Alternative motor windings and drive schemes

[Clugh]

Ein 5,8 mm Bohrer und eine 6 mm Reibahle. Mehr brauchen Sie auf Ihrer Drehbank nicht.

[Clugh]

Übrigens, Crocodile, du siehst ja auch, dass Zölle die Importpreise aus der EU und China erhöhen werden. Arme Witzbolde... Ich habe mir also überlegt, einen weiteren 10-poligen Motor für den V4-Contra-Antrieb zu bauen. Die Motoren der XNOVA 32er-Serie würden gut funktionieren, insbesondere wenn ich den 3215 Tareq oder den 3220 verwenden könnte, was eine Menge Gewicht sparen würde. Ich denke, ich kann den stark besteuerten Pyro in dieser Preisklasse schlagen. Das einzige Problem beim XNOVA ist, dass er eine 5-mm-Welle verwendet, während der v4-Antrieb eine 6-mm-Welle benötigt. Das kann ich sicherlich ändern. Der Motor kostet etwa halb so viel wie ein Pyro, daher kann ich die Einsparungen nutzen, um den XNOVA durch den Einsatz noch besserer Lager mit deutlich höherer Tragfähigkeit und Drehzahl noch robuster zu machen. Beispiele sind EMQ-Keramiklager, Keramik-Hybrid-Schrägkugellager mit Phenolkäfig oder durchgehende Schrägkugellager ohne Käfig. Alle diese Lager erreichen Drehzahlen von über 80.000. Die vollkomplementären Keramikhybriden erreichen 200.000 U/min, und alle Optionen bieten deutlich höhere Tragfähigkeiten und Drehzahlen als die orangefarbenen Standarddichtungen. Wolframdisulfid schützt die Stahllaufbahn vor dem Festfressen. Ich kann diese Elemente in meinen XNOVA einbauen und erhalte dennoch zum gleichen Preis eine deutlich bessere Maschine mit deutlich verbesserter Mechanik. Der XNOVA verfügt außerdem über einen besseren Radiallüfter, der ebenfalls abnehmbar ist.

[Clugh]

Here's some numbers from a running test!

The P650 5Y + 9D parallel hybrid in 22awg
Kv 1072
Rm 28.3 milliohms
Io .7 amps @ 16.5 volts

Stimmt es nicht, Dr. Ralph Okon, dass weder Sie noch Christian jemals einen 40–50 mm Stator mit einem Kv über 1000 und einem Leerlaufstrom von 7/10 Ampere gewickelt haben? Was halten Sie von den unzähligen Beispielen der Flussverteilung zwischen den beiden Wicklungsarten, die Ihnen gezeigt wurden? Sie sind doch nicht blind, oder? Warum raten Sie Piloten in Deutschland von einer Wicklung ab, die ihre Magnete schützt und die Rotortemperatur senkt, was sonst sehr schwierig ist? Einen Kern zu kühlen ist viel einfacher. Alle Kühlideen von Lucas/Kunzke gelten nur für den Stator. Lehner erreicht dies mit Wasserkühlung. Die Segmentierung der Magnete mildert lediglich die Auswirkungen von Wirbelströmen durch Lokalisierung, aber insgesamt befindet sich dort weniger magnetisches Material, und es ist ein spezielles Herstellungsverfahren erforderlich. Außerdem wird die Geräuschquelle dadurch nicht beseitigt. Ich möchte mich lieber nicht verletzen, als eine Verletzung mit einem Pflaster abzudecken. Ein Rotor mit einem höheren Trägheitsmoment ist auch kein großer Vorteil. Dies macht einen Großteil des vermeintlichen Vorteils zunichte. Ich glaube auch nicht, dass man schlüssige Daten finden wird, die belegen, dass offene Nuten in einem 41-mm-Stator den gleichen Vorteil bieten wie in einem größeren Motor. Auch der Betrieb bei niedrigen Drehzahlen dürfte schlechter sein. Es gibt viele wissenschaftliche Studien zu diesem Thema, die zu anderen Ergebnissen kommen als die der bayerischen Konstrukteure.

Schade, dass du vor der Wahrheit davonläufst, anstatt etwas Neues zu lernen. Ich sehe, du liest das hier. Du hast deinen Thread geschlossen, aber nicht dein Abonnement hier.



TTYL
Hubert

[Clugh]

I will also try these for a non magnetic wedge as well.

[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

P600 is what was meant.

[Clugh]

[Clugh]

An excellent read for those interested in bearings, lubrication, and lubrication intervals.

Thank you for your time and patience,
Hubert

[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

[Clugh]

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

[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]

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]

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]

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]

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

[Clugh]

Open your eyes.....



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]

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]

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]

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


Later gator...
Hubert

[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.