Alternative motor windings and drive schemes

[Clugh]

At Kontronics the latest motor stators are pinned and bonded now so to get them apart require more than removing the 2mm screw and simply pulling the stator off..

Thanks for your time and patience,
Hubert

[Clugh]

Ich habe hier zwei Scorpion HKIII 4025. Ich werde zwei Varianten auf den gleichen Kv-Wert wickeln. Eine einlagige mit halbmagnetischen Nutenkeilen und eine konventionelle zweilagige ohne Nutenkeilen (siehe Croocoworld) und die 7 x 10 mit ihnen vertauschen, um einen direkten Vergleich zu ermöglichen. Die Endplatten bestehen aus Hochtemperatur-PLA. Ich habe sie mit 3M TC2810 aufgeklebt. Sie werden beim Aushärten der Motorwicklungen ausglühen und noch härter und hitzebeständiger werden. Das undurchsichtige Material, das Sie auf einigen Zähnen sehen, ist der gequetschte Wulst aus wärmeleitendem Epoxidharz, bevor ich ihn mit einem Skalpell abschneide.

Ich werde außerdem die Konstanten aufzeichnen und prüfen, ob es deutliche Unterschiede im Wirkungsgrad gibt.


Danke
Hubert😛

[Clugh]

BTW if you have a P900 09 14 pole pyro then the right conventional winding for a Brenner drive v4 is approximately a 4+4 YY. I can probably fit 17 AWG with in a 3+3 YY then finish with 1 more turn on each tooth. The original 930 Kv winding is a 3 + 4 Delta in approximately 18 AWG.

The 10 pole 5+5 18 AWG has approximately 16.2mm^2 of copper cross sectional area in the slot. If I can get the 17 AWG on the stator in a 4+4 that will be 16.4mm^2 of copper cross sectional area in the slot.

Thank you for your time and patience,
Hubert

[Clugh]

LOWER FRICTION US-WS2-SP-13OZ Tungsten Disulfide Dry Lubricant

Around 50 dollars a can....

[Clugh]

Bearing Heater Cone.

They are not cheap but it will make your life with bearings much easier forever. You can also put the carrier with stator on it and it keeps the heat where it needs to be . This makes it alot easier to break a Loctite or epoxy bond of a stator that is bonded to the carrier. This is also what you use when the bearing needs to expand to install on the shaft and then cool for a shrink fit. That also will quiet things down if you put that interference fit into a design.

Industrial motors shrink fit bearings......

I see you looking Powercroco. You need to get you one....



Danke,
Hubert

[Clugh]

The posters calculator is no more accurate than any of the other calculators. If they were truly serious about numbers they would take mechanical measure and derive the true efficiency.

A joker motor is still a joker and hes still wont get over 300 dollars for a rewond 50 dollar motor from me. You can misquote the late engineers 2 paper 247 365 it will not make a joke worth 300.00.

Industry knows marcus has the best and most widely used calculator on the market.

This speed stiffness crap you wont find in academia. And it definitely doesn't apply to induction motors etc which must have slip to produce torque.

There are many that still see it as a joke. That " expert" doesn't stand alone in the idea that the claims are bs!

The thrust stand is also quite skewed on drawer slide with all the weight riding in it.

Been there done it already and itz really crude. It definitely does not Trump academic or true EE field findings.


It definitely falls short of diagnostic measure of discrete lab at place like ABB or Bundeswehr.

I see you Ralph Okon

You still in class here....

Thanks
HUBERT

[Clugh]

Its also kinda ignorant to ignore the idle current as much as you want everything to be about the dc resistance it's not. The AC can be 10x higher. The motor moves with AC.

[Clugh]

BTW SINCE YOU ARE NOZY OKON....

The 4 + 4 14 pole 600 is a little hot at over 1000 Kv so ill make it a 5+4 YY and that should settle it down. The 4+4 dl sings with triplen at WOT. So I prepared a few variants to see if that changes things. Im thinking the auto pwm on the castle set itself in an audible pwm to drive the 14 poles 8khz perhaps.


Maybe ill try ot on the APD and see how it deals with it.

[Clugh]

Get some sleep. Its 337 am here in the USA Ralph...


Later gator...
Hubert

[Clugh]

Hi!
This is the build program. For the V4 Brenner drive prepped pyro 600s boys. There are some special things to note about prepping the motor for the drive. Please be advised.

By way of summary, please allow me to list a “checklist” of all the things that need to be considered when assembling a motor for a V4 Drive.

1/.. Through hardened bearing spacer tube mated with the front and rear bearings.

2/.. A second front bearing flush with the front face of the motor, and mated with the original front bearing.

