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in Electric Power & Transmission & Distribution Forum , SAS absolutely stands for substation automation.

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...

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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...

scottf why you conclude that they are functionally equivalent? what equation You used to relate FS by Burden ?? shalhoob

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

long time ago, I have learnd that shunt capacitor bank is used to support system voltage and produces VAR's. and now i started reading about Static VAR compensator which almost have the same purpose of use in application side. kindly please explain breivly the difference between them from...