This document provides specifications and simulation results for a photovoltaic (PV) nickel-metal hydride (Ni-MH) battery system. It includes specifications for Ni-MH battery packs and solar photovoltaic panels. Simulation circuits and results are shown for charging the batteries from the solar panels under different conditions. Additional simulations model the full PV-battery system over a 24-hour period to analyze charging based on changing solar intensity over time. The document contains detailed specifications, modeling parameters, and simulation results to evaluate performance of the PV-NiMH battery system.

1. Design Kit
PV Ni-MH Battery System (DC Out)
All Rights Reserved Copyright (C) Bee Technologies Corporation 2013 1

2. Contents
Slide #
1. Nickel - Metal Hydride Battery
1.1 Ni-MH Battery Specification................................................................................. 3
1.2 Discharge Time Characteristics........................................................................... 4
1.3 Battery Voltage vs. SOC Discharge Characteristics............................................. 5
1.4 Charge Time Characteristics................................................................................ 6
1.5 Battery Voltage vs. SOC Charge Characteristics................................................. 7
2. Solar Cells
2.1 Solar Cells Specification...................................................................................... 8
2.2 Output Characteristics vs. Incident Solar Radiation............................................. 9
3. Solar Cell Battery Charger......................................................................................... 10
3.1 Concept of Simulation PV Ni-MH Battery Charger Circuit.................................... 11
3.2 PV Ni-MH Battery Charger Circuit........................................................................ 12
3.3 Charging Time Characteristics vs. Weather Condition......................................... 13
3.4 Concept of Simulation PV Ni-MH Battery Charger Circuit + Constant Current..... 14
3.5 Constant Current PV Ni-MH Battery Charger Circuit............................................ 15
3.6 Charging Time Characteristics vs. Weather Condition + Constant Current.......... 16
4. Simulation PV Ni-MH Battery System in 24hr.
4.1 Concept of Simulation PV Ni-MH Battery System in 24hr.................................... 17
4.2 Short-Circuit Current vs. Time (24hr.).................................................................. 18
4.3 PV-Battery System Simulation Circuit.................................................................. 19
4.3 PV-Battery System Simulation Result.................................................................. 20-25
Simulations index............................................................................................................ 26
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3. 1.1 Ni-MH Battery Specification
KAWAZAKI’s Ni-MH Batteries : Gigacell (10-180)
• Rated Voltage ..................12 [V]
• Capacity............................177 [Ah] (Approximately)
• Energy Capacity................2.1 [kWh]
• Max Output........................48 [kW] 10 Ni-MH cells are
in series.
• Rated Charge................ 0.2C5 [A] ( SoC=100% )
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4. 1.2 Discharge Time Characteristics
17V PARAMETERS:
rate = 0.2
CAh = 177
16V Hi
15V C1 U1 0
1C ( 177A ) IN+ OUT+ 1n + - GIGACELL_10-180
14V 2C ( 354A ) IN- OUT- TSCALE = 3600
G1 0 NS = 1
GVALUE SOC1 = 1
13V 0.2C ( 35.4A ) limit(V(%IN+, %IN-)/0.1m, 0, rate*CAh )
TSCALE=3600
12V 0
0.5C ( 88.5A ) means “Time Scale”
11V (Simulation time :
Real time) is 1:3600
10V
Batteries Pack Model Parameters
9V
NS (number of batteries in series) = 1 Unit (10 Ni-MH cells)
C (capacity) = 177 Ah
8V SOC1 (initial state of charge) = 1 (100%)
TSCALE (time scale) , simulation : real time
7V 1 : 3600s or
0s 1.0s 2.0s 3.0s 4.0s 5.0s 6.0s 1s : 1h
V(HI)
Time
Discharge Rate : 0.2C(35.4A), 0.5C(88.5A), 1C(177A) and 2C(354A)
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5. 1.3 Battery Voltage vs. SOC Discharge Characteristics
10 Ni-MH cells are in series for
total rated current 12V (Each
cell have 1.2V rated voltage).
Measurement Simulation
0.2C, Dch 2.0C, Dch 5.0C, Dch 8.0C, Dch 11C, Dch
17
16
15
Battery Voltage (V)
14
13
12
11
10
9
8
7
0 0.2 0.4 0.6 0.8 1
SOC (%)
• VBAT vs. SOC Discharge Characteristics are compared between measurement data and simulation
data.
