Re: Harmonic filter for better power quality

Home Electrical Engineering Forum General Discussion Harmonic filter for better power quality Re: Harmonic filter for better power quality

Alen Matanovic

I'm not going to post new topic, because this one is perfect for my question,, as well as i hope the help will be ;)..


I'm expirencing some problems (that are more “theoretical” nature) with harmonic filters.. I can't seem to find how to properly calculate the values for inductance and capacitance of “notch” filter, actually, I just don't know the way to do it..

I need to desing notch harmonic filters for 5th and 7th harmonic (eventually for 11th and 13th as well).. Actually, I have allready made my dijagrame in EasyPower programe, and I'm supose to do harmonic analysis of it.. Here You can see some “print screens” of my project (it's pretty simple one) that consists of 4 loads, 1 linear and 3 nonlinear.. transformer is able to atenuate “triplens” but, because at my loads 5th, 7th, 11th and 13th harmonics are dominant,, I still have significant current THDi at PCC point of sistem..

First I want to apologize in advance for facts that load names and other stuff are not in English,, as well as for my English because I'm no native speaker..

So,, here are my pics:

one-line diagrame:

harmonic analysis mode (filters off):

and options I have to specify them:

Loads spectrums:


and current spectrum @ delta winding of transformer:


I can see mister Johnson is really “into” the subject, so I hope he will be able to provide some help or advice ;)..

Every help is warmly welcome ;)..

Thanks,, Alen..