Audi Q7 e-tron quattro 4M - Page 35

35
Drive motor temperature sensor G712
The drive motor temperature sensor G712 is seated between
2magnetic coils, in order to ensure better signal acquisition. It is
an NTC sensor and indicates the temperature to the electric drive
power and control electronics module JX1. This signal is required in
order to prevent overheating of the e-machine. The measured
value can be read out as a measured value using the diagnostic
tester. If the stator is not suciently cooled, the e-machine is
restricted by the power electronics upwards of a measured tem-
perature of about 185°C
1)
and energised without load upwards of
215°C
1)
.
In this case, the e-machine operates neither as a motor nor as a
generator. An entry is made in the event memory of the electric
drive power and control electronics module JX1. To avoid heating
of the stator coils through voltage indication to a temperature in
excess of 215°C, the electric drive power and control electronics
module JX1 energises the stator coils with a three-phase current
which does not produce torque at the rotor (0 Nm control). In this
way, no voltage is induced in the stator coils by the magnetic fields
of the rotating rotor.
The e-machine will function again as a motor and generator as
soon as the measured temperature drops below approx. 210°C
1)
,
or the status of the terminals changes.
Eect of failure
If the sensor fails, the hybrid system warning lamp appears in the
dash panel insert. The vehicle can still be driven, albeit with very
limited hybrid drive.
Stator cooling
The stator is cooled via the die-cast aluminium stator support. The
cooling ducts are integrated in the stator support. Coolant flows
through the cooling ducts forming a coolant jacket. The die-cast
aluminium has the advantage of low weight in addition to having
high thermal conductivity. This highly eective cooling connection
allows a continuous peak power output of 60 kW and a continuous
peak torque of 200 Nm.
The low-temperature circuit for the high-voltage system in which
the stator cooling system is integrated is explained on page 84.
649_073
Coolant return Coolant feed
Drive motor temperature sensor
G712
1)
The given values provide a guideline and are not binding. They
may deviate depending on model version.
Stator support
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