UNH ECE 791 Senior Project I Design Proposal Presentation

1. UNH ECE 791 Senior Project I Design Proposal Presentation

2. Team Members: • Luke Vartuli • Stephen Doran • Doug MacMillan Advisor: • Dr. Gordon Kraft

3. Problem Statement Problem: • Noise • Emissions • Cost of operation Solution: • Electric snowmobile

4. ProjectOverview • Starting point => Polaris Snowmobile • Breakdown of snowmobile • Electric motor • Motor Theory • Motor Control • Pulse Width Modulation • PWM circuit • Power MOSFET’s • Mounting bezels • Battery type • Battery mounting • Timeline • Budget • Contributions

5. Starting Point Donor Sled: 1996 Polaris Indy XLT

6. Components Removed: Engine Exhaust Fuel tank Oil tank Starting battery Cooling system Breakdown of Snowmobile

7. Specifications: Mfg: General Electric Model: 2CM6501 Nameplate Ratings: Voltage: 120VDC Armature Current: 167 A Field Current: 10 A Place of Origin: WWII Era B-29 Aircraft Electric Motor

8. Armature • Main component of the DCMG • Uses multiple Armature windings for conduction • Undergoes Dynamo effect

9. Shunt DCMG • Armature and Inter-poles are in parallel to the Main poles. • As load changes only a fraction of the field will change. • Safer, but has bad torque characteristics

10. Shunt Diagram

11. Windings

12. Commutator • “Assembly line for current transfer” • As the commutator spins, current conducts from the brush (-) to the commutator bars the Load back to the Brush’s(+).

13. Inter-poles • Maintains a neutral field flux over the commutator as the load changes. • By having a neutral field flux over the commutator, this limits “sparking” on the commutator which then leads to pitting and damage. This will disrupt proper commutation.

14. Inter-poles at work!

15. Motor Control How the motor will be controlled: • Vary armature current, fixed field • Pulse Width Modulation (PWM) • Power MOSFET’s

16. Pulse Width Modulation (PWM) • Use PWM to control armature, fixed field • PWM controls power MOSFET’s • As duty-cycle increases, switches on longer, motor spins faster

17. PWM circuit

18. Power MOSFET’s Pros: • High current • Fast switching • Low resistance Cons: • No protection from fly back voltage • Get hot

19. Mounting Bezels Key Components: • Bed plate • Motor • Motor bezel • Bearing Bezel • Clutch assembly • Orig. Motor Mounts

20. Flooded Lead Acid, Why? Availability Low cost Ease of configuration Ease of mounting Ease of connection Source: www.carbasics.co.uk/inside_car_battery.gif Battery Type

21. Battery Mounting Configuration: Series Nom. Voltage: 120VDC Mounting: Battery rack with top straps

22. Timeline

23. Budget • Snowmobile: Donated • Electric Motor: Donated • Wire and misc. supplies: Donated • Mounting Bezel: $200 • Batteries: $1000 • Pulse Width Modulator: $150

24. Contributions Donations: • Snowmobile donated by Vincent Pelliccia • DC Motor donated by Kevin White • Wire and misc. electrical materials donated by Vartuli Electric, LLC Support and Guidance: • Prof. Kraft • Prof. Hludik • Prof. Clark • Prof. Smith • Adam Perkins • Matt Borowski

25. Thank you for your time

26. DC MOTOR THEORY • Same concept as AC Motor/Generators • Utilizes carbon brushes for DC characteristics

27. Flemings right Hand rule

28. Armature Physics

29. Commutation Diagram

31. Compound DCMG • Utilizes both series and shunt characteristics • More common DCMG

32. Compund Diagram

33. Series DCMG • Poles, Inter-poles, and Armature all in series. • Change in load is directly proportional to change in speed. • Reduction in load can cause a “run-away” motor which will then lead to mechanical failure. • High torque applications.

34. Series DCMG diagram