RaserTech, brushless power from induction...
 

Hey guys, check this out. RaserTech, a new motor licensing company, has a new type of AC induction motor that has PM brushless power density and efficiency, without PM (permanent magnets).

They have a 500hp AC motor that weights 147 lbs. Apparently, it uses magnetic resonance; I think i read that it pulses the motor and the motor self resonates at it's own frequency and creates a pure sine wave.

Anyways, this would mean really cheap electric motors for RC...

The power density allows 1500 watt motor for RC, and would weight 270 grams. They thing about this is that they would be alot cheaper, and more reliable. The controllers would be alot cheaper (simpler) also. The motor tech is rated 92% peak efficiency, 89% full load; the controller is 98% efficient also.

Just thought i'd show you another neat technology.

If they could make them in our size we could really test them

Well, thats the thing. It's only a matter of time. Heck you, me, or Joe could start a company to make them for RC...

Cool.

I made a magnet-less speakers, using a speaker that didn't used a magnet, made two windings, working in opposite phase to make the voicecoil move.

I find it hard to believe though that it's about the same efficiency than a parmanent magnet type, because the magnets nowadays are unbelievable strong and this is 'free energy' I'll dig into it a bit deeper when i get back from work. If it is the case; nice piece of engineering.


They won't have got as much torque in a little can such as an RC motor with a permanent magnet though.

Yah, it's very nice piece of engineering. I would rather have it than a neo magnet motor. So simple and durable. All there is would be an aluminum or copper rotor (copper would be smaller obviously and more efficient)

And just the way the motor works, the controller does not have to be that complicated. Basically just variable frequency, and not the specific timing of switching polarities 6 times a rotation. The AC Induction use magnetic slip to create torque, the more 'magnetic slip' the more torque, meaning that the bigger the difference in speed vs. frequency applied the larger the torque will be created. The Rasertech induction, you can use either standard method or their enhanced method which creates higher efficiency, and higher power. Their method, if i'm not mistaken pulses the motor, the motor then self resonates (because of capacitance coupled in series with the motor windings) at it's natural frequency, creating pure sine wave AT the motor.

They had their 147lb. motor creating 500hp, and 550nm (420ft/lbs) of torque for over a minute, thats on air cooling. Imagine liquid cooling...

Who knows, maybe pretty soon we attach battery power directly up to motor, and just give motor a signal to change speed/torque, etc. :027:

serum- Why do you say it wouldn't put out the torque of a brushless motor?

http://www.rasertech.com/tech_p-2.html That's the motor

http://www.rasertech.com/news_report_dyno.html Video of Dyno test

Thanks for the links! makes searching a bit easier.. :p

to answer your question;
Because of the permanent magnets that are missing.

As you can see; they claim a 92 percent eff. with a star, that star indicates that that efficiency is calculated (in which they admit that they didn't took all the variables in their calculating, and it will probably be lower) A proper brushless motor does a 94 eff at full load.

Now in terms of power;

this is impressive! a 67 kg motor producing over 500 bhp.

Now a little weird but understandable theory;

67 kg, that is 67/1.6= 41.9 Lehner 3080 motors, which are capable of doing 11kW per piece. As you know; the bigger the motor, the more efficient it becomes. and the better the weight/produced power ratio becomes.

Knowing this, 42 LMT3080 motors produce 462kW (630 bhp)

The point is; nothing beats brushless, here are some other facts you might like on the 42 LMT3080 motors;

Torque; (weight/torque ratio)

1 Lehner 3080 produces 7.4 N/m of torque at 42000 rpm. (94.6 percent eff. at this load) (Reduced with a gearbox to 6500 rpm, that would be a 6.46 factor) 6.46*42*7.4=2007N/m@6500 rpm of torque per 67 kg motor.

Not bad either, right? :017:

Considering it are all loose motors

Does that mean if use enough 3080s hooked to a rear car. it would spin wheels like no tomorrow.

Yeah, in other words... LOL

http://www.youtube.com/watch?v=37Aoy7KaL4A

Here is a link to my favorite car, the electric X1 car. Uses the Ariel Atom chassis. 0-60mph in 3 secs

Second favorite car, http://www.teslamotors.com/index.php?js_enabled=1 Tesla Roadster, 0-60mph in 4 secs

Ya, thats true the bigger the motor the more efficient, it's more that uncontrolled variables, slightly though. Ya, so far these brushless motors are the most efficient around. Are you sure the Lehners are rated 94% at full load? This doesn't seem right.

