Mechanical and Thermal Design of an Optimized PCB Motor for an Integrated Motor Drive System With GaNFETs

PCB motors are a viable alternative to commercial electric motors as they are easy to mass-produce and have low manufacturing costs. Moreover, integrated motor drives have gained popularity thanks to their high power density and ease of installation. However, the mechanical and thermal aspects are challenging due to reduced volume. In this paper, a GaNFET switched integrated motor drive axial-flux permanent magnet synchronous machine with a printed circuit board (PCB) stator is designed. The machine is optimized using a multi-objective, non-dominated sorting genetic algorithm (NSGA-II). Two stator types are designed and manufactured to compare the effect of eddy losses. A method for measuring eddy current losses on PCB stators is proposed and used. A mechanical and thermal solution is proposed and tested. Integrated motor drive with sinusoidal pulsed width modulation (SPWM) is used to drive the motor up to 5000 RPM at a 1 MHz switching frequency. The overall system‘s efficiency is 82% at 0.36 N.m and 90% at 0.18 N.m torque. The system has an output power of 270 W of output power with 59 °C stator temperature that proved the effectiveness of the proposed passive cooling method.