1. Department of Electrical Engineering
Senior Design Project ELEC 499
Qatar University First Solar Car to Compete in the World Solar Challenge: Design of Energy Management System
Mariam El-Menshawy
Mena El-Menshawy
Main Supervisor: Dr. Ahmed Massoud
Co- Supervisor: Prof. Adel Gastli
9/18/2018

2. Outline: Background & Problem Definition Objectives
Main Electrical Components of Solar Car
Practical Results
Conclusion
Future Work
9/18/2018

3. Outline: Background & Problem Definition Objectives
Main Electrical Components of Solar Car
Practical Results
Conclusion
Future Work
9/18/2018

4. Electric vehicles versus Conventional vehicles.
Background & Problem Definition:
Electric vehicles versus Conventional vehicles.
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5. Outline: Background & Problem Definition Objectives
Main Electrical Components of Solar Car
Practical Results
Conclusion
Future Work
9/18/2018

6. Objectives: System architecture.
Maximize the system through the effective usage of energy management that includes PV and energy storage systems technology.
System architecture.
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7. Outline: Background & Problem Definition Objectives
Main Electrical Components of Solar Car
Practical Results
Conclusion
Future Work
9/18/2018

8. Main Electrical Components of Solar Car:
Solar Array
Battery
Ultra-capacitors
Motor
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9. Solar Insolation Effect
PV Modeling:
Solar Insolation Effect
P-V output characteristics with different values of solar Insolation at constant Temperature level of 25˚C.
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10. Operating Temperature Effect
PV Modeling:
Operating Temperature Effect
P-V output characteristics with different values of operating Temperature at constant Insolation level of 1 kW/m2.
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11. Maximum Power Point Tracking:
PV Array
DC/DC Converter
Battery
Voltage & Current Measurement
PWM Generator
MPPT Algorithm (P&O) + Duty Cycle Adjustment
PV conversion system.
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12. Perturb & Observe Technique:
Pmax
Region B
Region A A1 A2 B1 B2 V1 V2
VPV (V) P2 P1
PPV
(W)
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13. Energy Storage System:
Batteries:
There are four battery choices which are: Lithium ion (Li-Ion), Lithium polymer (Li-Po), Nickel metal hydride (Ni-MH), and Lead acid (Pb-Acid).
WSC battery weight limitations.
Li-ion
Li-Polymer
LiFePO4
Ni-MH
Pb-Acid
20 kg
40 kg
70 kg
125 kg
9/18/2018

14. Batteries:
Lithium ion (Li-ion) battery is the ideal choice to be used for the solar car because of the following reasons:
High energy density
Fast & efficient charging
Relatively low self-discharge
Extended cycle life
Size & Weight advantages
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15. Energy Storage System:
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16. Energy Management: Iload IPV PV Array Vbus IB Battery IC
Ultra-capacitor
Unidirectional Buck-Boost Converter
Bidirectional Buck-Boost Converter
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17. Scenarios:
Closed loop scheme.
Open loop scheme.
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18. Outline: Background & Problem Definition Objectives
Main Electrical Components of Solar Car
Practical Results
Conclusion
Future Work
9/18/2018

19. Practical Results: System parameters. System Parameters PV Panel
Open Circuit Voltage Voc
Short Circuit Current ISC
Maximum Power Pmpp
40 V
4 A
120 W
Battery
Battery Type
Nominal Voltage VB
Rated Capacity
Lead-Acid
12 V
100 Ah
Ultra-capacitors
Voltage VUC
Capacitance
16.2 V
58 F
Resistive Load
Power
3.3 kW
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20. (a) PV curve at variable duty cycle; (b) Maximum Power Point.
Maximum Power Point Tracking:
(a) (b)
VPV (V)
PPV
(W)
PPV
(W)
VPV (V)
MPPT results at 10 W/div and 10 V/div with a perturb size of :
(a) PV curve at variable duty cycle; (b) Maximum Power Point.
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21. Maximum Power Point Tracking:
MPPT results with a perturb size of 0.01
4 W/div V/div mA/div
5 s/div
MPPT results with a perturb size of
4 W/div V/div mA/div
5 s/div
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22. Charging Case: PV charging the battery and supplying the load
Energy Management Cases:
Charging Case: PV charging the battery and supplying the load
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23. P Vloadi = 11.98 V Iloadi = 1.31 A Ploadi = 15.71 W R = 10 Ω D = 0.5
Efficiency = 66 %
Ploss = 5.31 W
Vloado = V
Iloado = 1.01 A
Ploado = W
Vpvo = 11.93V
Ipvo = 2.99 A
Ppvo = W
Vpvi = V
Ipvi = 1.66 A
Ppvi = W P
PV Array
DC Bus
DC/DC
Converter
Battery
Ultra-capacitor
R Load
D = 0.27
Efficiency = 67 %
Ploss = W
VB = V
IB = 1.75 A
PB = W
Total Ploss = W

