Hi guys

This is a Schematic of a transmission line, using Matlab.

The model I'm working on is a three phase.

I've run a number of fault simulations on the model, in particular a - single line to ground fault. The current surges along the fault point and the voltage sags. This is perhaps normal for that type of fault.
However when T1 and T2 is set to Y/Delta and T3 is set to Delta/Y - there seems to be no fault on the line at least that's the way my analysis is looking. I've double checked my results and parameters and they look fine.

Perhaps this is what I was meant to discover, in fact I think it was.

What I'd like to do is have a chat about this. I'd like you guys if possible to correct any incorrect terminology I'm using and if possible, hopefully we can at some point, reach some type of revelation with this. Though hopefully not too long away... pressures on.

 

I'm not sure if no one understands what's happening here, or perhaps I haven't put up enough information, or you're all keeping quiet cause you don't want to give the game away. I'm going to assume the second option and put up some more info.

Here are the results from the RMS readouts on my 3 phase model. Obviously the picture I've posted above here, is single phase.
Steady state = normal, no fault.
SFC = Symmetrical Short circuit fault - All phases
and SLG - Single Line to ground fault occurring on phase A.



Look at those final 2 rows there, under the D1 / Y to ground configuration. Matches the steady state values, as if nothing's happening...

Can anyone at guess if that's to be expected? or do you think I've possibly messed up somewhere and perhaps not applied the fault correctly? I don't know.... A little stuck here...

 

I was having a chat about this with some of the guys today. We think it has something to do with the ground on the star connection, draining off the fault voltage, operating like the neutral. What's your thoughts? And if this is correct can we talk about how that works exactly?