1. UNH ECE 791 Senior Project I Design Proposal Presentation

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

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

4. Project Overview 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. Donor Sled: 1996 Polaris Indy XLT
Starting Point
Donor Sled: 1996 Polaris Indy XLT

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

7. Electric Motor 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

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. Battery Type Flooded Lead Acid, Why? Availability Low cost
Ease of configuration
Ease of mounting
Ease of connection
Source:

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: Support and Guidance:
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