Can you run a Synchronous Servo Motor with a Standard Freq. Drive

[Rob S.]

I have taken off an old machine a SEW DFY 71S Synchronous Servomotor and I want to hook it up and see if it will still run. I am sorry for my stupidity , but I wondering if I can run this motor from a standard frequency drive.

Thanks in advance,

 

[dmargineau]

I don't think you will be able to accomplish this task using an ordinary VFD.
A synchronous motor does not rely on "electric slip" in order to produce torque whereas standard induction motors need "slip" to generate momentum.
If theoretically one could presume that both the sychronous and the induction motors' speed is proportional to the supplied frequency this is just about the only common characteristic.
Most "generic" synchronous motors ( except for the very small ones)need separate start-up excitation (due to the lack of "slip") and only dedicated Servo drives have this provision.
I think there are modern servo motors which started to bridge the gap between themselves and the simple and efficient induction motors, however, I don't think your old SEW is one of them.
I know you could perform servo applications using the PowerFlex 750 family VFDs, however, only when using specific, dedicated motors.

 

[Doug_Adam]

No, you cannot.
The SEW syncronous servos are actually the same as brushless DC motors. The VSD must have position sensing via a resolver to correctly syncronise the motor. You would be best to use an SEW Movidyne (obsolete) or one of the Movidrive range correctly setup for the servo.
Do not use an ordinary VSD.

 

[Rob S.]

Thanks gentlemen for educating me on the differences.

You and your families have a great Easter.

 

[paraffin power]

Hello
FYI - Omron's MX2 inverter can run a Permanent Magnet motor; I've used it to run an AC servomotor (out of interest if I'm perfectly honest)
If this particular motor is dc brushless, then no
Pp.