Samer Saleh Hakami, Laith M. Halabi, and Kyo-Beum Lee, "High Efficiency and Low Complexity Dual-Reference Voltage-Based Pulse Width Modulation for Three-Phase Five-Level HANPC Inverters," Journal of Electrical Engineering & Technology, vol. 19, no. 5, pp. > Paper

This study proposes a low complex and high efficient dual-reference voltage-based pulse width modulation (DRV-PWM) scheme for three-phase 

five-level hybrid active neutral-point-clamped (HANPC) inverters. Although phase-shifted carrier PWM (PSC-PWM) is capable of naturally balancing 

dc-link and flying capacitors voltages, such a process requires a tedious and sophisticated adjustment of the phase-shift between the PWM signals, 

particularly in a digital signal processor (DSP). As a result, a phase-delay eventually occurs, which leads to unevenly distributed thermal losses 

among the three phases of the five-level HANPC inverter. Therefore, this study introduces an alternative switching scheme that has the same merits 

as the conventional PSC-PWM in naturally balancing the voltages without requiring voltage sensors. It also balances the thermal losses across the 

three phases, which enhances the reliability and efficiency of the switching devices. The proposed DRV-PWM is experimentally evaluated in 

comparison to conventional PSC-PWM on a TMS320F28377S DSP. The experimental results reveal that the proposed DRV-PWM effectively 

synchronizes the execution of the three-phase pole voltages while also keeping the thermal losses evenly distributed among the three phases.