Zero Sequence Network

[Cerkit]

Hi,

Can anyone explain why the zero sequence network of the following diagram does not include the neutral of the delta/star transformer as per attached?

Thanks

 

[Cerkit]

Here is the zero sequence network attached...

 

[mgtrp]

It does include the zero-sequence impedance of the delta-star transformer, it is the j0.1pu on the left.

 

[7anoter4]

It seems that ZT it is the autotransformer to ground impedance. The transformer to ground impedance is 12% [0.1 p.u.]