Delta Configurations (Full Lecture)
Вставка
- Опубліковано 23 лип 2024
- In this lesson we'll examine the analysis of balanced and unbalanced delta configured loads in 3 phase AC systems. (Full Lecture)
___________________
If you wish to support this project please visit the Patreon page at: / bigbadtech
___________________
Copyright information: Use this lecture. Use it at home, at work, or at school. Put it in a playlist, embed it in a website, share it with your coworkers, family, friends, and enemies. I made this lecture and posted it on UA-cam so users everywhere have free access to this information.
This being said, this UA-cam channel is meant to be the sole point of distribution for this lecture. Users are not authorized to download it, change it, or charge for access. Don’t even think of downloading it and uploading to your own channel and pretending it’s your own work. Not cool. Use this lecture and let your friends know this free resource exists.
Use it. Don't steal it. Be cool.
__________________
For more FREE online technical training check out the following playlists available at the bigbadtech channel:
DC Circuit Analysis • DC Circuit Analysis
Single Phase AC Circuit Analysis • Single Phase AC Circui...
3 Phase AC Circuit Analysis • 3 Phase AC Circuit Ana...
Hydraulics • Hydraulics and Electri...
Motor Control • Motor Control
Motors and Generators • Motors and Generators
Motor Drives/Variable Frequency Drives (VFD) • Motor Drives
Programmable Logic Controllers (PLCs) • Programmable Logic Con...
Explain in layman's term
If it were easy we'd call it mechanical engineering. Yes, there's some confusion involved in 3 phase AC circuit analysis (especially deltas) but the big thing to realize is that loads inside delta configurations experience the line to line voltage. Treat each load impedance as a single ohm's law calculation. To calculate line current it's sqrt3 larger than load current with a 30 shift.
@@bigbadtech lol at mechanical engineering reference
Delta unbalanced is way easier than Y unbalanced at least :)... Awesome as usual xoxo
While applying Kirchoff current law did you assume the direction of current arbitrarily or is there some convention ? @34:46
Entirely arbitrary. This being said be consistent. Choose 1 OR 2.
1) A to B, B to C, C back to A.
2) A to C, C to B, B back to A.
I’m a 1 man.
Is it legitimate to double check the work by using a kind of black box calculation? ie, you know each line voltage referenced to an imaginary ground, and each line current (and the angle offset between the two). So, no matter what happens inside the unknown box, you should be able to do your power calculations without having to know what's happening inside....
Yes, ironically enough that's kind of what the "two wattmeter method" is (albeit with a trigonometric trick where L2 is used as the reference). ua-cam.com/video/pWxpa4NncJM/v-deo.html
Here's another trick I use ... if you can figure out complex numbers and angles in MS Excel (no easy task!) you can make a spreadsheet that'll do the calculations for you given known impedance and voltage magnitudes and angles. It takes some effort to develop the spreadsheet, however, it's time well spent because you never have to do it again.
In the example on 14:14 why does the current lag by 20 degrees. Typically doesn’t current lag voltage by 90 degrees?
Only for purely inductive elements does current lag by a pure 90 degrees. Imagine a motor winding modeled as the series combination of a resistor and inductor. This element would have a complex impedance angle of less than 90. Check out the series complex impedance lecture at: ua-cam.com/video/peH89MVBh6U/v-deo.html
19:40 The center column seems weird to me - isn't there mistake in drawings of currents? shouldn't they be in phase difference of 120 degrees?
For a balanced delta load each load current would exhibit a relative 120 phase shift. The center column however illustrates each line current being equal to a load current MINUS a load current. Example: I1 = IAB - ICA, -ICA would be equal to ICA with a 180 phase shift.
@@bigbadtech Now I dig it😀 Thanks Jim
Great work, thank you! Question - why is the apparent power S = 108.2 angle 20, not negative 20?
Z= R +j(xl-Xc) so I (current, therefore apparent power S) with positive angle is a capacitive load, negative angle an inductive load- that is sign of angle matters.
at 13:50
you do want positive values for power I suppose for P and Q
ah, you mention a relative angle formula, that's why the voltage angle is 0 each time.
@@pstark4 Check out the "AC Power" lecture at: ua-cam.com/users/edit?o=U&video_id=nse2vSlOoME Yes, current must always be measured relative to voltage. Additionally, AC power computations make use of the complex conjugate operation because inductive power (ie: lagging current) is historically considered as having positive sign and capacitive reactive power (ie: leading current) is historically considered as having negative sign.
But I understand some of your videos
This is too hard to learn