Automotive Engineering - April 2022 - 16

Airing on the side of
COVER STORY
INNOVATION
The battery is just the gas tank of
the EV. The motor and inverter are
more important to how we get the
range and efficiency.
Aero chief Jean-Charles Monnet
explains how the Air was designed
to generate undercar vortices that
improve efficiency.
semiconductor technology. It features a proprietary
connection system that's positive and virtually errorproof:
It connects to the motor when it's bolted down
during assembly.
The unit's close proximity to the motor (about two
The 'wonderbox' 19.2-kW bi-directional charger located centerline in the Air.
Developed in-house by Lucid, the unit enables vehicle charging up to 924V and
includes a DC-DC converter for a 400V intermediate bus to power vehicle systems.
With DC fast charging, the system can charge the Air at a rate of 300 to 350 kW,
delivering roughly 20 miles of range for each minute charging.
Thermal management is another detail noted by the engineers.
" We found space for the cooling channels right next to the copper,
where the motor heat is created, " Bach explained. " Nobody else has
done motor cooling this way because they feel it would weaken the
electromagnetic flux, " he said. " But we cultivated an electromagnetic
'dead zone,' as we call it, that doesn't contribute to torque generation.
We cool faster than anybody else. This comes from simulating
everything in-house. "
Another Lucid technology asset at play on the manufacturing side:
The company owns unique, continuous-wave winding equipment to
do its motor windings in a dedicated Arizona powertrain factory.
Bach describes the machinery as " fully automated, highly scalable,
and engineered for high-volume manufacturing. "
How is Lucid approaching reduction of rare earth metals? The current
motor design includes neodymium magnets and " low amounts " of dysprosium,
according to Bach. " Our roadmap includes new materials to
get rid of rare-earth metals as much as is humanly possible, " he shared.
Like the Lucid motor, transmission unit and battery pack, the power
electronics hardware and software are extensively patented. The
inverter is a 500-kW design that uses silicon-carbide (SiC) MOSFET
16 April 2022
Scaling up
Scale is critical to reducing cost, and the Lucid engineers
said their designs will scale according to volume
demand without issue. " We realize the ability to manufacture
economically is a guarantor of success and for
being competitive, " Hawkins stated.
As the company scales-up beyond its first product,
the team realizes the need for greater rigor in design
freeze, further DFMA (design for manufacturability
and assembly) advances and meeting start-of-production
(SOP) timing. To that end, another VW veteran,
Ralph Jakobs, was hired for the new role of VP of program
management. " He leads our cycle planning, "
Rawlinson said. " It shows how we're maturing. " Added
Bach: " All of our critical thinking has been focused on
the Air, but now we are parallelizing the work and creating
functional units per the classic matrix organization.
But we aim to keep that nimble edge. "
AUTOMOTIVE ENGINEERING
inches/5 cm), helps unlock more efficiency in transporting
electrons from the inverter, at three-phase,
into the motor. The inverter-to-motor distance on
Tesla Model S - admittedly a much older vehicle - is
about two feet, Hawkins observed: " Another vital fraction
of a percent, " he said.
BOTH IMAGES: LINDSAY BROOKE
Automotive Engineering - April 2022

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