08-12-2017 02:07 AM
08-11-2017 08:03 PM
Harmonics may cause voltage fluctuations, but usually don't have a significant impact on frequency, you may have a very active load profile, or a mechanical problem. If you have a fluctuation in both voltage and frequency, it could be that the frequency is changing and the voltage is following. How your voltage regualtor is configured can have an impact on this. If the knee frequency for the V/Hz setting is real close to nominal the voltage can drop off with a drop in frequency, and depending on the programmed volts/hertz slope, could be a fairly small or fairly big change.
In general I find a lot of "harmonic" complaints on generators are usually not really harmonic problems at all, but its a good excuse when no one really knows what the problem really is.
05-21-2017 10:27 PM
Some sizing programs and industry rules of thumb dictate to use a larger unit when load harmonic contect is high, however it really is much more complex than that. If you just use a larger unit, it will operate at a lower load factor that may lead to slobbering and poor performance.
In some cases adding resistive load to overall load changes the load profile enough for the unit to work better.
In reality you need to figure out what the actual fault is, and then record the power conditions when it occured. Then you can determine a proper repair or modification.
Sometimes addition of line reactors can help, sometimes adding ballast load, sometimes going to oversized generator ends to deal with long term low power factor issues.
By your questions and responses it appears you do not have a good grasp pf the fundementals of AC power theory in regards to real, reactive and apparent power, so here are a couple of links you may find helpful,
Hope that helps, MikeL.