Hi everyone,
In my country we have alot of new projects(substations) that have SAS in their designs.
Like many others I was supprised who will extend his responsibilties to be SAS engineer.
SAS as you know is mostly communication(f.o) ,Industrial servers, and IED's (numerical relays)!
and the...
rcwilson thanks for your participatin. this matter was raised after our consultant has proposed the use of this function but it was new for me as a protection engineer. calculation which you mentioned shall be done by planning division peronnel who have
parameters of the whole syetem and...
thanks every one.
I found this in SEL website.
Out-of-Step Tripping and Blocking Functions
Out-of-step tripping schemes are designed to protect the power system during unstable
conditions, isolating unstable generators or larger power system areas from each other with the
formation of...
Hi,
For the phenomena "out of step" or unstable power swing what shall be used in protection?
1- Just blocking the distance relay as stable power swing?
2- Tripping lines to protect generator?
3- If tripping is required to protect the system. What exactly is needed in the system study? R/X...
Please read this file about "The Importance of the X/R Ratio in Low-Voltage Short Circuit Studies"
www.powerstudies.com/articles/ImportanceofX-over-RRatios.pdf
Shalhoob
scottf , thank you for replay
you mentioned ,
(so the unit will still meet accuracy class).
2 VA * Fs 5 = 10
5 VA * Fs 2 = 10
so , why the manafacturer make to type of IPCT security
factor and burden if they will end up by the same Class as
you stated!.and why do you think designer choosen...
rbulsara
Not only burden is the difference. 0.5fs5 has security factor 5 where 0.5fs2 has different security fator which is
clearly 2
they are different in
1) VA Burden
2) security factor
hi all ,
I found during my commissioning work in substation that
Interposong CT used with an Ameter has the following class
0.5FS2( Burden 5 VA) but the required one as per drawing is 0.5FS5 with burden 2 VA. they match in other ch's
Ratio 1/1 , Rct = 1.3 ohm etc.contractor engineer told me...
Great valuable information that you added eng.saleh.
It's true that static VAR systems with thyrristor-controlled reactors (TCR)have some effects produced by injection of harmonics into the connected network.
therefor , filters are required to supress them.
shalhoob
Bilal . I really appreciate your answer to the question
DVC is a new thing to me which I will start searching to read more in this field.
waross thanks. when voltage supported and needed VAR's provided to system, then automatically power factor will be
corrected. they are related somehow but...
there is a feature in 'Transformer Diff.' ABB Typre RET541
Called Deblocking ! ( removing blocking of 2nd harmonic in
case of 'Switching on to fault'.but if there is no exist
of fault will continue blocking 2nd harmonic after energization.I don't know if new numerical relays solved
that in OHL...
thanks rbulsara , bacon4life for helpful info you post.
for me I need some more time to cover this topic which
is now applied in so many places in my country.
regards