I wouldn't really care if the motor is a little larger (Symetron), but the entire system would, I don't think it's to extreme saying it would cost 1/2 the cost of a brushless system. Along with higher reliability, probably higher max rpm's (not that brushless isn't reliable:027: ), the controllers would be more efficient though; this is a huge plus, which makes for more flexibility in design/engineering.

Also, note worthy is that every percentile makes a big difference in the motor as far as the size and power (for a given size).

omg...teh farraris GOT OWNED lol, love that vid!

Pretty cool huh, the Wright Speed X1 uses a standard AC Induction motor (made by AC Propulsion), has 220nm of torque from 0-6000rpm (flat), a max rpm of 15,000 rpm, 230hp, 150lbs. The Tesla Roadster also uses a similar motor (roomer has it its made by AC Propulsion).

I am currently designing an electric car (check signature), expected to weigh 550 lbs empty, moto-sport bike tires, fully independent un-equal length suspension arms, the motor will be a hybrid-synchronous motor br BRUSA (Swiss), inverter (controller) will be also be BRUSA, is the most efficient and power dense inverters on market, uses a new switching technology @ 24 KHz PWM(most use 6khz PWM) and 97% efficient. The car will accel. 0-60mph in 4 seconds (3 seconds possible). Be able to corner like a "son of a B$%#!" , and will all come back with an equivalent mileage (energy in gallon of gasoline) of 560mpg *highway.

Also, Serum, Zytek converted a Lotus Elise a couple of years ago and i think they put two 12 lbs motors in it @ 100hp EACH, 12lbs! That was brushless DC, it accel. in 4 seconds... better than the original Elise they converted.

Well, yeah, otherwise i wouldn't post it...

Needless to mention that this very same 1.6 kg motor produces 40000 watts in peak of power on the shaft.. considering 42 of these motor can do a rough 2284 bhp..

that's from only 67 kg of motor.

This all is an attempt to try to make you clear why a motor with a magnet will be even stronger/more powerful

That X1 is made by a person who works for Silicone Valley.

Yah, the X1 was built by Ian Wright, he used to work for Sisco Routers. He now started his own company.

How much is that motor you are talking about? For full scale EV's, brushless DC is far to expensive, it really is out of the question. Also to mention the less reliable, more sensitive, much higher costs in larger motors, more torque ripple, and less control of the motor. Induction does win out for full scale EV's.

But WOW, 2250hp from 67kg! That's mad, but i don't think you could do it in a larger motor, it would be too hard.

Torque of a bl motor is as flat as possible.

Is it? I suppose it does seem pretty damn flat with wheelies on demand. You wouldn't happen to have a graph of as many brushless motor torque curves?

Also, what is the maximum the 540C-7XL motor is capable of putting out?

thanks

I think in order to answer that, the question would be "how long?" Since torque is proportional to amps, the motor could put out as much torque as the input can supply. However, as the amp draw increases (after the peak efficiency), efficiency will drop. After an amount of time, the motor would become very hot due to the power converted to heat (from the low efficiency). And the longer the motor is putting out the high number of amps, the hotter it will get.

yes I know, but there is a magical behavior called back EMF which is going to limit the torque at higher rpm's, fundamental to what a motor is. But i said max power output, not the max torque output which would be at 0 rpm (if no cogging).

Just one other thought, LMT should start using Bifilar coils in their motors (or why doesn't any motor manufacturer use them.) They would drastically cut self-inductance of the winds would it not?! This would mean less loses in the motor, easier on the controller, and higher power densities i think. Any thoughts?

***A Bifilar, where two or more 'winds' are connected togethor via the end of one comes back and connects to the start of the other. Imagine a two planar spirals, the inner of one 'wind' will come back a loop into the second spiral 'wind'.

What about the EMF?

Controllers have a hard time sensing the possition of the rotor, with bifilar windings it would be even harder.

Costs; you are 'complaining' about the costs of a BL motor already, winding it bifilar wouldn't make it cheaper.

Did you ever observed a stator? it would be hard to nicely route the bifilar windings to start with.

Looking back at your post, I didn't see any mention of power, so I assumed you meant torque.

Zero; Reading you explanation on the bifilar windings; you mention a spiral. but bifilar has got nothing to do with a spiral; that's a Caduceus winding

A bifilar can be either/Or, a caduceus coil is a bifilar coil. I wam talking about a parallel-wound, series connected wind.

