Partial winding short, large reluctance, quicker heatup -How to diagnose/prevent?

Electric Motors and Controllers
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usertogo   10 W

10 W
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Joined: Nov 19 2014 9:31am

Partial winding short, large reluctance, quicker heatup -How to diagnose/prevent?

Post by usertogo » Jul 08 2018 10:40am

The symptoms are pretty clear now. It helped that I recently bought a new Motor and noticed it turns much more voluntarily than my old motor and one I bought used...
I wonder this might effect only some of the windings - might I be able to only rewind the affected ones? How to find those?

Any ideas welcome, other than buy a new motor, because I believe 'you don't really own it until you can repair it', so I am working up the faith to learn motor winding! 8)

I also don't want the new motor to go the same way, and I guess the major approaches are:
- Cooling external
- Cooling heat conducting internal (Ferrofluid?)
- Temperature sensing and limiting
- Protecting windings (vacuum infused resin?)
What else?
This thread is prepared to eventually migrate into the Wiki, or is it already there?

User avatar
usertogo   10 W

10 W
Posts: 89
Joined: Nov 19 2014 9:31am

Re: Partial winding short, large reluctance, quicker heatup -How to diagnose/prevent?

Post by usertogo » Aug 15 2018 8:22am

Meanwhile I watched quite a few videos where talking about used high mileage Tesla(Model S) the buyer noticed that often the car was on its 3rd or 4th motor - so even the big (r&d) guys have to live with the issue , have found out how to diagnose (relation of delta temperature in relation of the integral of power in minus power out).
So for hobby users so far the evaluation of the mobility efficiency in Wh/km is a minimal goal in order to approach what must have been done in those Teslas that have to balance so many variables in order to estimate if you can make it to the goal or the next charging stations...

Another realization I have is that with good reason Tesla avoids the permanent magnet motor - brushless induction is least maintanance intensive - the pros seem to vacuum infuse their stator windings with resin that isolates and keeps everything static even if high forces fluctuate.
And if no magnet looses field strength ideally an AC Induction cage runner will be the best choice for truly high torque from standstill, the field can slip and good question how the achievable field strength ranges. And what will happen after the advent of realistic superconductive windings?
Are there any exciting advances in calculating and simulation of multi physics design Challenges like such...
I want to look for DIY Ferrofluid and cooling, How many percent gain and loss due to friction and improved magnetic circuit ?

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