Does anyone have any recommendations for software to maintain operational single line diagrams for distribution utilities?
There does not seem to be much available to suit this purpose.
The challenges include constant changes to the distribution system (new customers, salvages, reconfigurations...
I'm having some trouble understanding why a radially fed transformer can be a source of fault current during an upstream fault.
SYSTEM:
[TRANSMISSION SYSTEM 25kV BUS]---[25kV BKR]-----------------------[FAULT]--------------------------------[TRANSFORMER]
I've heard that, for certain faults...
Interesting. This phenomenon would make sense given the fault data (volts, amps) that I have.
Our sub bkr reclose intervals are 5s, 35s, 35s, so I'm trying to rationalize how likely this is in this situation, but it's definitely something that could be considered.
I forgot to mention, an...
Have you seen this cause the upstream breaker to trip to lockout? The breaker requires 4 trip operations to lockout (3 reclose attempts).
When you say instances of the fault moving closer to the substation on reclose, do you mean it moved a little further upstream each reclose attempt?
How did...
I'm a little confused by where the FLA of ~3000A was plotted. Your x axis is current x10, but it appeared to be plotted in the 300A range. Same comment applies to the inrush dot @ 12x for 6 cycles.
Is the primary voltage 8.3kV, or is that just the rating of the fuse?
Something seems a little...
For the distribution power system protection engineers:
I am investigating 25kV distribution faults on an overhead system. A known fault occurred downstream of a recloser, which was downstream of the substation breaker on a radial distribution system (see ASCII SLD below).
[SUB...
I can appreciate that some cooling will occur during the open intervals.
However, our typical open intervals are on the order of seconds, and I doubt that the conductor would be able to cool to pre-fault temperature during the open interval.
It seems to me that there must be some kind of...
Are there any distribution protection engineers who consider the conductor damage curve when deciding on the number of reclose attempts?
It seems fairly common to compare the timed-overcurrent curves with the conductor damage curve.
However, if there are reclosing attempts, the conductor will...
