This paper presents the comparison of carrier based PWM techniques (Carrier Overlapping Pulse Width Modulation (COPWM) and non-overlapping PWM techniques) for the Flying Capacitor Multi Level Inverter (FCMLI). Due to switch combination redundancies, there are certain degrees of freedom to generate the five level AC output voltage. This paper presents the use of Control Freedom Degree (CFD) combination. The effectiveness of the Pulse Width Modulation (PWM) strategies developed using CFD are demonstrated by simulation. The simulation results indicate that the use of CFD combination is an important clue to realize high performance multilevel inverters and the COPWM-Astrategy developed exhibits reduced harmonics for moderate modulation indices and higherDCbus utilization than non-overlapping PWM methods.

Key words: Multilevel inverters, FCMLI,PWM,CFD, Sub-HarmonicPWM.