PROCEEDINGS ARTICLE | September 7, 2018
Proc. SPIE. 10754, Wide Bandgap Power and Energy Devices and Applications III
KEYWORDS: Semiconductors, Energy efficiency, Switches, Switching, Silicon, Gallium nitride, Silicon carbide, Renewable energy
DC microgrids are gaining significant attention for smart distributed power systems, particularly in commer- cial and residential sectors, because of their increased energy efficiency, improved power quality, and reduced generation cost. In DC microgrids, distributed renewable energy sources, such as wind turbines, photovoltaic (PV) arrays, and fuel cells, along with energy storage systems–batteries and ultracapacitors–are increasingly implemented as a method of sustainable and clean power generation. Power electronic converters, especially bidirectional buck/boost topologies, play a major role in interfacing these renewable energy sources and energy storage systems with the utility network. However, most existing bidirectional converters face serious conduction and switching losses caused by conventional silicon (Si) devices, which are reaching their theoretical and oper- ational limits. Wide bandgap (WBG) semiconductor devices, such as silicon carbide (SiC) and gallium nitride (GaN), are not only exceed the current Si devices’ limitations but also provide great potential for improving power converters. This paper presents the impact of cascode GaN power devices on a bidirectional DC–DC buck/boost converter in DC microgrids. The results reveal that cascode GaN power devices considerably im- prove the converter performance and efficiency at various switching frequencies, junction temperatures, and output power levels.
