VS - Electrical Systems From Stop-Start to Hybridization

StARS - in starter mode The same MOSFET bridge is used to control the machine in alternator and starter modes. In alternator mode the transistor bridge receives power from the stator phases, in starter mode it is the opposite situation. In starter mode, the machine behaves as a three phase motor, it reacts to interactions between the stator and the rotor electromagnetic forces and rotates accordingly.

The MOSFET bridges stimulate the stator phases generating a rotating field and thus torque to the rotor. The rotor angular position and speed, as well as the phase currents are monitored and processed to optimize the machine torque output.

Temperatures are monitored to take benefit from a maximum energy conversion.

The stator receives power

Phase U

+ -

Phase V

0 5 10 15 20

Phase W

StARS power stage in starter mode.

As in the alternator mode, in starter mode the rotor coil is energized. The power unit drives the stator phases according to a hall-effect magnetic position

sensor that gives at any time the rotor relative position from the stator, knowing this relative position is crucial to the machine performance, notably for the torque output.

PHASE 1

PHASE 1 PHASE 2 PHASE 3

Stator

Rotor

PHASE 3

PHASE 2

Strator and rotor electromagnetic forces interact creating a rotation

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