Nine-Level Cascaded H-Bridge Multilevel Inverter

The multilevel inverter utilization have been increased since the last decade. These new type of inverters are suitable in various high voltage & high power application due to their ability to synthesize waveforms with better harmonic spectrum and faithful output.. This paper presents a multilevel inverter configuration which is designed by insertion of a bidirectional switch between capacitive voltage sources and a conventional H-bridge module. The modified inverter can produce a better sinusoidal waveform by increasing the number of output voltage levels. By serial connection of two modified H-bridge modules, it is possible to produce 9 output voltage levels including zero. Multicarrier phase-shifted pulse-width modulation method is used to achieve balanced power distribution among the power cells. The analysis of the output voltage harmonics is carried out. From the results, the proposed inverter provides higher output quality with relatively lower power loss as compared to the other conventional inverters with the same output quality.