V = 0.9 pu. and cos ϕ = 0.8 lag.
Base power = 100 MVA
Base current = 437.38 A
P.U. value = Actual value / base value
Now, the base voltage \(= \frac{{MVA\;Base}}{\sqrt3\times{Base\;current}}\)
\({V_{Base}} = \frac{{100 \times {{10}^6}}}{\sqrt3\times{437.38}} = 132\;kV\)
Now, Vactual = 0.9 pu × 132 kV
⇒ Vactual = 118.8 kV
\( ⇒ {V_{L - L}} = {{{V_{actual}}}}\)
VL-L = 118.80 kV