1. parallel-wound, series connected ***
2. parallel-wound, parallel connected
3. counter-wound caduceus coil, series connected
4. counter-wound caduceus coil, parallel connected

How would it affect the controller sensing the rotor position? Wouldn't this just reduce the amount of energy the controller has to deal with during switching?

Caduceus is not good for a motor.. More air, less efficient.. anyway;

bifilar reduces EMF as well. this EMF is used to locate the rotors position by the speedcontroller.

No no, what i mean is back-emf and self inductance are two diff things, right? The back-emf has to do with the stator spinning within the magnetic field of the rotor (visa versa) thats how the controller knows what position the rotor is in. self-inductance is the amount of energy stored in the winding, and because of the amount of inductance, that create a kick-back to the controller while trying to switch from one polarity to other to effectively make the rotor spin. Self-inductance does, as far as i know, increase the switching time of the controller.

Yeah, but like i said; EMF will be lower with bifilar, no way around it, the signals are working in opposite direction from the loose wires one winding is made of. so locating the rotor will be harder for the controller.

I said series-wound bifilar, this is not working in opposite flux, otherwise the motor would not spin :024:

think of two coils wound in parallel, then the bottom of one connected to the top of the other... this would affectively cut the sefl-inductance in half.

where did you said serie wound?

two posts up ^

This?

Ah, yes i see.. in another post.

Right in that post where you posted the types of windings you know.. That didn't helped keeping it going straight.

Well; Shoot Lehner an email and post what his answer is, i think it are the production costs i mentioned earlier. If possible at all. >> the coils are pressed in place once the windings are positioned.

yah, that's the tricky part eh, trying to get the little 'run-back' wires pressed in there. Maybe printed tracers would work? like around the motor can...

Did you ever observed a BL motor? the thick wires going in (about 12 awg) are the actual wires/litze as used in the can.. they take the full power.

Printed tracers.. Wouldn't that add more to the production costs? LOL

hey, it's just a thought. yah, i know the 12 gauage is just all the internal wires bundled up, it's just easier to wind and compress that way, and probably more durable during compression. Do you know how many 'seperate' wires there are? Also, what is the ratio of each conductors current in the three phases, is it something like .71 or something, i can't remember the number. Or is it .66 of the total current going through motor?

The total current will go thru the motor. you mean per phase? I guess that would depend on the poles of the rotor..

I heard something about the Y and D winded Neu motors, what i heard is that the differences are not noticeable

well, the main reason is that thick round wires leave an awful lot of space (air) between the different wires. this would result in a less efficient motor.

That's the main reason. the fact that it's easier put in place (more flexible) is a nice feature that comes with it.

no, you can't tell. That depends on the current the motor needs to take, and the amount of winds it has. The less winds (higher KV), the more wires 1 phase will be made of.

The more winds a motor has, the thinner the input wires are. (and this is possible, because the motor is made for a higher voltage, so the current going thru it will be lower as well. (proportionally the other way around to reach the same power)

About the smaller winds, the air thing, i don't think that matters, a circle is a circle, the smaller wire would just spread the air gaps around more. And ya, i guess they need a certain amount of wires allow different turns of motors, and to keep consistency between each turn # motor. you know what i mean.

Why don't motors use square wires? Some high power speakers use this, but they call it "edge wound" and it eliminates the gaps, improves cooling, and improves current flow. Probably would be more expensive...

yah, i think square wire is harder to spin/make. i don't think it would work in a motor cuz of all the twisty turnings, you dig...

Would you know anything about using Bifilar in motors by any chance? BrianG

Yeah, the twisties would be a bit difficult to negotiate, but if the winding was done by machine, it could be done I think.

Yes, I know what Bifilar means, but in which way? There are several ways they can be connected; Straight parallel connected pair, series connected pair but parallel wound, parallel but opposing directions, etc?

I've also wondered at what inductance these motors have. If the inductive reactance value is too high, compared to the pure resistive, it may be "difficult" for an ESC to drive. Has anyone heard of a capacitive correcting netork that would help bring the voltage and current in phase, which would make the ESCs job easier?

Do you mean motor starting capacitors? Like that have a relay to disconnect when up to speed?


Has anyone heard of the Halbach array? It's magnetic sequence where each subsequent magnetic is turn 90' from the next, and this cancels the field on one side of the array, and magnifies it on the other side. A small company (couple guys) made a BL motor for solar races and it used Halbach array, the motor had a full load efficiency of 98%. WOW.

Also, can someone explain the Neu motor codes... like what does 1515 1/Y mean?