All-SiC 99.4%-efficient three-phase T-type inverter with DC-side common-mode filter

This letter presents a hardware demonstrator of an all-SiC three-level T-type (3LTT) inverter with the common-mode (CM) EMI filter stages placed on the DC input instead of the AC output side, targeting, for example, high-efficiency PV applications. The extensive experimental characterization shows that state-of-the-art SiC transistors and a DC-side CM filter enable an unprecedented peak/full-load efficiency of 99.4% (calorimetric measurement) at 12.5 kW and a power density of 2.4 kW/dm(3) (39 W/in(3)). The demonstrator fulfills CISPR 11 Class A EMI regulations as well as upcoming EMI standards for the frequency range of 9-150 kHz. Compared to other high-efficiency converters, which often employ bridge legs with more output voltage levels, the described 3LTT concept thus offers a very favorable trade-off between complexity and performance.