Nucular electronics - complete kit for ev!

VasiliSk said:
It's not so good for this, it uses a lot of amps to get any effect.
Click to expand...

Because the motor is IPM not SPM, it takes an additional look up value for rotor reluctance torque compensation to field weaken efficiently. The beautiful thing is, SPM motors rarely can field weaken more than 70-100%, and some IPM motors can field weaken up to 250% of base speed or more. Nissan leaf is an example of this. The more active iron mass to magnet mass in the rotor, the more the motor motor will be capable of efficiently exceeding it's base RPM*Kv speed. Motors that support lots of field weakening are magnetically sitting closer to a "stepper" motor when making peak torque at low RPM's, but they are exclusively "stepper" motor type drives when field weakening way above base speed, the PM function is supplementary and to enable efficient high torque density and control-ability.

It's not uncommon to eat 2-6% motor efficiency to extend useful RPM powerband by +100% in a high iron% IPM rotor motor, where an SPM motor might be eating 10% efficiency to get +50-60% over base speed.

At some point rotor magnet strength being high is almost a penalty to motor performance, and you end up just wanting the highest temperature permanent magnet material, and then using minimal amounts of it in a mostly iron rotor to leverage reluctance torque.
 
VasiliSk said:
Mine surron motor is not IPM, it is SPM
Click to expand...

My bad, I was thinking of the GoGro scooter IPM rotor, you're right Sur Ron is SPM. Should take around 50-70% above base RPM before getting a bad efficiency hit then.
 
VasiliSk said:
It's not so good for this, it uses a lot of amps to get any effect.
Click to expand...

Ive been seeing this sort of result also, using some of the most impressive (well, power density wise at 20+kw output for 2.7kg) motors on the planet like Joby's etc that are SPM -there seems to only be around 30% maximum extra rpm from field weakening before an approximate doubling of no load losses.

Justin had found a similar result from memory with some dyno testing on hubbies (SPM) only taking about 20% extra rpm before big losses, and the reason appears to be that the relative permeability of neodymium magnets is close to 1 (the same as air) meaning their state of magnetic flux cannot really be messed with -ie you cannot really "push back" on their magnetic flux to weaken it like you can on steel, thus IPM is the answer to get you anything like the 250% over base speed the (stock) Nissan leaf can achieve.

It would be awesome if we could get anything like even a 40% increase in rpm on our normal surface permanent magnet motors but unfortunately so far im not seeing it, not without them being IPM, so im curious Vasilisk what sort of rpm increase you found and what was the cost?
-ie it has been reported that a sur-ron motor uses around 700w no load loss at base speed (with belt and possibly wheel drag) so what were your findings on the effect of field weakening on this vs rpm?

BTW congrats on an awesome and well priced controller, reckon id be keen on a 24f when your ready..
 
This is good stuff folks!

Where do I find IPM motors in the 8-10kw range?

I wonder if GoGro uses FW in their scooters? They top out at a little less than 60mph. My XB-502 scooter on an HLD inrunenr does that without any FW and pulling 6kw. Not very impressive IMHO.

On any outrunner I've tried, I'm not seeing much benefit with FW...just more current and a few RPM's more. I'm guessing that's because the armature back iron tends to be fairly thin.


What about axial flux? Not much iron there at all in the rotor so I bet FW is almost pointless. This motenergy has the magnets mounted in an aluminum disk.

3031-001%20armature%202.jpg


I've only tried on an HLD inrunner on the bench under no load. I got 200% increase in RPM...with about 60% more amps. It has a pretty good amount of iron behind the magnets. If I were to get iron powder and mixed it with some kind of thin epoxy, could I fill those triangle shaped holes in the armature and increase the back iron significantly?

Driven%20end_zpsn8jgrsej.jpg


I'm going to wager that this AstroFlight 3220 wont get much benefit from FW either. The armature is almost totally aluminum with the magnets glued to it.

Astro%20Flight%203220%20stator%20view%2024%20teeth_zpsqvytfcsx.jpg
 
toolman2 said:
VasiliSk said:
It's not so good for this, it uses a lot of amps to get any effect.
Click to expand...

