Ewald Wachmann
Joint EC / European Green Cars Initiative
Workshop 2013, Brussels
10 April 2013
Energy STorage with lowered cost and improved
Safety and RELIAbility for electrical vehicles Coordinator/ Partners: May 2011 – April 2014 Austria: France: Germany: Italy:
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Safety
Longterm Battery Lifetime
High Costs
New Safety sensors
New BMS concepts
Ultra caps
Cost-efficient BMS ICs
and safety components
Concerns for electrical cars
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Battery Monitoring and
Management Software for
dynamical configuration Battery Monitoring
and
Active Balancing IC,
galvanic isolated
interface IC
New low cost
Power Antifuses
Gas Sensor for
Safety Monitoring
Li-Ion Battery
Ultra Capacitor battery pack power pack extension for Li-Ion
batteries
New high density
ultra capacitors
new MEMS based
spark detection
sensor
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
New Developments
Result of the study with simulations and first test samples:
The integration of the antifuse on a battery cell element is possible
The structure of the device has been defined to enable antifusing
Voltage inversion of the battery cell provides enough current to activate antifusing
Development of new antifuse devices
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Specifications:
Category Value Comment
Maximum current 100 A
Maximum leakage / self discharge current <5 mA 10% self discharge per month for a
40Ah cell
Maximum series resistance 1 mOhm 10 W dissipation at 100 A
Assembly and contacting section 5.3 mm² 20mm long Aluminum: a wire of 0.1mΩ
requires a X-section of 5.3mm²
Untriggered antifuse fusing technology Aluminum spiking
Externally triggered antifuse fusing technology Exothermic reaction
Material costs < 0.20 €
Development of new antifuse devices
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
based on Air Classification Module (ACM)
Terminals (3x)
PCB O-ring
Pall membrane
Springs (3x)
MQS connector
MEMS gas sensor
Membrane with
electrodes and
sensitive layer
Development of Li-Ion battery emission sensor
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Gas sensors at Li-cell abuse tests
Cell
Actuator
Gas sensors
Nail
Stress Tests
-Nail penetration test
-Overcharging
-Short-circuit
Automotive sensors
-Volatile organics sensor
-Hydrogen sensor
Automotive pouch cells
-LiFePO4, 10Ah
-LiMnO2, 20Ah
-LiCoO2, 5Ah
Development of Li-Ion battery emission sensor
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
200 250 300 350 400 450 500 550 600 650 700
0
20
40
60
80
100
1400
1500
1600
0
10k
20k
30k
40k
05
1015202530
time [s]
Tce
ll [°C
]
H2 [m
V]
VO
C [a
u]
Uce
ll [V]
cell voltage
VOC
Hydrogen
cell temp.
LiCoO2 pouch cell, 5Ah, I=60A
310⁰C
max
42 sec.
Overcharging
signal for shutdown
Development of Li-Ion battery emission sensor
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Further tests ongoing and show promising results
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Tests @ FhG and in final
demonstrator ongoing …
Li-Ion battery
module assembly
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Li-Ion cell demonstrator with BMS, sensors & fuse cells
EMC critical environment
Split communication in 2 domains
Daisy Chained direct action signals for Diagnosis, Trigger, Clock
Daisy Chained low speed serial communication for cell voltage broadcast and to read
cell data at widely spaced time slots
Go for autonomous balancing through simultaneous
comparison of cell voltages with a reference
more accurate compared to sequential measurement
synchronization with current not needed
Either passive or active balancing through
integrated switches
New cell balancer and monitor IC
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Cell Balancer / Monitor Supports 3-7 cells for cell voltages from 1,8V to 4,5V
Simultaneous and autonomous cell monitoring - digital or analog reference
