The three phase transformer, shown below, is connected in $\backslash ($ Y $\backslash )-\backslash ($ Y $\backslash )$ to provide power to unbalanced three phase load. the primary side voltage of the transformer is $\backslash (7680\backslash$mathrm$\{$~V$\}(\backslash$mathrm$\{$Y$\}\backslash )-$connected$),$ and the secondary side voltage is $240$ V $($ V $-$connected$).$

The three phase loads are described as follow:

Load $1$: Absorbing $5$ KVA at $\backslash (\backslash$mathrm$\{$pf$\}=0\mathrm{.}8\backslash )$ lagging.

Load $2$: Resistive load absorbing $5$ KW$.$

Load $3$: Absorbing $4$ KVA @ pf$=0\mathrm{.}8$ lagging.

Taking Van as reference $($phase$-$angle $\backslash (=0\backslash ))$ and positive sequence:

The line current flowing in the secondary phase wire la is: $|+$j A$.($P$.$S: Use $3-$digits precision$)$

The line current flowing in the secondary phase wire lb is: $+$j A$.($P$.$S: Use $3-$digits precision$)$

The line current flowing in the secondary phase wire Ic is: $+$j $-\backslash (\backslash$quad $\backslash )$ A$.($P$.$S: Use $3-$digits precision$)$