Thanks a lot for your deep root cause analysis of diverted young engineers !! I am trying my little best to share my experiences & knowledge to young engineers.
Thank you Nitesh sir. This is very knowledgeable video. As we know how important relay are in the operation of many equipment in switch Yard. Till now I never hear this type of protection relay once, again thank you for your dedication to familiar us with such complex topic in simplified manner.
What about if the system is a radial or antena system and there is no back feeding into the restricted area!? I think this protection configuration will not work because no current will be induced on the CT of the faulted line.
Hi Nitesh, this a good video on REF protection. Please do keep posting videos like this. Can also please share the references or textbooks you have referred for the preparing content in this video?
Sir nice explanation. I have one doubt @8:13 at out zone fault phase CT current direction will be towards relay through the stabilising resistor and neutral CT direction towards relay .As the phase CT current will passes through the stabilising resister there will not be any current drop ? As I=1/R . If there is a drop then how it is getting nullified at relay . In case of out zone fault with Phase relay unsaturated condition.
Dear sir super explanation , I'm so thankful to you for sharing your experience, When a through fault is there you are saying that (@ 7:45) both currents will nullify and relay will not operate, Here my doubt is when through fault occurred nuetral current will flow to one side of the relay and phase current has to flow in other direction but here we are having stabilizing resistor in between this, how this current will cross the resistor and will go to relay coil ,sir please explain
Hi Manoj ! Thanks to write. Let me draw your attention towards my explanation where I have clearly explained with an example of calculation at last of Videos that the value of Stabilizing resistor is calculated by assuming the maximum through fault current and based upon that, the value of Stabilizing resistor ( say XYZ Ohm ) is used. So that the fault current will be flowing to relay coil at the time of fault. But in healthy condition the phasor currents are being nullified before going into the relay itself.
@@NiteshKumarElectricalThank you for your reply sir, how the fault current is flowing through the stabilizing resistor to relay, yes your saying that by calculation only we kept stabilizing resistor, ok that's fine How the relay not operating in CT saturation time while fault current going up to stabilizing resistor only not to relay, And other doubt is how the phasor CT currents getting nullified without going to relay, there won't be any current in nuetral CT in healthy condition right?
Hi @@manojkumar-jd6ct , Q.1- Relay will not operate in CT Saturation time becoz the Saturated CT won't produce secondry Current I.e theoretically it will be Zero but practically some llitle spill value will be there which is considered almost zero. Hence in this situation your NCT secondary current will take a low impedance path of saturated CT(Plz Watch Video) and then it will be making close path itself through CT secondry Ckt as NCT secondary current won't flow through relay due to stabilize resistor. Q.2:- Phasor CT current in healthy condition are getting nullified because we have already connected that in parallel. Plz Watch full video. As I am busy right now.
@@NiteshKumarElectrical hi sir , 1. In the event of through fault NCT current and phasor currents in same direction and it won't flow to relay because of stabilizing resistor, and relay will not operate 2. If one phase CT is saturated in this condition the vector sum of phasor currents will be some value and it will flow to relay and NCT currents also flow to the relay right? 3. Sir we are having YNYNO vector group power transformer of 132/33 KV , HV Current 109 and LV current 406amps , CT ratio of HV side 600/1 and LV side 500/1 with an impedance of 10% ,HV Iref 40ma and LV ref 170 ma settings , how could I get ImaxT and I maxF and stabilizing resistor value, Sir please explain how to calculate this values , I'm waiting for your reply
Recently, I have uploaded a video on difference. Plz watch that. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-apT0mVCIQgk.html In Hindi. If you want to watch that in english then the link is given in the description box of this video. Thanks
Hindi me same video dekhne ke liye link us video ke description box me diya hai. Maine video me kaha bhi hai ko description box me link hai . Us pe click kar ke aap hindi me same video dekh sakte hai.
