anybody out there saturating CT's from inside relay room? we have 600V AC CT cables and I was wondering how much cable insulation can take since Saturation tests go up to 1200V AC?
any comments?
I ran some models with embeded generation on utility feeder and I found that SC level seen by the TS relay protection remained constant.
However I came across some papers that say relay will see SC current decrease with new generation connected downstream on the feeder. This doesn't make sense...
is it possible to have delta (or ungrounded wye)winding configuration on primary of the generator step up transformer (higher voltage side) that feeds 4 wire system?
I would think neutral is needed to feed 4 wire system (grounded or not, but neutral must be there? Am I right?
Even if this...
is there rule of thumb what causes harmonics in the system. Customer has single phase 240V motor pump and there is a cyclic sag in voltage and spike in current. THD is very hifg in range of 120% PREDOMINATE 3RD AND 5TH HARMONIC
Hi all:
I have hydraulic Cooper reclosers on typical distribution feeder, and need to coordinate them. Question is:
for fault downstream of second one both of them go on the fast curves, second operation both reclosers are on their slow curves, say there wasn't enough oordinating margine, and...
Hi all,
I have recloser installed downstream of Transformer Station. LDC I work for have guidlines for calculating relay settings , but I can't seem to find guidlines for revising of the relay (in the Station) settings when we introduce recloser downstream. This is not coordination question, my...
Hi all:
I need to model Induction generator farm. I understand fault current contribution from these generators is very low due to absence of voltage at terminals and consequently flux in the machine core. But I wonder if I should regardless chose Impedances Option. In my modeling software gives...
How is shunt-capacitor size chosen for this wind induction generators farms?
I need rule of thumb if possible. I understand there is range for generator power factor, i.e 0.9 leading p.f. to say 0.95 lagging. Does this mean that VARs are exported to the grid in preference? If gen is 1500KW then...
Hi guys,
how do you model load on the distribution feeder for steady condition Power Load Flow?
program I work with have options:
1. Constant Power load
2. Constant Current load
3. Constant Impedance load.
problem I have is at my company, we are so used to presenting loads (Power Flow Studies)...
There are 3 different ways we can model generators in PSS software.
1. PV Machine
2. Constant Power
3. Induction machine with negative active power
When are we supposed to use which model and why???
1. I noticed that when I use PV machine model machine (generator) pumps out as many +/- VAR’s...
I wonder what would Nuclear generation plant generator be modeled with? I use software that gives some generic recommended values for impedances and time constants. I wonder if I can use this as a setting for my NUG? Is this going to be Steam Turbine Large?
Please help me with this one.
I tried to prove results of the software we use in my company for simple radial generator system. I introduced fault at the end of the generator (made generator as Swing Source). My calculation on the paper yields 3 phase fault current result of 9.014 kA. When I ran...
