Cost comparison between TWO and TRHEE Winding - transformer. SAME Power!

[mcm00048]

Hi guys, I am working on a project of a PV Power Plant. We have made two designs.

Design A: Power transformer 150/185 MVA, 132/33 kV, YNd1 Price: 1412000 USD
Design B: Power transformer 180/90-90 MVA, 132/33-33 kV, YNd1d1 1220000 USD

Replacing two winding in three winding power transformer, change us the MV Switchhear design (from 1 incoming to 2 incoming, and doubles the number of some equipment. The unique possible advantage to change from three winding to two, is to reduce the number of electrical equipments, such as MV modules, LV , distribution transformers etc. But incresases the rating of those equipment from 2000 A ( MV Switchgears) to 3500 A. MV Voltage level is 33 kV. So, it is hard to find any suitable MVS with this current rating.

Anyone of you know if two winding vs three winding transformer makes difference in price, to evacuate the same power?

Thank you very much for your help!

 

[prc]

Three winding transformers are costlier than two winding transformers for the same power. Of course prices and costs are different and that may be the reason, you got a lower price for three winding transformer.

 

[mvcjr]

Aside from price, you may also have to consider the fault levels on the 33-kV side. For the same transformer MVA rating, a double LV winding will result in a lower fault current in your 33-kV system than with a single LV winding.

 

[HamburgerHelper]

You have to make sure to compare other things as well like losses. A cheap transformer is not cheap in the longterm if it has high losses and your load has a high utilization factor.