Synchronous generator

The current will increase if an synchronous generator is made to work at 60 Hz and then is used at 50 Hz.

Will the stator current increase if an synchronous generator is made to work at 60 Hz and then is used at 50 Hz?

And the voltage will decrease?

What changes must be done for this change of frequency? Not only on the revolutions.

hecto7 at yahoo. com

Unfortunately you did not give much details of the generator you have at hand. So the info given below is generic but still applicable to your case. Forget the approach you are taking. The following needs to be taken care of when changing the operating speed of a generator:

1. you should not exceed the design magnetic flux in the core. To ensure this you have to maintain the same V/f ratio, where V is the nominal generated voltage of the generator, and f is the operating speed when the generator is running at nominal real power load and nominal power factor. Given the frequency is reduced, the voltage needs to be reduced also. You need to work out the design generated emf when the generator is running at full load and 60Hz, and then lower this voltage as indicated above.

2. (1) above then brings in the question whether the setting range of the AVR you have can be set to operate in automatic mode within the range of 78% to 91%. Normally the AVRs' range lies from 95% to 110% of nominal voltage.

3. The generators windings' and magnetic circuit cooling is done by fans fitted onto the shaft. Given the fans will be running at lower speeds, and thus a lower cooling air flow will be present, you will have to lower the maximum current that will be passing through the stator and rotor windings, such that insulation temperatures do not exceed design limits.

At the end of all this you are going to end up with a generator which will most probably not be able to be loaded more than 75% of its original design capacity. Is it worth the effort?