How to Solve: Line to Ground Faults with Symmetrical Components - (Electrical Power PE Exam)

[@electricalpereview]

0:29 - Circuit parameters and SLG fault formula 3:51 - Solving for the positive sequence current component (Ia1) in per unit and amps 7:14 - Solving for the positive sequence voltage component (Va1) 8:47 - Solving for the negative sequence voltage component (Va2) 11:28 - Solving for the zero sequence voltage component (Va0) *note this is incorrectly written as Va3 in the video. 13:10 - Solving for the A phase voltage at the time of the fault (Va)

[@primetravelvlog1027]

Symmetrical components is one of the most important topic that a Power Systems Engineer must be very familiar. Zach made this topic easy to understand. This topic is much more clearer than before.

[@a.karalar1319]

These short videos are really well desgined. They are just about the correct size and keeps the student engaged. Symmetrical components explanation was an eye opener for me. Thank you for doing great job, Zach!

[@liger88OZQ8]

One of the hardest topics on the PE exam. Never covered this back in collage but this is great help. Easy steps to follow, got plenty of notes and added it to my materials.

[@electricalpereview]

Glad you enjoyed the video

[@d123miller6]

I didn’t have a whole lot of experience with Symmetrical components, but this video (in addition to the other videos in this series) really gives you a succinct and straightforward approach to solving. I recommend viewing the entire series.

[@rjulian1]

Way to go Zach. This explanation really simplified single line to ground fault analysis. It really made it pretty easy to solve.

[@orlandoortega369]

This is by far one of the best ways I've seen SLG Faults presented. I've read a few textbooks and it isn't as easy to understand as the way this video explains it. This has been very beneficial to understand faults.

[@ryanmeyer2223]

Using symmetrical components to solve for the different kinds of faults can be very confusing when trying to learn in from a book for the first time. This video and the other three fault videos in Zach's PE Electrical Review Course finally got me to understand and realize that each fault has it's one unique characteristics and formulas. I am no long scared when I see a symmetrical component problems! Bring it on.

[@pmm8272]

Symmetrical components is one of my toughest subjects on the electrical PE exam, but this video is extremely helpful in understanding how to attack these problems! No other reference material explains it as well as this video does!

[@hc6775]

This video really helps simplify a very complex topic, I would recommend it to anyone who is scared of symmetrical components. Zach has a great teaching style and gives helpful examples.

[@ngassthy]

Thank you Zach for making things so easier to understand. I was afraid of symmetrical components but you designed this lecture so that just the keys points can be understood without wasting time in non-essential. Now I feel confident when doing a PE exam symmetrical component problem.

[@michellequinn6196]

Symmetrical components are not the easiest topic to grasp. Thanks for breaking it down. I think watching your symmetrical Components videos and making reference sheets are really going to benefit me during the PE exam.

[@rfmoradkhani3049]

Very good video; explains all the required details about the symmetrical components and required ones for solving problems on PE exam. Zach is a great teacher.

[@mikemuchesi9895]

Symmetrical Components analysis can go so deep in complexity. Highlighting the foundations and how to tackle likely problems for the exam has boosted my confidence in this area.

[@ANEGRON69]

Great video to watch if you haven't had any experience with symmetrical components. This tutorial helped me understand the basic components behind zero, positive, and negative sequence components....Thanks Zach!

[@jynxdmonkey]

Again, Zach this was very helpful in understanding the concept. Was hoping to get more in depth on the other faults so I signed up to your class. Highly recommend

[@aymanantoun2083]

Wow! It helps me a lot for better understanding for Symmetrical components Please keep the great videos 👍

[@OB-gg1mo]

Symmetrical component is one of the more challenging topics for me to understand. However, the videos in this series have simplified things for me.

[@jacobcolston7733]

This is a great video that goes great with the study material that is provided in the Electrical PE online class on symmetrical components and how to use them on calculating faults .

[@thecajuneer]

Really takes the mystery out of symmetrical components. I have these examples in my PE reference material and use them often when solving problems.

[@andrew.kiefer]

Thanks Zach. This helped me gain a better understanding.

[@lilhopper100]

Hi zach, this video really made things make sense. I was really lost before watching this video and some others. thank you.

[@ralieghcowboy]

Very good video. Cleared up a lot questions that i had concerning single line to ground faults.

[@AIArchiveLabs]

Seeing it drawn this way makes it easier to understand, specifically when calculating voltage components.

[@aodugoudar]

Much more comfortable with symmetrical components - Helped me better understand the study I perform using softwares.

[@raniaelmarkizgenidy1074]

Hi Zach, thanks a lot for your dedication on this course, your way of simplifying the material in explaining and giving examples is amazing you are truly talented and expert

[@electricalpereview]

Thanks for the kind words Rania, I'm glad you enjoyed our online course.

