Question

A 3-phase equilateral transmission line has a total corona loss of 53 kW at 106 kV and loss of 98 kW at 110.9 kV. The critical disruptive voltage between the lines is

• A. 66.8 kV
• B. 22.2 kV
• C. 32 kV
• D. 53.4 kV

Answer 1

The correct option is D 53.4 kV

We know that, Power loss due to corona is
$P\propto (V_{ph}-V_c{)}^2$
$\Rightarrow \frac{P_2}{P_1}=\frac{(V_{ph2}-V_c{)}^2}{(V_{ph1}-V_c{)}^2}$
$\Rightarrow \frac{98}{53}=\frac{(\frac{110.9}{\sqrt{3}}-V_c{)}^2}{(\frac{106}{\sqrt{3}}-V_c{)}^2}$
$\Rightarrow V_c=53.4kV$