3/.. A longer replacement M2 cap screw with Loctite 620 holding the stator on. Alternatively, a small 1/4” long 5/64” diameter coiled roll pin can with Loctite 620 can be used.

4/.. Magnet wire rated for 250C.

5/.. An extended rear motor shaft pressed into the rear of the rotor using a hot air heat gun to expand the aluminum, and with Loctite 620 to fix it in position. Loctite must be used due to the risk that the shaft will pull out of the motor when it is hot under load.

6/.. An extended shaft set screw installed using hot air heat gun to heat the rear of the rotor to 80C when the set screw is tightened. This preloads the set screw so it won’t loosen when the motor heats up. Loctite 620 should also be used.

Brenner …

1/.. Durchgehärtetes Lagerdistanzrohr, passend zu den vorderen und hinteren Lagern.

2/.. Ein zweites vorderes Lager, bündig mit der Motorvorderseite abschließend und mit dem originalen vorderen Lager verbunden.

3/.. Eine längere Ersatz-M2-Zylinderschraube mit Loctite 620 hält den Stator fest. Alternativ kann ein kleiner, 6,35 mm langer, 16 mm dicker, gewickelter Spannstift mit Loctite 620 verwendet werden.

4/.. Magnetdraht für 250 °C.

5/.. Eine verlängerte hintere Motorwelle, die mit einem Heißluftgebläse in die Rückseite des Rotors gedrückt wird, um das Aluminium auszudehnen, und mit Loctite 620 fixiert wird. Loctite muss verwendet werden, da die Gefahr besteht, dass die Welle bei hoher Belastung aus dem Motor herausgezogen wird.

6/.. Eine Stellschraube für die verlängerte Welle, die mit einem Heißluftgebläse montiert wird, um die Rückseite des Rotors beim Anziehen auf 80 °C zu erhitzen. Dadurch wird die Stellschraube vorgespannt, sodass sie sich bei Erwärmung des Motors nicht löst. Zusätzlich sollte Loctite 620 verwendet werden.

[Clugh]

Dr Okon,
I know are here for information daily so let me tell you all about my experience with dual layer vs single layer windings on the castle. As you know I wound 4 + 4 parallel wye 14 pole pyro 600. Its Kv ended up being around 1016 at 20 degrees timing. I wound another stator with a six step single layer winding for the same amount of turns which was 8 turns and again I terminated it in a parallel wye. At a glance I can tell you that the 14 pole motor is much more audible in commutation than the 10 pole. My best guess is the auto pwm on a castle lowers the PWM to audible frequencies to drive it so 8 - 16 Khz perhaps. If anyone does not know a single layer 12N14P has a higher winding factor than the dual layers. That means per amp it delivers more torque. Ralph you have reported on the American forums and abroad that your dual layer winds were more ideal for speed flight but I find it hard to believe. Based on what the field of engineering has determined over the years that that could not possibly be true if the windings and test are conducted appropriately.

The field has determined through testing in discrete labs all over the world that a single layer winding is more suitable for BLDC operation and produces less torque ripple with a BLDC drive. A BLDC drive is what most of you use and even what many FOC drive turn to at WOT Most of your time in a speed trap even will be spent at WOT and WOT is full power. That torque ripple has an effect on the net torque output of the motor. More torque ripple means less net torque output. Then the winding factors for a dual layer is 93% while it is 96% for the single layer. 100% is the reference and comes from the single layer full pitch winding like a 12 slot 4 pole motor.

Considering my test result so far that seems to be the same results I am finding. I say this because the Kv of the single layer was approximately 988. The wire is the same DC resistance because it is essentially the same length . If that was the definitive factor it doesn't explain why the magnetic coupling is more defined in the single layer. It also means without a doubt the winding factor is higher for the single layer. That shows 2.8% higher winding factor. About 3% as the Academics have all said. If this is the case how does dual layer work better? Its strange.

It is also not good for the dc theory because the fact the Kv is less with the dual layer will actually allow me one less turn which means wires diameter can be the larger for lower dc resistance.

Its too bad you all on the German social media only speak in terms of ohmic losses with reference to DC but have not a clue that motor is an inductor whose resistance changes with frequency.

That's called impedance brother and you need to understand that the majority of iron and pm losses occur as a result on it and not the DC.

I have not taken a closer look at the idle currents but I will and will happily report those differences and see if there is any significant difference in efficiency but efficiency does not tell it all in terms or AC power. You need to consider the power factor as well. All the research I've seen seems to suggest the best motor minds will opt for a better power factor even if they lose a point in max efficiency. Its seems counter intuitive and you would think they are directly proportional to one another but they are not. That can be observed in the many results captured in places like Bundeswehr University in Munich and ABB corporate research labs.

