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regarding powerfactor

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kumar250688

Electrical
May 7, 2014
6
how to inmprove the powerfactor in ht side 33/11kv transformer,can we able to connect the caapacitor bank in ht side,see i am got in the powerfactor 33kv transformer primary side 0.96 and in secondary 0.97and ltside 440 volt0.98 ,how to improve the powerfactor in secondary side?
 
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I see no reason for improving on those numbers if I am interpreting you correctly. What is your goal here?

"Will work for (the memory of) salami"
 
reduce the losses and then improve the powerfactor0.999,?
 
You need to know the actual kVARs. Knowing the power factor isn't enough to size capacitors.

You also have to take into account low load periods to avoid over-correcting. A good Google search will turn up lots of advice on power factor correction.

But the decrease in losses between 0.96 and 0.99 will not be worth worrying about.
 
The goal of most power factor correction tasks it to improve to 0.95 or better. You are already there.

"Will work for (the memory of) salami"
 
You can connect the capacitors at any voltage. The VARs will feed back through the transformer(s). If the capacitors are on 11 kV or on 440 V, you may have to go a little leading to get 100% at 33 kV.
In some countries, I believe that India is one such country, power factor penalties start at 99% PF, lagging or leading. If that is the case, you should consider a power factor controller. You want to be at 100% power factor at whatever voltage the utility is metering to determine the PF penalties.
In many jurisdictions the penalties start at 90 % lagging power factor and correction needs only be to bring the power factor above 90%.
Power factor, when penalized at below 90%, is often based on monthly KWHr and monthly KVARHr readings. You just have to bring the average up.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
You asked if correcting the power factor on the primary side of your transformer will correct the power factor on the secondary side. It will not.

You can easily find statements saying that locally correcting the power factor will reduce the energy used and save money. My opinion is that it will not save money. You will save a little energy but the installed cost of the capacitors to achieve that savings has a very long payback that no accountant would ever approve. Locally correcting the power factor means you correct the power factor locally right at each individual load.

But, you did not ask about locally correcting the power factor. You asked about correcting the power factor at the source. Correcting the power factor at the source or utility does not change your plants energy usage.

For a factory, the only power factor correction savings with an acceptable payback are achieved by reducing the utility demand charges or power factor penalties.

Whoever sent you on this wild goose chase is either testing you or has also no clue about power factor correction.
 
how to inmprove the powerfactor in ht side 33/11kv transformer
You can improve the hi side power factor by adding capacitors on the high side. BUT, it is important to know where the PF is measured. If you connect the capacitors on the supply side of the metering equipment that is measuring the power factor the metering equipment will not see the improvement.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
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