Automotive Engineering - March 2023 - 18

The push for
e-powertrain
PROGRESS
Ben Schuler,
CEO of
Infinitum
Electric.
motors with no magnets. Magnet-less induction motors
typically are less efficient; Schaeffler's engineers
claim externally excited motors can be developed with
efficiencies " on par " with a permanent-magnet motor.
The company's most-recently revealed idea, the
" 4in1 " e-axle, integrates the traction motor, transmission,
power electronics and thermal management,
achieving an incremental efficiency gain over its 3in1
e-axle. A collaborative move to SiC power electronics
delivers more than 99% efficiency, the company claims.
Schaeffler's new 4in1 e-axle can incorporate a shifting
mechanism for a 2-speed transmission, which
some believe is a worthwhile addition for larger, higher
inertia-weight vehicles favored in the U.S. market.
There also is provision for a decoupling unit
The company isn't eying only EVs. It believes hybrids
will play an important transitional role, so
Schaeffler is focusing on hardware and electronics to
introduce " much higher voltages " for HEVs, said
Markus Steinberger, director e-mobility R&D.
ZF enhances motor power density
In November 2022, ZF revealed an all-new electric powertrain
with many benefits, including the capability to
accommodatie either 400V or 800V architectures. The
flexibility comes from the controller chip and inverters
with individual power switches.
The company asserted that this architecture results
in fewer components than today's power modules. The
system baselines at 100 kW (134 hp) per axle and can
generate as much as 300 kW.
An aspect of ZF's new e-drive system that likely will
intrigue competitors is the new braided-wiring technique
that enables higher power densities to be
achieved. " Hairpin wiring, the state of the art today,
18 March 2023
eLeap Power's integrated inverter takes advantage of the windings of an electric
motor (when it's not moving) to replace a vehicle's onboard charger and its
artificially slow charging speeds.
eLeap Power is under contract to
deliver 15,000 integrated inverters
for use in delivery vans made by
Chery Automotive.
was introduced five to seven years ago, [and] requires hundreds of
laser welding points, " said Roland Hintringer, head of e-motor product
lines. He said ZF's braided wiring is formed and braided in one
step, saving time and requiring less space, with a winding head of 15
mm versus 28 mm for hairpin winding. " It only requires 24 welding
spots, " he said, adding that the new technique also reduces the raw
material used by 10%.
Meanwhile, ZF joins Infinitum in the liquid-cooled stator movement.
In addition to the water-cooled motor housing, cooling oil is
pumped not only around the stator housing, but also through slots in
the braided windings themselves.
Hintringer said the result is an 85% increase in peak performance, a
50% increase in power and use of only 1% of the rare earth materials
compared to current technology.
eLeap Power: A charger-deleting inverter
eLeap Power also pitched at CES 2023 with a proposition that has
unquestionable appeal: The Canadian company says its inverter
technology eliminates the need for an onboard charger and voltage
converter by leveraging the already existing windings of the drive
motor. The result, eLeap said, delivers many benefits:
AUTOMOTIVE ENGINEERING
FROM LEFT: INFINITUM; eLEAP POWER
Automotive Engineering - March 2023

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