lithium ion battery simplified simulink model using matlab
TRANSCRIPT
All Rights Reserved Copyright (C) Siam Bee Technologies 2015 1
MATLAB Version
Lithium Ion Battery Simplified Simulink Model
using MATLAB
Bee Technologies
Contents
1. Benefit of the Model 2. Model Feature 3. Simulink Model of Lithium-Ion Battery 4. Concept of the Model 5. Pin Configurations 6. Li-Ion Battery Specification (Example) 6.1 Charge Time Characteristic 6.1.1 Charge Time Characteristic (Simulation Circuit) 6.1.2 Charge Time Characteristic (Simulation Settings) 6.2 Discharge Time Characteristic (Simulation Circuit) 6.2.1 Discharge Time Waveform - 1400mAh (0.2C discharge) 6.2.2 Discharge Time Waveform - 1400mAh (0.5C discharge) 6.2.3 Discharge Time Waveform - 1400mAh (1.0C discharge) 6.2.4 Discharge Time Characteristic (Simulation Settings) 6.3 Vbat vs. SOC Characteristic 6.3.1 Vbat vs. SOC Characteristic (Simulation Circuit) 6.3.2 Vbat vs. SOC Characteristic (Simulation Settings) 7. Extend the number of Cell (Example) 7.1.1 Charge Time Circuit - NS=4, TSCALE=3600 7.1.2 Charge Time Waveform - NS=4, TSCALE=3600 7.2.1 Discharge Time Circuit - NS=4, TSCALE=3600 7.2.2 Discharge Time Waveform - NS=4, TSCALE=3600 7.3 Charge & Discharge Time (Simulation Settings)
8. Port Specifications
Simulation Index
Appendix Diode
2 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
1. Benefit of the Model
• The model enables circuit designer to predict and optimize battery
runtime and circuit performance.
• The model can be easily adjusted to your own battery specifications
by editing a few parameters that are provided in the datasheet.
• The model is optimized to reduce the convergence error and the
simulation time
3 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
• This Li-Ion Battery Simplified 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 simplified model, the effects of cycle number and temperature are
neglected.
2. Model Feature
4
Battery Circuit Model
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
3. Simulink Model of Lithium-Ion Battery
5
Equivalent Circuit of Lithium-Ion Battery Model using Matlab
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
2
MINUS
1
PLUS
4. Concept of the Model
6
Li-Ion battery
Simplified 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) Bee Technologies Corporation 2015 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
5. 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.
7
Model Parameters:
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
Probe
“SOC”
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
6. Li-Ion Battery Specification (Example)
• The battery information refer to a battery part number LIR18500 of EEMB BATTERY.
8
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
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
Table 1
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
6.1 Charge Time Characteristic
9
• Charging Voltage: 4.20V±0.05V
• Charging Current: 700mA (0.5C Charge)
Current=700mA
Voltage=4.20V
Datasheet Simulation
SOC=0 means battery start
from 0% of capacity (empty)
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
%SOC
(Second)
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
6.1.1 Charge Time Characteristic Simulation Circuit
10
Over-Voltage Protector:
(Charging Voltage*1) - VF of Diode
Input Voltage
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
6.1.2 Charge Time Characteristic Simulation Settings
11 All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
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
6.2 Discharge Time Characteristic Simulation Circuit
12 All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
• Battery voltage vs. time are simulated at 0.2C, 0.5C, and 1C discharge rates.
battery starts from 100% of capacity
(fully charged)
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
13
0.2C discharge (280mA)
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
6.2.1 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
14
0.5C discharge (700mA)
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
6.2.2 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
15
1.0C discharge (1400mA)
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
6.2.3 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
16 All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
6.2.4 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
charg
e C
apacity
(%vs.
