A Three-Phase-Module-Parallel Si & SiC Hybrid Inverter with Smaller Filter Size and Low Cost

Abstract

With the rapid development of wide bandgap (WBG) power semiconductors, SiC and Si hybrid inverter has received high attention in both academic and industry due to their high switching frequency, low switching loss but appropriate cost. In this paper, a Three-Phase-Module-Parallel (TPMP) SiC & Si hybrid inverter targeted for low voltage applications is proposed, which consists of Si and SiC three-phase power modules. With the proposed coordinated current compensating modulation scheme, the Si IGBT three-phase module enables its low-frequency switching and takes major parts of active power, while the SiC module operates at high frequency to just compensate for the current ripple of Si IGBT modules. This proposed inverter has a lower cost since the power rating of the SiC converter only has 1/3 of the rated power. On the other hand, a smaller filter design is realized since the equivalent switching frequency is high. The proposed topology and modulation scheme are verified by simulation.