A cascaded asymmetric multilevel inverter with minimum number of switches for solar applications
TL;DR: In this article, a cascaded asymmetric multilevel inverter is proposed which contains minimum number of switches and can be employed in AC applications using solar energy, and the proposed topology consists of 25 output levels using 10 switches with near sinusoidal output.
Abstract: Solar energy is one of the renewable energy which is used to generate electricity with the help of PV arrays. DC-DC converter is used to step up the DC voltage from PV arrays and then it is connected to an inverter for AC applications. Conventional inverters have many issues like non sinusoidal output, high total harmonic distortion (THD), high switching stress and more number of switches. So multilevel inverter (MLI) have gained much importance over conventional inverters for high voltage and high power applications, due to the increased number of voltage levels producing less number of harmonics. In this paper, a cascaded asymmetric multilevel inverter is proposed which contains minimum number of switches and can be employed in AC applications using solar energy. The proposed topology consists of 25 output levels using 10 switches with near sinusoidal output, thereby reducing gate driver circuitry and optimizing circuit layout. Asymmetric multilevel inverter is more advantageous than symmetric multilevel inverter in obtaining more number of output levels using same number of voltage sources. The other advantages of proposed topology are low voltage stress and reduced THD. The THD for proposed inverter circuit is only 4.98%. Modeling and simulation is carried out using MATLAB/SIMULINK.
Citations
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27 Jun 2016
TL;DR: In this paper, the photovoltaic energy injection to microgrids using a hybrid approach that mixes the existing topologies: string, multistring and central inverter to implement an asymmetric structure that generate highly sinusoidal resulting waveforms.
Abstract: The massive penetration of renewable energy sources in the utility grid has emerged as the solution to obtain clean energy in modern electric systems, which are gradually replacing their generators that produce CO 2 emissions to achieve a sustainable growing. Power electronics is quite relevant in the deep penetration of renewable energy, because the use of such equipment is mandatory to integrate these new resources with the existing facilities. In order to reach higher power ranges, multilevel topologies are the state-of-the-art solution, due to the limited rating of the actual semiconductor devices. Furthermore, latest trends show that asymmetric multilevel configurations are an attractive technology to connect directly the power converters to the grid. This paper analyze the photovoltaic energy injection to microgrids using a hybrid approach that mixes the existing topologies: string, multistring and central inverter to implement an asymmetric structure that generate highly sinusoidal resulting waveforms. This document includes a simple analysis of the proposed configuration and highlights the advantages of using an asymmetric converter, supported with stationary and dynamic simulated results.
26 citations
Cites background from "A cascaded asymmetric multilevel in..."
...In fact, only few publications can be found related to the topic [14][16]....
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01 Nov 2015
TL;DR: In this paper, an improved Cascaded Multi-Level Inverter (CMLI) topology which can be "symmetric" or "asymmetric") is proposed.
Abstract: In this paper, an improved Cascaded Multi-Level Inverter (CMLI) topology which can be "symmetric" or "asymmetric" is proposed. The improved topology can produce higher number of levels using lower number of components. Higher number of levels leads to generation of a high quality with low Total Harmonic Distortion (THD) output voltage waveform. To increase number of voltage levels, two algorithms are proposed for determination of magnitude of dc voltage sources, which are investigated and the most effective one is introduced. To verify operation of proposed topology, it is modeled and simulated in PSCAD/EMTDC software. Proper performance of proposed topology is confirmed by obtained simulation results.
20 citations
Cites background from "A cascaded asymmetric multilevel in..."
...In general, the MLIs can be classified into three main categories: Diode-Clamped Multi-Level Inverters (DCMLIs), Flaying Capacitor Multi-Level Inverters (FCMLIs) and Cascaded Multi-Level Inverters (CMLIs) [5-8]....
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01 Jan 2018
TL;DR: In this article, a 3.4 kW, three-phase inverter for aircraft application is articulated, which consists of input filter, three phase output obtained by connecting three single-phase H-bridge inverter, transformers and LC filters at the star connected load end.
