System Operation - PHEV Charging System
HIGH VOLTAGE BATTERY CHARGING:
The High Voltage (HV) battery can be charged using the vehicle's engine or by connecting to the grid through an Electric Vehicle Supply Equipment (EVSE) Charging Cable connected to the Charging Port.
- PLUG IN CHARGING: When the vehicle is off and the Electric Vehicle Supply Equipment (EVSE) Charging Cable is plugged in, the Integrated Dual Charging Module (IDCM) converts the AC power from the grid into DC power used to charge the high voltage battery through the orange HV cables.
- CHARGING FROM THE ENGINE: During normal vehicle operation, when the HV battery voltage is below a calibrated threshold, the engine is started and the AC power from the P1 motor is delivered to the Power Inverter Module (PIM). The PIM converts the AC power into DC power used to charge the high voltage battery through the orange HV cables.
The PHEV is equipped with a battery charge indicator module mounted to the center of the instrument panel, is made up of five Light-Emitting Diode (LED) lights. The battery charge indicator module is a smart device that communicates with the PIM through a LIN bus circuit. It displays the current state of charge for the HV battery pack. Each bar indicates 20% state of charge. The battery charge indicator module will not illuminate any of the charge indicator lights unless the vehicle is connected to an Electric Vehicle Supply Equipment (EVSE) plug from a charge station or outlet. The charge level indicators will also inform the customer if an error has occurred in the charging system by blinking each end LED.
REGENERATIVE BRAKING:
The vehicle also charges the high voltage battery during regenerative braking. During deceleration the electric motor is used as a generator motor. This performs two functions:
- Allows the energy created in the electric motor created 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 Hybrid Control Processor (HCP) 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 HCP and brake system module.
LOW VOLTAGE BATTERY CHARGING: The low voltage system charge rate is controlled by the Powertrain Control Module (PCM). The PCM sends a desired charge rate message for the 12 volt battery over the CAN bus to the Individual Dual Charging Module (IDCM). The Auxiliary Power Module (APM), internal to the IDCM, is a DC/DC converter. The APM converts the high voltage from the HV battery system over to 12 volt system at the commanded voltage to charge the 12 volt battery.