Multilevel Inverter is an energy conversion device that is generally used in medium voltage and high power applications. It offers lower total harmonic distortion, switching losses, voltage stress on switches than conventional inverter. This paper presented a 15 level asymmetric H-bridge multilevel inverter using a topology with less number of switches. In asymmetrical MLI, DC source magnitudes are unequal and it is designed as to maintain a ratio of 1:2:4. The modulation technique that has been used here to get proper switching is PDPWM. The input PWM signals have been generated using MATLAB Simulink and real time simulation and subsequent interface with hardware has been done using d-SPACE and MicroLab Box (DS-1202). A 2kHz multiple carrier signal is used to develop phase disposition pulse width modulation (PD-PWM).A study of this modulation technique used has been done and received results provides better efficiency , less low order harmonics and less switching loss.
Keywords: Multi-Level Inverter (MLI), Phase Disposition Pulse Width Modulation (PD-PWM), Fast Fourier Transform (FFT), Total Harmonic Distortion (THD)