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6. 1.4 Charge Time Characteristics
PARAMETERS:
rate = 0.2
CAh = 177
17V G1
GVALUE
Limit(V(%IN+, %IN-)/0.1m, 0, rate*CAh )
16V Hi
OUT+
OUT-
15V 1C ( 177A ) C1 U1 0
1n + - GIGACELL_10-180
IN+
IN-
14V TSCALE = 3600
0 NS = 1
SOC1 = 0
13V 0.2C ( 35.4A ) Vin
18Vdc
12V
0.5C ( 88.5A ) TSCALE=3600
0
means “Time Scale”
11V
(Simulation time :
10V
Real time) is 1:3600
Batteries Pack Model Parameters
9V
NS (number of batteries in series) = 1 Unit (10 Ni-MH cells)
8V C (capacity) = 177 Ah
SOC1 (initial state of charge) = 1 (100%)
7V TSCALE (time scale) , simulation : real time
0s 1.0s 2.0s 3.0s 4.0s 5.0s 1 : 3600s or
V(HI) 1s : 1h
Time
Charge Rate : 0.2C(35.4A), 0.5C(88.5A), and 1C(177A)
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7. 1.5 Battery Voltage vs. SOC Charge Characteristics
Measurement Simulation
0.2C, Ch 2.0C, Ch 3.0C, Ch 5.0C, Ch
17
16
15
Battery Voltage (V)
14
13
12
11
10
9
8
7
0 0.2 0.4 0.6 0.8 1
SOC (%)
• VBAT vs. SOC Charge Characteristics are compared between measurement data and simulation
data.
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8. 2.1 Solar Cells Specification
Suntech’s photovoltaic module : STP140D-12/TEA
• Maximum power (Pmax)............140[W]
• Voltage at Pmax (Vmp).............17.6[V]
• Current at Pmax (Imp)...............7.95[A]
• Short-circuit current (Isc)...........8.33[A]
• Open-circuit voltage(Voc)..........22.4[V]
1482mm
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9. 2.2 Output Characteristics vs. Incident Solar Radiation
STP140D-12/TEA Output Characteristics vs. Incident Solar Radiation
10A
SOL=1
8A
Current (A)
6A
SOL=0.5
4A
+
U1 2A SOL=0.16
STP140D-12TEA
0A
SOL = 1 I(Isense)
150W
SOL=1
Power (W)
100W
Parameter, SOL is added as SOL=0.5
normalized incident radiation,
50W
where SOL=1 for AM1.5 SOL=0.16
conditions SEL>>
0W
0V 5V 10V 15V 20V 25V
V(V1:+)*I(Isense)
V_V1
Voltage (V)
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10. 3. Solar Cell Battery Charger
• Solar Cell charges the Ni-MH battery pack (STP140D-12/TEA) with direct connect
technique. Choose the solar cell that is able to provide current at charging rate or more
with the maximum power voltage (Vmp) nears the batteries pack charging voltage.
• Gigacell 10-180 (Ni-MH Battery)
– Charging time is approximately 5 hours with charging rate 0.2C or 35.4A
– Voltage during charging with 0.2C is between 11.8 to 14.2 V
17V
16V
15V
14V
14.2 V
13V
0.2C or 35.4A
12V 11.8 V
11V
10V
9V
8V
7V
0s 1.0s 2.0s 3.0s 4.0s 5.0s
V(HI)
Time
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11. 3.1 Concept of Simulation PV Ni-MH Battery Charger Circuit
Over Voltage
Protection Circuit
Short circuit current ISC
depends on condition: SOL
14.01V Clamp Circuit
Photovoltaic
Ni-MH Battery
Module
STP140D-12/TEA (Suntech) Gigacell 10-180 (Kawasaki)
10 panels (parallel) DC12V (10 cells)
Vmp=17.6V 177Ah
Pmax=1.4kW
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12. 3.2 PV Ni-MH Battery Charger Circuit
D1
PARAMETERS: DMOD
sol = 1
Voch
14.01dc
pv 0
Hi
+ + + + + + -
U6 U5 U4 U3 U2 C1 0
STP140D-12TEA 1n
SOL = {sol}
0
0 0 0 0 0 U1
GIGACELL_10-180
TSCALE = 3600
NS = 1
+ + + + + SOC1 = 0
U11 U10 U9 U8 U7
0 0 0 0 0
• Input value between 0-1 in the “PARAMETERS: sol = ” to set the normalized incident
radiation, where SOL=1 for AM1.5 conditions.
