The drive motor is a three-phase Alternating Current (AC)
induction motor powered by the 320-volt system. It is composed of a
rotor, field windings, a drive motor speed and direction sensor, and a drive
motor gear box containing a reduction gear set and a differential gear set.
The differential allows the wheels to turn at different rates of speed
while the drive motor continues to transmit the driving force. This prevents
tire scuffing and premature wear on internal drive motor parts.
Drive motor operation is primarily controlled by the Power Inverter
Module (PIM). The PIM processes inputs from the vehicle operator
and inputs from other systems to determine the control of the drive motor.
The primary vehicle operator inputs for the drive motor are:
| • | Transmission Range (TR) Switch |
| • | Accelerator Pedal Position (APP) Sensor |
The PIM converts the 320-volt Direct Current (DC) from the battery
pack to 320-volt AC. The PIM then controls the three AC phases of the
drive motor. The PIM can also control the following characteristics of the
drive motor:
