Given a specific cable size I am trying to figure out what t

Given a specific cable size I am trying to figure out what the MVA limit is when I bundle. I know the equation for a single line; (sqrt(3)*VA)/(1*10^6). My question is, let\'s say I bundle three different cables together. Will my MVA limit now be three times bigger?

Solution

The practical maximum power carrying capacity of a line is given by

P =0.5[(V^2)/X],

where V = Voltage of the transmission line , X=inductive reactance of the line.

Using bundle conductors, line reactance decreases owing to reduction in GMD of bundle conductors. So from the above relation Power carrying capacity increases which in turn increases MVA limit.

In other words, the current carrying capability of bundled conductors increases because

1. The resistance of bundled conductors is lesser than single ones.

2. The influence of skin effect in bundle conductors is subordinate than single ones.

Hence MVA limit also increases.