Power Control System: Description and Operation

GF54.10-P-3012GQH Component Description For Battery Management System Control Unit

Component Identification:

Location
The battery management system control unit is integrated into the high voltage battery module.

Interlock circuit
The interlock circuit is used as contact protection to protect people against inadvertent contact with high-voltage batteries. For this purpose, a 12 V/20 mA interlock signal is looped through all high-voltage system components that are to be dismantled or opened. To do this there is a contact bridge in each removable high-voltage connection which interrupts the interlock circuit during removal of the high-voltage connection. The interlock circuit is also led switched in a series over the 12 V control unit plug connection of the high-voltage components.

High-voltage connector cover
There is a removal cover over the screw high-voltage connections. This cover interrupts the interlock circuit during disassembly.

Task
General
The battery management system control unit operates in an electrical network with the sensors and actuators to provide the battery management high voltage system.

The battery management constantly determines and monitors the following high voltage battery data:
- Charge state
- High voltage interlock
- Voltage
- Current
- Temperature
- Status of protection switch contactor (A100s1)

CAN data bus
The battery management system control unit is connected through the hybrid CAN (CAN L) to the vehicle's CAN network and exchanges data with the other control units.

Input and output signals
The following input signals are evaluated by the battery management which also issues the corresponding output signals:
^ Direct input signals
^ Direct output signals
^ CAN input signals
^ CAN output signals

Direct input signals
- Circuit 30
- Circuit 30c (Crash signal)
- Circuit 31
- High voltage interlock
- High-voltage battery coolant inlet temperature sensor (A100b1)
- High-voltage battery cell temperature sensors (A100b2)
- High-voltage battery coolant outlet temperature sensor (A100b3)
- Protection switch actuation

Direct output signals
- High voltage interlock
- High voltage battery coolant pump (M43/2)
- High-voltage battery cooling system two-way valve (Y21/1)

Power connections
- High voltage 288 V+
- High voltage 288 V -

CAN input signals
Restraint system control unit (N2/7)
- Crash signal

ME-SFI [ME] control unit (N3/10)
- Engine hood closed/open

DC/DC converter control unit (N83/1)
- Standby mode, status
- Boost mode, status
- Buck mode, status
- Jump starting mode, status

Central gateway control unit (N93)
- Request for diagnostic data

CAN output signals
Instrument cluster (A1)
- Multifunction display (A1p13) actuation
- Power display (A1p17) actuation

Radio and navigation unit (A2/56)
- Battery management display

Electric refrigerant compressor control unit (N19/4)
- Cooling request

Central gateway control unit (N93)
- Diagnostic data

Power electronics control unit (N129/1)
- High-voltage battery, status

Design
The following components are integrated into the battery management system control unit:
- Separate protection switch for high voltage + and -
- Precharging protection
- Main contactor
- Precharging resistor
- Precharging circuit
- Current sensor