Three-level ANPC Inverter Common-mode Voltage Analytical Characterization

Abstract

Evident in previous literature, in the motor drive system, the research on the analytical models for common-mode (CM) performance evaluation is inadequate but needed. Especially for the 3-level inverter system. The majority of work focuses on simulations and experiments. In this paper, an analytical model of CM voltage (CMV) in a 3-level inverter is presented based on Double Fourier Integral (DFI). The model could be extended to different 3-level modulation schemes such as conventional space vector PWM (CSVM), nearest three space vectors modulation (NTSVM), and reduced common-mode voltage modulation (RCMVM). The impact of these three modulation schemes on the CMV is comprehensively compared across varying modulation indices. An 800V/50kW 3L inverter will be built using off-the-shelf automotive-qualified 650V/60A GaN HEMTs from GaN Systems.