Single Phase Symmetrical Nine level Cascaded Multilevel Inverter by Single Carrier PWM Scheme

Multilevel inverters are used for high power applications because they provide good quality output waveform with less amount of current and voltage stresses on the power electronic switching elements which make sure quality performance. This paper presents a symmetrical single-phase, nine-level, cascaded multilevel inverter. Building block of this cascaded multilevel inverter is configured on the basis of h-bridge inverter having two dc-link switches and two diodes linked to these switches. This topology uses twelve controlled switches and two DC sources instead of sixteen controlled switches and four DC sources which is required in conventional cascaded h-bridge inverter. PWM method based on phase opposition disposition carrier scheme is implemented which requires merely one carrier signal. Through Matlab simulation work is carried out of the proposed topology.