paper comprises design techniques to prevent these failures. The previous failure mechanisms come from the inverter's power stage, except switching interference from control signal cables and directly affecting the control device functionality. This work also proposes a circuit topology based on FPGA resources to reduce switching interference from control signal cables. It behaves like a fault tolerant digital input that effectively filters bouncing events shorter than 2μs. Measurements report satisfactory experimental results upon constructing a 45kVA ac-side-isolated 13-level inverter.</div>

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A Simplified Control Strategy for an Enhanced Performance of Six Level Dual Inverter Fed Induction Motor Drive

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.f8164.088619 ◽

2019 ◽

Vol 8 (6) ◽

pp. 1563-1567

Keyword(s):

Induction Motor ◽

Output Voltage ◽

Simulation Analysis ◽

Harmonic Distortion ◽

Industrial Applications ◽

Motor Drives ◽

Motor Drive ◽

Induction Motor Drive ◽

Induction Motor Drives ◽

Multilevel Inverters

Induction motor drives are employed in many of the industrial applications. The drives output depends on the inverter. Multilevel inverters are generally used in the induction motor drives but the dual inverter fed induction motor drive found more advantageous than the multilevel inverters. The performance of the Induction motor drive with open end winding for various levels of output voltage is presented in this paper. The inverter configuration implemented produces three-level, fourlevel, five-level and six-level in the output voltage waveform. The voltage and current harmonic distortion decreases as the number of levels are increased. The performance of the motor drive with the proposed inverter topology was found effective for sixth level. The simulation analysis of Induction motor drive with dual inverter is carried out in MATLAB-Simulink environment

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A Symbiotic Organism Search-Based Selective Harmonic Elimination in a Switched Capacitor Multilevel Inverter

Energies ◽

10.3390/en15010089 ◽

2021 ◽

Vol 15 (1) ◽

pp. 89

Author(s):

Manita Kumari ◽

Adil Sarwar ◽

Mohd Tariq ◽

Shafiq Ahmad ◽

Adamali Shah Noor Mohamed ◽

...

Keyword(s):

Industrial Applications ◽

Multilevel Inverter ◽

Power Sources ◽

Multilevel Inverters ◽

Dc Power ◽

Harmonic Elimination ◽

Three Phase ◽

Selective Harmonic Elimination ◽

Heuristic Technique ◽

Symbiotic Organism Search

Multilevel inverters are increasingly being employed for industrial applications, such as speed control of motors and grid integration of distributed generation systems. The focus is on developing topologies that utilize fewer lower-rating switches and power sources while working efficiently and reliably. This work pertains to developing a three-phase multilevel inverter that employs switching capacitors and a single DC power supply that produces a nine-stage, three-phase voltage output. A recently proposed powerful meta-heuristic technique called symbiotic organism search (SOS) has been applied to identify the optimum switching angles for Selective Harmonic Elimination (SHE) from the output voltage waveform. A thorough converter analysis has also been done in the MATLAB/SIMULINK environment and is validated with the real-time hardware-in-the-loop (HIL) experiment results.

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Contribution of Multilevel Inverters in Improving Electrical Energy Quality: Study and Analysis

European Journal of Electrical Engineering ◽

10.18280/ejee.230310 ◽

2021 ◽

Vol 23 (3) ◽

pp. 255-263

Author(s):

Saliha Rezini ◽

Zin-Eddine Azzouz

Keyword(s):

Output Voltage ◽

Electrical Energy ◽

Industrial Applications ◽

Point Of View ◽

Multilevel Inverters ◽

Static Converters ◽

Harmonic Pollution ◽

Multi Level ◽

Quality Study ◽

Better Than

The work proposed in this paper concerns the study of harmonic pollution generated by static converters, particularly inverters, which largely contributes to the degradation of the supplied electrical energy quality. So, we studied in first the EMC of the conventional two-level inverter to highlight the harmful pollution of this kind of converter. We then looked at multi-level inverters to characterize their degree of pollution according to their number of levels in order to propose practical solutions for industrial applications. Thus, we considered three structures of multi-level inverters namely: a diode clamped inverter, a flying capacitor clamped inverter and a cascaded h-bridge inverter. At the end of this study, we retain that these three structures make it possible to obtain a waveform of the output voltage close to the sinusoidal form. The results of simulation obtained and compared to the STD international standard templates, also allowed us to conclude that among the three structures studied the cascaded h-bridge inverter is the most interesting from the electrical energy quality point of view. In addition, this converter has the advantage of owning a reduced number of switches which results in a weight and a cost, better than those of the other two studied inverters.

