BEV Electrified Powertrain System
SYSTEM DESCRIPTION:
The Plug-in Battery Electric Vehicle (BEV) can consist of the following components:
- High Voltage Battery Pack Control Module (BPCM)
- Power Inverter Module (PIM)
- Integrated Dual Charge Module (IDCM)
- Electric Drive Motor (EDM) used for propulsion
The generic graphic below shows all possible electric motor combinations for BEV vehicles.
This vehicle is equipped with an Electric Drive Module (EDM). The EDM is three units in one, an electric motor, drive differential and an external park pawl motor.
SYSTEM OPERATION: This Plug-in Battery Electric Vehicle (BEV) uses a P2 electric 3-phase motor for propulsion. A high voltage direct current (DC) battery is used as the energy source for the electric motor. The PIM converts the high voltage DC power into AC power to drive the 3-phase electric motor. The PIM controls the interaction between the battery and the electric motor by controlling voltage, current, and frequency to control the torque applied to the EDM. The frequency of the three phase AC current being generated by the PIM is what controls the angular velocity of the output shaft. The amount of current directed to the electric motor is directly proportional to the torque generated at the output shaft.
When charging of the high voltage battery is needed, the PIM provides AC power to drive the EDM motor.
The vehicle also charges the high voltage battery during regenerative braking. During deceleration the electric motor is used as a generator. This performs two functions:
- Allows the energy created in the electric motor that is generated from the drivetrain to charge the high voltage battery.
- The electric motor creates drag on the drivetrain to help slow the vehicle, reducing the amount of brake input required.
There are two modes of regenerative braking:
- Coast down regeneration - The electric motor acts to gradually slow down the vehicle with minimum energy recuperated. The amount of coast regeneration is dependant on the creep-coast calibration curve. This is controlled completely by the Motor Control Processor A (MCPA) inside the PIM.
- Brake regeneration - A higher amount of regeneration is possible. During light to moderate brake pedal application, only the electric motor is slowing the vehicle. No friction brake needed. With heavier brake pedal application, the conventional friction brakes also are applied. This requires coordination between the MCPA and brake system module.
For detailed description and operation on the Battery System, refer to BATTERY PACK CONTROL MODULE (BPCM) .