0.2
C)
Battery Discharge Current (vs. C Rate)
Mesurement
Simulation
6.3 Vbat vs. SOC Characteristic
17
• Nominal Voltage: 3.7V
• Capacity: 1400mAh (0.2C discharge)
• Discharge cut-off voltage: 2.75V
2.60
2.80
3.00
3.20
3.40
3.60
3.80
4.00
4.20
4.40
-0.200.20.40.60.81
Vo
ltag
e (V
)
Capacity (%)
0.5C
0.2C
1C
Datasheet Simulation
Simulation
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
6.3.1 Vbat vs. SOC Characteristic Simulation Circuit
18 All Rights Reserved Copyright (C) Bee Technologies Corporation 2015 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
6.3.2 Vbat vs. SOC Characteristic Simulation Settings
19 All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
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
• The battery information refer to a battery part number PBT-BAT-0001 of BAYSUN
Co., Ltd.
20
The number of cells in
series is input as a model
parameter
Output Voltage DC 12.8~16.4V
Capacity of Approximately 4400mAh
Input Voltage DC 20.5V
Charging Time About 5 hours
Basic Specification
Li-ion needs 4 cells to
reach this voltage level
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
7. Extend the number of Cell (Example) NS=4, TSCALE=3600
1 hour into a second
(in simulation)
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
7.1.1 Charge Time Circuit NS=4, TSCALE=3600
21
Input Voltage
Over-Voltage Protector:
(Charging Voltage 4) - VF of Diode
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
Number of Cells
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
22
• Input Voltage: 20.5V
• Charging Voltage: 16.8V
• Charging Current: 880mA (0.2 Charge)
Current=880mA
Voltage=16.8V
Capacity=100%
(hour)
The battery needs 5 hours to be fully charged
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
7.1.2 Charge Time Waveform NS=4, TSCALE=3600
BATTERY PACK LI-ION 12.8~16.4V
Number of Cells: 4
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
7.2.1 Discharge Time Circuit NS=4, TSCALE=3600
23 All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
Number of Cells
• Output Voltage: 12.8~16.4V
• Capacity: 4400mAh
• Discharge Current: 2200mA (0.5C)
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
24
2200mA (0.5C)
16.4V
12.8V
Output
voltage
range
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
7.2.2 Discharge Time Waveform NS=4, TSCALE=3600
• Output Voltage: 12.8~16.4V
• Capacity: 4400mAh
• Discharge Current: 2200mA (0.5C)
BATTERY PACK LI-ION 12.8~16.4V
Number of Cells: 4
(hour)
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
7.3 Charge & Discharge Time Simulation Settings
25 All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
Table 5: Simulation settings
Property Value
StartTime 0
StopTime 8, 3
AbsTol auto
InitialStep auto
ZcThreshold auto
MaxConsecutiveZCs 1000
NumberNewtonIterations 1
MaxStep 0.01
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
8. Port Specifications
26 All Rights Reserved Copyright (C) Bee Technologies Corporation 2015
Table 6
Parameter Simulink Simscape
NS O
C O
TSCALE O
%SOC O
VSOC O
PLUS O
MINUS O
Battery Model
All Rights Reserved Copyright (C) Siam Bee Technologies 2015
Simulation Index
27
Simulations Folder name
1. Charge Time Characteristic..................................................
2. Discharge Time Characteristic..............................................
3. Vbat vs. SOC Characteristic...................................................
4. Charge Time Characteristic - NS=4, TSCALE=3600.............
5. Discharge Time Characteristic - NS=4, TSCALE=3600.........
Charge_Time
Discharge_Time
Discharge_SOC
Charge_Time(NS)
Discharge_Time(NS)
All Rights Reserved Copyright (C) Bee Technologies Corporation 2015 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
Appendix
28 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
If Diode is error, Please choice Diode of SPICE-Compatiable
Semiconductors/Diode
Appendix
29 All Rights Reserved Copyright (C) Siam Bee Technologies 2015
Setting of Diode
Emission coefficient ,ND Default Value change 0.01