High power 3-phase to 3-phase matrix converter using dual-gate GaN bidirectional switches

Highly efficient three-phase to three-phase matrix converters using Gallium nitride (GaN) bidirectional switches with both high current and high breakdown voltage are demonstrated. The GaN switch with dual gates works as a bidirectional switch by a single device, while a conventional bidirectional switch consists of four devices by two Insulated Gate Bipolar Transistors (IGBTs) and two diodes. In addition, the GaN bidirectional switch is also free from the voltage offsets for the current conduction so that the GaN-based matrix converter enables small size and highly efficient AC/AC conversion. Improvement of the device performance including the introduction of the recessed gate enables the low on-state resistance with stable operation free from current collapse. The maximum drain current reaches 100 A together with the breakdown voltage of 1340 V. The fabricated three-phase to three-phase matrix converter exhibits the maximum conversion efficiency of 98% at 1 kW output power with the expectation that the maximum output power can reach 10 kW or more by the high current device.