Speaker
Description
The controlled turn-less structure motor (CTM) described in other papers of this conference requires arrays of high current low voltage inverters occupying a width of ~6mm and distributed around the periphery of a motor.
The recently developed class of semiconductor switches which operate at the 10 to 50Volts range and planar current density in the 3-4kA/cm2 range both in Si and GaN, opens the opportunity to integrate these devices directly with electro-mechanical systems so that each stator conductor in the gap is separately switched controlled in an H-bridge 3- phase manner. Lastly, the integration of high power density batteries and micro channel coolers in a compact configuration results in an overall enhanced specific power and performance of motors, generators and actuators.
Separately, the low voltage allows proximities of semiconductor dies on their original wafers, which eliminates the need of individual packaging and allows arrays of high power H-bridges to be integrated with their loads more compactly and economically.
We will discuss the underlying semiconductors characteristics and limitations of both Si and GaN MOSFETs when operating in the low voltage high current regime, and the overall power density limits associated with dense packaging and enhanced cooling using micro channel coolers.
Furthermore, we will discuss the various manufacturing choices for such a motor and tradeoffs. While the present devices are prototypes, and thus their construction is not representative of mass manufacturing, due to the planar topology of the windings, MEMS manufacturing can be used here for etching the conductor grooves and depositing insulator layers and electroplating the copper conductors to form the turn-less structures in one operation.
