الفهرس 
Nature of Power ElectronicsOnly 14 pages are availabe for public view
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Abstract
The multilevel inverter (MLI) is a tremendous choice for renewable energy applications and is used in high, medium, and low power applications. MLIs can generate the output voltage waveforms with better harmonic spectrum with less voltage stress on switching devices. On the other hand, producing the output voltage at higher levels needed a lot of components and the boosting feature is missing. Switched capacitor boost multilevel inverters (SCBMLI) are used to produce the output voltage waveforms that are near sinusoidal and to boost input voltage at the output terminals. This thesis presents a simplified design of two topologies for
multilevel inverter based on switched capacitor technique with a few number of semiconductor switches. The First proposed inverter generates five levels in the output voltage with double boosting gain. While, the second proposed produces nine levels with quadruple boosting gain. The
five-level topology uses six switches and one capacitor but the nine-level topology uses eight switches and two capacitors. Single DC source is used in both proposals. The switched capacitors in both topologies are used as an alternate DC power supply to produce the output voltage waveform with boosting capability in the output terminal. The series-parallel charging and discharging of the capacitor helps it reach the desired voltage, without the need for auxiliary circuits or complex algorithms to balance the capacitor voltage. Design and analyses of both power circuits are demonstrated for the proposed multilevel inverters. Modes of operation for the switching states
are described. Modulation switching strategy is explained in details Computer simulations are carried out via Matlab/Simulink software for the proposed topologies. The experimental setup of the both proposed topologies are built and tested in the laboratory to verify the theoretical analysis. The experimental setup and hardware implementation are
described for both circuits. The simulation and experimental results for the proposed topologies are discussed at different conditions such as input DC
voltage, switching frequency and load.
The simulation and the experimental results allow the investigation of the output voltage and load current of the proposed MLIs under various conditions. Also, harmonic spectrum of output voltage and current are studied. Variable switching frequency is also investigated. The simulation results are giving a great matching with the experimental results.
The results show that the proposed MLIs can achieve near sinusoidal output voltage waveform with reduced number of power electronic components and boosting ability at the output voltage. Total harmonic distortion (THD) in the output waveform of both proposed circuits is within accepted limits in comparison with other recent
topologies in the same output levels with the same boosting gain, so, using filter to improve output waveform is unnecessary.