Sensorless LYEN Controller+Turnigy RC Motor Maximum RPM Test

[Jeremy Harris]

If you won't run above 75V, why don't you try the irfb3077 instead? IMHO it's even better than the 4110.
-Olaf

Very true. I'm running 3077s and they run very cool indeed, probably due to their very low Rdson.

Jeremy

 

[gwhy!]

If you won't run above 75V, why don't you try the irfb3077 instead? IMHO it's even better than the 4110.
-Olaf

+1 Much Much Better

 

[liveforphysics]

Okay, so now it looks like we are running up against a processing speed limit.

If he hasn't corrected the hardware instant-current fault problem (which is sounds like he hasn't if he is still getting speed readings that change depending on throttle percentage, with less throttle giving higher RPMs), then we actually have no clue what it's up against. Hardware may be good way past 10krpm.

 

[drewjet]

I am glad to see this working. However, no-load tests are good to get it operational. You need to put it on a bike and see what happens under load. I thought I had my Astro sensored working great. No load was sweet, put it on a bike and it had little power to the wheel yet was pulling huge amps.

 

[GGoodrum]

Frankly, I have no problem with using the 3077s instead of 4110s, but I'm guessing Edward has a quantity of 4110s already, and may not have any of the 3077s. It is up to him.

I think the instant-current fault problem definitely needs to be investigated next, but since I only need 5700-6000 rpm, this may not be something that absolutely has to be fixed now. What we do need to test, however, is "under load" capability. Not sure if we can do that without an actual bike installation load test, which I can certainly try.

-- Gary

 

[gwhy!]

I think the instant-current fault problem definitely needs to be investigated next, but since I only need 5700-6000 rpm, this may not be something that absolutely has to be fixed now. What we do need to test, however, is "under load" capability. Not sure if we can do that without an actual bike installation load test, which I can certainly try.

-- Gary

Hi Gary this have been solved.

 

[Jeremy Harris]

It has indeed. It involved the joint efforts of a few of us (and more than a few furrowed brows!) but we finally managed to work out exactly how the two current limit circuits work in these XieChang controllers.

Jeremy

 

[MitchJi]

Hi Gary,

In any case, My 3220-7t has a kV of 97, and I want to run it on 18s, or about 66-70V, so the rpm will be just under 6k, which this module seems to handle quite well. Put me down for a 4110-based 12-FET version, just as soon as you can build one.

-- Gary

What we do need to test, however, is "under load" capability. Not sure if we can do that without an actual bike installation load test, which I can certainly try.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=12267&start=180#p327993

Actually, I'm not interested in "fixing" this setup at all...

Anyway, I'm over this, and want to move on to something different. For one thing, my next 3220-based setup will not be hampered with a 50V limit. This 3220-7t will either get sensors, or it will use Lyen's sensorless module, and it will be powered from an 18s2p Turnigy pack. This much is a given. I'm also pretty sure it will end up in a friction drive, of some sort...

-- Gary

It would be nice if Lyen can ship you one promptly and if you can test it on your existing build before you tear it apart. That might be quite a bit sooner than waiting for your new build and a direct comparison with the HV110 or HV160 you originally used would be interesting.

 

[MitchJi]

Hi,

http://endless-sphere.com/forums/viewtopic.php?f=28&t=19983&hilit=+hv160

Latest information on RC systems (HV160 use mainly)

I just wanted to share what I have learned in extensive testing over the last few months. This is primarily regarding the HV160 controller.

#6 Added caps are really only needed below 5kw if very good cells and wiring are used. Keep an eye on the ripple and add caps if it exceeds 3 volts max.

#7 These controllers are very reliable with high impedance motors. For instance, if running a 3210 ten turn motor is almost impossible to blow a 160. Conversely, my 4 turn Delta 3220s were a bit much and would eventually blow the 160 if I stayed on the power more than a few seconds at a time. 6 turn Deltas are totally safe to run. 5 turn Deltas are "The Edge" so to speak.

Will additional caps be required or advised with the Lyen Controller?

Does the impedance of a particular Astro Motor ( 4 turn Delta 3220 vs 6 turn Delta 3220 for example) a potential issue with the Astro Motors and the Lyen Controller?

