A Modified Seven Level Cascaded H Bridge Inverter

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Presently Multilevel inverters are extensively used for high-voltage applications and their execution is exceptionally better to that of regular two-level inverters due to minimized harmonic distortion, lower electromagnetic interference and larger DC link voltages. Nevertheless certain shortcomings are faced such as adding in number of components and voltage balancing problem. In order to overcome these, a seven-level hybrid inverter has been proposed. This topology requires a lesser number of power switches which results in the decrease of multifaceted nature, add up to cost and weight of the inverter. Finally this can be able to generate near sinusoidal voltages and approximately fundamental frequency switching. The simulation and the experimental results of a modified cascaded seven level H bridge inverter with and without LC filter are presented for validation.

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A Modified Seven Level Cascaded H Bridge
Inverter
ABSTRACT:
Presently Multilevel inverters are extensively used for high-voltage applications and their
execution is exceptionally better to that of regular two-level inverters due to minimized harmonic
distortion, lower electromagnetic interference and larger DC link voltages. Nevertheless certain
shortcomings are faced such as adding in number of components and voltage balancing problem.
In order to overcome these, a seven-level hybrid inverter has been proposed. This topology
requires a lesser number of power switches which results in the decrease of multifaceted nature,
add up to cost and weight of the inverter. Finally this can be able to generate near sinusoidal
voltages and approximately fundamental frequency switching. The simulation and the
experimental results of a modified cascaded seven level H bridge inverter with and without LC
filter are presented for validation.
KEYWORDS:
1. Cascaded H-bridge inverter (CHBI)
2. Seven level hybrid inverter
3. Asymmetrical DC sources
4. Total harmonic distortion (THD)
5. Pulse Width modulation (PWM)
6. Multi-level Inverter (MLI)
7. Real time Interface (RTI)
SOFTWARE: MATLAB/SIMULINK

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New Approaches for Harmonic Reduction Using Cascaded H-Bridge and Level Modules

ijiert bestjournal

This paper analyzes and compares two approaches for dc to ac power conversion i.e. inverter . First method uses cascaded H - Bridge Inverter and second uses new Multi - level Scheme having Level Modules and H - Bridge. The simulation is done in MATLAB Software. Also the hardware can be done by taking the AC supply from the mains and converts it into DC suppl y by using rectifier. MOSFET can be used for switching purpose. The Total Harmon ic Distortion in output load voltage,produced by both the approaches is compared. It is shown that THD produced in second scheme is better up to a certain stages of the first scheme. The Total Harmonic Distortion produced in output load voltage when casca ded H - Bridge is used is 12.64% while t he Total Harmonic Distortion produced in output load voltage when Level Modules and H - Bridge are used is 7.94%.

Design and simulation of single phase five-level symmetrical cascaded h-bridg...

Asoka Technologies

Multilevel inverter is an effective and practical solution for increasing power demand and reducing harmonics of ac waveforms. Such inverters synthesize a desired output voltage from several levels of dc voltages as inputs. This paper analyzes the performance of five level cascaded H-bridge multilevel inverter with reduce number of power switches. Further by reducing switches and increasing level will reduce filter cost & harmonic content. 5- Level cascaded H-bridge asymmetrical multilevel inverter topology requires 8 switches but in this new multilevel inverter it requires 6 switches in which same multilevel is obtained. Invariably switching losses and cost also reduced. In this .paper only multilevel inverter circuitry will be studied. The performance has been analyzed by the MATLAB/Simulink.

Comparative Analysis of Various Z-source Based Five Level Cascaded H-bridge M...

journalBEEI

Z-source based multilevel inverters are the recent topologies as they have boosting ability and near sinusoidal output waveforms. This paper proposes different inverter topologies such as Z-source multilevel inverter and quasi Z-source multilevel inverter. This paper also deals with switched inductor and improved switched inductor topologies with quasi Z-network. The proposed switched inductor system reduces the voltage stresses caused by capacitors, power devices and diodes. In addition to multilevel inverter advantages, the proposed configuration employs Z-source inverter advantages. The Z-source inverter as compared to the traditional inverter is less costly, less complex, more efficient and more reliable. The performance of the proposed configurations is analysed by varying passive elements in impedance network and is simulated in MATLAB/SIMULINK. Phase disposition (PD) pulse width modulation (PWM) technique is applied on the proposed configurations and performance parameters are measured by the fast Fourier transform FFT analysis. The object of this paper is to develop an inverter which is used for variable speed drives with increase in output voltage by eliminating transformer and filter circuit. The performance is checked with standared parameter of the inverter.

