loading of 500kv transmission line

[jan63]

We have 500 kv transmission line which have four conductors per phase each can carry 900 amp.But still loading of lines is limited to about 1100 MW due to characteristic impedence of line.What will happen if load on lines is more than 1500 MW

 

[lume7006]

Hello,

I am not an expert about transmission but, as far as I remember, the loading of the transmission lines is "ruled" by three factors:

1) Thermal limit.- This is related to the ampacity of the conductors and also the environment, I mean the ambient temperature.
2) Voltage drop
3) Stability.- If the line is loaded above certain level, then the angle separation between both sides may be so high that stability is lost.

I understand that in your case, the most critical is the last one I above mentioned and because of that the limit you have.

I recommend you to check with somebody of planning or operations at the transmission utility and determine if under some specific conditions the power flow through the line can reach 1500 MW.
There are some studies to be performed to get this number, otherwise the security of the system may be in risk