Autonomous balancing through simultaneous cell voltage capture and comparison with
reference
Either passive balancing or active balancing through small external fly back converter
40pin QFN package
Diagnosis functions:
• Connected cells
• cell voltage ok
• balance done
• temperature ok
• absolute temperature
• absolute cell voltage
• status data
C-GND
Comp7
Comp6
Comp5
Comp4
Comp3
Comp2
Comp1
5V
5V
5V
5V
5V
5V
5VC_out1
C_out2
C_out3
C_out4
C_out5
C_out6
C_out7
0V
0V
0V
0V
0V
0V
0V
Vref
Vref
Vref
Vref
Vref
Vref
Vref
Vref
VCELL1
VCELL2
VCELL3
VCELL4
VCELL5
VCELL6
VCELL7
Cell1_V1
Cell2_V2
Cell3_V3
Cell4_V4
Cell5_V5
Cell6_V6
Cell7_V7
Cnt1H
Cnt2L
Cnt7H
Cnt1L
Cnt2H
Cnt3L
Cnt3H
Cnt4L
Cnt4H
Cnt5L
Cnt5H
Cnt6L
Cnt6H
Cnt7L
Cnt1
Cnt2
Cnt3
Cnt4
Cnt5
Cnt6
Cnt7
V5V
CELL-THUanalog option
CELL-THLanalog option
CVT-NOK-OUT
CVT-NOK-IN
CLK-IN
CLK-OUT
BD-OUT
BD-IN
MS-SL
TEMP-IN1
TRIG-IN
TRIG-OUT
RC
Osc
Temp
sensor/
s/w
cap ckt
FSM,
DIGITAL,
SAR ADC
Logic
3V
5V
3V
0V
0V
0V
Pre_Reg,
POR,LDO
0V
VUSP
Cell OK,
LS,OTM
0V
42V5V
SDI SDOSCLK CS
VSUP FD
-IN
FD
-OU
T
V5
V-I
N
PPTrim
5V
0V
TS
EC
H
TS
EC
L
WAKE_IN
CLK TO
COMPAR
ATOR
5V
0V
TEMP-IN2
DAC
High
precision
reference
DAC_IN
5V
0V
CLK level
shifter to
sample cell
voltage
Vcell
0V
SSW
_LS
VCELL
REF_T
WA
KE
_O
UT
NCGNDGNDVREF
_IN
VREF
_H
VSUP
Vref_H
uC
uC
uC
To GND
for Master,
To VSUP
for Slave
uC
R discharge for passive
option
Compoments for active
balancing option
Signal connections in
chained system
analog Vref option
analog treshold/ref
option
New cell balancer and monitor IC
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
AS8506 Specifications
Test board for autonomous
battery balancing with
AS8506
New cell balancer and monitor IC
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Example of 3 cell balancing
Active balancing for 3 cells
New cell balancer and monitor IC
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
• Most bottom IC is configured as Master,
others are Salves (up to 31 slaves)
• Communication through Master SPI
• Chained 3 wire SPI communication from
master to slaves
• Synchronized autonomous monitoring
and balancing on Trigger
• When active balancing:
– One transformer for up to 14 cells
– Charge redistribution if energy is taken
from pack
– Isolated driver for slaves >14 cells
14 cell application example
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Stacked BMS ICs
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Electro kart: daisy-chain communication demonstrated!
Development of Ultra Caps
New Ultra Cap cells
delivering energy
densities in the range
of 7-9 Wh/l
Final module
assembly started
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Development of Ultra Caps
• Measurements taken for
delivered cells
• Model matches leakage
current and self-discharge
behavior of cells @ 25C
• Single cell model can be
integrated into overall system
electrical simulation
• Pack simulation implemented
by placing multiple cells in
series.
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
• New BMS ICs for an integrated flexible battery management system enabling simultaneous cell compare and active cell balancing for ultra capacitors and Li-Ion cells: daisy-chaining demonstrated assembly into demonstrator
• new cost effective power antifuse for dynamical configuration of energy storage units: prototype building
• safety sensors: new gas sensor with high sensitivity and fast response and new MEMS based spark detection sensor to improve safety monitoring of energy storage systems: tests demonstrating early sensing capability
• new ultra capacitor power cell with 50% higher energy density: prototypes available
• new high voltage (several kV) capable test and characterization equipment and galvanic isolated BMS driver ICs: verification tests ongoing
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013
Thank you for your attention!
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www.estrelia.eu
Joint EC / European Green Cars Initiative Workshop 2013 10. April 2013