Q$1)$

Three identical single$-$phase transformers are each rated $15$MVA,$\frac{200}{40}kV,60Hz.$ They are connected to form three phase $-Y$ transformer bank as shown below. A three phase load of $30$ MVA at $0\mathrm{.}866$ PF leading is connected to the secondary of the transformer bank. Neglect exciting currents and voltage drops across the transformer. Choose $V_{AB}$ at the primary as reference phasor. For the given transformer bank configuration

Determine $($magnitude and phase$)V_{ab},V_{ca},$ and $V_{BC}.$

Calculate $($magnitude and phase$)I_a,I_{AB},$ and $I_A.$