[IEEE 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Atlanta, GA, USA (2018.10.31-2018.11.2)] 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Self-powered Gate Driver Design for a Gallium Nitride Based Phase Shifted Full Bridge DC-DC Converter for Space Applications

摘要： Radiation hardened Gallium Nitride (GaN) Field Effect Transistors (FETs) for space DC-DC converter applications have been released to the market recently. However; space qualified digital isolators with small propagation delays, fast rise and fall times, and high common mode transient immunity necessary for isolated GaN gate drivers are not currently available. In this work, a self-powered isolated GaN gate drive circuit for a Phase Shifted Full Bridge DC-DC converter for space applications is designed and tested. Signal isolation and energy transfer to bias GaN gate driver chips are achieved using pulse transformers. Operation is successfully verified in a converter using 200 V radiation hardened GaN FETs and delivering 400 W from a 100 V DC bus. Experimental results show the effects that the voltage rate of change of the switch nodes have on dead time accuracy for the top switches in the proposed implementation, and a description of how better dead time accuracy was obtained is included.