It would be awesome if we could get anything like even a 40% increase in rpm on our normal surface permanent magnet motors but unfortunately so far im not seeing it, not without them being IPM, so im curious Vasilisk what sort of rpm increase you found and what was the cost?
Click to expand...

The 2013 through 2016 Zero motors were SPM and have over 40% base speed gain. This is because of the design of the back iron capacity for reluctance torque. The hubmotors (and some joby motors) had limited reluctance rotors to keep the iron mass low. After 2016 they went IPM rotor, which offers greater reluctance torque based powerband, but requires a reluctance control scheme to leverage it to get any benefit.
 
Sorry. I'll clear my post.

I am interested in the 24fet and to set different amount of field weakening for different rpm to optimise the IPM motor performance.

Can it be done?

What's your estimate on price and leadtime for a 24fet with display?
 
liveforphysics said:
The 2013 through 2016 Zero motors were SPM and have over 40% base speed gain. This is because of the design of the back iron capacity for reluctance torque. The hubmotors (and some joby motors) had limited reluctance rotors to keep the iron mass low. After 2016 they went IPM rotor, which offers greater reluctance torque based powerband, but requires a reluctance control scheme to leverage it to get any benefit.
Click to expand...
From what i found out during my IPM vs SPM research, is that SPM cannot make any reluctance torque. The potential is always zero.
On IPM motors the torque potential depends on the design of the rotor. I think the more iron there is between the magnet poles (the part which is facing the stator teeth), the higher the potential. I might be wrong, but thats what most papers did say.

larsb found a great teaching vid
https://endless-sphere.com/forums/viewtopic.php?f=30&t=93627&start=125#p1428284

here another thread:
https://endless-sphere.com/forums/viewtopic.php?f=6&t=95100

ElectricGod said:
It has a pretty good amount of iron behind the magnets. If I were to get iron powder and mixed it with some kind of thin epoxy, could I fill those triangle shaped holes in the armature and increase the back iron significantly?
Click to expand...
the amount of iron BEHIND the magnets does not matter as it will be always SPM, so you would gain nothing if you do this.

VasiliSk said:
Guys, this thread not about motors ;)
Click to expand...

Yes we should not mess up your thread any longer with this subject. Sorry and thanks!
 
VasiliSk said:
FW currently activated only at regulator voltage limit, when you need to speed up motor more.
i will work on IPM reluctance torque later, since i've got QS3k ipm for my test bench ;)
Click to expand...

I agree...we did hijack your thread. Sorry about that. BUT at the same time, it got you thinking about new functionality. All in all...probably worth it.
 
larsb said:
So can i set FW at rpm-dependent value?

Like 20% at 100 rpm
50% at 2000 rpm
80% at 5000 rpm

I think you should add 24F estimated specs, price and timing on first post in this thread
Click to expand...


You want to have mechanically optimized commutation event timing for as long as you have pack voltage > BEMF. For this reason it's not something you start with a little bit and move upwards like automotive timing advance. You run with mechanically optimized timing, and then when your torque would otherwise begin to fall-off because you ran out of pack voltage to drive higher RPMs, this is the moment field weakening begins. If you set your field weakening for some extreme value, it doesn't hurt you anywhere with respect to efficiency or torque or power, aside from the efficiency hit taken while using that over-speed RPM. Some motors like the Nissan leaf manage to stay from 93% to 96% efficiency over the whole 0% to 250% of base speed range with a high iron IPM rotor motor.

I'm also interested to try out a 24F asap to see what it's like on a Sur Ron.
 
I think you're wrong for once LFP 8)
Check this post out:https://endless-sphere.com/forums/viewtopic.php?f=30&t=93627&start=125#p1424929

The torque map indicates that this motor already at stall benefits from around 50% field weakening current. I'm building a dyno in 2019, that's my new years resolution :D
Then i'll map some IPM motors..
 
When do you think the 12f controller will be ready? Don’t want to kill myself having a bike ready for spring or summer. The thought of the possibility is nice though.
 
Hi, I am interested in a 6f and display and also a 12f and display. How do I order from you?
 
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