A short 3phase transmission line is delivering 80 MW at 09 l

A short, 3-phase transmission line is delivering 80 MW at 0.9 (lagging) power factor at 115 kV at the load end. The transmission line can be represented by series impedance: Z = 5 + j 20 ohms per phase. Estimate the approximate line length.

Solution

Generally short transmission lines are characterized by lumped parameters.

lines less than 80kms are comes under this category.

resistance of line will be in the order of 0.1 ohms/km.

length= R/(resistance per km)=5/0.1=50 kms approximately