High Efficiency Three-Phase-Inverter with 650 V GaN HEMTs

GaN power devices offer great performance improvements compared to Si transistors. The lower conduction and switching losses of GaN transistors enable to build high efficiency power converters with high switching frequencies. An increase of the PWM frequency has many advantages in motor drive applications like reduced motor current ripple, lower motor losses and reduced filter size and cost. This paper presents the evaluation of a normally-off 650 V, 30 A GaN transistor in a motor drive application. The switching performance of the GaN HEMT is investigated by using a double pulse tester. Furthermore, design and experimental results of a high efficiency 1.5kW three-phase-inverter with sine-output filter and a PWM frequency of 100 kHz are shown. The GaN inverter with sine-output filter achieves 97% efficiency.