Hi,
Here's a quick block diagram of all the major parts and their connections for the
battery subsystem. Info from what we know already and what seems to make sense.
Going from left to right:
External comms datalink:
Provides external comms access to the battery subsystem,
for control and status purposes from other a/c systems.
Charger & Control:
Manages the overall subsystem and has several functions:
Conditions input power to charge the battery.
Monitors the charge and discharge processes to keep
battery operation within safe limits.
Records normal and abnormal operation and events.
Provides a command set for control and status from
external systems.
Has extensive continuous built in test functions.
Control, Status and Heartbeat datalink:
Communication between charger and Battery Management System
Detects failure of communication between charger and BMS.
Battery Management System, BMS:
Measures each cell's voltage and temperature.
Balances cell voltages in relation to each other.
Communicates with the charger to report cell voltage,
temperature, normal and abnormal conditions.
Has it's own built in test functions.
Cell Voltage Measurement and Cell Balancing, a-i:
Measures each cell's voltage
Balances each cell's voltage
Temperature Sensors, 1-8:
Individual sensor mounted on each cell to provide cell
temperature measurement.
8 Cells:
4 volts nominal, 75 ampere hours each.
Contactor / Relay:
Provides electrical isolation for the series string of cells.
For the 787 system, some of above is guesswork, but is what I would
consider a minimum set of functionality for such a system. It's only
a back of envelope description though and a bare bones example.
Anyway, feel free to tear it apart, criticise, whatever...
PS: Posting images: they changed the interfaces on Photobucket, but got there
eventually
