FAST SVM BASED 3 PHASE CASCADED FIVE LEVEL INVERTER

Jaison P Paul, Arun S

Abstract: Introduction of nearest three vector algorithm is a major achievement in the area of space vector technology. Complexity and severe computations are still the drawbacks of SVM methods mainly for multilevel inverter applications. A fast SVM technique is introduced in this project which allows the calculation of switch time duration and the efficient determination of switching times based on the two level inverter scheme. SVM modulating waves are generated based on the two level system and then this modulating waves are compared with required number of carrier signals in order to generate the switching pulses for the inverter. Four triangular carrier signals are needed for a five level system in order to generate the switching pulses. Coordinates of the nearest three voltage vectors is not needed, so the complexity of the SVM technique can be reduced and it is the major advantage of the proposed technique compared with conventional SVM techniques used for multilevel inverters. A three phase five level cascaded H bridge topology is used here to verify the effectiveness of the proposed technique. MATLAB simulation and hardware implementation of the proposed system is done. From the analysis of both simulation and hardware it is clear that proposed SVM technique have more fundamental output and less THD than sinusoidal PWM technique.

Keywords: Cascaded H bridge, Multilevel, Modulating wave, Space vector

DOI: https://doi.org/10.15623/ijret.2015.0411050