Automotive Engineering - September 2022 - 29

ELECTRONICS FEATURE
Industry
veteran Joe
Vollmer spent
years at GM,
Bosch and
Sturman
Industries
before joining
Eberspaecher.
Eberspaecher's
new 4thgeneration
heater
technology
generates
more
heat
performance
with fewer
components,
explained
applications
engineer
Robert Tate.
example, you might be able to get away with a 2kW3kW
heater. But automotive designs for the 100-percent
use case, not 20- or 50-percent. " Roughly 10% of an EV
battery is scaled for cabin heat and cooling.
Tate's team sees various EV heater strategies emerging.
Some OEMs are focusing on larger heaters they
plan to run for shorter periods, with the goal of maintaining
temperature in the coolant and in the cabin.
Others are adopting a " localized approach " including
electric seat heaters incorporating blowers that vector
warm air on the occupant's neck. " They're called an 'air
scarf' and we're involved with that technology, " he said.
" It's very popular in Europe on convertibles. " Another
more costly strategy is decentralized heating that fits
mini heaters in the vents, closer to the seats, to warm
customers more efficiently.
Eberspaecher's latest heater is designed to be located
on the coolant loop. According to Tate, engineers
debate whether a coolant loop heater is the right
choice for an EV versus an air heater, the output of
which feels more direct. " One thing that gets overlooked
is these systems are putting out 5kW to 8kW of
heat - that's equivalent to house heating, " he noted.
AUTOMOTIVE ENGINEERING
48V supercapacitors are
among the company's
expanding product portfolio.
" That may be a bit overpowering, but it's necessary to warm the occupants
and clear the windshield. "
The company's fourth-generation heater technology is entering
production. Its design boasts a reduced number of heating elements.
" We're generating more heat performance with fewer components, "
Tate explained. " In relation to the battery it's not that impressive,
but in terms of design cost and overall size, we've made
year-over-year improvements. "
Latency and liquid cooling
Looking ahead in electronics technology to meet industry trends,
Vollmer and Tate note the move to higher system voltage levels.
" There's a lot of talk about 800 volts, and we have definite development
plans in that realm, " Vollmer said. He added that OEM development
cycles " are wild right now - faster, with changing component
requirements - because of all the improvements that are coming. "
The automakers also are " learning quickly about high-voltage component
requirements and how they need to interact with one another.
This has led to communication-network changes, from CAN to
LIN, for mixed-signal vehicles. We've had to be quick at adapting to
the different vehicle networks, " he explained.
In the automated-driving space, in-vehicle data-processing speed
with decreasing latency is another challenge. " The AV world is going
after 100-microsecond latency, " Vollmer said. " The first question the
vehicle topology people ask us is, 'How fast can we switch?' That determines
how to build up the hardware set. Does it need to be an
ASIL-D microprocessor? All the components we select must be able to
meet the specified switching times. " There also are discussions on
cooling strategies. Liquid cooling is a current topic with Eberspaecher's
commercial vehicle customers, he noted.
September 2022 29
CLOCKWISE FROM TOP LEFT: LINDSAY BROOKE; EBERSPAECHER; LINDSAY BROOKE
Automotive Engineering - September 2022

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