Jim,
Yes it is a single phase fault. CB1 is closed - normal operating conditions - in both sketches. Your guess doesn't apply to the second scenario that current is increased in Generator Side. This increased current is due to the existence of the grid (the only difference between my two schemes).
No, we don't mix transient reactances. The currents appear in my sketches are short circuit current (symmetrical rms) during subtransient state of the fault, meaning actually the short circuit current for the first 0.2 - 0.5 seconds (before the whatever protective device operates). For the...
Hi guys,
For one more time I need your opinion in a kind of strange issue, which escapes my understanding.
Performing a single line to ground short circuit calculations (Low Voltage Side) in a simple Generator power plant using a step up to transformer, we can observe the two following...
Thank you for the book recommendation Jim. I'll manage to get a copy, seems interesting.
In any case, the configuration of my system is advised in the "attached" single line drawing found on my very first post in this thread.
For sure high impedance grounding would be much more "safer" and...
Well, thank you guys for your valuable support.
I have to admit that was some kind of stupid (or "rush") thought of mine to worry for a short circuit fault current in F2 red arrow , since it is obvious there is not any kind of resistance , no voltage , no current.
I would like your opinion also...
Ok... What really confuses me is the fact that in the same sketch, currents measured by differential protection device at two winding ends (F1 and F2) is exactly the same (when everything works ok).
So playing in reality with my 87G device in this application, i can read same load current on...
Circuit Breakers need a way to operate. This can be locally (when you stand in front of the CB) or remotelly by giving an electrical signal commanding the circuit breaker to close.
Before to be able to close CB you have to charge a strong spring inside CB. This charged spring is used to close CB...
Hi Jim,
Thank you for your time to reply.
Clarifications:
There is no resistance in the neutral. Neutral is solid grounded (thru a 4P circuit breaker but solid grounded).
When you say fault current would be low... how low...? Is there a way to determine that low fault current on F2 point...
Hi guys,
Kind of newbie in this forum, i would like to ask your opinion in the following issue.
I have an application using one Generator (50Hz-400Volts) connected in parallel to the grid (50Hz-20kV) thru a step up transformer (Ynd, 0,4 to 20kV).
I have performed a short circuit study for...