Turnigy Monster 12S 200A ESC

[lawsonuw]

So, ideally, one would have either an easily movable hall sensor collar or two sets of hall sensors, each set enabled using some kind of switch (Like, maybe, a 3-pole 2-throw switch or is it the other way around?) and each optimized for delta or wye. Maybe?

Or a higher resolution commutation sensor and two commutation look up tables. One for Wye and one for Delta.

Lawson

 

[swbluto]

So, ideally, one would have either an easily movable hall sensor collar or two sets of hall sensors, each set enabled using some kind of switch (Like, maybe, a 3-pole 2-throw switch or is it the other way around?) and each optimized for delta or wye. Maybe?

Or a higher resolution commutation sensor and two commutation look up tables. One for Wye and one for Delta.

Lawson

You're talking about modding the firmware or adding additional firmware, no?

 

[Miles]

Maybe this is the time to ask whether Delta/Wye switching is going to be worth all this trouble? It might help if you want gut-wrenching acceleration but it won't help the motor much on that long steep hill....

 

[12p3phPMDC]

So, ideally, one would have either an easily movable hall sensor collar or two sets of hall sensors, each set enabled using some kind of switch (Like, maybe, a 3-pole 2-throw switch or is it the other way around?) and each optimized for delta or wye. Maybe?

Or a higher resolution commutation sensor and two commutation look up tables. One for Wye and one for Delta.

Lawson

Timing look up tables are commonly done in ICE engine controllers like the open source MegaSquirt originally done by Bowling and Grippo.
It'll be cool when eBike controllers approach that level of open source dev and sophistication. It's getting close. 8)

 

[swbluto]

[I'm not taking the research to find out, but substitute "delta" or wye" with "higher kv" or "lower kv" with where appropriate. I don't know which is which, and you'd have to look it up as much as I would.)

Maybe this is the time to ask whether Delta/Wye switching is going to be worth all this trouble? It might help if you want gut-wrenching acceleration but it won't help the motor much on that long steep hill....

Well, that depends. Assuming no current limiting, higher kv would have a higher torque and power potential, though at with increased strain on the controller and batteries; the continuous power output limit of higher kv should also be increased at higher motor RPMs, though one would probably need variable gearing to take advantage of it, so it could help out on the right setup for long steep hills.

For a single "good" gear ratio with a current limit, the only benefit that I found at lower motor RPMs is that lower kv reduces the battery and motor current which makes the controller and battery happier, while higher kv allows one a higher top speed on the flats.

With no current limiting and single "good" gearing, I could see it being used as two different full throttle speeds so that one could minimize the strain on the controller (Which is essential for ESCs, I've found. Otherwise, you'll need to stick with lower powers for partial throttle and you'll need to have active cooling like a running cpu fan with a cpu heatsink or an exposed ESC with a cpu heatsink to the air.).

 

[12p3phPMDC]

One could argue that Y is a better choice in general because of the lack of circulating harmonic currents (assuming a trapezoidal drive and not sinuisoidal).
Efficiency is always good.

 

[Miles]

I'm a bit puzzled that there is so much of a problem with circulating currents - see Tom Cimato's post here: http://groups.yahoo.com/group/lrk-torquemax/message/9534

 

[johnrobholmes]

maybe the timing advance on the Turnigy ESC was too much? It is sensorless, so one would think it has floating timing.

Maybe a leg was hooked in backwards? Not sure if that is possible, but it seems plausible.

 

[Miles]

Well, that depends. Assuming no current limiting, wye would have a higher torque and power potential, though at with increased strain on the controller and batteries; the continuous power output limit of wye should also be increased at higher motor RPMs, though one would probably need variable gearing to take advantage of it, so it could help out on the right setup for long steep hills.

For a single "good" gear ratio with a current limit, the only benefit that I found at lower motor RPMs is that delta reduces the battery and motor current which makes the controller and battery happier, while wye allows one a higher top speed on the flats.

I think you mixed up Delta and Wye, sw....

 

[swbluto]

Well, that depends. Assuming no current limiting, wye would have a higher torque and power potential, though at with increased strain on the controller and batteries; the continuous power output limit of wye should also be increased at higher motor RPMs, though one would probably need variable gearing to take advantage of it, so it could help out on the right setup for long steep hills.

For a single "good" gear ratio with a current limit, the only benefit that I found at lower motor RPMs is that delta reduces the battery and motor current which makes the controller and battery happier, while wye allows one a higher top speed on the flats.

I think you mixed up Delta and Wye, sw....

With binaries, I always believe that's a possibility. (Substitute "higher kv" or "lower kv" with "delta" or wye" where appropriate.)

 

[12p3phPMDC]

Well Miles, according to that link, Burtie should be seeing less heat. But alot of the literature regarding the circulating currents
says that Delta is avoided specifically for that reason. I'll try to quote Duane Hanselmans book when I get home.

Tom from Maxcim didn't point out the type of drive system used (or at least I couldn't find it)...
That's important too. Trapezoidal contains high harmonic content, whereas sinusoidal doesn't (miniscule if digitally generated).
I wonder if his statements holds true across the board (speed and load)...

What are some of the other differences between the 9C, HXT, and the Astro?

Based on pics, it appears that the Astro has a distributed winding (phases spread across multiple poles), whereas the HXT and Turnigies have (I forget the term)
discrete windings per pole, and I'm not sure about the 9C, but I'm guessing discrete.

I have no idea if that will cause additional problems between Delta/WYE switching or not.

 

[Miles]

Well Miles, according to that link, Burtie should be seeing less heat.

Where does it imply that?

