Power Electronics Control Unit - SMART Fortwo 451 Series Introduction Into Service Manual

The power electronics control unit is installed on
the electric drive motor and is connected directly
to the high-voltage adapter plate fuse box and the
coolant circuit. It has the following tasks:
Power supply and control of electric drive
motor
The inverter in the power electronics control unit
generates the 3-phase alternating voltage for
operating the electric motor from the direct
voltage of the high-voltage battery. In the
process, the power electronics control unit
records the rpm, rotor position and temperature
of the electric motor.
If the electric motor is operated as a generator in
deceleration mode, the power electronics control
unit converts the induced alternating voltage into
direct voltage and uses it to supply the high-
voltage on-board electrical system.
Electric drive system
1 Transmission
Introduction of smart fortwo electric drive (3rd Generation) • Model Series 451

Power electronics control unit

DC/DC converter
The DC/DC converter in the power electronics
control unit generates the 12 V direct voltage for
the 12 V on-board electrical system from the
direct voltage of the high-voltage battery.
It charges the 12 V battery directly and thus
performs the function of the alternator on a
vehicle with combustion engine.
F34/6 High-voltage adapter plate fuse box
M5 Electric drive motor
N129/1 Power electronics control unit
P08.10-2052-00
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