Comparing the Phase-Shifted and Level-ShiftedPWM Techniques for Multilevel Flying Converters

This paper evaluates the performance of two common carrier-based techniques to control the voltageof the flying capacitor multi-level inverter (FC_MLI). These two techniques are Phase shifted Pulse WidthModulation (PS-PWM), and Level shifted Pulse Width Modulation(LS-PWM). First, the structure of FCMLIis studied. Also, the principle of operation of PS-PWM and LS-PWM are explained. Then using the PSIMsimulation software a three-level and five-level flying capacitor inverters are simulated. The effect of PS-PWMand LS-PWM on ۳ levels and ۵ level FCI performance is investigated. The time-domain simulation andharmonic analysis results indicate that the PS-PWM has a better performance than the LS-PWM. Also, theseresults show that increasing the voltage level in the flying capacitor structure decreases the voltage and currentharmonics.