Can i replace grid transformer 11/33 kV star/delta by 11/33 KV delta/star transformer.?

Answer 1

depends upon what is your incoming and outgoing voltages, but in the design of transformers, it is economical to connect in wye, and wye cancels the third harmonics. basically in actual practice, as long as you have the correct voltages for primary and secondary, step up or step down, you can replace your transformer with the same kva or mva.

Answer 2

Star/delta and delta/star connections both give a 30 degree phase shift. The voltages are the same (assuming these are all phase-phase voltages). So that leaves whether or not the associated circuits have a neutral and in which direction power is allowed to flow.

A circuit with a neutral (4-wire) must be supplied by either a wye winding or a delta winding with an added grounding transformer. A 3-wire circuit may be supplied by either a delta or a wye connection. So this substitution will work for power flow from 11 to 33 kV.

For power flow from 33 kV to 11 kV this substitution will work only if the 11 kV circuit is 3-wire (no neutral) or a grounding bank is added if it is 4-wire.

Answer 3

I think you have terminology problems. 132 kV versus 33 kV is a voltage 4 time higher. So an application that used 33 kV would be severely overloaded at 132 kV. I suspect you mean 132 kVA vs 33 kVA? That is totally different. And represents the power level of the transformer by a factor of 4. Why do you think there would be less heat loss? .

Answer 4

No u cant go for such replacements because the point which require neutral to be earthed wont get path to earth,if u make it delta.
and neutral current will flow in loop of delta so current per phase will increase and will cause mal operation of u r Over current protection.

if u specify the incominf or outgoing X former then ans wuld be more clear to u r interest.

Answer 5

For some extent yes you can, but due to the neutral line is not connected to the generator neutral then there will be more heating of the primary winding due to the net current flowing if the load is not properly balance. Therefore, this connection is not advisable.

Answer 6

As stated, no.
You generally have a choice in the wiring of a transformer, and can wire it in star or delta at your option.