24. Losses of the IGBT module.
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25. Discharging Case: PV and battery supplying the load
Energy Management Cases:
Discharging Case: PV and battery supplying the load
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26. P Vloadi = 11.13 V Iloadi = 7.09 A Ploadi = 78.63 W R = 7 Ω D = 0.67
Efficiency = %
Ploss = W
Vloado = V
Iloado = 2.44 A
Ploado = W
Vpvo = V
Ipvo = 3.48 A
Ppvo = W
Vpvi = V
Ipvi = 1.97 A
Ppvi = W P
PV Array
DC Bus
DC/DC
Converter
Battery
Ultra-capacitor
R Load
D = 0.27
Efficiency = 65.4 %
Ploss =21.27 W
VB = V
IB = 3.51 A
PB = W
Total Ploss = W

27. Discharging Case: Battery supplying the load
Energy Management Cases:
Discharging Case: Battery supplying the load
9/18/2018

28. P D = 0.23 Vloadi = 11.66 V Iloadi = 2.52 A Ploadi = 29.36 W R = 20 Ω
Efficiency = %
Ploss = 10.3 W
Vloado = V
Iloado = 0.96 A
Ploado = W
Vpvo = V
Ipvo = 0 A
Ppvo = 0 W
Vpvi = 40 V
Ipvi = 0 A
Ppvi = 0 W P
PV Array
DC Bus
DC/DC
Converter
Battery
Ultra-capacitor
R Load
VB = V
IB = 2.44 A
PB = W
Total Ploss = 10.3 W

29. Discharging Case: Battery charging the ultra-capacitors
Energy Management Cases:
Discharging Case: Battery charging the ultra-capacitors
9/18/2018

30. P PV Array Battery VB = 11.53 V IB = 3.24 A PB = 37.29 W
VUC = V
IUC = 1.24 A
PUC = W
VB = V
IB = 3.24 A
PB = W
VUCi = V
IUCi = 3.19 A
PUCi = W
VUCo = V
IUCo = 1.22 A
PUCo = W
D = 0.67
Efficiency = 62.5 %
Ploss = W P
PV Array
DC Bus
DC/DC
Converter
Battery
Ultra-capacitors
Total Ploss = W
R = 3 Ω

31. Design Limitations: Silicon devices instead of Silicon Carbide devices
Low efficiency
Ultra-capacitors closed loop operation
Low voltage DC bus
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32. Outline: Background & Problem Definition Objectives
Main Electrical Components of Solar Car
Practical Results
Conclusion
Future Work
9/18/2018

33. Conclusion:
Three different sources are used to transfer power according to the load requirements which are PV modules, battery, and ultra-capacitors.
Fixed perturbation size results in a trade-off between fast response and steady state oscillations.
Low efficiency is due to the fact that:
The converters are designed for high power ratings.
The IGBT’s losses.
Parasitic elements.
Low voltage DC bus.
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34. Outline: Background & Problem Definition Objectives
Main Electrical Components of Solar Car
Practical Results
Conclusion
Future Work
9/18/2018

35. Future Work: Closed loop operation scheme.
Multiport Power Electronic Interface.
Multiport
DC/DC Converter
PV Array
Battery
Ultra-capacitors
Regulated DC Voltage
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