Abstract: In this article 2.4 kW, three-phase inverter for aircraft application is articulated. When aircraft above 1000 m altitude, power amplifiers are employed to increase the strength of signal during transmission. The circuitry consist of input filter, three-phase output obtained by connecting three single-phase H-bridge inverter, transformers and LC filters at the star connected load end. The (THD) of proposed three-phase inverter is 2.8%. The Total Harmonics Distortion (THD) of the circuit is reduced by using sinusoidal pulse width modulation technique (SPWM). The component size is reduced by using high frequency modulating signal (400 Hz). The proposed circuit performance is verified with experimental and simulation result. The experimental and simulation result confirms the feasibility of proposed converter.
7 citations
01 Dec 2015
TL;DR: In this article, a new multilevel inverter (MLI) with fewer number of control switches is proposed, which can reduce complexity and the total cost of circuit and can be easily extended to N-level by adding (N-3)/4 repeating stages.
Abstract: Multilevel inverters (MLI) plays a vital role in high voltage and high power applications due to its capability of converting DC to AC with reduced total harmonics distortion (THD). In this paper, a new multilevel inverter (MLI) with fewer number of control switches is proposed. The proposed topology requires a fewer number of control switches compared to conventional and recently derived topologies, thereby reducing complexity and the total cost of circuit. The topology operation is discussed for a seven-level and it can be easily extended to N-level by adding (N-3)/4 repeating stages. N-level proposed topology requires (N+3)/2 unidirectional power switches and 2N-2 diodes. The proposed topology is simulated for 100W; seven levels with level shifting SPWM technique in MATLAB/SIMULINK and results shows the validity of topology.
7 citations
TL;DR: In this paper, a multilevel inverter with level shifting sinusoidal pulse width modulation (SPWM) is proposed, which uses multicarrier waveforms with level shift ensuring the reduction in total harmonics distortion (THD).
Abstract: A multilevel inverter (MLI) is a popular inverter for solar based high power applications. The drawback of conventional H-bridge inverter is non-sinusoidal output voltage, which reduces the output quality of inverter. Later, the drawback of conventional Hbridge was overcome by conventional MLI. But, conventional MLI needs maximum number of diodes and switches. In order to overcome this drawback proposed MLI topology with level shifting sinusoidal pulse width modulation (SPWM) technique can be employed. Proposed MLI contain fewer number of switches and diodes, which helps in optimizing the circuit layout, reducing gate driver circuit for those switches. SPWM technique uses multicarrier waveforms with level shifting ensuring the reduction in total harmonics distortion (THD). In this Paper level shifting SPWM technique has been incorporated in which 5 kHz carrier wave is compare with 50Hz of sinusoidal wave with a modulation index of 0.8. THD of proposed 9-level inverter is 17.27% without filter and 4.29% with LC filter. Simulation of proposed inverter is carried out in MATLAB/SIMULINK.
6 citations
Cites background from "A cascaded asymmetric multilevel in..."
...In [17], 25-level asymmetrical inverter with 10 switches for solar application is proposed....
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References
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TL;DR: The most important topologies like diode-clamped inverter (neutral-point clamped), capacitor-Clamped (flying capacitor), and cascaded multicell with separate DC sources are presented and the circuit topology options are presented.
Abstract: Multilevel inverter technology has emerged recently as a very important alternative in the area of high-power medium-voltage energy control. This paper presents the most important topologies like diode-clamped inverter (neutral-point clamped), capacitor-clamped (flying capacitor), and cascaded multicell with separate DC sources. Emerging topologies like asymmetric hybrid cells and soft-switched multilevel inverters are also discussed. This paper also presents the most relevant control and modulation methods developed for this family of converters: multilevel sinusoidal pulsewidth modulation, multilevel selective harmonic elimination, and space-vector modulation. Special attention is dedicated to the latest and more relevant applications of these converters such as laminators, conveyor belts, and unified power-flow controllers. The need of an active front end at the input side for those inverters supplying regenerative loads is also discussed, and the circuit topology options are also presented. Finally, the peripherally developing areas such as high-voltage high-power devices and optical sensors and other opportunities for future development are addressed.
