3 phase alternator

[ehall]

We have a 15kVA alternator of Italian manufacture. It comprises of a squirel cage rotor and wound stator with 3 leads to the load terminals, and 3 leads to star connected capacitors.

Any info on control excitation would be appreciated.

Many thanks.

[marke]

Hello ehall

 

This sounds like it is essentially an induction generator rather than and alternator.

If you connect an induction motor to the supply and overdrive it, it will behave as a generator and feed power back into the grid. The power comes from the engine and the excitation comes from the supply. Once the motor is generating, you can use it as self excited by connecting capacitors across the stator to provide the KVARs for the magnetising current etc. I have heard that it is possible to get these runing provided there is sufficient residual magnetism in the rotor, but if you run in a self excited mode, ther is going to be poor voltage regulation and no control over the output voltage.

I do not have much experience with self excited induction generators, but perhaps a search on the net may yeild some results.

 

Best regards,

[ehall]

Many thanks marke for your prompt reply.

Yes is is basically a squirel cage motor directly coupled to a prime mover.

best regards,

ehall.