 3-ph PM motor spinning all by itself? | |
I've just tried my servos in torque control mode, and I'm wondering a bit about their behaviour.
This is a 200 W 3-ph PM servo. I tried it without load.
If I set the torque reference to 0 (or very close), I can of course turn the motor by hand. It has considerable cogging. (Is this normal? This is the only servo motor model I've played with.)
But if I give the rotor a spin, it then continues to spin at about 1000 RPM all by itself! This it does no matter what direction I spin it. It is very easily stopped with just a finger though. I guess this has something to do with the cogging, but am not sure. Anybody experienced this before?
Arvid |