Comparative study on three phase cascaded inverter for various bipolar PWM techniques

This paper represents the comparison of carrier-based bipolar pulse width modulation technique such as phase disposition, phase opposition disposition, alternating phase opposition disposition, carrier overlapping and variable frequency for the choice of three phase nine level cascade multilevel inverters. In this paper, cascade multilevel inverter topology with a multiconversion cell consists of two unequal voltage sources and it produces nine level output voltages at load terminal. Simulation results are performed by using MATLAB/Simulink. It indicates that alternating phase opposition disposition pulse width modulation provides higher output voltage with less harmonic distortion for all pulse width modulation techniques. It is also observed that the carrier overlapping pulse width modulation technique provides higher fundamental RMS output voltage for all pulse width modulation techniques.