Single Phase 9 Level Symmetrical Cascaded H-Bridge Inverter for different PWM techniques

Multilevel inverters are best suitable for high power applications as they provide quality output waveform with less amount of voltage and current stresses on the switching elements which ensure good quality performance, among the various topologies of multilevel inverter cascaded H-Bridge is more reliable, simple in design and can be implemented easily and has better performance compared to other topologies. In this paper analysis is done on single phase 9 level symmetrical cascaded H-Bridge inverter and the performance of the inverter is analyzed for different PWM techniques such as In Phase Disposition (IPD), Phase Opposition Disposition (POD), Alternate Phase Opposition Disposition (APOD) using POWERSIM simulation software and the inverter is also implemented in hardware and the programming for the switching pulses is done in Code Composer Studio software using Digital Signal Controller TMS320F28335. A comparison of the Total Harmonic Distortion at a modulating frequency of 1.25 kHz and Modulating Index 1 AND 0.8 is done for all the above PWM techniques in both simulation and hardware.