100V GaN for Highly Efficient 1kW Motor Drive Applications

In this work, Infineon’s 100V 3mΩ CoolGaN™ is evaluated and compared with a 100V similar Rdson MOSFET using OptiMOS™5 silicon technology in a three-phase inverter for battery powered motor drive applications. In order to minimize conduction losses, 30ns dead time is achieved for GaN due to its lower gate and output charge in comparison to 60ns of dead time for silicon. A motor-generator setup is developed to evaluate a 48V drone motor up to ~1kW of inverter power. For a motor speed of 4000RPM, with a bus voltage of 48V and 100 kHz switching frequency, GaN shows higher efficiency across the entire load range. At 1/3rd load (~300W), 98.67% and at full load (~900W) 98.10% power efficiency values are achieved. At light load (~45W), a significant increase of ~5% is also observed in efficiency. This experimentally demonstrates that 100V CoolGaN™ is ideal for developing high frequency switching inverters with high power densities and motor efficiencies in the kilowatt power range.