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rebuild syncrounous motor as induction motor

rebuild syncrounous motor as induction motor

rebuild syncrounous motor as induction motor

(OP)
Can anyone provide general comments about the challenges that would be involved in rebuilding/rewinding a 4KV syncronous motor to be a 13.2kv 324 rpm  3500 hp induction motor.

I realize that I haven't provided enough info to judge the stator rewind (nameplate data for the sync motor and number of slots etc).  But I'm interested in general thoughts.  Can a sync motor rotor be easily converted into a squirrel cage induction rotor?  Doesn't an induction motor require a smaller air-gap?  Has anyone ever heard of this type of conversion being done?

RE: rebuild syncrounous motor as induction motor

TECHNICALLY POSSIBLE .
BUT YOU HAVE NOT MENTIONED WHETHER IT IS SALIENT POLE OR NON SALIENT POLE CONSTRUCTION. IT IS QUESTION OF DESIGN ASPECTS OF EXISTIG MOTOR VIS A VIS NEW OUTPUT REQUIRED ALONG WITH OTHER PARAMETERS LIKE TORQUE(NORMAL) AND PULLOUT AND STARTING TORQUE REQUIRED

K.S.RAGHAVAN

K.S.RAGHAVAN

RE: rebuild syncrounous motor as induction motor

Anything is possible, but I think this may be impractical. I can't imagine any way to accomplish a conversion without replacing the rotor (and it would be a big one, maybe 6 feet in diameter??). I would be interested in hearing more about what Raghavan knows about this type of conversion with respect to the rotor.

RE: rebuild syncrounous motor as induction motor

(OP)
I have since found out that the shop would scrap the rotor. More details on the same thread in the power engineering forum.  Thanks

RE: rebuild syncrounous motor as induction motor

Suggestions:
1. There is no need to be discouraged that the industry will not use a high-power low-speed winduction motor. E.g. ships would use plenty of them of your type.
2. I would suggest that you simulate the intended induction motor first by using a suitable software.
3. As an option, the permanent magnet synchronous motor is also a very attractive machine (a "dirty" competition to the squirrel-cage induction motor)
4. There will probably be a need to ground bearings, if you intend to use an AC motor drive to protect bearings from common-mode currents.
5. Consider a double cage rotor.
6. The power rating could be somewhat reduced since the squirrel-cage induction motor may be mechanically more demanding on the stronger stator. This is pending results of the motor simulation.
7. Inquire around, if any motor service/repair firm has done similar conversion to obtain some guidance.

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