BMW I01 Product Information page 175

I01￿High-voltage￿Components
11.￿Cooling￿the￿Electrical￿Machine
Components
Index
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Similar￿to￿the￿cooling￿systems￿of￿current￿BMW￿vehicles￿with￿combustion￿engines,￿the￿control￿in￿the
I01￿is￿also￿effected￿depending￿on￿the￿cooling￿power￿requirement.￿This￿control￿is￿integrated￿in￿the
Electrical￿Digital￿Motor￿Electronics￿(EDME).
The￿following￿input￿signals￿are￿used￿for￿the￿control:
• Component￿temperature￿of￿electrical￿machine
• Component￿temperature￿of￿electrical￿machine￿electronics
• Component￿temperature￿of￿convenience￿charging￿electronics
• Component￿temperature￿of￿range￿extender￿electrical￿machine￿electronics
• Component￿temperature￿of￿range￿extender￿electrical￿machine
• Current￿power￿used￿in￿the￿electric￿motor￿or￿convenience￿charging￿electronics
• Driving￿speed.
In￿comparison￿to￿the￿familiar￿cooling￿systems￿of￿conventional￿vehicles,￿the￿coolant￿temperature￿is￿not
used￿as￿an￿input￿variable￿for￿the￿control.￿Accordingly,￿there￿is￿no￿coolant￿temperature￿sensor￿in￿the
cooling￿system￿for￿the￿electric￿motor￿of￿the￿I01.￿Instead,￿the￿electric￿coolant￿pump￿and￿the￿electric
fan￿are￿activated￿according￿to￿the￿listed￿input￿variables￿and￿also￿the￿current￿cooling￿requirement.￿The
coolant￿can￿reach￿a￿maximum￿temperature￿of￿about￿85 °C/￿185 °F￿(return￿from￿the￿electrical￿machine).
In￿comparison￿to￿the￿cooling￿system￿for￿BMW￿combustion￿engines,￿the￿temperature￿level￿is￿lower.￿The
cooling￿circuit￿for￿the￿range￿extender￿has￿a￿higher￿temperature.￿Therefore,￿using￿the￿coolant-coolant
heat￿exchanger￿the￿temperature￿of￿the￿coolant￿in￿the￿cooling￿circuit￿for￿the￿range￿extender￿can￿be
reduced.￿Also￿in￿the￿I01￿the￿familiar￿precautionary￿measures￿must￿be￿observed￿before￿working￿on￿the
cooling￿system.
The￿activation￿of￿the￿coolant￿pump￿and￿electric￿fan￿can￿be￿effected￿in￿the￿following￿vehicle￿conditions:
Explanation
Signal,￿temperature￿in￿the￿electrical￿machine
Temperature￿sensor￿in￿the￿convenience￿charging￿electronics
Signal,￿temperature￿in￿the￿convenience￿charging￿electronics
Dynamic￿Stability￿Control
Vehicle￿speed
Temperature￿sensor￿of￿the￿range￿extender￿electrical￿machine
Signal,￿temperature￿in￿the￿range￿extender￿electrical￿machine
Electrical￿Digital￿Motor￿Electronics
Temperature￿sensor￿in￿the￿range￿extender￿electrical￿machine￿electronics
Signal,￿temperature￿in￿the￿range￿extender￿electrical￿machine￿electronics
Electric￿coolant￿pump
Power￿requirement￿at￿electric￿coolant￿pump
Electric￿fan
Speed￿requirement,￿electric￿fan
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