Modelling and simulation of a multilevel inverter using space vector modulation technique

ABSTRACT Master Thesis MODELLING AND SIMULATION OF A MULTILEVEL INVERTER USING SPACE VECTOR MODULATION TECHNIQUE Ayşe KOCALMIŞ Firat University Graduate School of Natural and Applied Scieces Department of Electric and Electronics Engineering 2005, Pages: 83 Recently, developments in power electronics and semiconductor technology have lead improvements in power electronic systems. Hence, different circuit configurations namely multilevel inverters have became popular and considerable interest by researcher are given on them. The output voltage waveforms in multilevel inverters can be generated at low switching frequencies with high efficiency and low distortion. In recent years, beside multilevel inverters various pulse width modulation (PWM) techniques have been also developed. Space vector PWM technique is one of the most popular technique gained interest recently. In this thesis, modeling and simulation of a multilevel inverter using cascaded inverters with separated DC sources have been performed. In multilevel inverters, it is easy to reach high voltage levels in high power applications with lower harmonic distortion and switching frequency, which is very difficult to get this performance with conventional two level inverters. Minimum level number of a multilevel inverter is three and three level inverter structure is chosen for this work. In this thesis first, basic information on multilevel inverters are given. Then, pulse width modulation techniques are investigated and detailed analysis is performed on the space vector PWM technique. Finally, modeling and simulation of the three level multilevel inverter using cascaded inverters with separated DC sources have been done with R-L and induction motor load using MATLAB/Simulink package program. Simulation results have been analyzed and compared to corresponding results obtained using sinüsodial PWM technique. Keywords: Space Vector PWM,Three Level Inverters, Multilevel Inverters. XIII