Page 49 - ATZ WORLDWIDE

AUTHORS

Dr. Markus Wawzyniak
is Director Advanced Engineering,
Air Conditioning Systems at Mahle Behr
in Stuttgart (Germany).
Thermal Management

as a Basic Prerequisite for

Electric Mobility is Director Advanced Engineering,
Dipl.-Ing. Laurent Art
Powertrain Cooling at Mahle Behr
in Stuttgart (Germany).

Dipl.-Ing. Matthias Jung
is Manager Thermodynamics and Systems,
Advanced Engineering, Air Conditioning
Systems at Mahle Behr
in Stuttgart (Germany).

Dr. Fahmi Ben Ahmed
is Manager Advanced Engineering,
Powertrain Cooling Systems at Mahle Behr
in Stuttgart (Germany).

COMPLEX THERMAL parison with the combustion engine. At The reason for this is that the Li-ion bat-
MANAGEMENT FOR PLUG-IN the same time, however, the tasks for tery not only needs to be cooled but sub-
HYBRID ARCHITECTURES thermal management are more varied, jected to active temperature control and
both in terms of the number of circuits conditioning.
Doubling the powertrain architecture in and in terms of the temperature levels and The maximum temperature require-
a plug-in hybrid makes thermal manage- their interactions with each other: ment of 40 °C for Li-ion batteries can no
ment especially complex, FIGURE 2. For a – maintaining battery temperature longer be maintained by a passive cool-
plug-in hybrid, up to five circuits, some of regardless of the outside temperature ant circuit when temperature require-
which are coupled, must be rapidly con- to optimise battery life ments are moderate to high. As a heat
trolled to various temperature levels with – temperature safeguards for power exchanger, the battery chiller forms a
tight temperature spreads in response to electronics to a maximum of 60 °C node between the battery coolant, the
different situations, because the use of – cooling the electric motor at up to low-temperature coolant circuit, and
Li-ion batteries presents particular chal- 140 °C (for the windings) or 120 °C active cooling by the refrigerant circuit.
lenges for plug-in hybrids. At first glance, (for the magnets). In turn, the Li-ion battery’s temperature
the cooling of the important electrical The refrigerant circuit of the air condi- is controlled by a cooling plate, whereby
energy storage seems simple because tioning system becomes part of the ther- it must be ensured that the temperature
there is less heat to be dissipated in com- mal management of the entire vehicle [1]. spread between the cells at the coolant
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