 

[GGoodrum]

It would be nice if Lyen can ship you one promptly and if you can test it on your existing build before you tear it apart. That might be quite a bit sooner than waiting for your new build and a direct comparison with the HV110 or HV160 you originally used would be interesting.

Edward is going to make me up a 12-FET version just as soon as he gets all the parts together. He said it will take 1-2 weeks. Whethr or not it will have the current "fix" implemented, I don't know. Hope so.

Anyway, my plan will be to test this on my existing Port Runner folding bike, which currently still has the 3220-7t "direct drive" setup. It doesn't have an HV160, though, just an HV110. Still, in 1st gear it is enough to flip me off the back. I can only run this current setup on 12s/46V, so I'll have to initially do the same with Lyen's controller, but at least this way will be an apples-to-apples comparison. I'll also try it on 18s/70V, but not in 1st.

-- Gary

 

[Lyen]

Hello everyone,

I have made some more progress today with Gary's lent Astro 3210 motor. I have bypassed the overload protection circuitry as suggested by members here. It really helped get more speed from the motor. The controller no longer shutdown even with full throttle. The maximum RPM achieved as of today is 7102 RPM.

Observation: The motor did rattles at the last 85-90% or the 4th quarter of the throttle. The tiny controller was hot to touch telling me 6 FET is definitely not enough. I will retest to using the 12 FET version soon.

Here's the video:
[youtube]VfkXdgVwWw8[/youtube]

Regards,
Lyen

 

[Hillhater]

Why would the controller get hot on a "no load" test ??
What current is it drawing at max rpm ?
how do more FET's help for no load testing ?

 

[Lyen]

Why would the controller get hot on a "no load" test ??
What current is it drawing at max rpm ?
how do more FET's help for no load testing ?

That is a very good question. Unfortunately, I accidentally burned my Wattsup meter at 86v and is being sent to Tmaster for repair so I cannot test the current draw with it right now. I will try to find a way to measure the current draw at the maximum RPM.

You are also correct that more FETs may not really help in this case unless more current can push the RPM higher.

Regards,
Lyen

 

[Jeremy Harris]

Why would the controller get hot on a "no load" test ??
What current is it drawing at max rpm ?
how do more FET's help for no load testing ?

The current peak needed to trip the current overload interrupt on a standard 6 FET XieChang controller is around 120 amps.............

Obviously this is massively greater than the continuous current, but nevertheless is really pushing the FETs hard. The reason is down to the combination of the low inductance and low winding resistance of this motor. The PWM frequency of these controllers is 15kHz, which is fine for motors with a reasonably high inductance, but as soon as you try and drive a low inductance motor the inductance isn't enough to adequately limit the peak current to a safe value. I suspect the FETs are seeing very short duration peaks of maybe 150 amps or more when the motor accelerates.

More FETs help by reducing the losses in the controller (because the paralleled FETs have a lower on resistance) which reduces heat build up. It also increases the allowable peak current. A 6 FET controller with IRFB4110 FETs is OK for maybe 120 amp peak current, because that's the package limit of the FET. Even then, it will only take that sort of current for short pulses, it's maximum continuous current is likely to be less than half this figure (due to it's inability to get rid of heat from the junction).

Jeremy

 

[Tiberius]

I followed the thread with big interest.
Has anyone checked the 'deadtime' between high and low Fets? Maybe its too short and the current control trips because of a shoot thru?
-Olaf

Good point. I don't have a fast enough 'scope to make a meaningful measurement, but if one of you guys with nice, fast 'scopes wants to have a look it would help a great deal, not just with this problem either.

Jeremy

Hi Jeremy,

I have a couple of fast scopes, as you would expect, given the frequencies I work with.
Bring something over for testing if you like.

Nick

 

[Lyen]

I have some more testing done and observation today. I managed to borrow another WattsUp meter to measure the no load current. For this test, I am using an add-on module on an 18 FET 4110 controller.

