Symmetrical Components - Fault Between Two Transmission Lines

[111R]

I'm not having any luck finding a symmetrical component example for a fault between two separate transmission lines. I'm attempting to analyze a fault that occurred between a 69 kV and 138 kV line that share the same tower. One phase on the 69 kV line came into contact with a different phase on the 138 kV line.

Can anyone provide insight into sequence network connections or what to expect when a fault like this occurs from a fault current magnitude and angle perspective on each circuit?

Thanks

 

[marks1080]

Great topic. I've asked similar questions before... I've tried drawing out simple examples to solve the network equations, using the voltage difference between the two line and general impedances (lines, transformers), but I can't say i feel comfortable with using it in a real world scenario. I'll be paying close attention to this thread; I have a feeling some of the regulars here have a clever/crafty ways of at least having a decent educated guess.

Sorry i don't have anything useful to add

 

[HamburgerHelper]

This is sometimes referenced as a cross country fault. There is a section in "Analysis of Faulted Power Systems" by Anderson that covers how to handle simultaneous faults. DavidBeach did a presentation on this at a conference once. It is complicated and if I were wanted to model what you are talking about, I would use ATP-EMTP or PSCAD to do a transient study. Working it out by hand is hairy and I personally wouldn't trust my results.

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If you can't explain it to a six year old, you don't understand it yourself.

 

[davidbeach]

ASPEN OneLiner can do those faults.

What I did the paper on was far easier in that it was radial circuits from a common source and looking at phase-ground-phase faults between two portions of a high resistance grounded system. Goes back to 2006 and a different job, don’t know how easily I could find it now.

 

[waross]

From the consumers point of view, years ago I experienced that as a home owner.
There was a transmission line taking power westward into a city at about 60,kV.
Under-built on the same poles was a distribution line feeding eastwards at about 13 kV.
A car hit a pole and a 60 kV line slapped a 13 kV line.
The 13 kV load was mostly residential.
I was watching TV when the TV flashed brilliant white and then all the lights went out.
Our transformer fuse cleared almost instantly.
When the power was restored the TV set had survived.
Mother in law lived a few miles closer to the fault and her TV did not survive.
I understand that there was more damage closer to the fault.

Bill
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"Why not the best?"
Jimmy Carter

 

[cranky108]

Because so few people have done fault studies by hand, it only seems difficult to draw.

But it can be done, but start with good sequence network maps.

ASPEN One-liner would be faster, but doing it by hand will make you understand it better.

waross,
Do you think the newer TVs would survive such an event?