I have a Tecnotion QTR-A-105-25-N that is the only unit I can find that fits my application. My problem is driving the unit; I need a small 3 phase synchronous drive only 230Vacrms or 300Vdc. Input preferrably 12-18Vdc. Controls (halls, temperature etc), ideal but not necessary at this stage (just need to test the concept). I am a newbie with some high school electronics so am completely out of my depth!

 

Are you hoping to build a controller?
This is no small feat, especially for a beginner.
Max.

 

Are you hoping to build a controller?
This is no small feat, especially for a beginner.
Max.

If nothing else is available, but I would prefer to find something 'good enough' to do the job that's already available. I neither need nor want to complicate this especially as the motor is only needed for short bursts of a few seconds. Thanks for replying and thanks also for reminding me of a great show.

 

That's an awful lot to go thru for a short burst. How about a hammer?

Perhaps a different strategy.

 

That's an awful lot to go thru for a short burst. How about a hammer?

Perhaps a different strategy.

been there - and occasionally return to the hammer idea (especially after running down yet another dead end), its just not that reproducible, accurate or consistent.

 

You could use a 12 volt DC to 230 volt inverter of suitable rating to feed the three phase inverter (You have not told us what power rating you need) If your DC supply ia varying between 12 and 18 volts you would need to build a voltage regulator that had a very low dropout voltage. (For when your DC supply dropped to 12 volts.)

Les.

 

A synchronous motor isn't synchronous until it is up to speed and the rotor is hit with the DC pull in voltage. Until that point it is just a 3 phase induction motor. How long in actual units of time measure is "a short burst"?

 

Unless the rotor is a magnet and not just iron.

 

Unless the rotor is a magnet and not just iron.

Thanks for your questions.
The rotor consists of 20 NdFeB magnets on a steel ring. The short bursts are 15 - 20 seconds

 

You could use a 12 volt DC to 230 volt inverter of suitable rating to feed the three phase inverter (You have not told us what power rating you need) If your DC supply ia varying between 12 and 18 volts you would need to build a voltage regulator that had a very low dropout voltage. (For when your DC supply dropped to 12 volts.)

Les.

the literature I have tells me that the motor is rated for max voltage of 230Vacrms (300Vdc), peak current 7.56A. I have a 18Vdc supply that I would use as a preference (the 12V being a power reducing backup if needed). do you have any stock items that you are thinking of for the two inverters?

 

I was researching similar frameless torque motors for an application last year. I spoke with some who had driven them using Elmo controllers with good success.

http://www.elmomc.com/products/gold-digital-servo-drives-main.htm

I never got funding for my project so I can't speak from experience but I did see these in operation

 

I think I have had the wrong idea of what you wanted. I thought you were already using a standard 230 volt single phase AC to 3 phase converter to power the motor. (These are very often called VFDs (Variable frequency drives.) as the output frequency can be adjusted to change the speed of a normal 3 phase induction motor.) I thought you just wanted a way to get the 230 volts single phase AC to power this inverter ftom your 12 to 18 volt DC supply. I have had a look at the web site and now realise that probably requires special drive electronics. (I have not seen this type of motor before.)

Les.

 

(I have not seen this type of motor before.)

Les.

Very close to the motor used now in washing machines, originally a Fisher-Paykel type.
They are outrunners, the centre that carries the coils is stationary and the PM outer rotates.

Max.

 

Hi Max,
I have heard about these Fisher-Pakel motors but I have never looked in detail how they work. I had assumed that were a larger version of the brushless motors used in model aircraft. I would have expected "Tecnotion" to sell the electronics to go with the basic motor but I did not see anyting about it in the short time I was looking at their website.

Les.

 

Hi Max,
I have heard about these Fisher-Pakel motors but I have never looked in detail how they work. I had assumed that were a larger version of the brushless motors used in model aircraft. I would have expected "Tecnotion" to sell the electronics to go with the basic motor but I did not see anyting about it in the short time I was looking at their website.

Les.

Yes basically a BLDC with a high power:size/weight ratio. Pretty awesome motors. The project I was working on would have turned out a motor about 65hp in a frame size about that of a 15hp industrial induction motor.

The company making the motors might not sell compatible controllers but I bet they know who to talk to. Wouldn't hurt to call them and ask for a recommendation. I wouldn't be surprised if they recommend Elmo. Problem with Elmo is they only want to sell in bulk to OEMs. I talked my salesman into pulling some strings and getting me a couple for prototype testing but when it came time to pay for them I couldn't get any cash to flow. Sorry Elmo dude for wasting your time.

 

Hi Max,
I have heard about these Fisher-Pakel motors but I have never looked in detail how they work. I had assumed that were a larger version of the brushless motors used in model aircraft. I would have expected "Tecnotion" to sell the electronics to go with the basic motor but I did not see anyting about it in the short time I was looking at their website.

Les.

Essentially yes, a 3ph brushless motor, but BLDC and RC motors are BLDC and not true 3phase, the Fisher motor AFAIK is powered 3ph and the wound poles are wired in groups around the stator, I have yet to see a viable design for one of these motors as they are often available in scrapped washers etc, can be very useful. The controller is $150++.
Max.

 

http://www.microchip.com/design-centers/motor-control-and-drive/motor-types/pmsm

http://cache.freescale.com/files/industrial/doc/brochure/BBPRMMAGSYNART.pdf