Power Module

1. Steven Goh
San Jose State University
Joe Lau
San Jose State University
Eric Near
San Jose State University
Spartan Superway – Power Module

2. Traffic congestion and CO2 emission due to personal vehicle is
causing problems in our world today
Eric Near
https://www.weforum.org/agenda/2019/06/
chart-of-the-day-the-cities-with-the-worst-congestion/

3. Moreover, extensive use of personal vehicles promote ineffective
land use
Eric Near

4. SPARTAN Superway comes as a solution by providing a reliable
mode of public transportation
Joe Lau
Solar
Powered
Automated
Transit
Ascendent
Network

5. The power module is designed to store solar energy and output
power to onboard motors
Joe Lauhttps://www.amazon.com/Jackery-SolarSaga-Explorer-
Portable-Generator/dp/B07PGS2WN8

6. Before the coronavirus situation, the design goals of this project
are as follows
Description Quantity
Mass of the system < 100 kg
Maximum Velocity of Bogie 1 m/s
Desired Acceleration 2.45 m/s2
Total Track Length 10 m
Factor of Safety > 10
Power Module Dimensions 47 cm x 35 cm x 25 cm
Supercapacitor Charging time < 120 seconds
Joe Lau

7. According to our calculations, 110W is needed to power our
system to its desired capacity
0
0.02
0.04
0.06
0.08
0.1
0.12
0 2 4 6 8 10
Power(kW)
Time [s]
Power Curve
Steven Goh

8. 16 Supercapacitor in series can store up to 11 kJ of energy and
will be used to power bogie’s acceleration
17.5
Farads
36 V
16 Series Cell
Capacitance
Supply
Voltage
Steven Goh
https://www.baddhor.com/index.php?main_page=product_info&
products_id=311252

9. 12 Lithium-ion batteries is connected 3s-4p, have a capacity of
111 Wh and will be used to power the bogie’s cruise speed
Steven Gohhttp://www.hessprecisionlaser.com/lithium-ion-
battery-packs/

10. A battery management System (BMS) will be used to monitor the state
of charge and promote balance charging of individual cells
Eric Nearhttps://www.banggood.com/3S-11_1V-25A-18650-Li-ion-Lithium-
Battery-BMS-Protection-PCB-Board-With-Balance-Function-p-
1120250.html

11. Using SolidWorks, we designed a power module that houses the
necessary components
Joe Lau

12. Finite Element Analysis (FEA) was performed to ensure factor of
safety <10
Joe Lau

13. Joe Lau

14. Progress Since Last Presentation

15. Switching mechanism has been successfully tested pre-shelter in
place order
Steven Goh

16. The current sensor was tested using 12V Motor, Power Supply,
Arduino and a multimeter
Steven Goh

17. The current sensor was then connected with relays and transistors
to verify switching capabilities
Steven Goh

18. Steven Goh
=> Initialize the current sensor
=> Measurement Collection & Data Processing
=> Output low level signal to transistor
]
]
]

19. Due to the coronavirus situation, we aim to complete the following
tasks for rest of the semester
• Sizing all components for full scale deployment
• Computer simulation of full-model
• PCB design for future use
• Final report and part drawings
Joe Lau

20. The design goals was updated to size for full-scale deployment
Steven Goh
Description Pre-Coronavirus Post-Coronavirus
Mass of the system < 100 kg 1500 kg
Maximum Velocity of Bogie 1 m/s 13.41 m/s (30 mph)
Desired Acceleration 2.45 m/s2 2.45 m/s2
Total Track Length 10 m 1.6 km (1 mile)
Factor of Safety > 10 > 10
Power Module Dimensions 47 cm x 35 cm x 25 cm 21 in x 27 in x 13 in
Supercapacitor Charging time < 120 seconds < 120 seconds

21. Based on the updated parameters, the system now require 350 kW
worth of power to operate at its full capacity
Steven Goh

