A Single-Phase Three-Winding Transformer Has the Following Parameters $Z_{1}=Z_{2}=$ $Z_{3}=0+j 0.06, \mathrm{G}_{c}=0$

Essay

A single-phase three-winding transformer has the following parameters: $Z_{1}=Z_{2}=$ $Z_{3}=0+j 0.06, \mathrm{G}_{c}=0$ , and $\mathrm{B}_{m}=0.2$ per unit. Three identical transformers, as described, are connected with their primaries in $\mathrm{Y}$ (solidly grounded neutral) and with their secondaries and tertiaries in $\Delta$ . Draw the per-unit sequence networks of this transformer bank.