CHARGER COOLING
Of all the facts and fi gures produced by
manufacturers about new electric vehicle
models, often the one that most interests
potential consumers is how long the car’s
battery takes to charge. Having been used
to instantly refueling an ICE-powered vehicle, waiting
around for the car to regain its power can be a shock to
the system, but with fast-charging technology, the situation
is improving.
The increased rate of charging isn’t without issue though,
one of which is an increase in the temperatures found on
the equipment. The charging station itself isn’t aff ected by
the move from 50kW to 350kW – it’s the ancillary
components that bear the brunt and have to be controlled.
“Cables and connectors on EV chargers were designed for
much smaller currents compared to those now being put
through them. So the challenge for us is keeping the copper
cable and the surface temperature of the outside cool
enough for people to comfortably use,” says Dr Suzanne
Koblitz, head of charging technology at Ionity. “The cooling
systems and cables are pretty standard, but the challenge
is new to the automotive industry. People are having to get
used to it because these cooling systems haven’t been in
the industry before.”
Although Ionity merely buys and installs chargers,
Koblitz’ knowledge comes from a previous role where she
110 // January 2020 // www.electrichybridvehicletechnology.com
was responsible for writing the standard for
cooled charging cables. The biggest issue is
that when the copper in the cable gets too hot
due to the level of power being run through it,
the e ciency drops, the rate of charge slows
and suddenly fast-charging becomes much
more medium-paced.
“The most important change – and where
most of the development has been – has been
actively cooling down the contact system,
which is the point where the connector and the
vehicle meet,” she explains. “There is a lot of
heat generated at that point and you have to
cool something that has up to 1,000V. It needs
to have the electrical isolation, but at the same
time cool the connectors.” Koblitz says that the
key elements to ensuring this cooling is
achieved are special connector designs for
high-power cables as well as hoses that carry
coolant through the system. “You essentially
have a cooling body added to the connector
that takes out the heat of the connector
system. This cooling body enables the heat
to be regulated thanks to the coolant.”
Excessive heat can impact on the e ciency
of the cables and so can damage them, either
1
/www.electrichybridvehicletechnology.com