Post on 23-Jul-2015
All Rights Reserved Copyright (C) Siam Bee Technologies 2015 1
Lithium-Ion BatteryMATLAB/Simulink Model
Bee Technologieshttp://www.bee-tech.info/
Device Modeling Service
Charge Characteristic
Discharge Characteristic Device Modeling
ServiceDevice Modeling
Service MATLAB/Simulink Model
Contents
1. Model Feature
2. MATLAB/Simulink Model of Lithium-Ion Battery
3. Concept of the Model
4. Pin Configurations
5. Li-Ion Battery Specification (Example)5.1 Charge Time Characteristic
5.1.1 Charge Time Characteristic (Simulation Circuit)5.1.2 Charge Time Characteristic (Simulation Settings)
5.2 Discharge Time Characteristic (Simulation Circuit)5.2.1 Discharge Time Waveform - 1400mAh (0.2C discharge)5.2.2 Discharge Time Waveform - 1400mAh (0.5C discharge)5.2.3 Discharge Time Waveform - 1400mAh (1.0C discharge)5.2.4 Discharge Time Characteristic (Simulation Settings)
5.3 Vbat vs. SOC Characteristic 5.3.1 Vbat vs. SOC Characteristic (Simulation Circuit) 5.3.2 Vbat vs. SOC Characteristic (Simulation Settings)
6. Port Specifications
2All Rights Reserved Copyright (C) Siam Bee Technologies 2015
• This Li-Ion Battery MATLAB/Simulink Model is for users who require the model of a Li-Ion Battery as a part of their system.
• Battery Voltage(Vbat) vs. Battery Capacity Level (SOC) Characteristic, that can perform battery charge and discharge time at various current rate conditions, are accounted by the model.
• As a model, the effects of cycle number and temperature are neglected.
VSOC
2
MINUS
1
PLUS
VOC
+-
Rtransient_S
+-
Rtransient_L
+-
Rseries
Ibatt
+-
Ctransient_S
+-
Ctransient_L
+-
Capacity
1. Model Feature
3
Concept Circuit of Li-Ion Battery Circuit Model
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
2. MTALAB/Simulink Model of Lithium-Ion Battery
4
Equivalent Circuit of Lithium-Ion Battery Model using MATLAB
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
1
VSOC
2
MINUS
1
PLUS
f(x)=0
SolverConfiguration
PSS
V+
-
PS S
+-
0.03
RTS
0.034
RTL
IBAT
RTS
CTS
CAH
N
TSCALE
RTCT_S
RTCT_S_EQV
IBAT
RTL
CTL
CAH
N
TSCALE
RTCT_L
RTCT_L_EQVIBAT
RS
N
CAH
RSO
RS_EQV
0.045
RS
PS S
PSS
+
-
U
+
-
U
-K-
-K-
f(u)SOC VOUT
EOCV
I+
-
1800
CTS
15000
CTL
TSCALE
CAH
IBAT
SOC_SETTING
SOC0
CAPACITY
+-
4
%SOC
3
Tscale
2
C
1
NS
3. Concept of the Model
5
Li-Ion batteryMATLAB/Simulink Model
[Spec: C, NS]
Adjustable SOC : 0-100(%)
+
-
• The model is characterized by parameters: C, which represent the battery capacity and SOC, which represent the battery initial capacity level.
• Open-circuit voltage (VOC) vs. SOC is included in the model as a behavioral model.
• NS (Number of Cells in series) is used when the Li-ion cells are in series to increase battery voltage level.
