Three single$-$phase step$-$up transformers, each rated at $15$ MVA, $24/39\mathrm{.}84$ kV$,$ are connected in delta$-$wye on a $24$ kV distribution line. This three$-$phase transformer feeds a $30$ MVA, $69$ kV three$-$phase load. Each transformer terminals has polarity marks H$1,$ H$2,$ X$1,$ and X$2.$ You are required to: i$.$ Make a schematic drawing of the delta$-$wye connection of the transformers. ii$.$ Calculate the incoming primary line currents and the outgoing secondary line currents.iii Calculate the currents in the transformer primary and secondary windings.iv Select suitable Current Transformers $($C$.$T$.$s$)$ to be connected to the primary and secondary sides of the transformer as part of a differential protection scheme for this three$-$phase transformer. Available C$.$T$.$ ratios are $200$:$5,250$:$5,300$:$5,400$:$5,800$:$5,900$:$5,1200$:$5$ and $1500$:$5.$ Calculate the phase currents in the secondary windings of the selected C$.$T$.$s$.$v$.$ State how you would connect the C$.$T$.$s on each side of this three$-$phase transformer as part of a differential protection scheme and explain your reason for doing so$.$