F=(P*N)/120
There might be angular differences between machines, but significant frequency differences? No. Not even 0.1 Hz for any appreciable period of time (more than milliseconds).
As suggested by others, acceleration differences will result in momentary (millisecond) frequency differences, but the poles of the generator rotor will not run at any other speed than the above formula will allow relative to frequency for even 1 second. That would mean that the poles have slipped and that would mean catastrophic damage has occurred.
I have been doing some World Wide Web research on out-of-step relays and their application, and while there can be losses of synchronism between generation areas in a power system or between interconnected systems when detected these events should very quickly result in separation of the affected areas to prevent widespread outages and even damage. In no paper I have read does it ever talk about individual generators being out of synchronism with each other. And even areas of generation which are detected to be out of synch (which is usually much before actual "slipping" of poles occurs) the protection is supposed to operate to isolate the affected areas to protect them against damage.
Many of the manufacturers of out-of-step protective relays have extensive papers on their application and operation.
There might be angular differences between machines, but significant frequency differences? No. Not even 0.1 Hz for any appreciable period of time (more than milliseconds).
As suggested by others, acceleration differences will result in momentary (millisecond) frequency differences, but the poles of the generator rotor will not run at any other speed than the above formula will allow relative to frequency for even 1 second. That would mean that the poles have slipped and that would mean catastrophic damage has occurred.
I have been doing some World Wide Web research on out-of-step relays and their application, and while there can be losses of synchronism between generation areas in a power system or between interconnected systems when detected these events should very quickly result in separation of the affected areas to prevent widespread outages and even damage. In no paper I have read does it ever talk about individual generators being out of synchronism with each other. And even areas of generation which are detected to be out of synch (which is usually much before actual "slipping" of poles occurs) the protection is supposed to operate to isolate the affected areas to protect them against damage.
Many of the manufacturers of out-of-step protective relays have extensive papers on their application and operation.