Replacing Si-IGBTs with SiC-MOSFETs in Low Voltage Grid Converters

Abstract:
For low voltage, medium power grid converters interfacing renewable energy sources (RES), two competitive converter technologies using either well established Silicon (Si)-IGBTs or new Silicon- Carbide (SiC)-MOSFETs are available. Introducing a new technology like SiC usually requires new, optimized designs to fully benefit from the semiconductors’ properties. However, for a direct comparison of the two technologies, two available power modules using the same package are investigated in a 3-phase converter, minimizing the effort associated with the replacement of IGBTs by SiC MOSFETs. This work presents a comparison of the converter efficiencies in different operation scenarios. Furthermore, it shows how filter effort and size can be reduced by operating at higher switching frequencies.