Transformer Losses compensation

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Sajid khan

Sajid khan

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Dear All,

Please help me in calculating KVAR required for a 3150KVA 13.8kV/400V dry type transformer for the transformer losses (load losses+no load losses). The total losses i obtained for a dry transformer from manufacturer is (26kW+6kW = 32kW). while searching i found that above 1000kVA transfomer the kvar compensation required is 8% of the transformer rating i.e for 3150kVA it is 252kVAR .

The valuable comments from the forum members are required.

Thanks in advance
 
Sajid khan said:
Dear All,

Please help me in calculating KVAR required for a 3150KVA 13.8kV/400V dry type transformer for the transformer losses (load losses+no load losses). The total losses i obtained for a dry transformer from manufacturer is (26kW+6kW = 32kW). while searching i found that above 1000kVA transfomer the kvar compensation required is 8% of the transformer rating i.e for 3150kVA it is 252kVAR .

The valuable comments from the forum members are required.

Thanks in advance
Click to expand...
Waiting for the replies
Thanks

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Sajid khan said:
Dear All,

Please help me in calculating KVAR required for a 3150KVA 13.8kV/400V dry type transformer for the transformer losses (load losses+no load losses). The total losses i obtained for a dry transformer from manufacturer is (26kW+6kW = 32kW). while searching i found that above 1000kVA transfomer the kvar compensation required is 8% of the transformer rating i.e for 3150kVA it is 252kVAR .

The valuable comments from the forum members are required.

Thanks in advance
Click to expand...
Typically transformer losses at that sort of rating would be around 2%.
 
Besoeker said:
What do you want to compensate for?
Click to expand...
I required the compensation for laod losses and no load losses that will always be present when the transformer is energizes even without any load on the transformer. There required the fixed steps of capacitor bank to compensate these losses only.
What will be the KVAR required to compensate these losses.
Thanks


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Sajid khan said:
http://www.academia.edu/8290859/CALCULATION_OF_kVAr_REQUIRED_For_Distribution_Industrial_Networks

Please go through the above link. Please comment on this as this is not from a trusted source.

similarly i have a motor of 150HP, RPM 1785,Code B motor and the Max KVAR required for the motor is 36.7 KVAR. I think same applies for the case of transformer.
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This is type of information (losses percentage) is given as per the manufacturer catalog and it is differ from one to other but in concept we put the capacitor bank in order to compensate the KVAR from the load side not the transformer losses as i did in many projects before.
 
Sajid khan said:
http://www.academia.edu/8290859/CALCULATION_OF_kVAr_REQUIRED_For_Distribution_Industrial_Networks

Please go through the above link. Please comment on this as this is not from a trusted source.
Click to expand...
Going to link requests that I register for download. I am not going to do that.

Sajid khan said:
... I think same applies for the case of transformer.
Click to expand...
Go here...

https://en.wikipedia.org/wiki/Transformer#Real_transformer

...and scroll down as necessary to heading "Equivalent circuit". The best you can compensate for is the inductive portion in the equivalent circuit. The resistive portion is a total loss.
 
Smart $ said:
Going to link requests that I register for download. I am not going to do that.


Go here...

https://en.wikipedia.org/wiki/Transformer#Real_transformer

...and scroll down as necessary to heading "Equivalent circuit". The best you can compensate for is the inductive portion in the equivalent circuit. The resistive portion is a total loss.
Click to expand...

I found something more, please refer to the attached PDF. Now this document is from Schneider electric explaining that we require KVAR compensation for transformer losses . Refer highlighted page number 601 & 621.
 

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Sajid khan said:
I found something more, please refer to the attached PDF. Now this document is from Schneider electric explaining that we require KVAR compensation for transformer losses . Refer highlighted page number 601 & 621.
Click to expand...
Reactive power (kVAr). Not losses.
 
Sajid khan said:
OK reactive power compensation for inductive portion of the transformer as smart says above.

Thanks
Click to expand...
It isn't something I've seen done. At the incoming voltage level, typically 11kV in the UK, it is often bulk power factor correction for the plant, not for individual transformers.
But if you have the equivalent circuit for the transformer you calculate what's required. Maybe that's what Schneided did.
 
Abdel Rahman Mohamed said:
This is type of information (losses percentage) is given as per the manufacturer catalog and it is differ from one to other but in concept we put the capacitor bank in order to compensate the KVAR from the load side not the transformer losses as i did in many projects before.
Click to expand...

^^^ What he said ^^^

Even though the power factor for an unloaded transformer may be very low and the kVAR very high on a relative basis, the actual losses will be very low. Compensate for the loaded conditions, not the unloaded ones.
 
Sajid khan said:
I found something more, please refer to the attached PDF. Now this document is from Schneider electric explaining that we require KVAR compensation for transformer losses . Refer highlighted page number 601 & 621.
Click to expand...
OK. I looked at this for the highlited 1000kVA entry.
The 72.4kVAr would make the PF of the transformer at full load about 0.997.
Do you really want to correct for that?
 
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