Advanced Modulation Scheme with Loss Balancing Effect Under Low-Modulation Operation for FC-T2C Converter

Multilevel converters are widely applied in the field of high-power machine drives. The flying capacitor-T-type converter (FC-T
²
C), which is derived by combining the T-type converter and flying capacitor converter, is suitable for high current operation. Under the traditional phase-shifted PWM (PSPWM) scheme, uneven distribution of power device temperature occurs under low modulation coefficient, and it will affect the reliability and durability of the converter. In this paper, an advanced phase-deposition PWM (PDPWM) is proposed to realize loss balancing among power devices by introducing new redundant switching states. In addition, the flying capacitor and dc-link capacitor balancing control for the advanced PDPWM is presented and applied. The proposed scheme is verified by the simulation and experiment.