Hi, Thank you for your nice lectures ... To enhance this lecture technically more correct, we can go by taking industrial powersystem as an example (where it ll be YNd1/11 - step down trafo ... and Delta side will be grounded via grounding trafo... ) and to add one more point, Generating stations usually have YNd1/11 (step up trafos) :)
Good video. We have an 11kV earthing transformer with an earthed star connected primary winding and a secondary winding with a broken delta connection with a resistor that limits the primary winding current to 60A. How do you determine/model the zero sequence impedance of a broken delta connected transformer. thanks
Hi, thanks for these kind of videos. 1- How can we calculate zero sequence impedance of zig-zag transformer ? As you mentioned, during phase to ground fault, only impedance that effect to our ground fault short circuit current is zero sequence of zig-zag transformer. Also other component will be effect on the path of that faulty line. System Voltage (L-L)=10,5Kv Irated/phase=100A Short Circuit current in neutral=1000A, 10sec Ohm/per phase = 18,2 ohm/phase 2- On ETAP program, below informations are needed. But I could not understand these value is ohm or pu values of zero sequence. Even I am not sure these values zero or not ? If I put ohm/per phase values, ground fault is going to limit from 15kA to 2kA. I do not know how it calculate ? Do you have any advice ? Impedance; Ohm= ..... --> Etap Help page said that ''Enter grounding resistor or reactor in ohms'' X/R= ...... --> Etap Help page said that ''Enter the grounding transformer X/R ratio''
Hi Sir, its a very informative lecture. I have a question, can we convert IT Earthing network to TN using Zigzag transformer at LV side (415V), but we cant use Earthing resistor in neutral of Zigzag transformer. Is it possible?
Thanks a lot sir for the sequence diagram for earthing transformer..these kind of informative videos helps a lot in our work field....sir i have 1 more request..can u provide sequence diagram of autostransformer having delta as tertiary stabilising winding(YNyn0d11 as well as Yy0d11)?
Sir can u provide a sequence network of 3 phase transformer consists of HV star,intermediate volatage star and lv voltage delta for example 220/132/33 KV transformer
Beautifully described. Very nice.
Hi,
Thank you for your nice lectures ...
To enhance this lecture technically more correct, we can go by taking industrial powersystem as an example (where it ll be YNd1/11 - step down trafo ... and Delta side will be grounded via grounding trafo... )
and to add one more point, Generating stations usually have YNd1/11 (step up trafos)
:)
Thank you for providing comprehensive lecture
Very good lecture Sir. Thanks 🙏🙏🙏🙏🙏🙏🙏
Good video. We have an 11kV earthing transformer with an earthed star connected primary winding and a secondary winding with a broken delta connection with a resistor that limits the primary winding current to 60A. How do you determine/model the zero sequence impedance of a broken delta connected transformer. thanks
Sir what happens if there is no path for circulating currents.
Superb sir
Hi, thanks for these kind of videos.
1- How can we calculate zero sequence impedance of zig-zag transformer ? As you mentioned, during phase to ground fault, only impedance that effect to our ground fault short circuit current is zero sequence of zig-zag transformer. Also other component will be effect on the path of that faulty line.
System Voltage (L-L)=10,5Kv
Irated/phase=100A
Short Circuit current in neutral=1000A, 10sec
Ohm/per phase = 18,2 ohm/phase
2- On ETAP program, below informations are needed. But I could not understand these value is ohm or pu values of zero sequence. Even I am not sure these values zero or not ? If I put ohm/per phase values, ground fault is going to limit from 15kA to 2kA. I do not know how it calculate ? Do you have any advice ?
Impedance;
Ohm= ..... --> Etap Help page said that ''Enter grounding resistor or reactor in ohms''
X/R= ...... --> Etap Help page said that ''Enter the grounding transformer X/R ratio''
Lectures in Electrical Engineering
Let me ask different way. How can we calculate zero sequence impedance of zigzag grounding transformer ?
Hi Sir, its a very informative lecture. I have a question, can we convert IT Earthing network to TN using Zigzag transformer at LV side (415V), but we cant use Earthing resistor in neutral of Zigzag transformer. Is it possible?
Thanks a lot sir for the sequence diagram for earthing transformer..these kind of informative videos helps a lot in our work field....sir i have 1 more request..can u provide sequence diagram of autostransformer having delta as tertiary stabilising winding(YNyn0d11 as well as Yy0d11)?
Sir can u provide a sequence network of 3 phase transformer consists of HV star,intermediate volatage star and lv voltage delta for example 220/132/33 KV transformer
sir please add subtitles
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