Functional Description - Electric 3 Phase Motors

WARNING: This page is about a different variant/trim than selected.

MOTOR DESCRIPTION:

The 3-phase motors used for starting, charging and propulsion consist of three main components:

STATOR: The stator consists of the 3-phase winding coils and evenly spaced insulated conductors.
ROTOR: The rotor is separated from the stator by a small air gap and consists of the rotor winding. The rotor is part of the output shaft of the motor.
ROTOR POSITION SENSOR (RESOLVER): The resolver is used to monitor the speed and direction of the 3-phase motor.

MOTOR OPERATION:

The 3-phase motor works on the principle of electromagnetic induction. The AC power from the Power Inverter Module (PIM) is supplied to energize the three stator windings. This creates a rotating magnetic field which rotates around the stator at a synchronous speed. The magnetic force acts on the rotor conductors creating mechanical movement of the rotor and output shaft. This is known as electromagnetic force (EMF).

The frequency of the three phase AC current supplied to the motor is what controls the speed and rotation of the output shaft.
The amount of current directed to the electric motor is directly proportional to the torque generated at the output shaft.

The large traction P2 motor, located at the transmission input, is used to propel the vehicle. The P2 motor has a direct ratio to the wheels. When the engine is running, the rotor in the P1 motor is being mechanically driven by the crankshaft of the engine. In this case the electric motor becomes a generator, creating AC power that is supplied to the PIM. The PIM converts the AC power into DC power to charge the high voltage battery.

RESOLVER OPERATION: The resolver is an electrical device that acts as a rotor position sensor. The resolvers are attached to the stator of each electric motor. It's structure is similar to the stator of the electric motor. At ignition ON, the MCP outputs a fixed excitation signal to the coils in the resolver which creates a magnetic field. The rotation of the rotor induces a voltage into the resolver coil windings. The resolver feedback signal is used to determine the angular position, speed and direction of the motor. This allows the PIM to determine which windings of the stator must be charged with the correct phase of current. If any resolver signals are lost, the vehicle will not operate.