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13. 3.3 Charging Time Characteristics vs. Weather Condition
1.00V
0.75V
0.50V
0.25V sol = 1.00
sol = 0.50
sol = 0.16
0V
0s 1s 2s 3s 4s 5s 6s 7s 8s 9s 10s
V(X_U1.SOC)
Time
• Simulation result shows the charging time for sol = 1, 0.5, and 0.16.
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14. 3.4 Concept of Simulation PV Ni-MH Battery Charger Circuit
+ Constant Current
Over Voltage
Protection Circuit
Short circuit current ISC
depends on condition: SOL
14.01V Clamp Circuit
Constant
Photovoltaic Current
Ni-MH Battery
Module Control
Circuit
STP140D-12/TEA Icharge=0.2C (35.4A) Gigacell 10-180 (Kawasaki)
(Suntech) DC12V (10 cells)
10 panels (parallel) 177Ah
Vmp=17.6V
Pmax=1.4kW
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15. 3.5 Constant Current PV Ni-MH Battery Charger Circuit
D1
PARAMETERS:
PARAMETERS: DMOD
rate = 0.2
sol = 1 CAh = 177
Voch
14.01dc
pv 0
Hi
OUT+
OUT-
+ + + + + + -
U6 U5 U4 U3 U2 C1 0
STP140D-12TEA 1n
SOL = {sol}
IN+
IN-
0
0 0 0 0 0 G1 U1
GVALUE GIGACELL_10-180
Limit(V(%IN+, %IN-)/0.1, 0, rate*CAh) TSCALE = 3600
NS = 1
+ + + + + SOC1 = 0
U11 U10 U9 U8 U7
0 0 0 0 0
• Input the battery capacity (Ah) and charging current rate (e.g. 0.2*CAh) in the
• “PARAMETERS: CAh = 177 and rate = 0.2 ” to set the charging current.
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16. 3.6 Charging Time Characteristics vs. Weather Condition
(Constant Current)
1.00V
0.75V
0.50V
0.25V sol = 1.00
sol = 0.50
sol = 0.16
0V
0s 1s 2s 3s 4s 5s 6s 7s 8s 9s 10s
V(X_U1.SOC)
Time
• Simulation result shows the charging time for sol = 1, 0.5, and 0.16. If PV can
generate current more than the constant charge rate (0.2C), battery can be fully
charged in about 5 hour.
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17. 4.1 Concept of Simulation PV Ni-MH Battery System in 24hr.
Over Voltage
The model contains 24hr. Protection Circuit
solar power data (example).
14.01V Clamp Circuit
Photovoltaic
Ni-MH Battery
Module
Low-Voltage Gigacell 10-180 (Kawasaki)
STP140D-12/TEA Shutdown DC12V (10 cells)
(Suntech) Circuit Vopen=11. 6(V) 177Ah
10 panels (parallel) Vclose= 13.8(V)
Vmp=17.6V
Pmax=1.4kW
DC/DC
DC Load
Converter
VIN=10~18V VL = 5V
VOUT=5V IL = 50A
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18. 4.2 Short-Circuit Current vs. Time (24hr.)
The model contains
24hr. solar power data
(example).
15A
10A U1
+
STP140D-12TEA_24H_TS3600
5A
0A
0s 1s 2s 3s 4s 5s 6s 7s 8s 9s 10s 12s 14s 16s 18s 20s 22s 24s
I(Isense)
Time
• Short-circuit current vs. time characteristics of photovoltaic module STP140D-12/TEA
for 24hours as the solar power profile (example) is included to the model.
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19. 4.3 PV-Battery System Simulation Circuit
Solar cell model
with 24hr. solar
power data.
