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e motor with more efficiency | RC-Network.de
Dr Okon
Im glad to see that the German social media is now onto thermally conductive compounds on the wires and how that improves efficiency. Aluminum oxide is interesting as a coating. It is an electrical insulator yet it has a thermal conductivity of 30 W/mk.
It also can occur naturally as Corundum crystal. Saphire and Ruby are in the Corundum family. At my place of employment we grow it and the SiC boules. But what is interesting about the aluminum oxide as it may work even better on aluminum windings than copper because you can get a very uniform and thin insulation by hard anodization.
Corundum Crystal
Aluminum Oxide
Did you know Aluminum Oxide is also in sunscreen and nail polish so you may be able to paint the wires with nail polish or wipe them down with sunsceen.
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To me it makes better sense on the aluminum windings because it can utilize better the high thermal conductivity it has. In this case, the conductor itself is the limiting factor.
Cool Therm 320 that I tried to tell you about several months ago contains zinc oxide, which also has good thermal conductivity and does not require a VIP process to work really well. The data I have already shared with you several time that it increases the efficiency of the machines. It is 3.2 W/mk so you could only imagine what the Aluminum Oxide is capable of as an improvement to keep the working motors winding resistances lower by keeping the wires cooler
Synthetic Zn0 Crystal
Zinc Oxide
As a physician you may recognize it as an anti bacterial.
It's nice to see some real understanding forming there on the GSM while the non sensical that talked about how these things do not work falls to the bottom....
TTYL
Hubert
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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.
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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.Originally posted by Clugh View Post
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
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P600 is what was meant.Originally posted by Clugh View PostBTW 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
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An excellent read for those interested in bearings, lubrication, and lubrication intervals.
Thank you for your time and patience,
Hubert
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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
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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
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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.
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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
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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 Cwr, 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 Cwr. 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.
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This is the natural direction NMB steel bearings balls will go with a VFD inverter like you use without shielding.
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