Harmonic reduction

You should really analyse or look at what harmonics you have and apply the necessary capacitors and reactors. There are commercially available multistage filters available from companies such as Ampcontrol in Australia. Have a look at their website.

First you have conduct a detailed study of harmonics of entire plant. Single filter will not solve your problem if you got varying loads. Viste ABB web site to gain more knowledge. I am also facing this problem and we could not filter them out, just managing harmonics. Best is active filter but too costly.

Obviously, you have to solve the problem with an "LC" filter (or an "RC" filter)... But, first of all, you have to examine carefully what is the source of the noise (the noise is not, necessarily, originated from the power supply itself... Maybe it is caused by the active load, e.g. by a specific chip)... You, also, have to measure the noise with the apropriate way (the correct measurement often gives you a smaller amplitude of the noise than you had estimated at the first sight)... This means a realy sort wire, for ground connection, which is soldered to the "ground ring" of the osciloscope's probe and is connected to a ground point which is as close as possible to the point of the noise measurement (and, often, a small capacitor 100nF with realy short leads is soldered between the tip and the "ground ring" of the probe for a good measurement of the "switching noise" of a power supply)... So disconnect the active loads (circuits) from the power supply and connect a corresponding passive load to its outout in order to verify if the power supply is actually the source of the noise... If you don't see this noise by doing this, this means that the noise comes from a part of the active load (i.e. a specific circuit or chip)... Then connect, again, the original circuit to the output of the power supply and, now, you have to indentify the part of the circuit that is the cause of the noise (which is not an easy thing) by, carefully, isolating different parts of the circuit and see what happens... If you succeed to find the part which is the cause of the problem you have to put an appropriate filter at the supply of this part, in an appropriate way (maybe a p-filter is a solution... some experimental trials will show you the way)... There is, also, a possibility that the noise is caused by inadequate ground connections or inappropriate ground routing (e.g. "ground loops" e.t.c.)... But I suppose that you have payed attention in all the "noise reduction issues" during the design (e.g. decoupling capacitors, proper grounding e.t.c.)...

I hope that these infos may help you...

Sir,

Thank you for your detailed solution.I will workedout Practically and come again for sharing with others.

Check product called SineWave manufactured by Merlin Gerin France www.mge.com

i"m sorry the site is not correct but you can still try with merlin Gerin - UPS Systems & sinewave systems

This is like saying I'm sick, What kind of medicine should I take?

What are the harmonics, odd, even, triplen.

Each one requires a different prescription.

Snakers.

u r not sick, try to visit this site http://en.wikipedia.org/wiki/Power_factor_correction

or http://en.wikipedia.org/wiki/Inverter_(electrical)

http://en.wikipedia.org/wiki/Inverter_(electrical)

Once you have established what harmonics you are dealing with, try a company name Grant Transformers Pty Ltd in Western Australia.

email: grant.transformers@westnet.com.au

That company will have a solution for you.

Greg Lynch

You basically need to carry out a harmonic analysis of your system.This will bring out the exact predominant harmonics present.Your load like AC drives etc comprising of inverter are the major culprit.After the harmonic content is known you can either use passive filters-reactors or opt for active filters.Passive filters would be tuned as per the data found out on Harmonic analysis.Or more effectively the Active Filters can be used.These generate current (180 degrees out of phase) to compensate the harmonics present and also improve the PF.

most of electrical manufacurer such as telemecanique, Merlin Gerin, Siemens, ABB, Allen-Bradley, etc, they provide you what it's called as "harmonic filter", go to their website (or start from google keyword ABB, siemens, or others you like) and have fun.

They also provide technical assistance.

if ur sub station is having a capacity of 220 kv then u can apply static var compensator systam which can help u to reduce the harmonics and reactive components too...

u can get the prospectose for this system from abb switch gears ltd.......

thanks.....

regards....

jay

The Harmonic current is a problem for every main panel of factory. Usually we can reduce effect of harmonic wave by a serial RL to the capacitor. RL circuit may be a reactor or choke coil. The condition choose the capacity is 6% capacity of capacitor.