Switched Reluctance - Ideal for DD Hubs?

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macribs
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Re: Switched Reluctance - Ideal for DD Hubs?

Post by macribs » May 11, 2017 2:44 pm

Hmm a quick googling gave various chinese SRM's. From 2kw and upwards >300 kw.
What I could see was that they all was 300+v motors. I guess not really suited for LEV.

But I do see advantages of dropping the magnets. It should be possible to make more power for less money with the SRM vs BLDC PM. Also no magnet overheat.

Stator and axle is spinning while the motor shell is stationary? So cooling by axle mounted fan or even in tandem with LCS cooling jacket?

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Re: Switched Reluctance - Ideal for DD Hubs?

Post by MurmurTech » May 11, 2017 3:04 pm

Synchronous machine on sinus nourishment in our university department has been fully tested. More than 76% of the efficiency from it is not obtained. In our engine, the theoretical efficiency can be 98%. We reduce the moment ripple by increasing the phases. And the mass of the wheel motor is very large. On my motor SRM (for Cessna 152) 66 kW rated power 120 kW maximum. Also 4 phases but 12 poles. We get 300NM 2700rpm. Also I have a three-phase machine of 2400 rpm. 3 kW for helicopter or copter. But you need another steel for 600-800Hz.

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liveforphysics
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Re: Switched Reluctance - Ideal for DD Hubs?

Post by liveforphysics » May 11, 2017 3:59 pm

bobc wrote: They are intermediate between IM and BLDC/PSM in efficiency but should be cheaper than IM to make, which is why we were interested,..
Thank you for your input Bob, it's great you've got experience with them and I appreciate you sharing it.

I would like to respectfully disagree they have some inherent efficiency disadvantage though. I happen to have a client with an SR drivetrain that's just over 96.5% including controller losses in a running prototype.
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Re: Switched Reluctance - Ideal for DD Hubs?

Post by bobc » May 12, 2017 5:38 am

MMtech - sorry for littering your thread about your mighty motor with ramblings about synchronous reluctance motors, it was a response to lebowski that got out of hand......
everyone else - SRM can stand for "synchronous reluctance motor" or "switched reluctance motor". These are very different beasts, and both are, or will soon be, important motive powerers!

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Re: Switched Reluctance - Ideal for DD Hubs?

Post by Animalector » May 12, 2017 4:24 pm

Image

looks like a beast

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Re: Switched Reluctance - Ideal for DD Hubs?

Post by spinningmagnets » Sep 14, 2017 10:29 pm

The Finnish company "Visedo" has developed a prototype SR motor that they claim has minor improvements over previous designs (a hybrid SR plus permanent magnet configuration, "SRPM"). They are developing large motors for city buses, boat-ferry's, etc. Based on the performance of the prototypes, they have raised a lot of money for expansion...

150-kW/650-kW, liquid-cooled
http://www.apc-hirel.co.uk/visedo/perma ... et-motors/

In the pic above, I am very impressed by how large the hairpin copper-bar coils are, fairly easy to replicate in a garage, using laser-cut steel to assemble a stator. (it sounds like the poles in an SR motor don't change magnetic orientation, so laminations are not a requirement, I just meant that the stator is so thick, it would be easier to order sections that we rivet together)

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Re: Switched Reluctance - Ideal for DD Hubs?

Post by Username1 » Dec 01, 2017 3:39 am

I'm wondering, with SR motors if you don't require the capability of self starting from 0 speed, would an 8/4 configuration produce more torque than a 6/4 configuration? The thinking being that all 4 poles of the rotor would be active at once instead of just 2. Would that not help with torque ripple as well?

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