Automotive
Traction Applications
Two-slice SEMA wheel motor concept
Future Truck traction motor
The high torque capability and efficiency of SEMA technology makes it an excellent candidate for direct-drive propulsion of electric and hybrid-electric vehicles. At this time, a number of gear reduction and direct drive traction systems have been studied for use in hybrid and pure electric vehicles, including in-wheel motors for heavier vehicles (4,000–6,000 kg vehicle weight). In a previous study, the leading candidate for traction systems was based on a SEMA motor paired with Oak Ridge National Laboratory’s Dual-Mode Inverter Control (DMIC) inverter system. This pairing offers the high efficiency of ironless SEMA technology with a high constant-power speed range (CPSR) afforded by the DMIC. The resulting system can utilize a smaller motor due to the lower thermal demands and requires a lower primary switch current rating due to the elimination of circulating currents in the motor winding. CPSR ratios in excess of 10:1 are possible with the SEMA/DMIC pairing. Research projects have been completed at Lynx to evaluate and demonstrate SEMA motors for use in vehicle traction applications.
Electric-Assisted Power Steering
The elimination of the need for power steering fluid is a benefit from both a maintenance and environmental perspective. SEMA motors are well suited to both the electro-hydraulic and electric-motor steering-assist systems being planned by many manufacturers. This torque servo application benefits greatly from the high bandwidth and peak torque attainable by SEMA-based motors.
Air-Conditioning or Fuel-Cell Compressor Motors
A SEMA motor electric drive is well suited to direct-drive compressor applications. The high torque-to-inertia ratio possible using a SEMA system is particularly well suited to the high transient load capabilities required by future fuel cell compressors. A motor intended for use in air-handling and compressor applications was developed with commercial partners and government-sponsored research projects.