Analysis of L-L-G Fault (Double line-to-ground fault)

[@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

[@tahmidhussain8]

Next level simplification of such a vast topic.

[@raghulg6155]

Love you 3000 sir💖..Awesome lecture this goin to help me a lot for my exams... And i've watched all of the three fault types continuously for more than 2 hr and its not still boring. Best way of lecturing...

[@DrAfrozAlam]

Thank you so much Raghul G

[@raghulg6155]

@@DrAfrozAlam You deserve it sir💖

[@paulsugu]

Crystal Clear Explanation | Your handwriting is very much appreciable | I would like to watch all your Power system Analysis videos, Sir. | Thank you, Sir.

[@DrAfrozAlam]

It's my pleasure

[@AshokMeena-vn4fi]

I am extremely grateful to you sir for your wonderful explanation of this subject. this topic had bothered me for so long but after i saw your lectures all my worries are gone. May god bless you sir and may you continue dissipating knowledge among needy students like this..allah aapko slamati aur barakat de

[@DrAfrozAlam]

Thank you Ashok for your kind words. If you need Electrical Machines lectures too, you may watch the following video lectures: DC Machines: kzbin.info/aero/PLEVP-S4VFKO8U8DMTGIytVJ8-L4KIwqLX Synchronous Machines: kzbin.info/aero/PLEVP-S4VFKO96Bao3uSYtCRw5wbJPbtYu

[@caDet07]

Answer of fault current (I f) = j 8.57 pu ❤

[@mdh7739]

Sir Mazaa aagya , May Allah (SWT) shower his mercy on you. Please continue the lectures sir. Power System Protection please sir. The lectures weren't boring. I'm a fresher , studying this subject for the first time. Gained a lot from this Alhumdulillah

[@tesfayekefale2308]

Thank you Dr. Afroz Alam ,you explain fantastically .

[@DrAfrozAlam]

You are most welcome Tesfaye Kefale

[@Akash-ek5fy]

Sir your lectures are extremely helpful for cleaning all the doubts. ❤️❤️

[@afjalansari0325]

خدا ہافظ سر I am seeing this lecture for the first time. Enjoyed sir.

[@jasonbojorcelo3695]

I have been watching your lectures sir. Thank you for sharing this on YT!

[@DrAfrozAlam]

My pleasure

[@surendrakverma555]

Excellent lecture Sir. Thanks and Regards 🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏

[@arifahmed3219]

Sir, @ 33: 12, you have said that there will be no fault current if the neutral of alternator is ungrounded. But it is evident from the sequence network for LLG Fault that, if the neutral of alternator is ungrounded, the system will behave as if L-L fault has occurred. Thank you Sir, for excellent lecture

[@DrAfrozAlam]

Please note that in L-L-G fault, the fault current If=3*IRo. For IRo (Zero sequence current) to flow, there must be a path through neutral. Don't be confused with L-L fault as in L-L fault, the terminal voltages of two phases (Short-circuited phases) are not at ground potential as in case of L-L-G fault (whether neutral grounded or ungrounded).

[@DrAfrozAlam]

Alternatively, for an ungrounded neutral, you may substitute the value of Zn as infinity in the expression of L-L-G fault current. You will see that the value of this fault current will be zero.

[@arifahmed3219]

Thank you Sir, for your kindness to quickly clear my doubt, but still I am confused. In LLG sequence network if I substitute Zn as infinity (considering neutral ungrounded) there is still another path for current to flow. Although the current through ground(If) will be zero but large amount of current will be flowing between shorted phases limited by positive and negative sequence impedences.

[@Aspirant-lp8cw]

Excellent explaination sir..

[@Binilbabu42]

Thanks for this wonderful lecture..! Really helpful..👍👍

[@rajivvyas9190]

Thank you sir 🙏 amazing board work

[@MohamedSaad-jn3po]

best regards from egypt

[@DrAfrozAlam]

Thank you dear

[@shafqatimam3690]

So useful explaination👍

[@smdshareef2861]

Mashallah bahut bahut sukriya sir.

[@varshanancy2735]

Lots of love sir❤❤❤

[@bilalberkdemir9745]

God bless you Sir

[@talhalaiq6452]

thanks a lot, sir.. great lecture..

[@DrAfrozAlam]

Most welcome

[@shahinurrahman6400]

Love from Bangladesh.

[@DrAfrozAlam]

Thank you Shahinur Rahman

[@sreeragkr5381]

Thank You so much sir...

[@shariefmahaboob2363]

Sir you are awesome And sir can u please make one video on what is the difference between ups and inverter please.....

[@surendrakverma555]

Sir I have two doubts. 1. Why no load condition is considered during fault analysis though in practice all lines are loaded and fault will occur on loaded phase. What will be it's effect? 2. As positive sequence current is not flowing in neutral then how circuit is completed for a.c load? Regards

[@DrAfrozAlam]

1. In order to make calculations easy. Load conditions are considered in higher studies (M.Tech, Ph.D etc.) 2. For a balanced system, potential at neutral is zero (as Va + Vb + Vc = 0). For current in phase a, other phases provide return path. For more details, please observe the current waveforms of a 3-phase balanced system where phase currents have a progressive phase dusplacement of 120 degrees. i.e. when current in a particular phase is positive, the currents in other phases may be negative (providing return path).

[@surendrakverma555]

@@DrAfrozAlam Thanks for your kind reply Sir. Regards

[@surendrakverma555]

Very good

[@surendrakverma555]

Sir which book should be concerned for fault analysis? Regards 🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏

[@DrAfrozAlam]

Hadi Saadat

[@surendrakverma555]

@@DrAfrozAlam Thanks Sir

[@Haider_Waseem_445]

Amazing.

[@DrAfrozAlam]

Thank you Waseem.

[@Tsxvb108]

Sir is it possible to upload lectures on "Transmission line" and " Travelling waves"

[@safwan1771]

Yes sir fault current is j8.5714 p.u

[@DrAfrozAlam]

👍👍👍

[@seeker8028]

Fault current is 8.57

[@DrAfrozAlam]

Absolutely correct,,,,,,,Just now, I also calculated. It is coming out to be the same i.e. j8.571 p.u.

[@upscwaalla]

Sir it means if there is no neutral then llg fault cannot exist

[@muhammadrizdaal-aziz9754]

sorry i am have a question, when the logic have a IR0 + IR1 + IR2 = 0 and why not IR0=IR1=IR2 = 0 or IR0 - IR1- R2 = 0

[@andystark8598]

sir maa kasm bol raha hu, meine 5 hrs me pura kar liya aur number bhi aa gaye!

[@jubinissac4398]

thanks sir

[@faisalrahman5697]

SIr, if neutral is ungrounded in case of L-L-G fault, then what will we consider? Fault current = 0 or we will consider it as L-L fault

[@caDet07]

If it's LLG fault you can't say that it's ungrounded it's common sense and fault current will be 0 And Yes we can say LL fault to it

[@amankumaaryadava1627]

Sir wo aapne neutral ke pass jo zn liya h wo jaruri h kya uska kya importance h. Kuchh video lecture me wo nhi liya gya h.

[@DrAfrozAlam]

Haan, zaruri hai. If neutral is solidly grounded only then it's value will be zero. For better understanding, don't skip previous lectures.

[@ijaharalam8024]

Assalam walekum sir I'm electrical Engineering student , I want Hindi lecture of fault . please

[@ADARSH.VASHISTH]

Jai shree ram 🚩