rhitee05 wrote:There was only one thing wrong with your model - direction. You modeled the coil correctly, but on one side the number of turns needs to be negative to indicate the opposite current direction. <snip>
rhitee05 wrote:<snip> If memory serves, the current design was 10 coils/phase, so total torque would be ~1.3 N-m. A little comparison shows that is nowhere near the 33.9 N-m design torque. Something seems amiss in either calculations or model...
And that there are 10 coils/phase; 10 * 0.127 N-m = 1.27 N-m / phase.0.0706N * 20 * 0.090m = 0.127 N-m torque for the 2nd case (both coils producing torque)
Kingfish wrote:With the first plot, other than delete the materials for the rest of the model, what were the precise steps you took to model the coils?
Kingfish wrote:From Plan-D
32 Poles / 16:1, 30 Teeth / 10 teeth per phase
F = Ãâ€ž / r = 33.9 / 0.090 m = 377 N
Wheel spins at 7 rps.
@ 16:1 & 7 rps, the Frequency (f) = 7 * 16 = 112 Hz
The original problem has Current (I) = 44 A.
We calculated that the actual Current/Phase = I/Ã¢Ë†Å¡3 = 44 A / 1.732 = 25.4 A / single phase of a 3-phase circuit.
Therefore 25.4 A / 112 = 0.227 A / phase
However Ã¢â‚¬â€œ we changed the original radius from 0.3048 m to 0.09 m for Plan-D, a factor of 3.387. Therefore the new phase current is
0.227 * 3.387 = 0.769 Ã¢â€°Ë† 0.8 A
This is the actual value applied to the coils in the model; math is validated.
What happens if we reverse the math for Torque / phase?
Given 1.27 N-m / phase, @ 112 Hz * 3-phases =>
1.27 * 112 * Ã¢Ë†Å¡3 = 246 N-m applied Torque per second
Would this not imply that our magnetic utilization is very good?
What did we miss?
Kingfish wrote:I think a local tribe pow-wow is in order! Arlo, git on down here!
Luke, name a date/time and letÃ¢â‚¬â„¢s go from there. Pot-luck? Tell us what you want us to bring.
Brushless, just a couple of questions:
From that information we will be able to provide more substantial feedback.
- What is your targeted system geometry? Hub, out/inboard motor?
- What is the size of the driving wheel(s)?
- What is the top-speed that you intend?
- What is your target voltage?
Pine St.-Capitol Hill: Oh I know that route! I thought a good urban hill-climber was the one Luke and I took after a day of exploring SeaFair, beginning at Lake-WA Blvd/Lake Park Dr (at the park) up McClellan then north on MLK to E. Madison @WOT, then SE up on over the hill and down past Broadway, and at this point we corked around looking for food and wound up at about 8th and Marion (sushi). TheyÃ¢â‚¬â„¢re all big long steep hills we take for granted in a car. IMM, Seattle has steep hills that parallel SF: How about that winding-burner from Alaskan Way to 5th Ave up Marion? With the right voltage, battery, and controller (likely modified) ~ any urban hill is possible (and 2WD is better).
What is your targeted system geometry? Hub, out/inboard motor?
What is the size of the driving wheel(s)?
What is the top-speed that you intend?
What is your target voltage?
Arlo1 wrote:Im not invited
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