BMW I01 Product Information page 165

I01￿High-voltage￿Components
10.￿REME
If￿a￿convenience￿charging￿electronics￿is￿installed￿in￿the￿vehicle,￿the￿REME￿is￿connected￿via￿a￿two-pin
HV￿cable￿and￿a￿flat￿HV￿connector￿to￿the￿KLE.￿The￿KLE￿is￿also￿connected￿to￿the￿EME￿via￿a￿two-pin
high-voltage￿cable￿and￿a￿flat￿high-voltage￿connector.￿The￿3-phase￿AC￿voltage￿generated￿by￿the￿range
extender￿electrical￿machine￿is￿converted￿by￿the￿REME￿to￿direct￿current￿voltage￿and￿fed￿from￿the￿REME
via￿the￿KLE￿to￿the￿EME￿via￿the￿high-voltage￿cables.￿The￿energy￿required￿to￿start￿the￿range￿extender
combustion￿engine￿is￿provided￿by￿the￿high-voltage￿battery.￿The￿direct￿current￿voltage￿is￿directed￿via
the￿EME￿and￿KLE￿to￿the￿REME￿by￿two-pin￿high-voltage￿cables.￿The￿EME￿and￿the￿KLE￿do￿not￿convert
this￿direct￿current￿voltage,￿it￿is￿used￿solely￿for￿the￿contact.￿With￿this￿type￿of￿contact￿(via￿KLE)￿only￿one
version￿of￿the￿EME￿(irrespective￿of￿the￿equipment)￿has￿to￿be￿installed￿in￿the￿I01.
10.3.3.￿Connections￿for￿coolant￿lines
The￿range￿extender￿electrical￿machine￿electronics￿is￿integrated￿in￿the￿cooling￿circuit￿of￿the
electric￿motor.￿This￿cooling￿circuit￿is￿described￿in￿detail￿in￿chapter￿11￿"Cooling￿the￿electric￿motor
components".
10.3.4.￿Connection￿for￿potential￿compensation￿line
The￿housing￿of￿the￿REME￿is￿connected￿to￿the￿rear￿axle￿module￿and￿thus￿ground￿via￿a￿potential
compensation￿line.￿The￿potential￿compensation￿line￿is￿secured￿using￿a￿screw￿connection.
10.4.￿Structure￿and￿functions
The￿range￿extender￿electrical￿machine￿electronics￿is￿made￿up￿internally￿of￿two￿subcomponents:
the￿bidirectional￿DC/AC￿converter￿and￿the￿REME￿control￿unit.￿The￿link￿capacitors￿for￿smoothing￿the
voltage￿and￿filtering￿high-frequency￿parts￿are￿also￿an￿element￿of￿the￿power￿electronics￿switching.￿It
performs￿the￿following￿functions￿with￿help￿of￿the￿subcomponents￿mentioned:
• Control￿of￿the￿electrical￿machine￿(engine￿speed,￿torque)￿using￿DC/AC￿converter
• Reading￿and￿evaluation￿of￿the￿temperature￿sensor￿of￿the￿range￿extender￿electrical￿machine
• Reading￿and￿evaluation￿of￿the￿rotor￿position￿sensor
• Contact￿of￿the￿range￿extender￿electrical￿machine
• Contact￿of￿the￿electrical￿machine￿electronics￿or￿the￿convenience￿charging￿electronics
• Communication￿with￿other￿control￿units
• Active￿and￿passive￿discharging￿of￿the￿link￿capacitors￿to￿voltages￿less￿then￿60 V
• Self-test￿and￿diagnostic￿function
The￿power￿electronics￿for￿the￿activation￿of￿the￿electrical￿machine￿are￿mainly￿made￿up￿of￿the
bidirectional￿DC/AC￿converter.￿It￿is￿a￿pulse￿converter￿(also￿called￿"inverter")￿with￿a￿two-pin￿DC￿voltage
connection￿and￿a￿3-phase￿AC￿voltage￿connection.￿This￿DC/AC￿converter￿can￿work￿as￿an￿inverter￿and
conduct￿electrical￿energy￿from￿the￿high-voltage￿battery￿to￿the￿range￿extender￿electrical￿machine￿when
it￿should￿work￿as￿an￿engine.￿However,￿it￿can￿also￿work￿as￿a￿rectifier￿and￿transfers￿electrical￿energy
from￿the￿range￿extender￿electrical￿machine￿(via￿EME￿or￿KLE)￿to￿the￿electrical￿machine￿or￿high-voltage
battery.
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