Design and Qualification of a 100 kW Three-Phase SiC-Based Generator Rectifier Unit Rated for 50,000 ft Altitude Jiewen Hu, Member, IEEE, Xingchen Zhao, Student Member, IEEE, Lakshmi Ravi, Student Member, IEEE, Rolando Burgos, Senior Member, IEEE, Dong Dong,

 

Design and Qualification of a 100 kW Three-Phase SiC-Based Generator Rectifier Unit Rated for 50,000 ft Altitude Jiewen Hu, Member, IEEE, Xingchen Zhao, Student Member, IEEE, Lakshmi Ravi, Student Member, IEEE, Rolando Burgos, Senior Member, IEEE, Dong Dong, Senior Member, IEEE, Richard Eddins, Sriram Chandrasekaran and Saeed Alipour 

VIEW FULL PAPER: https://www.osti.gov/servlets/purl/2446561

Abstract—Featuring higher blocking voltage, smaller parasitic elements, faster switching speed, and a more compact package, wide-bandgap semiconductor devices like Silicon Carbide devices (SiC), can enable compact aircraft generator-rectifier units (GRUs) thus making them highly desirable. Yet, the combination of the increased voltages, high power density, and the lower pressure environment associated with aircrafts can pose a significant threat to the converter operation due to the increased sensitivity to electric field (E-field) intensity inside the GRU components and their assembly. To this end, a comprehensive design and qualification of a 100 kW three-phase SiC-based GRU rated for a flight altitude of 50,000 ft (11.6 kPa) is presented in this paper. First, an insulation coordination that based on Paschen-curve is proposed to improve the power density. High E-field areas of the GRU are determined and preemptively solved with the use of an E-field control methodology to prevent partial discharge (PD) under normal operating conditions. Second, the gate-driver and EMI filter components are optimized for operation at 70 kHz. Finally, the insulation design is qualified through low-pressure PD tests, and it is verified that the unit successfully operates at rated conditions to achieve 33.3 kW/l power density, 99.2 % efficiency, and PD-free operation at 50,000 ft.