You need to let go of the IDEA that low DC resistance means everything in AC operation . Apparently you didn't hear my say that it can be 10x's the DC. Thats not a myth or gimmick that's reality.

Daran ändert auch Helmuts These nichts.

I don't believe for a minute you or Audiosmith dual layer winds out performs a properly executed single layer in BLDC operation for these reasons plus more.

I think the Decepticons are running wild on the forums and have not posted results or executed a fair test to report accurately on the subject matter.

Thomas, dein Freund aus Bayern und du sagst in den Foren nicht die Wahrheit.

Danke,
Hubert

[Clugh]

For BLDC operation at high rpm and high power I do not think Powercrocos dual layers can touch a single layer with a shielded rotor. I know already that the conventional DL wye wont match a Hybrid of equivalent Kv either. The flux density and distribution is superior by a long ways.

Thank you for your time and patience,
Hubert

[Clugh]

Open your eyes.....



Hubert

[Clugh]

This is the natural direction NMB steel bearings balls will go with a VFD inverter like you use without shielding.

[Clugh]

6. Conclusions

The source of the bearing voltage is primarily the asymmetrical nature of the voltage that occurs when the machine is powered from a power electronic converter. In order to reduce the negative effects associated with it, the authors suggest the use of two additional shielding windings in the machine. The main advantage of the suggested solutions is that there is no need to redesign the magnetic core of the machine.
The only fundamental change is to equip the machine with stator slot wedges in which the wires are placed, which, from the technological point of view, is a relatively easy task to perform. This solution is also supported by technical reasons—the grounded shielding winding is protected from short-circuiting to the main winding located in the stator slots.
From the presented calculations of bearing voltages, it can be seen that the use of a shielding winding placed in the stator slot wedges causes a reduction in the value of the capacitance C_wr, resulting in a decrease in the amplitude of the bearing voltage from 17.2 V to 6.8 V.
Simulation research has shown that the overhang length of the shielding winding does not significantly reduce the resultant capacitance C_wr. Therefore, for technological reasons, it is reasonable to use the shortest possible connections between wedges. It reduces the problems of ensuring the electrical insulation of these connections and also has a beneficial effect on their stiffness.
If the above solution turns out to be insufficient from the point of view of bearing voltage levels, equipping the machine with a helix-shaped shielding winding located in stator end-winding region may be considered. This solution, together with the shielding winding in wedges, increases the effectiveness of the bearing voltage limitation. Compared to the reference model, the bearing voltage amplitudes were reduced from 17.2 V to 4.7 V (when the machine is powered from a conventional two-level converter).
The calculations obtained using converter circuit models showed that the method of limiting bearing voltages can additionally be successfully combined with other available methods. For example, when the levels of bearing voltages cause their accelerated wear, it is possible to additionally consider the use of a three-level converter to power the machine. For this supply type, the bearing voltage amplitudes of the machine under consideration were reduced to about 3.1 V.
Due to the nature of the 3D FEM models used, capacitance calculations are time-consuming. The most time-consuming variant turned out to be the model with two shielding windings—for this model, calculations took more than 8 days. For the other cases, the calculations were correspondingly shorter.
The presented results of the simulations justify the desirability of using shielding windings in machines powered by converters, particularly where the high operational reliability of drive systems is required.

[Clugh]

Stall is the DC! There is no frequency there so how could it drive frequency driven losses in the iron and pm Ralph....

Did you forget Steinmetz Dr?



YT,
Hubert

[Clugh]

Do you notice that the alternating current is almost ten times higher than the direct current with eight parallel paths, Powercroco?

That's proximity loss for you.

Ask Dr. David Dorell.


Merkt ihr, dass der Wechselstrom fast zehnmal so hoch ist wie der Gleichstrom mit acht parallelen Pfaden, Powercroco?
Das ist für euch Näherungsverlust. Fragt mal Dr. David Dorell.

You truly have to love you and your friends on the GSM total emphasis on dc resistance.

[Clugh]

Now that I have your attention Dr Okon. Help your cheap full steel NMB's. I bet you don't remember how to remove the metal shields like I showed you on helifreak....




You cannot apply it if you do not know how to remove the shields. But you are a bearing expert based on your remote comments about the subject matter right?

Danke
Hubert

[Clugh]

I know you've never done it "Dr." you wont find this on powerditto or in crocoworld

[Clugh]

The American winding program is quite different than yours.

We are always looking for an edge, and that's no cap. I want it fully understood with the hobbyist and the forums what the difference is between us.

Thanks for your subscription,
Hubert