 

[Miles]

Based on pics, it appears that the Astro has a distributed winding (phases spread across multiple poles), whereas the HXT and Turnigies have (I forget the term)
discrete windings per pole, and I'm not sure about the 9C, but I'm guessing discrete.

I have no idea if that will cause additional problems between Delta/WYE switching or not.

I wondered about that, too.....

Concentrated windings is the usual term, I think.

Wouldn't a distributed winding have a bEMF that was closer to sinusoidal?

 

[Miles]

I'll try to quote Duane Hanselmans book when I get home.

Voila! http://www.eece.maine.edu/motor/BPMM_Ch8.pdf

 

[John in CR]

Miles,
Sorry to jump in in the middle, but am I reading that correctly? ie Forget Delta if given the option and gear accordingly for a Y motor wiring?
John

 

[Miles]

Miles,
Sorry to jump in in the middle, but am I reading that correctly? ie Forget Delta if given the option and gear accordingly for a Y motor wiring?
John

Well, I guess it depends what you want to achieve.... If your batteries can deliver enough current for the torque required and your controller can take it without overheating, then what advantage is there in having delta/wye switching? How much does the duty cycle effect the efficiency of the motor itself? What else am I missing...?

 

[12p3phPMDC]

Well Miles, according to that link, Burtie should be seeing less heat.

Where does it imply that?

Well, I guess I implied that. Here's my basis. IF you have circulating currents that contribute nothing to the torque production, then they
turn into heat. If Tom @ Maxcim claims that for the motors we deal with (assumption), that the circulating currents are miniscule, then miniscule = less heat?

 

[Miles]

Ah! You mean less heat than he is.... For some reason, I assumed you meant less heat than in Wye config.

 

[12p3phPMDC]

Based on pics, it appears that the Astro has a distributed winding (phases spread across multiple poles), whereas the HXT and Turnigies have (I forget the term)
discrete windings per pole, and I'm not sure about the 9C, but I'm guessing discrete.

I have no idea if that will cause additional problems between Delta/WYE switching or not.

I wondered about that, too.....

Concentrated windings is the usual term, I think.

Wouldn't a distributed winding have a bEMF that was closer to sinusoidal?

ah yes, thank you, concentrated windings.

It makes sense that bEMF would be more sinuisodal. The windings are spread out across poles, therefore, magnetic flux would be maximum in the center of the winding centered on a pole and probably tapers in
from the outskirts of the windings.

But how does that affect circulating currents in delta driven trapezoidally, and why does Burtie have a 3.5 A no load current?

 

[Miles]

But how does that affect circulating currents in delta driven trapezoidally,

In Hanselmann, it says that the circulating currents are caused by 3rd harmonic component in the bEMF. Or am I misunderstanding...?

 

[12p3phPMDC]

Re: Heat generation, No problem Miles...

But how does that affect circulating currents in delta driven trapezoidally,

In Hanselmann, it says that the circulating currents are caused by 3rd harmonic component in the bEMF. Or am I misunderstanding...?

Um...Yea, I read that as well.......But, I think you can get circulating currents in Delta from both the Drive and the BEMF.
Too bad the pdf jumps around...it would make a great reference! It was enough to tease me into plunking down the change
for his book.

In a delta config, If you excite it sinuisoidally, then you avoid adding additional "triplen" harmonics as Hanselman describes.
But if you excite it trapezoidally, then you are adding additional harmonics, including the triplens that don't cancel which cause more circulating currents.

Does that make sense, or am I off my rocker?

I dunno...more reading.

But, It sounds like even the experts disagree! :lol: It probably means that it depends heavily on other parameters that I don't even begin to understand.
That's probably why David says "some motors just don't like Delta".

But, what is the difference in topology/windings/poles in a PMSM or PMAC (Permanent Magnet Synchronous) and a BLDC?
Does a PMSM/PMAC motor have distributed windings? Whereas a BLDC is typically concentrated? and is the Astro a blend that has no problem being
driven trapezoidally in Y??? and because it is driven in Y, all phase currents are forced to sum to zero by KCL?

I wonder what the BEMF waveform of the Astro looks like when spun up by a drill? Is it trapezoidal or is it sinusoidal?

 

[Miles]

But, what is the difference in topology/windings/poles in a PMSM or PMAC (Permanent Magnet Synchronous) and a BLDC?
Does a PMSM/PMAC motor have distributed windings? Whereas a BLDC is typically concentrated? and is the Astro a blend that has no problem being
driven trapezoidally in Y???

I guess the bottom line is that you want the bEMF waveform to match the drive waveform. Then you get smooth continuous torque, no?

 

[12p3phPMDC]

Yea, that sounds right...

Maybe I can get Burtie to oblige, and spin up the Astro to show the BEMF without a controller hooked up since he seems to be setup?

 

[Burtie]

No problem :wink:

http://endless-sphere.com/forums/viewtopic.php?f=30&t=14210&p=248687#p248687


Burtie

 

[blitzwagen]

Well, I've blown my Turnigy 200A after exactly 2 short rides. I suffered from the dreaded loss of sync issue at close to full throttle which I attempted to fix by fiddling with the timing and PWM. After fiddling with the timing, the controller set itself alight in exactly 5 seconds after switching it back for a 3'rd shakedown ride. This is all with a 12S lipo and 80-100 130kV Turnigy motor.

I'm extremely impressed and excited by the development of the sensored ESC and I'd like to give it a go instead of going the CC HV160 route. I need advice- which sensored speed control is a good starting point? The ecrazyman controllers seem popular, is the 1500W/72V the one to get and can it be upgraded to say 4kW with the addition of better mosfets? Is the throttle response with this controller acceptable?