BATTERY MANAGEMENT SYSTEM
5/2015
OVERVIEW
R-BMS
FUNCTIONALITIES
COMPLETE BATTERY
MANAGEMENT SOLUTION
The RIMAC AUTOMOBILI BATTERY MANAGEMENT SYSTEM (R-BMS) is a full solution
for monitoring and controlling of complex battery
systems for various applications.
The latest R-BMS is our fifth generation system,
where we have implemented new functionalities
and all our experience gathered during the implementation of high-power battery systems in
extremely demanding applications ranging
from electric supercars to boats, bicycles and
wheelchairs.
The system is primarily designed for electric vehicles but is also used in various applications
such as hybrid vehicles, battery test-benches
and dyno systems.
The newest R-BMS generation features extremely compact dimensions, ultra-low
power consumption, very high measurement accuracy and fast refresh rates.
CELL
MONITORING
CELL
BALANCING
TEMPERATURE
MONITORING
STATE OF CHARGE
ESTIMATION
ABILITY TO
CONTROL SEVERAL
EXTERNAL DEVICES
SYSTEMS
FOR RETAINING
MAXIMUM
BATTERY LIFETIME
STATE OF HEALTH
ESTIMATION
OVERVIEW
THE R-BMS CONSISTS OF:
BATTERY PACK
•BMS SLAVE UNIT(S)
•BMS MASTER UNIT
POWER DISTRIBUTION UNIT
BMS MASTER UNIT
BMS SLAVE UNIT(S)
HIGH VOLTAGE
COMMUNICATION AND SIGNAL LINE
R-BMS SLAVE
BMS SLAVE UNIT FUNCTIONAL OVERVIEW
BMS SLAVE
SMART SLAVES
The R-BMS consists of one or more distributed R-BMS Slave devices, which
can monitor and balance a series from 3 up
to 12 battery cells.
Several R-BMS Slave devices can be used
in a battery pack or module, being able to
supervise a complete HV battery ranging
from 6V, up to 1000V.
R-BMS Slave devices have no power consumption from the monitored cells while
the system is not active or the vehicle is
off. This feature ELIMINATES “VAMPIRE
LOADS” that are common with traditional
BMS systems, which can cause the battery to discharge completely and permanently damage the cells. There is no need
to charge the battery in case the vehicle is
not being used for a longer period of time.
During the normal operation, power consumption is less than 5mA per cell.
CELLS
BALANCING
MODULE
CELL
TEMPERATURE
TEMPERATURE
MEASUREMENT
PCB
TEMPERATURE
CELL
MEASUREMENT
MICROCONTROLLER
INSULATION
ISOLATED
PART
COMMUNICATION
MODULE
CAN OR FO
R-BMS SLAVE
The R-BMS slaves are supervised by
the R-BMS Master unit.
The R-BMS system is capable of supervising all types of available battery chemistries. Flexible hardware design allows the
system to measure single cell voltage in
a range from 0V to 5V with measurement
accuracy of 1mV. The measurement accuracy is consistent for the whole battery for
voltages up to 1000V. Furthermore, each
R-BMS slave measures 2 cell temperatures and 2 PCB temperatures allowing it
to supervise the temperature throughout
the whole battery pack. Each R-BMS slave
device is equipped with passive resistive
balancing that can balance overcharged
cells with the current of 1A.
By using very precise measurements and
implementing smart balancing algorithms
102
mm
OPTIMISED BATTERY USAGE
AND LIFETIME
117 m
m
the R-BMS has shortened needed balancing several times.
Collected R-BMS slave data is constantly
distributed through the high speed CAN
ing the data available on other devices 20
times per second. Due to the fast refresh
rate, it is possible to implement SMART
CONTROL ALGORITHMS which maxi-
mum lifetime. In applications with the
high EMC noise, the R-BMS can be used
with the Fiber Optic communication instead of CAN, making it entirely immune to
network with transmit period of 50ms, mak-
mize cell usage while retaining maxi-
the EMC noise.
R-BMS SLAVE
SPECIFICATIONS
R-BMS MASTER
BATTERY SUPERVISION
AND CONTROL
The R-BMS Master device is the central
unit supervising and controlling the
whole battery pack.
It is capable of calculating very accurate
State of Charge (SoC) and State of
Health (SoH) of the battery pack. Some
of the used cell chemistries have a very flat
voltage curve throughout most of the SoC
making it impossible to determine (or even
estimate) the SOC based on the cell-voltage alone. Therefore a very accurate SOC
calculation is needed, as well as a very effective balancing method.
In order to achieve a very high accuracy
of SOC and energy consumption estimation, the R-BMS system uses a MORE
SOPHISTICATED METHOD than the
industry-standard
single-current-sensor
set-up. Each high-voltage system can be
monitored individually through separate
energy measuring channels.
MASTER
DIGITAL
INPUTS
CURRENT SENSORS
MICROCONTROLLER
CURRENT SENSORS
HIGH-SIDE
SWITCHES
(6A)
HALF-BRIDGE
SWITCHES
(4A)
R-BMS MASTER
CONTROL AND
COMMUNICATION
The R-BMS Master system can be used
either as a stand-alone unit or fully controlled through different communication protocols. If configured to work as a
stand-alone unit, the R-BMS system can
control the pre-charge of several highvoltage devices. It is also capable of
128 mm
The R-BMS Master system is capable
of controlling (supplying power to)
several external devices through the intelligent high-side drivers. All of those drivers are equipped with several protections
and are capable of DETECTING AND
PREVENTING the overcurrent, overvoltage, overtemperature and reverse polarity
conditions. The high-side drivers are usually used to control several high-voltage
relays.
291 m
m
monitoring the status of each high-voltage
relay and able to detect the welded state
or the state in which the relay will not close.
The R-BMS system is equipped with several CAN, Fiber Optic, RS232 and RS485
communication lines that can be used
to distribute the collected and calculated data. The R-BMS system is also
equipped with the bootloader capability, making it possible to fully program and
configure any R-BMS device without the
need to directly access them.
R-BMS MASTER
SPECIFICATIONS
R-BMS & INFOTAINMENT
EASIER INTEGRATION
FOR FASTER DEVELOPMENT
During the development and testing
phase of the project it is desirable to
show as much system data as possible on the vehicle In-Vehicle Infotainments
system.
With the R-BMS system this is easily done
as the system sends all cell-voltages, temperatures and currents to the In-Vehicle
Infotainment which displays all data in realtime. This gives the development engineers
a very good overview of the behavior of all
systems.
As most of those values are not relevant
to the end-user, once the development is
completed, only a summary of values such
as the SOC and battery-temperature is
available to the user.
RIMAC AUTOMOBILI
CONTACT:
MARKO PEJKOVIC
Business Development Manager
tel. +385 91 333 6162
solutions@rimac-automobili.com