6,472 citations
01 Jan 1980
TL;DR: In this article, a neutral-point-clamped PWM inverter composed of main switching devices which operate as switches for PWM and auxiliary switching devices to clamp the output terminal potential to the neutral point potential has been developed.
Abstract: A new neutral-point-clamped pulsewidth modulation (PWM) inverter composed of main switching devices which operate as switches for PWM and auxiliary switching devices to clamp the output terminal potential to the neutral point potential has been developed. This inverter output contains less harmonic content as compared with that of a conventional type. Two inverters are compared analytically and experimentally. In addition, a new PWM technique suitable for an ac drive system is applied to this inverter. The neutral-point-clamped PWM inverter adopting the new PWM technique shows an excellent drive system efficiency, including motor efficiency, and is appropriate for a wide-range variable-speed drive system.
4,432 citations
TL;DR: The neutral-point-clamped PWM inverter adopting the new PWM technique shows an excellent drive system efficiency, including motor efficiency, and is appropriate for a wide-range variable-speed drive system.
Abstract: A new neutral-point-clamped pulsewidth modulation (PWM) inverter composed of main switching devices which operate as switches for PWM and auxiliary switching devices to clamp the output terminal potential to the neutral point potential has been developed. This inverter output contains less harmonic content as compared with that of a conventional type. Two inverters are compared analytically and experimentally. In addition, a new PWM technique suitable for an ac drive system is applied to this inverter. The neutral-point-clamped PWM inverter adopting the new PWM technique shows an excellent drive system efficiency, including motor efficiency, and is appropriate for a wide-range variable-speed drive system.
4,328 citations
TL;DR: This paper first presents a brief overview of well-established multilevel converters strongly oriented to their current state in industrial applications to then center the discussion on the new converters that have made their way into the industry.
Abstract: Multilevel converters have been under research and development for more than three decades and have found successful industrial application. However, this is still a technology under development, and many new contributions and new commercial topologies have been reported in the last few years. The aim of this paper is to group and review these recent contributions, in order to establish the current state of the art and trends of the technology, to provide readers with a comprehensive and insightful review of where multilevel converter technology stands and is heading. This paper first presents a brief overview of well-established multilevel converters strongly oriented to their current state in industrial applications to then center the discussion on the new converters that have made their way into the industry. In addition, new promising topologies are discussed. Recent advances made in modulation and control of multilevel converters are also addressed. A great part of this paper is devoted to show nontraditional applications powered by multilevel converters and how multilevel converters are becoming an enabling technology in many industrial sectors. Finally, some future trends and challenges in the further development of this technology are discussed to motivate future contributions that address open problems and explore new possibilities.
3,415 citations
TL;DR: This paper covers the high-power voltage-source inverter and the most used multilevel-inverter topologies, including the neutral-point-clamped, cascaded H-bridge, and flying-capacitor converters.
Abstract: This paper presents a technology review of voltage-source-converter topologies for industrial medium-voltage drives. In this highly active area, different converter topologies and circuits have found their application in the market. This paper covers the high-power voltage-source inverter and the most used multilevel-inverter topologies, including the neutral-point-clamped, cascaded H-bridge, and flying-capacitor converters. This paper presents the operating principle of each topology and a review of the most relevant modulation methods, focused mainly on those used by industry. In addition, the latest advances and future trends of the technology are discussed. It is concluded that the topology and modulation-method selection are closely related to each particular application, leaving a space on the market for all the different solutions, depending on their unique features and limitations like power or voltage level, dynamic performance, reliability, costs, and other technical specifications.
2,254 citations