Here's the test result at 38v (no high voltage is needed due to known limitation on the add-on module):

Motor used for testing: Astro 3210 from Gary
No load current: around 3A
Maximum RPM with the add-on module: 4255 RPM (after that the motor starts to rattle)

Observation: The current draw at no load is five times as much or around 15A when the motor started to rattle.

[youtube]nhqX-JXDGU4[/youtube]

 

[7circle]

Sorry, I think I'm stating the obvius to ya all.

It needs some intertia like a fly wheel.
- Its like adding capacitance to a DC circuit to stop the ripple.

It might start rattling because it is loosing sync.

If the field is not strong enough it can't overcome the friction torque due the wind and bearing and magnetic losses.

This is even worse if the timing of the ESC to the hall sensors has a delay that is not compensated for.

The rattling may indicate that their will are more losses due to high frequencies ripple as the rotor tries to pull back into sync with the next polar alignment.

Yeah ,10Mhz Scope would show up thinks nicely if you can attach it without ground loop.

 

[spinningmagnets]

I am still learning so, sorry for the noobish questions...does high PWM ripple cause lots of RF static noise? if yes, could that be making the sync issues worse? if that is also yes, what could shield the BEMF sampling-and-calculating chip from the RF?

 

[rebelpilot]

Electrical noise can make it hard to determine what the issue is.
I was an early user of International Rectifier's IRAMX16UP60B, a 16A 600V Integrated Power Hybrid IC. The early literature for this IC claimed the circuit had built in deadband protection. I was controlling a large three phase airconditioner. The motor would run well with a small load, but when the compressor kicked in all hell would break loose. The laptop and test equipment would go south and I was unable to capture a waveform (all optoisolated and running off batteries). The control modules would explode, and usually the pcb and filter caps. Awesome EMP generator, every electronic device in the room was affected! What had happened was IR had farmed out the project to an Italian company, and did not fully understand the project. The deadband control was in software.
I think the problem people have been having with sensorless control of the larger motors is due to no synchronization. This wll become evident when a load is applied or the speed is increased to a point where the drag is significant.

 

[John in CR]

While mine has the older sensorless module, maybe my results can help point the way to an even better solution, since the new module seems to work to a higher rpm. The difference between the two just needs to be taken further. I used it on the bike under load. The issue doesn't occur at a finite point like the loss of sinc problem of controllers used with geared hubs 2 years ago, where it occurred at a specific point only and things were fine at a higher rpm.

Under load the issue with mine has a gradual effect. I say this because the audible noise from the motor, that sounds to me like inaccurate commutation, starts at moderate speed and increases with speed until the lower than normal (with a sensored controller) maximum speed is reached. While mine starts more silent and smooth than with a sensored at low rpm, the motor sound at high rpm is quite similar to the low rpm high load noise using a sensored controller.

Could it be that the programming starts with a timing that is retarded which gradually changes to an advanced timing? Then wouldn't the default programming be for a specific motor or for motors with a lower maximum electrical rpm? Is this a program setting we might be able to change?

Also, I've been thinking about a potential solution. I loved the smooth and silent takeoff my sensorless. Except at 0 rpm it is obviously better and likely more efficient than it's sensored cousins. With the only hiccups being at 0 rpm, it must be rotor position dependent. Wouldn't rewiring the motor to 6 phases and using 2 controllers solve the issue, since the 2nd controller will see the rotor at a slightly different position? I don't think it will solve the rpm issue, since the magnet count doesn't change, but I'm unclear on the effect of advanced timing with 6 phases.

John

 

[Lyen]

I have got the part to make the 12 FET 4110 sensorless controllers over the last few days. Here is the test run video made today with the Cycle Anayist connected. Using more MOSFET transistors really does help preventing the controller from generate heats. The 12 FET also have more power to push the Astro 3210 motor close to 6800-6900RPM at 70v without cutting out. The maximum RPM limit however is still the same as with the 6 FET controller. I will bypass the overload circuitry and see what will happen soon.