Set initial battery D1
voltage, IC=13.7, for DMOD
convergence aid. Voch
14.01Vdc
pv 0
D2
batt
DMOD
+ U6 + U5 + U4 + U3 + U2
C1 0
Low-Voltage Shutdown Circuit 10n + -
STP140D-12TEA_24H_TS3600 IC = 13.7
VON = 0.7 0
0 0 0 0 0 VOFF = 0.3 E1
RON = 0.01m Ronof f EVALUE
ROFF = 10MEG 100 IF(V(batt1)>V(dchth),5,0) Ronof f 1 U1
+ Lctrl batt1 GIGACELL_10-180
+ OUT+ IN+
+ U11 + U10 + U9 + U8 + U7 C3 TSCALE = 3600
- - OUT- IN- dchth 100
100n Conof f NS = 1
S2 1n SOC1 = 1
0 OUT+ IN+
S IC = 5 Conof f 1
OUT- IN- 100n
PARAMETERS: E2
0 0 0 0 0 EVALUE
Lopen = 11.6
IF( V(lctrl) > 0.25 ,Lopen ,Lclose) SOC1 value is initial
Lclose = 13.8 0
State Of Charge of
the battery, is set as
DC/DC Converter
Lopen value is load 70% of full voltage.
shutdown voltage. PARAMETERS:
out_dc
n=1
Lclose value is load IN OUT
Iomax
reconnect voltage G1 E3 I1
IN+ OUT+ IN+ OUT+ IN+ OUT+
IN- OUT- IN- OUT- IN- OUT-
50Adc
GVALUE ecal_Iomax EVALUE
EVALUE IF( I(OUT)-V(Iomax) > 0 ,n*V(%IN+, %IN-)*I(IN)/(I(OUT)+1u), 5 )
0
n*V(%IN+, %IN-)*I(IN)/5
Limit( V(%IN+, %IN-)/0.1, 1m, 5*I(out)/(n*limit(V(%IN+, %IN-),10,25)) )
250W Load 0
(5Vx50A).
0
 Simulation at 500W load, change I1 from 50A to 100A
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20. 4.3.1 Simulation Result (SOC1=1, IL=50A or 250W load)
150A
PV generated current 100A
50A
0A
I(pv) PV module charge the battery
16V 100A
1 2
Battery voltage
14V 0A
Battery current  >>
12V -100A Battery supplies current when solar
1 V(batt) 2 I(U1:PLUS) power drops.
1.0V
Fully charged,
Battery SOC SOC1=1 (100%) stop charging
SEL>>
0V
V(X_U1.SOC)
7.5V 50A
DC output voltage
1 2
5.0V
DC/DC input current
2.5V
>>
0V 0A
0s 3s 6s 9s 12s 15s 18s 21s 24s
1 V(out_dc) 2 I(IN)
Charging Time
time
 When battery is discharging , current I(U1:PLUS) is minus and when the battery is charging, the current is plus.
• .Options
• C1: IC=13.7
• RELTOL=0.01
• Run to time: 24s (24hours in real world)
• ABSTOL=1.0u
• Step size: 0.01s
• ITL4=1000
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21. 4.3.2 Simulation Result (SOC1=0.7, IL=50A or 250W load)
150A
PV generated current 100A
50A
0A
I(pv)
15V
1 2 50A V=Lopen
Battery voltage
0A
(8.3138,13.797)
Battery current >> -50A V=Lclose
(5.7490,11.595)
10V Battery supplies current when solar
1 V(batt) 2 I(U1:PLUS) power drops.
1.0V
SOC1=0.7
Battery SOC Fully charged,
stop charging
SEL>> 699.201m)
0V
V(X_U1.SOC)
7.5V 50A Shutdown
DC output voltage
1 2
5.0V 38A
DC/DC input current 25A
2.5V Reconnect
>>
0V 0A
0s 3s 6s 9s 12s 15s 18s 21s 24s
1 V(out_dc) 2 I(IN)
Charging
Time
time
• .Options
• C1: IC=13.7
• RELTOL=0.01
• Run to time: 24s (24hours in real world)
• ABSTOL=1.0u
• Step size: 0.01s
• ITL4=1000
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22. 4.3.3 Simulation Result (SOC1=0.3, IL=50A or 250W load)
150A
PV generated current 100A
50A
0A
I(pv)
15V 75A
1 2
Battery voltage 25A (2.0552,11.595)
(8.2938,13.798)
