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Topic: 24V 3-phase asynchronous motor control? (Read 1 time) previous topic - next topic

ghanek

I want to control 24V 3-phase asynchronous motor with PWM on Arduino mega.
I test it with ESC, but it didn't work. I have DC 24V 15A power Supply for this motor.
Is there any driver for that type of motor or any other way how to control this motor?

Any help/links will be greatly appreciated.

shooter


MarkT

BLDC ?  Are we sure this is a BLDC?  "Asynchronous 3-phase motor" is a new one on me,
I'm suspecting its a kind of induction motor.

Can we have any information about it please (datasheet, part number, etc etc).
[ I won't respond to messages, use the forum please ]

ghanek

I want to control speedometer (Hasler).
From railway workshop i get information that this motor is 24v 3-phase asynchronous motor. I don't have any other information.

MarkT

Can you find more information about it?  It looks really ancient tech!

BTW that photo might be useful if you took it of the motor's info plate, because
that's what will have the information on it...
[ I won't respond to messages, use the forum please ]

michinyon

Why would anyone make a 24V three-phase induction motor ?

michinyon

What is that thing,   the speedometer from an old locomotive ?

It is unlikely to actually be an electric "motor" in there.    It is probably getting some kind of variable frequency FROM an electric motor somewhere,    and the resulting magnetic field is moving the needle to display the speed.

michinyon

If you google "Hasler train speedometer",  there are quite a lot of hits.   I didn't read all of them.

MarkT


Why would anyone make a 24V three-phase induction motor ?


Its intriguing, but before the days of semiconductors there were a lot more electromechanic
devices in common use.
[ I won't respond to messages, use the forum please ]

jackrae

It's not by any chance a selsyn receiver unit.  Google synchro for how a selsyn transmitter/receiver system works.  This system was used extensively in military mechanical "computer" systems as well as industrial controls.

michinyon



Why would anyone make a 24V three-phase induction motor ?


Its intriguing, but before the days of semiconductors there were a lot more electromechanic
devices in common use.


"In the days before semiconductors",   there still would have been very little point in making a 24V three-phase induction motor.   You'd have to have a power supply for it,  which "in the days before semiconductors"  would have been very inconvenient at anything other than a fixed frequency.  And then,  you still don't have a precise speed with an induction motor.   And unnecessarily and inconveniently high currents at a low voltage if you expect to do any actual work with this "motor".

Anyway,   that's beside the point,    this device is obviously not a "motor",  it is train speedometer,   the way in which is driven electrically remains a mystery.

michinyon

But that is one possible reason for making a 24V three-phase induction motor,  right there.     If you put a 24V three-phase alternator and stuck it on the axle of the train,    you would have a 24V three-phase variable frequency power supply to drive your induction motor.    You could then use the the induction motor to drive a mechanical speedometer drive.  Provided the mechanical load was low,    you could calibrate to compensate for the induction motor slip.

Which is what jackrae says,    that is basically what a "selsyn" does.  Or very similar to it.

Creating a 24V three phase variable frequency to drive it,    would be a fairly simple project.   You would just need to make a three-phase H bridge   and a DC power supply for it.    In fact,   you may be able to use or adapt a BLDC driver device for it.


jackrae

There is no slip with a Selsyn system.  It's a synchronous device so there is "perfect" resolution between transmitter and receiver, otherwise gun trainers etc would never have managed to hit the target !

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