Output Characteristics
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
VBATT
Voch(4.24*Ns)-0.07
VIN5V
1
Tscale
100
Soc
+-V
+-
I+
-
SENSE_IBAT
PSS
PS S
OUTPUT
1
Ns
NS
C
Tscale
%SOC
VSOC
PLUS
MINUS
LI-ION_BATTERY
ICHG0.5C (700mA)1.4
Capacity
4. Pin Configurations
C is the amp-hour battery capacity [Ah]
– e.g. C = 0.2, 1.4, or 2.0 [Ah]
NS is the number of cells in series
– e.g. NS=1 for 1 cell battery, NS=2 for 2 cells battery (battery voltage is double from 1 cell)
SOC is the initial state of charge in percent
– e.g. SOC=0 for a empty battery (0%), SOC=100 for a full charged battery (100%)
TSCALE turns TSCALE seconds into a second
– e.g. TSCALE=60 turns 60s or 1min into a second TSCALE=3600 turns 3600s or 1h into a second
• From the Li-Ion Battery specification, the model is characterized by setting parameters C, NS, SOC and TSCALE.
6
Model Parameters:
Probe “SOC”
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
VBATT
Voch(4.24*Ns)-0.07
VIN5V
1
Tscale
100
Soc
+-V
+-
I+
-
SENSE_IBAT
PSS
PS S
OUTPUT
1
Ns
NS
C
Tscale
%SOC
VSOC
PLUS
MINUS
LI-ION_BATTERY
ICHG0.5C (700mA)1.4
Capacity
5. Li-Ion Battery Specification (Example)
• The battery information refer to a battery part number LIR18500 of EEMB BATTERY.
7
Battery capacity is input as a model parameter
Battery capacity is input as a model parameter
Nominal Voltage 3.7V
Nominal Capacity
Typical 1400mAh (0.2C discharge)
Charging Voltage 4.20V±0.05V
Charging Std. Current 700mA
Max Current
Charge 1400mA
Discharge 2800mA
Discharge cut-off voltage 2.75V
Table 1
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
5.1 Charge Time Characteristic
8
• Charging Voltage: 4.20V±0.05V• Charging Current: 700mA (0.5C Charge)
Current=700mA
Voltage=4.20V
Measuremet Data Simulation
SOC=0 means battery start from 0% of capacity (empty)SOC=0 means battery start from 0% of capacity (empty)
%SOC
(Second)
VBATT
Voch(4.24*Ns)-0.07
VIN5V
1
Tscale
0
Soc
+-V
+-
I+
-
SENSE_IBAT
PSS
PS S
OUTPUT
1
Ns
NS
C
Tscale
%SOC
VSOC
PLUS
MINUS
LI-ION_BATTERY
ICHG0.5C (700mA)1.4
Capacity
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
VBATT
Voch(4.24*Ns)-0.07
VIN5V
1
Tscale
0
Soc
+-V
+-
I+
-
SENSE_IBAT
PSS
PS S
OUTPUT
1
Ns
NS
C
Tscale
%SOC
VSOC
PLUS
MINUS
LI-ION_BATTERY
ICHG0.5C (700mA)1.4
Capacity
5.1.1 Charge Time Characteristic Simulation Circuit
9
Over-Voltage Protector: (Charging Voltage*1) - VF of Diode
Over-Voltage Protector: (Charging Voltage*1) - VF of Diode
Input VoltageInput Voltage
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
5.1.2 Charge Time Characteristic Simulation Settings
10
Table 2: Simulation settings
Property Value
StartTime 0
StopTime 12000
AbsTol auto
InitialStep auto
ZcThreshold auto
MaxConsecutiveZCs 1000
NumberNewtonIterations 1
MaxStep 1
MinStep auto
MaxConsecutiveMinStep 1
RelTol 1e-3
SolverMode Auto
Solver ode23t
SolverName ode23t
SolverType Variable-step
SolverJacobianMethodControl auto
ShapePreserveControl DisableAll
ZeroCrossControl UseLocalSettings
ZeroCrossAlgorithm Adaptive
SolverResetMethod Fast
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
5.2 Discharge Time Characteristic Simulation Circuit
11
• Battery voltage vs. time are simulated at 0.2C, 0.5C, and 1C discharge rates.
