High Power Density System Design for GaN-based LV Motor Drives

Abstract:
This work presents a complete motor drive system design that leverages Gallium Nitride (GaN) transistors to improve power density, especially in battery-powered applications. These applications such as drones, cobots, and e-mobility require small and powerful motor control boards, which are often integrated within the motor enclosure where the thermal budget is limited. The design presented here reaches a maximum power of almost 2kW with a supply voltage of 48V, corresponding to a power density of 3.2 kW/in³ (200 W/cm³). It includes the power stages for each phase leg, as well the control, sensing/protection, and auxiliary supply circuits to form a complete system. The paper presents the methodology of the PCB and thermal design used to integrate all the necessary components into one small board (29 x 51 x 9mm), as well as experimental verification of its performance.