GaN Dual-Stage Power Supply

Current military vehicles use COTS inverters to provide power to 120 Vac loads. These inverters are large and inefficient and do not meet military requirements. However, an inverter constructed from GaN devices could result in a system with the minimum possible volume and weight and improved efficiency. With these goals in mind, during the Phase I Mainstream designed, built, and tested the output-stage of a 2.5 kW single-phase inverter, experimentally verifying <1.7% output voltage THD and 2.5 kW of output power. The power supply is bi-directional, can provide full power with 71 °C air temperature and meets the Army’s “Touch-safe” requirement at 29 °C air temperature. The power supply has an efficiency of 94.6%, and when using natural-convection cooling, the power density and weight are 8.1 W/in3 and 16.0 lbs, representing a 3.3x increase when compared to the legacy system. Building on the highly successful Phase I Base, during Phase II we will perform two rounds of inverter builds for experimental testing. Conformance to military EMI, power quality, and environmental requirements will be verified. At the completion of Phase we will achieve a TRL of 6, with a system prototype validated in a relevant environment.