The observation for today is you will notice the Ah (amp hours) doubles as soon as you hear the motor starts to rattle as shown on the CA display.
[youtube]8yGXzqglHr4[/youtube]

P.S. Please excuse my wet clothes hanging on the chairs on the video. It was raining hard in San Francisco for the last two days while I was riding my ebike. LOL

 

[GGoodrum]

I just got a 12-FET version, with the sensorless mod, from Edward. He brought out the overload override enable signal, so I can try it both ways. I'm going to try this with the 3220 "direct drive" setup I still have on one of my folding bikes. Eventually this setup will get replaced with some sort of friction drive setup, as I've never been happy with the racket this current configuration makes, but for now, it will make a good testbed for this controller.





The current setup has a 3220-7T driving a large #35 sprocket, which is attached to a 3-speed Sturmey-Archer hub. It has a CC HV110 controller and one of Richard's throttle boxes, both of which will get replaced by the Lyen's modified 12-FET. The pack used on this bike was a 12s3p Turnigy-based 44V/15Ah setup, which I will try initially to get a comparison baseline. Then, I'll try this with a couple other packs I have, a 16s2p 60V/11.6Ah pack and an 18s2p 66V/10Ah configuration.

What will be interesting is to see how the controller handles the loads and the rpm. With the 12s setup, the max rpm is fairly low, about 3800, but the current can be fairly high, with 80-85A peaks, if I push it. The 18s/66V configuration will push the max rpm up closer to 6000, which is right at the apparent limit, based on Lyen's tests. The peak current demands will be a lot less, though, maybe 55-60A. The 16s/60V setup should be right in the sweet spot, with a max rpm around 5000-5100 and max peak currents of 60-65A.

Anyway, should be an interesting set of tests. I've got a lot on my plate at the moment, but I'll try and get this going this week. First up I'll get some video (I got one of those small GoPro HD cameras the other day...) of the existing setup, with the 12s3p pack.

-- Gary

 

[hydro-one]

Any updates? how does the controller handle the load? sync?

very interesting thread, i dont like the reliability records of r/c controllers. lyens on the otherhand, rock solid...

mike

 

[deVries]

on Nov.30th... The current setup has a 3220-7T driving a large #35 sprocket, which is attached to a 3-speed Sturmey-Archer hub. It has a CC HV110 controller and one of Richard's throttle boxes, both of which will get replaced by the Lyen's modified 12-FET. The pack used on this bike was a 12s3p Turnigy-based 44V/15Ah setup, which I will try initially to get a comparison baseline. Then, I'll try this with a couple other packs I have, a 16s2p 60V/11.6Ah pack and an 18s2p 66V/10Ah configuration.

What will be interesting is to see how the controller handles the loads and the rpm. With the 12s setup, the max rpm is fairly low, about 3800, but the current can be fairly high, with 80-85A peaks, if I push it. The 18s/66V configuration will push the max rpm up closer to 6000, which is right at the apparent limit, based on Lyen's tests. The peak current demands will be a lot less, though, maybe 55-60A. The 16s/60V setup should be right in the sweet spot, with a max rpm around 5000-5100 and max peak currents of 60-65A.

Anyway, should be an interesting set of tests. I've got a lot on my plate at the moment, but I'll try and get this going this week. First up I'll get some video (I got one of those small GoPro HD cameras the other day...) of the existing setup, with the 12s3p pack.

Bump... Ok Gary, since you posted Nov.30th... Christmas is coming... :lol: :lol: :lol: (2011 :lol

This is a VERY interesting topic, so I hope you can clean your plate with the New Year & do something with all that beautiful (It's a California day! My Uncle would say.) weather you keep poking us with...

and, GET GOING on it...

Btw, did you do any torque calculations to begin to understand what the SA 3-speed hub can take? Do these RC motors put out more torque than humans do "jammin" at the crank? Will we have to let-off the throttle before shifting???

Well, Happy New Year & I want to thank you for all your wonderful contributions to ES over the years! Seriously! , wish we had a dozen or so of you on ES though, then you'all could paint the house sooo much faster all the while doing ES tests & posting results here! alright! already!

:lol: :lol: :lol:

 

[GGoodrum]

Well, I'm afraid I haven't done a thing with this yet. The holidays took up every waking second I had so I've not even had time to read/post here much. This is still on my "bucket list", but it will have to wait until another few weeks.

-- Gary