Optimized Design of 1 MHz Intermediate Bus Converter Using GaN HEMT for Aerospace Applications

Abstract

This paper presents the possibility of using Gallium Nitride (GaN) high-electron-mobility transistors (HEMTs) instead of the conventional silicon metal oxide semiconductor field effect transistor (MOSFET) to implement a high-frequency intermediate bus converter (IBC) as part of a typical distributed power architecture used in a space power application. The results show that processing the power at greater frequencies is possible with a reduction in mass and without impacting the system efficiency. The proposed solution was experimentally validated by the implementation of a 1 MHz zero-voltage and zero-current switching (ZVZCS) current-fed half-bridge converter with synchronous rectification compared with the same converter using silicon as the standard technology on power switches and working at 100 kHz. In conclusion, the replacement of silicon (Si) transistors by GaN HEMTs is feasible, and GaN HEMTs are promising next-generation devices in the power electronics field and can coexist with silicon semiconductors, mainly in some radiation-intensive environments, such as power space converters. The best physical properties of GaN HEMTs, such as inherent radiation hardness, low on resistance and parasitic capacitances, allow them to switch at higher frequencies with high efficiency achieving higher power density. We present an optimized design procedure to guaranty the zero-voltage switching condition that enables the power density to be increased without a penalization of the efficiency.