22. 3.5 kW fan was added to the calculation as an HVAC unit for cooling
the lithium-ion batteries
Steven Gohhttps://oge.onegene.com/en/product/25

23. The updated battery system will have 8 modules of lithium-ion
batteries with total capacity of 21.2 kWh
Steven Gohhttp://media3.ev-tv.me/TeslaModuleController.pdf

24. Each module will have 210 batteries arranged in 6s-35p configuration
with total capacity of 122.5 Ah
Steven Goh
Samsung 25R 18650 Battery Specifications
Nominal Voltage 3.6V
Nominal Capacity 2500 mAh
Continuous Discharge Rate 20A
Samsung 35E 18650 Battery Specifications
Nominal Voltage 3.6V
Nominal Capacity 3500 mAh
Continuous Discharge Rate 8A
https://www.18650batterystore.com/Samsung
-18650-p/samsung-35e.htm

25. To prolong the batteries’ life, we do not want to discharge more
than 80%, so the usable capacity is 17 kWh
Steven Gohhttps://batteryuniversity.com/learn/article/how_to_prolong_lit
hium_based_batteries

26. 2-D Electrical Chart will be completed by the end of the semester
to help future teams
Steven Goh

27. Several part drawings has been completed, and more will follow
as we progress
Joe Lau

28. Full Scale Power Module will incorporate fans and free air cooling
Joe Lau

29. Full Scale Power Module will incorporate fans and free air cooling
Joe Lau

30. PCB design for Supercapacitors will reduce wiring
Eric Near

31. PCB connections will be able to handle 50 Amps of current
Eric Near

32. PCB will use connectors to handle the high current requirement
Eric Near

33. The BOM is constantly updated following new design parameters
Eric Near
Date Purchased Description Quantity Price/ Item Price
14-Oct-19 Ampeak 2/10/25A Smart Battery Charger 1 $74.28 $74.28
17-Nov-19 Nickel Strips (3 meter) 10 $7.64 $76.40
17-Nov-19 Bestol 200pcs 18650 Battery Cell Holder Safety Spacer 9 $21.84 $196.56
14-Feb-20 Samsung SDI 18650-25R Li-on Battery 12 $2.89 $34.68
Samsung SDI 18650-35E Li-on Battery 1680 $3.05 $5,124.00
Terminal Blocks 1 $3.47 $3.47
Fuse 50/100A 1 $2.04 $2.04
12-Mar-20 12V Automotive grade Relay 1 $14.20 $14.20
npn Transistor 1 - -
Diode 1 - -
Molex - 428160212 10 $2.50 $25.00
2-Mar-20 Current Sensor (DFRobot 50A AC/DC Current Sensor) 1 $19.56 $19.56
Molex - 428180212 10 $2.50 $25.00
Arduino 1 -
Li-On battery Smart Charger 1 $58.99 $58.99
Power Module Case (Custom) 1
PCB Fabrication (Supercapacitor) 1
Total Expenses $5,654.18
Current Total Spending: $ 172.20

34. We are currently on schedule, and the Gantt Chart is updated
following the new tasks
April May
Tasks 8 15 22 29 6 13
Ordering Parts
Testing
PCB Design and Fabrication
Thermal Analysis/Cooling System
Sizing Components for Full-scale
Simulation of Full Model
Final Presentation/Report
Eric Near
Joe Lau
Steven Goh
All
Eric Near

35. Dependencies and Contingencies

36. PCB thickness increased to reduce trace width
Eric Nearhttps://www.4pcb.com/trace-width-calculator.html

37. Uniform Supercapitor pack design will be
maintain to prevent the need for new PCB design
Joe Lau

38. In the case of full scale deployment, our team will depend on
communicating with bogie team, wayside power team and the
solar panel integration team
http://proceedings.ises.org/paper/solar2016/solar2016-0019-Furman.pdf Joe Lau

39. Thank You!
Questions?