Oscillations in Voltage/Current in 750 kW Genset

[jdub4]

This 480V, 750 kW generator set is on a isolated power system (barge) and will be replaced as part of a modification package we are working on.
The client has provided some recorded data of the power system and I can see a small oscillation in the voltage and current waveforms.
The oscillations are at about 15 Hz, which might put the oscillation at rotational speed for the generator. The magnitudes are relatively small, 1V & 30A.
Has anyone run into this before? If it's caused by the genset, no problem, the whole thing is getting ripped out. My concern is that it might be some load on the barge that we don't know about.

Thanks in advance for any assistance.

 

[dpc]

One volt? These are low level oscillations and I don't think I'd be too concerned. Could be some type of cyclic load. There will be voltage changes as the load changes - that is perfectly normal. It could also be an artifact of the measurement system.

But stick around for the experts...

David Castor

http://www.cvoes.com

 

[catserveng]

Are you also seeing minor frequency changes along with the voltage and current changes? If so, this would be typical of a standalone generator and probably not a problem.

To further verify you may want to measure your AVR field output, is it stable?

In general a single generator feeding normal loads like you would find on a barge will never be rock solid, 1 volt and 30 amps sounds like a better than normal load on most marine systems I see.

What kind of work does this barge do?

Mike L.