Analysis of L-L Fault (Line-to-line fault)

[@DrAfrozAlam]

At time 17:50, put "Alpha minus Alpha square" as j√3 instead of - j√3.

[@TonmoyBhowmik]

Sir, at 25:45 there will also be a minus sign as you clear it in description box, isn’t it sir?

[@DrAfrozAlam]

Yes, the same has been written at page no. 25 of the following hand-written lecture notes (pdf): drive.google.com/file/d/18Zvgdi3YD6iAIkWJwz5-s7dVHRgM6lwZ/view?usp=sharing

[@Imran52Feb]

Very nicely explained . Thanks. Achcha revision ho raha hai. Symmetrical Components method proves the beauty of Mathematics. Shukriya.

[@surendrakverma555]

Excellent lecture Sir. Regards 🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏

[@ofogharya9038]

Nice Lecture and very good writing and explaining...

[@zaheersuhabuth2677]

Awesome teaching

[@Aspirant-lp8cw]

Great lecture sir. Thank you sir.

[@tashbeebahsan7699]

assalamualaikum... your lecture is playing a role of bridge between the coursework of POLIMi and what we have studied in AMU. Without your lectures, the lectures here are difficult to understand specifically the lectures on symmetrical n/w and faults.

[@DrAfrozAlam]

Wa Alaikum Assalam Tashbeeb. Hope you are doing good there.

[@surendrakverma555]

Very good lecture Sir. Thanks

[@karbonaterol9751]

So if there is a load current on R phase ,that means we will see a ground current even if it is a L-L fault?

[@kingsingh2616]

mashallah sirrrr.......

[@transientmatter6088]

Good 👍

[@qinisophilani7208]

dankie MUT APPROVES

[@DrAfrozAlam]

Most welcome dear

[@arundhatipatil4264]

Sir would you please provide lectures for power frequency control , reactive power control , interconnected systems

[@DrAfrozAlam]

kzbin.info/www/bejne/naLLeI2fp7GciZo

[@kyawswarphonemaungroger3267]

Dear Professor Thank you for posting the lecture. But I am not sure what Fault Impedance exactly refers to in your lecture. When we develop sequence network for fault study, during the calculation of positive sequence impedance, negative impedance and zero sequence impedance, we can already add those impedances of power system components such as generators, lines, and transformers respectively in the calculation. Should we then still need to consider fault impedance while calculating sequence components of fault current? In some research paper, it is referred to arcing impedance of the breaker (it may form only when fault is not a bolted type). Can you kindly explain for that? Thank you. Regards, KSPM

[@DrAfrozAlam]

Yes, if fault is not bolted type, then you need to consider fault impedance (given in the problem).

[@crisrobersonsantos9192]

Thank you very much for sharing this very inspiring lecture Dr. Afroz Alam. regarding with the final formula for Fault Current (If), may I kindly consult if it would have a negative sign before "j", like shown below? If = ( - j√3)[Er/(Z1+Z2)] and the source of the negative sign is from: 3/(a - a²) = -j√3 your response would be greatly appreciated

[@DrAfrozAlam]

Yes, you are right Crisroberson Santos. This has already been indicated in the description of this video as well as in the Pinned comment.

[@crisrobersonsantos9192]

Thank you very much for your response Dr. Afroz Alam, I was a bit concerend about the resulting Final formula of the fault furrent since it would have a negative sign based from the note at the description and pinned comment. Your lectures had enlighten me on how the connections of sequence network had been made based from your clear derivations. I would share your lectures to my colleagues who are studying also power system. Thank you very much again, more power to your page and God bless!

[@DrAfrozAlam]

You are most welcome dear

[@Imran52Feb]

I also noticed but also found the correction mentioned by Sir.

[@DrAfrozAlam]

Download Fault Analysis handwritten lecture notes (pdf) using the following links: drive.google.com/file/d/18Zvgdi3YD6iAIkWJwz5-s7dVHRgM6lwZ/view?usp=sharing drive.google.com/file/d/1sfMf8BDsZ1BlKoehLLkokwizgtWHIbrr/view?usp=sharing drive.google.com/file/d/1eYOtrSzN7VwsqiLwjnrJ79BQd2LcE_Vy/view?usp=sharing

[@sarminkhatun81]

How can the sequence network is parallel??

[@DrAfrozAlam]

As per the two boundary conditions on sequence currents and sequence voltages, the sequence networks are connected in parallel. For more clarity, watch the complete video.

[@sarminkhatun81]

Without any node, any interred or outgoin path or if there is no way to apply kcl, can we called that is parallel circuit??

[@DrAfrozAlam]

The voltage drop across the parallel branches are always same. Can't you observe this?

[@chiragmittal9805]

thank you sir, for wonderful lecture. sir i had one question that why only zero sequence current flows through neutral? and secondly when we take fault impedance into consideration then also you told only zero sequence current will flow through it can you please answer both queries.

[@DrAfrozAlam]

In our previous lectures, we have already discussed that In = 3*I0 = IR + IY + IB. In order to have more understanding, please watch my lectures in sequence. Don't directly jump to Unsymmetrical faults. Start with Symmetrical components using the following link: kzbin.info/www/bejne/o4SngJmdqZyknKs

[@chiragmittal9805]

@@DrAfrozAlam OK SIR,thanks

[@ashutoshdimri6514]

Good afternoon sir