Assessment of Switching Frequency Effect on a Compact Three-Phase GaN-Based Inverter Design

As wide-bandgap devices enable the high switching frequency, their potential is explored in the high-efficiency and high-power-density converter design. This paper first presents a compact 650V/60A gallium-nitride (GaN) half bridge module with ultra-low power loop inductance and standard double-side thermal solution. A high-power-density three-phase 1 kW 400 Vdc inverter is built and tested at 500 kHz switching frequency. With the design approach, the switching frequency effects on the two-level three-phase inverter performance are assessed, including losses, efficiency, heat sink volume, common mode (CM) and differential mode (DM) conducted electromagnetic interference (EMI). The CM and DM EMI filters under different switching frequency are designed based on the unterminated EMI behavioral mode with optimization, based on which the effect from the switching frequency on EMI filter volume is evaluated.