Performance Evaluation of a Novel High Voltage Monolithically Integrated SiC MOSFET-DIODE for Solar String Inverters

There has been an increase in large-scale solar power plants around the world. Most large-scale solar power plants operate at a DC bus voltage of 1000Vor less. It has been shown in current literature that an increase in DC bus voltage enhances the performance of the solar string inverters. The commercially available Si-based string inverters use complex multi-level inverter topologies to reduce the filtering requirements, eliminating the high-frequency operation of SiC MOSFETs. But SiC MOSFETs are associated with reverse recovery losses owed to its body diode. A novel device namely, Integrated MOSFET-DIODE was developed to eliminate this loss, where the reverse conduction is through a SiC diode rather than the MOSFET’s body diode. This paper demonstrates the advantages of a novel Integrated MOSFET-DIODE over Si devices and SiC MOSFETs in applying solar string inverters.