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Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

How to change v/f control?
Is it recommended to change this?
Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

Thanks mike once again for your helpful reply.
But what cause engine hunting more than particular load ?
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Super Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

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.

 

MikeL.

Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

Sometimes there is a hunting of engine and speed &voltage fluctuations ...
Is it due to harmonics?
Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

Thanks a lot mikel once again...
Your replied really very helpful to me
Super Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

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,

 

http://www.aptsources.com/resources/pdf/True%20vs.%20Apparent%20Power.pdf

 

http://www.electronics-tutorials.ws/accircuits/power-triangle.html

 

Hope that helps, MikeL.

 

 

Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

I mean to avoid harmonics effect we need to use higher rating of diesel generator?
Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

So to avoid we need to use higher rating Diesel Generator?
Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

But generator runs on 0.6 pf at site that means its only able to give 60 % of total load.....?
Contributor

Re: Which load bank is best for Diesel generator which are having more harmonics distortion at site?

Thanks a lot mikel for your quick response...