ElectricGod
10 MW
I have this idea...
All you really smart folks out there this is your big chance to blind us with your intellect.
Please feel free to point out the flaws in my logic or where I flat out missed things, made mistakes or you know something I don't. That's the whole idea.
1. Make a custom tooth count stator. So that there is enough teeth to wind 2 or 3 adjacent teeth in the same direction and have 3 or 6 phases.
2. I want to remove the factory magnets. They are typically the same width as a single stator tooth. I want to replace them with magnets that are as wide as 2 or 3 stator teeth. That depends on the stator tooth count and if you are winding 2 or 3 teeth.
3. Start from an empty stator.
4. Depending on the stator tooth count, adjacent 2 or 3 stator teeth would be wound in the same direction. This effectively makes them into a single stator tooth.
5. Typically you wind 3 adjacent stator teeth forward/reverse/forward. I want to wind 2 or 3 adjacent teeth all forward, then 2 or 3 teeth all reverse and then 2 or 3 teeth all forward again. I also want to have 3 or 6 phases.
6. There is an implication which to my limited experience sounds absolutely fantastic. KV is based on turns per tooth. Since you are winding wire in the same direction around 2 or 3 teeth, you've effectively dropped Kv by 2 or 3X (I think). Well that's great if you want a really slow motor such as a hub, but this in an outrunner and I want something like 4000 RPMs. So then put 1/3 (ish) as many turns on the 3 adjacent teeth to get back to the original Kv. Now for the cool part. Turns of wire takes up space on the stator teeth. Since each tooth now has 1/3 as many turns on it, it's about 66% less full. Use 66% more copper per turn. This means each phase is now 66% more capable of handling current. A 10kw motor ideally becomes a 30kw motor. Right?
7. The kv is going to be higher...probably 2X or 3X higher depending on if you wind 2 or 3 adjacent teeth the same direction. This is because turns per tooth define Kv and you've reduced the number of teeth quite a lot. This sounds like it means the opposite of number 6. I frankly don't understand the implications in this area yet.
8. If there's 6 phases, then there's now half as many teeth per motor on top of the 2 or 3 tooth adjacent winds. I think this too will increase Kv by 2X.
9. Pole counts will go down significantly so eRPM constraints will matter less despite the higher Kv...hopefully.
10. Adjacently wound teeth in the same direction and lower pole counts also means fewer transitions per rotation and therefore less iron losses.
Conclusion: Wont this make for a motor that has 2-3X more current handling, probably has a somewhat higher Kv and has a much lower overall stator and magnet count so fewer transitions per rotation which reduces iron losses.
Like I said earlier tear it apart, point out the logic flaws or missteps I made, add additional ideas, corrections and so on. I'm certainly no expert on this. I've wound 2 outrunners. I just found out about 6 phase motors a few weeks ago. What do I know? LOL!
All you really smart folks out there this is your big chance to blind us with your intellect.
Please feel free to point out the flaws in my logic or where I flat out missed things, made mistakes or you know something I don't. That's the whole idea.
1. Make a custom tooth count stator. So that there is enough teeth to wind 2 or 3 adjacent teeth in the same direction and have 3 or 6 phases.
2. I want to remove the factory magnets. They are typically the same width as a single stator tooth. I want to replace them with magnets that are as wide as 2 or 3 stator teeth. That depends on the stator tooth count and if you are winding 2 or 3 teeth.
3. Start from an empty stator.
4. Depending on the stator tooth count, adjacent 2 or 3 stator teeth would be wound in the same direction. This effectively makes them into a single stator tooth.
5. Typically you wind 3 adjacent stator teeth forward/reverse/forward. I want to wind 2 or 3 adjacent teeth all forward, then 2 or 3 teeth all reverse and then 2 or 3 teeth all forward again. I also want to have 3 or 6 phases.
6. There is an implication which to my limited experience sounds absolutely fantastic. KV is based on turns per tooth. Since you are winding wire in the same direction around 2 or 3 teeth, you've effectively dropped Kv by 2 or 3X (I think). Well that's great if you want a really slow motor such as a hub, but this in an outrunner and I want something like 4000 RPMs. So then put 1/3 (ish) as many turns on the 3 adjacent teeth to get back to the original Kv. Now for the cool part. Turns of wire takes up space on the stator teeth. Since each tooth now has 1/3 as many turns on it, it's about 66% less full. Use 66% more copper per turn. This means each phase is now 66% more capable of handling current. A 10kw motor ideally becomes a 30kw motor. Right?
7. The kv is going to be higher...probably 2X or 3X higher depending on if you wind 2 or 3 adjacent teeth the same direction. This is because turns per tooth define Kv and you've reduced the number of teeth quite a lot. This sounds like it means the opposite of number 6. I frankly don't understand the implications in this area yet.
8. If there's 6 phases, then there's now half as many teeth per motor on top of the 2 or 3 tooth adjacent winds. I think this too will increase Kv by 2X.
9. Pole counts will go down significantly so eRPM constraints will matter less despite the higher Kv...hopefully.
10. Adjacently wound teeth in the same direction and lower pole counts also means fewer transitions per rotation and therefore less iron losses.
Conclusion: Wont this make for a motor that has 2-3X more current handling, probably has a somewhat higher Kv and has a much lower overall stator and magnet count so fewer transitions per rotation which reduces iron losses.
Like I said earlier tear it apart, point out the logic flaws or missteps I made, add additional ideas, corrections and so on. I'm certainly no expert on this. I've wound 2 outrunners. I just found out about 6 phase motors a few weeks ago. What do I know? LOL!