Effect to Transmission Line Reliability

[GRAEE]

Hi All,

Need help on this.

We have an existing Double Circuit 138kV Grid Transmission Line with a length around 100km.
Its a looped line where different generation sources and substations are connected at both ends of the 100km line.
We are about to connect ("bus-in" or "cut-in") a 70MW generation facility in between to that 100km line using a breaker-and-a-half scheme.
The proposed generator location is 1/3 of the 100km distance from the grid substation (or 2/3 from the other end grid substation).

My questions are:
1. Is there an effect to the existing 100km transmission line in terms of reliability? How & Why?
2. Can you show an illustration in terms of computing the reliability indices before and after the generation facility is connected?
Would really appreciate any references for this purpose.
3. What are your recommendations to improve further the transmission line reliability in case we'll pursue the proposed project?

Thanks very much...
GRAEE

 

[crshears]

I'm confused...

A 'line' is the same as a 'circuit', at least as I understand it, so how can you have a 'double-circuit line'?

Assuming you have two circuits, are you planning to break both circuits at the new generation site so you will have four lines terminating in a new switchyard? It would seem in my view that in this case you would require a breaker-and-a-half scheme.

Or are you only planning to split one of the circuits and leave the other as an express circuit from the original Point A to Point B? in this instance you would only require a ring bus, not a full breaker-and-a-half yard.

Explanation, please.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[GRAEE]

The plan is to break 2 circuits where four lines are terminated and connected to 2 bays breaker-and-a-half scheme.
Then additional breaker-and-a-half bay for the new generation.

Thanks