[@sunilpsoni5]

great explanation on a very challenging subject to teach. well done zach

[@SOLOTHUG]

Thank you for covering this topic Zach.

[@egisbulcis516]

all your videos very helpfull and easy understand, and always had hard time with symmetrical components and fault calculations, after watching video it so easy to understand and visualize, i always now use your sketches, which help makes less mistakes

[@electricalpereview]

Thanks Egis, glad they were helpful. Best of luck on the PE exam.

[@aja51792]

I had never seen this before this class on Zach's live class series and now I'm less afraid of symmetrical components.

[@fredericosimonflores8998]

Very detailed Symmetrical Components explanation recommended to try the premium course.

[@electricalpereview]

Thanks Frederico.

[@jeffsams1344]

this video was very helpful, first I have this but going through the sequence step by step helps to understand.

[@sohailjanjua123]

Superb !! Wonderful video !

[@eminvalikhanov1245]

Does this apply to Bolted SLG too? (Zf=0)

[@electricalpereview]

Yes. The example problem in this video is indeed a bolted fault since there is no impedance included in the short circuit, it is a zero impedance ideal short circuit. The only impedance in the circuit is the equivalent positive, negative, and zero sequence impedance of the system at the fault locateion.

[@eminvalikhanov1245]

@@electricalpereview Thank you for your answer. I don't have Z values instead I have X0/X1/X2. Can I just simply replace those with Z's?

[@electricalpereview]

@@eminvalikhanov1245 Absolutely. Transmission line conductors and the loads on them are mostly inductive (+jX) loads. When you see impedance values instead in these types of problems, it's just the magnitude. For example a 2Ω inductive reactance (X = 2Ω) can be represented as an impedance in rectangular form as: Z = 0 +j2 Ω Or it can be represented as an impedance in polar form like this: Z = 2Ω

[@eminvalikhanov1245]

@@electricalpereview Woow thank you for great explanation. One last question: If I am turning grounding reactance of transformer to zero(T2=0.07=>0) what we can see the changes of magnitude?

[@drewlebowitz313]

Thanks Zach this is helpful - the signs on V=IZ are tricky

[@justinobenchain93]

This video was one that really gave me an 'ah-ha' moment. I knew literally nothing about symmetrical components before I started the Electrical PE course. After watching this video, among the others in the Premium course, I am confident I will be able to solve any of these problems on the exam!

[@electricalpereview]

Those "ah-ha" moments are what I live for Justin, glad I was able to help in delivering some of them to you. Best of luck on the PE exam, we enjoyed having you in our online course this semester.

[@eminvalikhanov1245]

Hir sir, in 3 bus 2 generator and 2 transformer system, if I make reactance grounding of transformer and generator equal to zero, what will be happening on the magnitude of fault current in both cases? Thanks.

[@Joseph-vh4ei]

the most helpful course

[@electricalpereview]

Thanks Youssef.

[@irishchocolate3872]

There must be round off error. When I add VZ0, VZ1 & VZ2 together I am getting 0. 076 which isn’t zero after storing the values in memory to add them.

[@jmnunnelee]

How are you determining that Va(1) is 72.5kv and then Va(2) is a negative value. Shouldn't they all be negative or positive? In your initial simplified diagram, you show the polarity as + to -.

[@electricalpereview]

When a complex number is "negative" it really just means that it is ±180 degrees out of phase. For example: For voltage, just swap the positive and negative voltage polarity references (the "+" and "-" signs trade places), and for current, change the direction from forward to backward (or vice versa). Va(1) is positive due to KVL, since the voltage drop across Z(1) is smaller than Vp(1): Va(1) = Vp(1) - Vz1 Va(1) = Vp(1) - Ia(1)•Z(1) [see 7:14 for these steps]. Va(2) and Va(0) are "negative" due to where these are located on the circuit and their polarity direction. They appear across each sequence impedance Z(2) and Z(0), however, they are in the opposite polarity compared to the actual voltage drop across each of these sequence impedances (for a load, the voltage drop is positive where the current enters, and negative where the current exists). [See 8:47 for Va(2) and 11:28 for Va(0)]. The reason why these sequence voltages are "negative" is because during fault conditions they act as a temporary voltage source that delivers fault current. A voltage source has opposite polarity compared to a load, the voltage polarity is negative where the current enters and positive where the current leaves.

[@gavincedana7547]

Very Helpful. But i think you should increase the volume of your voice. ^_^

[@electricalpereview]

Thanks for the feedback, glad you enjoyed the video.

[@nitaikiran7303]

Helpful