Ford Escape: High Voltage Battery Charging System - Plug-In Hybrid Electric Vehicle (PHEV) / Description and Operation - High Voltage Battery Charging System - Plug-In Hybrid Electric Vehicle (PHEV) - System Operation and Component Description

System Diagram

System Operation

  Network Message Chart — SOBDM

Component Description

SOBDM

The SOBDM , also known as the BCCM (Battery Charger Control Module), charges the high voltage battery.

When the EVSE (Electric Vehicle Supply Equipment) cord is plugged into the vehicle, the SOBDM wakes up by sensing a control pilot signal. The pilot signal duty cycle is analyzed to determine AC line capacity and the frequency is monitored to make sure it is in the proper range. The EVSE monitors the pilot signal to determine when to turn on AC output. A separate proximity circuit signal is analyzed to confirm if the connection is stable and the S3 button on the external charger cord is released. If both signals are in correct range, the SOBDM transmits an on-plug message via CAN . The SOBDM confirms the vehicle is not in torque producing mode by looking at the vehicle operating mode on HS-CAN1 from the Inverter System Controller (ISC) and closes an internal S2 switch signaling the EVSE to send AC voltage to the SOBDM .

If the AC voltage input is within range the SOBDM enables the DCDC . The DCDC uses the voltage required to maintain the 12V system before the high voltage charges the high voltage battery.

The SOBDM internally transitions from a ready state to charging state of the high voltage battery upon receipt of a battery charge ready or charging message from the BECM via the HS-CAN1 . The vehicle gear position must be in PARK or the BECM will not transition to a charge ready state. When the BECM status goes from a charge ready to a charging state the charge contactors internal to the high voltage battery junction box are closed to begin charging the high voltage battery. The SOBDM limits the voltage and current to the high voltage battery based on the maximum voltage and current requests from the BECM via the HS-CAN1 . The SOBDM transmits high voltage and current output internal measurements to the BECM via the HS-CAN1 .

During high voltage charging the SOBDM can transmit a coolant flow request based on internal module temperature conditions. The BECM turns the coolant pump on and can set a DTC if a fault is detected. The SOBDM monitors its internal temperature and commands the engine cooling fan speed accordingly to prevent overheating. When high-voltage charging is complete the BECM charging state HS-CAN1 message switches from charging to charging complete and opens the high voltage charge contactors.

If the release button (S3) on the EVSE is pressed while low-voltage or high-voltage charging is in progress, the SOBDM detects a change of proximity circuit voltage the high-voltage battery charging stops. The SOBDM disables power conversion and opens the internal S2 switch. When the EVSE detects an open S2 switch by sensing a pilot signal voltage change, it drops the AC voltage output to zero so the charger cord can be safely removed. This prevents arcing of the charge port terminals when the Electric Vehicle Supply Equipment (EVSE) cord is disconnected.

The SOBDM controls the CSI on a LIN . There are five light segments that indicate the state of charge (SOC). The CSI LED s flash simultaneously when a fault is present.

COMPONENT OPERATION

The SOBDM is an liquid cooled component that converts an input voltage of (120 or 240 volts) AC to high-voltage DC power, while maintaining electrical isolation between the systems. The SOBDM is known as the on-board charger. When plugged into an external power source, the SOBDM is enabled and charges the high voltage battery. The DCDC is activated by the SOBDM and steps the high-voltage down to a low-voltage (between 12 and 15 volts, depending on vehicle needs), providing power to charge the vehicle low-voltage battery. When a fault is sensed by the SOBDM , a DTC is set and can be retrieved using a scan tool connected to the DLC .

To remove the EVSE cord, press the release button to stop the charging process. All the LED s shut off indicating it is safe to unplug the cord. There is a customer preference setting in the APIM to customize the operation of the Charge Status Indicator (CSI). The options available include: LED s On (normal operation), LED s Off except for Cord Acknowledgements and Puddle Light Activation requests, LED s Off (this setting prevents LED operation for any reason).