Powertrain Tech Deep Dive

CAR OF THE YEAR WINNER

Everybody is enthralled with the 2022 Lucid Air Dream Edition P's biggest number: 1,111 horsepower. But smaller numbers point the way forward to mass electrification: 3.9 horsepower per pound and 4.6 miles per kilowatt-hour. The former represents the Dream P's drive unit (motor, reduction gear, and integrated power inverter), which produces 670 peak horsepower and weighs 163 pounds, for roughly triple the power density Tesla achieves. The latter represents the range the Air Dream Edition R gets from its 113-kWh battery pack. These mass-reduction and efficiency measures are just the tip of Lucid's (slower-melting) efficiency iceberg. Imagine how small and light a 200-hp version of this motor would be and how many fewer kilowatt-hours of battery you'd need for a smaller, lighter, 300-mile family car that achieves 5 or 6 miles/kWh. That's where this tech is headed.

Shrunken Drive Unit

By innovating a new type of square-bar winding that produces a denser magnetic field in the stator, and by reducing the permanent magnets' size and improving their placement in the rotor, the Lucid Air motor develops 20 percent more reluctance torque from the same magnetic mass as is used in the Tesla Model 3 (about 3.7 pounds). All of this allows the motor to generate more power in a package that's 30 percent smaller than the Model 3's. Utilizing planetary gears for the drive reduction saves a bit more space. The power inverter connects directly to the three phases of the stator to form an ultra-compact package.

Woven Winding for the Win