Compact high-speed drive with integrated inverter for mobile applications

The implementation of Li-ion battery technology in recent years has significantly increased the power of mobile devices. Furthermore, the use of brushless DC motors results in a higher efficiency and a longer battery run time. In this paper, a newly developed drive with a high power density is presented for hand-held devices. The motor is driven by a field oriented control with sinusoidal commutation to increase the efficiency at high speeds. In addition, the low voltage control electronics has been integrated into the motor design to obtain a compact drive system. To improve the heat dissipation of the power transistors, a single sided insulated metal substrate (IMS) PCB is used for thermal coupling with the housing of the BLAC motor. The structure of the actuator is optimized with regard to a simple manufacturing. Therefore, the motor is equipped with tooth coil windings and a segmented stator. The design of the rotor takes into account the requirements of the sinusoidal operation and the high rotational speeds.