U26130135

IJERA Editor

Line and Grid Impedance Impact on the Performances of a Parallel Connected Mo...

IAES-IJPEDS

With the rising fuel cost, increasing demand of power and the concerns for global climate change, the use of clean energy make the connection of power electronics building bloc in the heart of the current research. The high output current applications make the parallel connection of modular inverters to be a solution for the use of low power building block inverters where the output power cannot be handled by a single inverter configuration. In this context, average-modeling using average phase–leg technique allows the n-parallel connected inverters to be analyzed accurately and rapidly without requiring the complexity of the full switched inverter topology. The obtained analytical solution along with the equivalent circuit model makes easier the design of the control loop. The analytical solution of the n-parallel connected inverters shows the impact of the line and grid impedance on the performance of the overall system. The impact of this coupling has to be investigated such that the main feature of paralleling inverters is guaranteed and that the inverter mode of operation will not be compromised. The main advantage of paralleling inverters can be lost for a certain coupling impedance considerations.

COMPREHENSIVE ANALYSIS AND SIMULATION OF MULTILEVEL POWER CONVERTERS TO CURTA...

ecij

Present day industrial applications require higher power apparatus for power conversion. At medium voltage grid, to connect only one power semiconductor switch directly is a not practically successful concept. To overcome this multilevel power converter structure has been introduced and studied as an alternative in high power and medium voltage applications. Renewable energy sources like photovoltaic, wind, fuel cells can be conveniently interfaced to a multilevel converter system for high power applications. In this study it is discussed in detail for different levels of the multilevel converters using pulse width modulation technique (PWM) the harmonics contents decreases gradually. The simulated results are presented and compared thereafter. Total harmonic distortion decreases as the number of levels increased are tabulated accordingly. All the simulation results are carried out under MATLAB/Simulink environment.

COMPREHENSIVE ANALYSIS AND SIMULATION OF MULTILEVEL POWER CONVERTERS TO CURTA...

ecij

11 4oct 6629 10634-1-ed neoteric (edit ari)

IAESIJEECS

With the purpose of rein in the high voltage of flexible power systems, renovation and amendment of multi-level structures aimed at acquisition of high quality voltage is certainly required. In this regard, robust topology must be occupied that encompass the maximum output voltage levels along with minimum of switch number, of course, with taking into account of Peak Inverse Voltage (PIV). In this paper, a neoteric high-performance multilevel cascaded inverter is suggested up to the problem of repetitive output levels to be unraveled and also number of output voltage levels to be maximized. It has been constructed by series-connected multilevel inverters blocks and three-level inverter. The simulation results along with experimental results extracted by manufactured prototype have transparently approved high efficiency of proposed inverter as well as its feasibility. Apart from above, new mathematical approach has been presented to calculate and define the DC voltage sources magnitudes in asymmetric converter.

Improved 25-level inverter topology with reduced part count for PV grid-tie a...

International Journal of Power Electronics and Drive Systems

A new bidirectional multilevel inverter topology with a high number of voltage levels with a very reduced number of power components is proposed in this paper. Only TEN power switches and four asymmetric DC voltage sources are used to generate 25 voltage levels in this new topology. The proposed multilevel converter is more suitable for e-mobility and photovoltaic applications where the overall energy source can be composed of a few units/associations of several basic source modules. Several benefits are provided by this new topology: Highly sinusoidal current and voltage waveforms, low Total Harmonic Distortion, very low switching losses, and minimum cost and size of the device. For optimum control of this 25-level voltage inverter, a special Modified Hybrid Modulation technique is performed. The proposed 25-level inverter is compared to various topologies published recently in terms of cost, the number of active power switches, clamped diodes, flying capacitors, DC floating capacitors, and the number of DC voltage sources. This comparison clearly shows that the proposed topology is cost-effective, compact, and very efficient. The effectiveness and the good performance of the proposed multilevel power converter (with and without PWM control) are verified and checked by computational simulations.

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