Question $8$

$[12]$

A $20$kVA,$\frac{8000}{277}V$ distribution transformer has a primary resistance and reactance of $32$ and $45$ respectively. The secondary impedance is $0,\frac{078}{{?}_{50}},2.$ The core parameters are given as; $R_C=250k$ and $x_M=25k.$

a$)$ Find the equivalent circuit parameters of this transformer referred to the high voltage side.

b$)$ If this transformer is supplying a rated load at $277$ V and a power factor of $0,8$ lagging, determine the voltage regulation and efficiency of the transformer.