Component description for battery management system control unit

 Interlock circuit:

The interlock circuit is intended to protect persons against inadvertent contact with high-voltage components.

A 12 V/88Hz interlock signal is looped here 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 plug connection which interrupt the interlock circuit during removal of the high voltage plug connection. The interlock circuit is also led switched in a series over the 12 V control units plug connection of the high-voltage components.

P08.20-2043-76

1 High-voltage battery module

N82/2 Battery management system control unit

Location

The battery management system control unit is integrated in the high-voltage battery module.

Task

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 system constantly collects and monitors the following data:

- Interlock circuit signal

- Voltage of high-voltage battery (G5)

- Current flow in high-voltage on-board electrical system

- Temperature of high-voltage battery

- Condition of protection switches

The battery management system control unit has the following tasks:

 Reading in of sensors and signals

 Evaluation of input factors

 Actuation of components

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Reading in of sensors and signals

The input factors are read in via the following connections:

 Direct line

 Electric vehicle CAN (CAN EV)

Direct line

The battery management system control unit continuously evaluates the signal from the interlock circuit.

Electric vehicle CAN

The signals are read in by the battery management system control unit via the electric vehicle CAN.

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

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Evaluation of input factors

The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Actuation of components

The actuation of the components takes place via the following connections:

 Direct line

 Electric vehicle CAN

Direct line

The battery management system control unit actuates the following components via direct lines:

- Coolant pump 1 (feed) (M43/1)

- Coolant pump 2 (return) (M43/3)

- Electric expansion valve (interior compartment) (Y19/1)

- Electric expansion valve (battery) (Y19/3)
(with code V03 Battery cooling system)

- High-voltage battery coolant pump switchover valve (Y133/2)

Electric vehicle CAN

The signals are sent by the battery management system control unit via the electric vehicle CAN.

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).