Evaluation of Hybrid Si/SiC Three-Level Active Neutral-Point-Clamped Inverters

Abstract

Compared with silicon (Si) devices, wide-bandgap (WBG) devices have lower switching loss and lower conduction loss. Using Silicon Carbide (SiC) devices has been an effective solution for achieving high efficiency and high power density. However, except the superiorities mentioned above, the price of SiC MOSFET is 8 times higher than that of Si IGBT in higher current rating. Therefore, it is expected to realize the hybrid utilization of SiC switching devices and Si switching devices. Different hybrid solutions were proposed by replacing Si switching devices with SiC switching devices in three-level Active Neutral-Point-Clamped (3L-ANPC) inverters. However, analysis and quantitative evaluation of different hybrid Si&SiC solutions in 3L-ANPC converters is not yet to be revealed. In this paper, two hybrid 3L-ANPC strategies (2-SiC&4-SiC) are introduced. Three PWM modulation strategies for the 4-SiC hybrid 3L-ANPC inverters are analyzed in details. The power loss calculation of 4-SiC hybrid 3L-ANPC with three different modulation strategies is presented as well. Finally, a 2-kW experimental prototype is built, which verifies the correctness of the analysis and evaluation.