Turnigy Monster 12S 200A ESC

[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! 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

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?

[Burtie]

blitzwagen wrote:
After fiddling with the timing, the controller set itself alight in exactly 5 seconds after switching it back for a 3'rd shakedown ride.

Yeah, that was pretty much the same way mine went, but after changing the pwm switching rate.

The ecrazyman 12 FET (48v 600w) controller was the base that I used for my HXT 80-100-130 powered bike. Upgrade the FETS, tracks and wires. I have it running well at 12s 100 amps and it barely gets warm.

The throttle response seems faster than the Turnigy (set to fast) was, although not instant It is quite acceptable.

Make sure you also buy a usb programming cable from keywin when you get the controller, you will need it for tweaking!

Burtie.

[blitzwagen]

Thanks for the advice Burtie, I'm now one step closer. Do you have a feeling for the accuracy required for the relative positioning of the sensors with respect to each other. I assume that the phase angle of the 3 sensors as a unit can be tweaked as an offset in the software?
I'm wondering if hand tools will sufficient for the construction of the sensor holder or if milling the slots is what is really required.

[Burtie]

Due to the high pole count (14) of these outrunners, the positioning and spacing of the halls relative to each other needs to be quite accurate.
1 mechanical degree = 7 Electrical degrees, small mechanical error = larger electrical error.

I constructed my external hall mounts using a mill and a precision rotary table. If you do not have access to these, you may find that glueing the sensors into the stator slots is your best bet, there is less scope for error (I am curently running my bike using internal hall sensors, and it works well).

There is no way to adjust the sensor timing in the software.

Burtie.