Development and Validation of a SiC Based 50 kW Grid-Connected PV Inverter

The future power grid will involve increasing numbers of power converters while growing the complexity of the power systems. The future of the power converters is driven by developments in the wide-bandgap semiconductor devices. In this paper, a 50-kW string photovoltaic (PV) inverter designed and developed using all silicon carbide (SiC) semiconductor devices is presented. The inverter design includes an additively manufactured power block, symmetrical Y-core inductors for the ac-side filter, and advanced inverter controls for grid support functionality. This inverter uses the conventional three-phase voltage source inverter topology and optimizes the design for SiC-based devices. The paper includes details on power module design, heatsink optimization, symmetrical Y-core filter inductor design, inverter thermal design, and further experimental validation of the inverter performance. In addition to presenting the quantification of inverter efficiency and quality of the output, the paper presents the validation of advanced grid-support functions required by the IEEE 1547 standards for the interconnection of distributed energy resources.