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Harmonic Elimination of a PV Based Cascaded H-bridge Seven Level Inverter for Induction Motor Drive

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.c8354.019320 ◽

2020 ◽

Vol 9 (3) ◽

pp. 668-676

Keyword(s):

High Power ◽

Pulse Width Modulation ◽

Current Source ◽

Harmonic Distortion ◽

Industrial Applications ◽

Total Harmonic Distortion ◽

Multilevel Inverters ◽

Switching Losses ◽

Novel Approach ◽

Harmonic Elimination

In today’s era, reliable and good quality power is an essential requirement in industry, which can be supplied by inverters at medium and high power. Most of the appliances in the industry require high power or medium power for their operation. Power electronics devices such as inverters work on medium voltage and high power and are suitable for industrial applications and renewable particularly Photovoltaic (PV) integration. Multilevel inverters are more superior to conventional inverters because of lower harmonics and switching losses, but as the number of levels increases, complexity also increases. Therefore, maintaining the harmonics at lower level and lesser complexity of multilevel inverters is a challenge for researchers. In this research paper, a novel approach for implementation of seven level cascaded H- bridge configuration of multilevel inverter using direct current source and photovoltaic panels has been demonstrated. The basic working principle of seven level cascaded hybrid bridge inverter, pulse width modulation techniques and total harmonic distortion are explained through simulations in Matlab and Xilinx 14.3 software and the same is experimentally validated through FPGA controller based Spartan 6. The designed seven level inverter results in lower total harmonic distortion with lesser complexity when used to connect PV panels.

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Critical Failure Mechanisms in Isolated Three-phase Multilevel Inverters Design

10.36227/techrxiv.14794842 ◽

2021 ◽

Author(s):

Juan Carlos Iglesias-Rojas

Keyword(s):

Fault Tolerant ◽

Short Circuit ◽

Failure Mechanisms ◽

Low Frequency ◽

Industrial Applications ◽

Control Signal ◽

Design Stage ◽

Inrush Current ◽

Inductive Load ◽

Multilevel Inverters

<div>Isolated multilevel inverters are widely used in renewable energy systems and industrial applications. Isolated IGBT topologies exploit the usage of low-frequency transformers that improve robustness and reliability. However, critical failure mechanisms should be considered at the design stage to ensure proper performance. This paper describes these critical failure mechanisms, such as short circuit, cross-conduction, IGBT high inductive load avalanche, IGBT second turn-on, VS-undershoot, transformer inrush current, IGBT thermal runaway, and cable switching interference. Furthermore, this paper comprises design techniques to prevent these failures. The previous failure mechanisms come from the inverter's power stage, except switching interference from control signal cables and directly affecting the control device functionality. This work also proposes a circuit topology based on FPGA resources to reduce switching interference from control signal cables. It behaves like a fault tolerant digital input that effectively filters bouncing events shorter than 2μs. Measurements report satisfactory experimental results upon constructing a 45kVA ac-side-isolated 13-level inverter.</div>

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The Application of Ultra-Thin Sectioning Techniques to Non-Biological Samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101402 ◽

1968 ◽

Vol 26 ◽

pp. 332-333

Author(s):

C. F. Oster

Keyword(s):

Biological Sciences ◽

Epoxy Resin ◽

Cross Sections ◽

Biological Samples ◽

Industrial Applications ◽

Photographic Film ◽

Silver Particles ◽

Thin Sectioning ◽

Embedding Medium

Although ultra-thin sectioning techniques are widely used in the biological sciences, their applications are somewhat less popular but very useful in industrial applications. This presentation will review several specific applications where ultra-thin sectioning techniques have proven invaluable.The preparation of samples for sectioning usually involves embedding in an epoxy resin. Araldite 6005 Resin and Hardener are mixed so that the hardness of the embedding medium matches that of the sample to reduce any distortion of the sample during the sectioning process. No dehydration series are needed to prepare our usual samples for embedding, but some types require hardening and staining steps. The embedded samples are sectioned with either a prototype of a Porter-Blum Microtome or an LKB Ultrotome III. Both instruments are equipped with diamond knives.In the study of photographic film, the distribution of the developed silver particles through the layer is important to the image tone and/or scattering power. Also, the morphology of the developed silver is an important factor, and cross sections will show this structure.

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