battery starts from 100% of capacity (fully charged)battery starts from 100% of capacity (fully charged)
VBAT
1
Tscale
100
Soc
V+
-
PSS
1
Ns
NS
C
Tscale
%SOC
VSOC
PLUS
MINUS
LI-ION_BATTERY
IDIS0.2C (280mA)
1.4
Capacity
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
12
0.2C discharge (280mA)
5.2.1 Discharge Time Waveform 1400mAh (0.2C discharge)
• Nominal Voltage: 3.7V• Discharge cut-off voltage: 2.75V
(Second)
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
13
0.5C discharge (700mA)
5.2.2 Discharge Time Waveform 1400mAh (0.5C discharge)
• Nominal Voltage: 3.7V• Discharge cut-off voltage: 2.75V
(Second)
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
14
1.0C discharge (1400mA)
5.2.3 Discharge Time Waveform 1400mAh (1.0C discharge)
• Nominal Voltage: 3.7V• Discharge cut-off voltage: 2.75V
(Second)
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
15
5.2.4 Discharge Time Characteristic Simulation Settings
Table 3: Simulation settings
Property Value
StartTime 0
StopTime 24000, 9600, 4800
AbsTol auto
InitialStep auto
ZcThreshold auto
MaxConsecutiveZCs 1000
NumberNewtonIterations 1
MaxStep 10
MinStep auto
MaxConsecutiveMinStep 1
RelTol 1e-3
SolverMode Auto
Solver ode23t
SolverName ode23t
SolverType Variable-step
SolverJacobianMethodControl auto
ShapePreserveControl DisableAll
ZeroCrossControl UseLocalSettings
ZeroCrossAlgorithm Adaptive
SolverResetMethod Fast
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 0.2 0.4 0.6 0.8 1
Dis
char
ge C
apac
ity(%
vs. 0
.2C
)
Battery Discharge Current (vs. C Rate)
Mesurement
Simulation
5.3 Vbat vs. SOC Characteristic
16
• Nominal Voltage: 3.7V• Capacity: 1400mAh (0.2C discharge)• Discharge cut-off voltage: 2.75V
2.602.803.003.203.403.603.804.004.204.40
-0.200.20.40.60.81
Vo
ltag
e (V
)
Capacity (%)
0.5C
0.2C
1C
Measurement Data Simulation
SimulationVbat vs. SOC
1
Tscale
100
Soc V+
-
PSS
1
Ns
NS
C
Tscale
%SOC
VSOC
PLUS
MINUS
LI-ION_BATTERY
IDIS1400mAh*(discharge rate)
1.4
Capacity
100
Cal
VBAT
SOC
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
5.3.1 Vbat vs. SOC Characteristic Simulation Circuit
17
Vbat vs. SOC
1
Tscale
100
Soc V+
-
PSS
1
Ns
NS
C
Tscale
%SOC
VSOC
PLUS
MINUS
LI-ION_BATTERY
IDIS1400mAh*(discharge rate)
1.4
Capacity
100
Cal
VBAT
SOC
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
5.3.2 Vbat vs. SOC Characteristic Simulation Settings
18
Table 4: Simulation settings
Property Value
StartTime 0
StopTime 19200
AbsTol auto
InitialStep auto
ZcThreshold auto
MaxConsecutiveZCs 1000
NumberNewtonIterations 1
MaxStep 10
MinStep auto
MaxConsecutiveMinStep 1
RelTol 1e-3
SolverMode Auto
Solver ode23t
SolverName ode23t
SolverType Variable-step
SolverJacobianMethodControl auto
ShapePreserveControl DisableAll
ZeroCrossControl UseLocalSettings
ZeroCrossAlgorithm Adaptive
SolverResetMethod Fast
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
6. Port Specifications
19
Table 6
Parameter Simulink Simscape
NS O
C O
TSCALE O
%SOC O
VSOC O
PLUS O
MINUS O
Voch(4.2*Ns)-6.5m
VSOC
VIN5V
VBAT60
Tscale
0
Soc
+-V
+-
SENSE_VBAT
I+
-
SENSE_IBAT
PS S
PS S
1
Ns
NS
C
Tscale
%SOC
VSOC
PLUS
MINUS
LI-ION_BATTERY
ICHG0.5C
IBAT
1.4
Capacity
Battery Model
All Rights Reserved Copyright (C) Siam Bee Technologies 2015