BMW I01, Product Information

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I01�High-voltage�Components
10.�REME
161
Index Explanation
12 Temperature�sensor�of�the�range�extender�electrical�machine
13 Signal�from�temperature�sensor
14 Range�extender�electrical�machine
15 Bidirectional�energy�flow�between�REME�and�range�extender�electrical
machine
16 High-voltage�battery
17 Bidirectional�energy�flow�between�REME�and�high-voltage�battery
The�operating�mode�of�the�DC/AC�converter�is�defined�by�the�REME�control�unit.�The�REME�control
unit�receives�the�setpoint�value�as�an�important�input�variable�from�the�EME�control�unit.�From�this
setpoint�value�and�the�current�operating�condition�of�the�range�extender�electrical�machine�(engine
speed�and�torque)�the�REME�control�unit�determines�the�operating�mode�of�the�DC/AC�converter,�as
well�as�the�amplitude�and�frequency�of�the�phase�voltages�for�the�range�extender�electrical�machine.
According�to�these�specifications,�the�power�semiconductors�of�the�DC/AC�converter�are�activated�in
sync.
In�addition�to�the�DC/AC�converter,�the�power�electronics�also�contains�current�sensors�in�all�three
phases�on�the�AC�voltage�side�of�the�DC/AC�converter.�Using�the�signals�from�the�current�sensors,�the
REME�control�unit�monitors�the�electrical�power�which�is�used�in�the�power�electronics�and�the�range
extender�electrical�machine�and�what�torque�the�range�extender�electrical�machine�generates.�The
control�loop�of�the�range�extender�electrical�machine�electronics�is�closed�by�the�signals�of�the�current
sensors�and�the�rotor�position�sensor�in�the�range�extender�electrical�machine.
The�performance�data�of�the�range�extender�electrical�machine�electronics�and�the�range�extender
electrical�machine�are�coordinated�in�development.�The�range�extender�electrical�machine�electronics
is�thus�able�to�permanently�provide�an�electrical�power�of�about�23.3 kW�(DC�power�at�4300 rpm).�In
order�to�avoid�overloading�the�power�electronics,�there�is�also�another�temperature�sensor�at�the�DC/
AC�converter.�If�an�excessive�temperature�of�the�power�semiconductor�is�identified�using�this�signal,
the�REME�control�unit�reduces�the�power�delivered�to�the�range�extender�electrical�machine�or�used
by�the�range�extender�electrical�machine�in�order�to�protect�the�power�electronics.�The�customer�is
informed�via�a�Check�Control�message�in�the�case�of�a�noticeable�power�reduction.�The�customer
receives�the�same�error�response�(power�reduction)�and�the�same�Check�Control�message�if�the
temperature�of�the�range�extender�electrical�machine�exceeds�the�permissible�range.