Gallium Nitride Semiconductors in Power Electronics for Electric Vehicles: Advantages and Challenges

Electric and Hybrid Vehicles mostly use Silicon-based IGBTs for driving the motor and controlling DC/DC converters in their powertrain. IGBTs transition times usually limit their switching frequencies in the 10-100 kHz range. Gallium-Nitride semiconductors have been introduced which indicate nano-second range switching times and operating temperatures up to 200°C, with the promise of many advantages in the automotive market. Faster GaN devices will eventually lead to higher switching frequencies and lower switching losses, lower power electronic volume and weight reduction. Faster switching comes with cheaper inductors and capacitors. The silicon (Si) has reached its limits regarding the dynamic performance and conduction losses, which is why several manufacturers and researchers are working on new materials, such as gallium nitride (GaN) for new power devices development. In the paper, a comparison is made between GaN and Si in terms of cost, performance advantages and upcoming improvements. Challenges are highlighted, as driving a high-power device in nanoseconds comes with many unresolved difficulties.