Battery current >> V=Lclose
10V -75A
V=Lopen Battery supplies current when solar
1 V(batt) 2 I(U1:PLUS) power drops.
1.0V
Fully charged,
,299.176m)
Battery SOC stop charging
SEL>> SOC1=0.3
0V
V(X_U1.SOC)
7.5V 50A
DC output voltage
1 2
5.0V 38A Shutdown
DC/DC input current 25A
2.5V
>> Reconnect
0V 0A
0s 3s 6s 9s 12s 15s 18s 21s 24s
1 V(out_dc) 2 I(IN)
Charging time
Time
• .Options
• C1: IC=13.7
• RELTOL=0.01
• Run to time: 24s (24hours in real world)
• ABSTOL=1.0u
• Step size: 0.01s
• ITL4=1000
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23. 4.3.4 Simulation Result (SOC1=0.07, IL=50A or 250W load)
150A
PV generated current 100A
50A
0A
I(pv)
15V 100A
1 2
Battery voltage
0A
Battery current SEL>> (8.2938,13.798)
10V -100A
V=Lclose Battery supplies current when solar
1 V(batt) 2 I(U1:PLUS) power drops.
1.0V
Battery SOC Fully charged,
SOC1=0.07 stop charging
0V
V(X_U1.SOC)
7.5V 50A
DC output voltage
1 2
5.0V 38A
Shutdown
DC/DC input current 25A
Reconnect
>> 13A
0V 0A
0s 3s 6s 9s 12s 15s 18s 21s 24s
1 V(out_dc) 2 I(IN)
Time
Charging time
• .Options
• C1: IC=13.7
• RELTOL=0.01
• Run to time: 24s (24hours in real world)
• ABSTOL=1.0u
• Step size: 0.01s
• ITL4=1000
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24. 4.3.5 Simulation Result (SOC1=1, IL=100A or 500W load)
150A
PV generated current 100A
50A
0A
I(pv) V=Lclose
V=Lopen
15.0V 100A
1 2 (4.2247,11.627) V=Lopen
(21.778,11.600)
Battery voltage
12.5V 0A
Battery current (8.2850,13.799)
SEL>>
10.0V -100A
1 V(batt) 2 I(U1:PLUS) Battery supplies current when solar
1.0V power drops.
Battery SOC Fully charged,
SOC1=100 stop charging
0V
V(X_U1.SOC)
7.5V 50A
DC output voltage
1 2 Shutdown Shutdown
5.0V
DC/DC input current
2.5V Reconnected
>>
0V 0A
0s 3s 6s 9s 12s 15s 18s 21s 24s
1 V(out_dc) 2 I(IN)
Charging Time
time
• .Options
• C1: IC=13.7
• RELTOL=0.01
• Run to time: 24s (24hours in real world)
• ABSTOL=1.0u
• Step size: 0.01s
• ITL4=1000
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25. 4.3.4 Simulation Result (Example of Conclusion)
The simulation start from midnight(time=0). The system supplies DC load 250W.
• If initial SOC is 100%,
– this system will never shutdown.
• If initial SOC is 70%,
– this system will shutdown after 5.749 hours (about 5:45AM.).
– system load will reconnect again at 8:19AM.
• If initial SOC is 30%,
– this system will shutdown after 2.055 hours (about 2:03AM.).
– system load will reconnect again at 8:18AM.
• If initial SOC is 7%,
– this system will start shutdown.
– this system will reconnect again at 8:18AM (Morning).
• With the PV generated current profile, battery will fully charged in about 5.7 hours.
The simulation start from midnight(time=0). The system supplies DC load 500W.
• If initial SOC is 100%,
– this system will shutdown after 4.225 hours (about 4:14AM.).
– system load will reconnect again at 8:17AM.
– this system will shutdown again at 9:47PM.
• With the PV generated current profile, battery will fully charged in about 6.7 hours.
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26. Simulations index
Simulations Folder name
1. PV Ni-MH Battery Charger Circuit.................................................. charge-sol
2. Constant Current PV Ni-MH Battery Charger Circuit..................... charge-sol-const
3. PV-Battery System Simulation Circuit (SOC1=1, 250W)............... sol_24h_soc100
4. PV-Battery System Simulation Circuit (SOC1=0.7, 250W)............ sol_24h_soc70
5. PV-Battery System Simulation Circuit (SOC1=0.3, 250W)............ sol_24h_soc30
6. PV-Battery System Simulation Circuit (SOC1=0.07, 250W).......... sol_24h_soc7
7. PV-Battery System Simulation Circuit (SOC1=1, 500W)............... sol_24h_soc100_500W
All Rights Reserved Copyright (C) Bee Technologies Corporation 2013 26