17e harmonic from a 6000hp synchronous motor

[MichelT]

We have a 18 poles, 3 phases and 153 slots synchronous motor, generating 1.6% THD with 1.3% corresponding to 17th (seventeenth) harmonic on its 4160 volts supply and 2.1% harmonic current of the 420.6 amp. 60 Hz supply.

Could you please reply with your comments ?

PS : This harmonic does not come from the supply.

Regards

 

[busbar]

IEEE Std 519 §10-11 seem to indicate that the cited values are below action levels for distortion limits. They are likely of no significant consequence.

Have you observed any suspect operation of related systems that might lead to concern?

 

[jbartos]

Suggestion: Every machine with slots will produce some harmonics. These are available from the motor manufacturer on the motor test data sheet. The measured harmonics should be close to what the manufacturer states on the motor test data sheet.