starting sychronous motors
starting sychronous motors
(OP)
How do variable frequencty drives start synchronous motors
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starting sychronous motors
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RE: starting sychronous motors
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If we learn from our mistakes I'm getting a great education!
RE: starting sychronous motors
RE: starting sychronous motors
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If we learn from our mistakes I'm getting a great education!
RE: starting sychronous motors
The problems were mostly due to the fact that there was no position feed-back (encoder) and that the manual said it couldn't be done. We got the machine running up to about half synch speed and then got heavy pole angle oscillations that eventually tripped the drive. We tried several modes, the sensorless vector did not work (as the manual had told us), scalar mode (U/f) didn't work either. It was only by using the current source mode that we finally got that thing up and running. Took us two very full days to get there.
"Cogging" is a thing of the past. The old CSI inverters that were used had some cogging due to the block shape of the output current. Today's PWM inverters do not cause cogging and that should not be a problem in your case. It wasn't a big problem with the CSI inverters either - it just seemed strange to see the torque oscillate heavily just before the motor was transferred to the mains.
What could do some damage to a "virgin" and unprepared motor is the PWM, which is known to produce ozone (O3) and that kills insulation if the motor is run continuously. But, if you use the inverter just to start the motor, the time will usually not be more than a minute or two. Not much will happen in that short time.
Do you have an actual problem with this installation? Or is it just an on-going discussion?
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: starting sychronous motors
RE: starting sychronous motors