Transformer zero sequence impedance compared to positive

[salem]

Is it possible that zero sequence impedance is equal to or greater than positive sequence impedance for a power transformer, whose connection is Dyn 11 33/11 kV, 15 MVA ?

 

[davidbeach]

Generally not, there isn't generally anything that can add to the impedance in the zero-sequence. In a bank of three transformers Z0 will equal Z1, as it will in a shell form three-phase transformer. But, in a 3-phase core form transformer Z0 will usually be in the range of 85% of Z1.