A Study on High Quality Single-Phase Seven-Level Grid-Connected Inverter
Department of Electrical Engineering
Graduate School, Chonnam National University
Le Tuan Vu
A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIRIMENTS FOR MASTER OF ENGINEERING IN ELECTRICAL ENGINEERING
(Abstract)
Multilevel inverter technology has emerged recently as a very important alternative in the area of
high-power medium-voltage energy control. Multilevel inverters include an array of power
semiconductors and capacitor voltage sources, the output of which generate voltages with stepped
waveforms. The commutation of the switches permits the addition of the capacitor voltages, which reach
high voltage at the output, while the power semiconductors must withstand only reduced voltages. There
are three commonly topologies have been proposed for multilevel inverters: diode-clamped (neutralclamped);
capacitor-clamped (flying capacitors); and cascaded multicell with separate dc sources. The
most attractive features of multilevel inverters are that they can generate output voltages with extremely
low distortion, they draw input current with very low distortion and they can operate with a lower
switching frequency.
In this paper, a new type of the multilevel single-phase grid-connected inverter is proposed. Like
other multilevel inverters, the proposed inverter has fully all the features of the multilevel inverters but
has less number of switches than the ones of three types of commonly multilevel inverter with the same
number of levels output voltage. The operational principle and the switching functions are analyzed in
this paper. To verify the performance of the proposed inverter, PSIM simulation and experimental results
are also shown in this paper.
JOSIL ARTISTA PLASTICO FORTALEZA CEARA BRASIL AV.HERACLITO GRAÇA 41 TEL(85)32542378