Talk:Mathematics of three-phase electric power

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Early comments[edit]

I still have a lot to write here and i will probablly virtually rewrite the peice to fit this articles style more but i feel that the main information in it fits here better than in three-phase electric power. Im still getting used to wikipedias system for typing forumulae as well so this article may take a while. Plugwash 22:52, 21 Dec 2004 (UTC)
Carry on! I was impressed at the math notation, and it looks pretty reasonable.

The description of "complex power" is just not found in my books, usually the phrase refers to "real" and "reactive" power - nothing to do with three phases. I think 2 phases also has the "constant power" property, I was incorrect.

Not sure if the title should change - "three phase" and "three phase power" might merge together in a while. --Wtshymanski 20:27, 22 Dec 2004 (UTC)

OpenOffice.org will export pictures in .PNG form - my next project is to draw delta and wye connected sources. --Wtshymanski 02:37, 26 Dec 2004 (UTC)

Nice that you have found a way to make diagrams. The title complex power isn't really right for that section but the content is important. I may comment it out until i get chance to rewrite it. Three phase power is currently a redirect to Three phase electric power which is an article on where why and how three phase is used. That article is already pushing the reccomended size limits of a wikipedia article so merging this lot with it is probabblly not a good idea. Plugwash 12:02, 26 Dec 2004 (UTC)

A better, or at least more encyclopedic, title would be Three-phase systems. --Wetman 23:02, 21 Dec 2004 (UTC)

can't say im a fan of long titles myself. Short titles are easier for people to remember and im not really convinced that adding the word systems to this title adds anything usefull Plugwash 12:03, 26 Dec 2004 (UTC)

I'm an electrical engineering student, and this is the first (and only) Wikipedia article I've read that shows caculations without getting to the fundamental issues I need to understand the material. I assume that "star connected" is a more general term for "wye connected" but I would like to see how this relates to delta connections. Particularly helpful would be some talk about the difference between line voltage and phase voltage and the difference between line current and phase current. These are the types of simple-yet-confusing issues that Wikipedia articles can explain like noone else. It would also make sense to discuss the difference between complex, real, and reactive power. If no one has any objections, I might right the complex power bit at the end of the semester. However, I'm not qualified to tackle the other issues I mentioned. I sincerely hope that one of you will write that stuff. Raeyin 21:17, 13 December 2006 (UTC)[reply]

'Star' connection is the English useage. 'Wye' connection is the American useage. 86.179.167.116 (talk) 18:03, 18 December 2010 (UTC)[reply]

For the non engineering person like myself might be useful to have a paragraph on why such a mechanism is used and some examples


math changes[edit]

Purpose of this edit:

  1. Avoiding setting dimensional quantities equal to 1. Instead achieve a similar simplification (removing constant factors from the math) by working in terms of a non-dimensionalized quantity, and substituting back and the end.
  2. Use as symbol for peak voltage instead of , as slightly more self-explanatory.
  3. Adding a line explaining what the "star" configuration is.

— Alan 21:20, 16 April 2007 (UTC)[reply]

i'd like to send out a big thankyou to whoever put this piece together. i have finished my first year of electrical engineering and we are yet to cover three phase systems, however this has definitely given me a strong head start for the upcoming year.(i particularly like the rotating phase diagram at the bottom, this is a very good visual aid.) two thumbs up & keep up the good work. —Preceding unsigned comment added by 203.49.139.142 (talk) 21:56, 4 February 2008 (UTC)[reply]

The break down of the trig functions is incorrect. The second minus sign should be a plus sign. —Preceding unsigned comment added by 64.95.214.18 (talk) 19:38, 26 March 2008 (UTC)[reply]

three phase current[edit]

how do i get input current of the three phase power supply if i dont have any power analyzer equipment? if the my supply will be delta or wye, will ther be a difference in current derivation? —Preceding unsigned comment added by 122.248.16.2 (talk) 08:19, 23 April 2008 (UTC)[reply]

Introduction[edit]

Within the intro, could someone with knowledge on this topic inject a sentence or two of the practical application of three-phase systems? I'm sure this technology is more than just an exercise in mathematics...

maybe someone can digest this article: http://science.howstuffworks.com/environmental/energy/power3.htm 218.186.17.10 (talk) 13:11, 12 June 2011 (UTC)[reply]

copyvio accusation[edit]

As I said on my talk page I wrote the original content on this page myself from scratch, futher the site I was accused of copying it from didn't even exist at the time I wrote the content as can easilly be seen from a whois on thier domain. Plugwash (talk) 22:51, 28 February 2010 (UTC)[reply]

I agree that my accusation of Plugwash was probably misplaced, but I don't know that the copyvio tag is. See Plugwash's talk page for a full discussion, including a possible revision number. —Voidxor (talk) 07:00, 5 March 2010 (UTC)[reply]

Copyright problems[edit]

In February 2010, this article was quite properly tagged for copyright investigation given its resemblance to [1]. However, investigation suggests that this is a case of reverse infringement. The oldest archive of that external site is June 15 2006. Focusing solely on the duplicate sentence, "Generally, in electric power systems the load is distributed as evenly as practical between the phases." That sentence enters our article in December 2004, as part of a copy-editing of what previously existed. Another duplicate sentence, "To keep the calculations simple we shall normalize A and R to 1 for the remainder of these calculations", is already in the article by that time, placed by a different contributor.

Noting the above conversation, I look to see that the external site seems to have duplicated the article at some point around here.

Contributors to this article who may be interested in complaining about what seems to be a copyright violation created by the unlicensed reuse of their text may wish to see Wikipedia:Mirrors and forks for the process.

The Wikimedia Foundation takes copyright concerns seriously. Noting and helping resolve the problem very much appreciated. :) --Moonriddengirl (talk) 13:19, 6 March 2010 (UTC)[reply]

doubt[edit]

what are three phase balanced and unbalanced load? —Preceding unsigned comment added by 218.248.64.205 (talk) 17:22, 14 December 2010 (UTC)[reply]

A balanced load is when the current flowing in all 3 phases are equal in amplitude and exactly 120 degrees apart in phase. In 4 wire delta (or wye) connected system, the 3 currents will sum to zero with the result that there is no current flowing in the neutral. Any other condition is an unbalanced load. The absence of a neutral current does not mean that the load is balanced. 86.179.167.116 (talk) 17:13, 2 January 2011 (UTC)[reply]

Spelling[edit]

It's "triplen" in this context. Google books gives about 1700 hits on 'triplen harmonic current' , most of the ones I've looked at are relevant to this article. Changing one letter drops the Google books hits to around 14 results, mostly in music theory, and many with the spelling 'tripluM'. Your move. --Wtshymanski (talk) 15:38, 3 January 2011 (UTC)[reply]

I noted a couple of the 'triplen' hits are from publications in India, so both majority dialects of English spell this word the same way. --Wtshymanski (talk) 15:46, 3 January 2011 (UTC)[reply]

Illustration?[edit]

The rotating magnetic field of a three-phase motor

Does this illustration support the understanding of a rotating field? Being an electric engineer, I hardly understand it and its function. I have discussed it with a number of colleges - same result. In addition to the confusing vectors, there are a number of disturbing figures and shadows which does not add any understanding to the phenomenon of a rotating field. I suggest to remove this confusing illustration. KjellG (talk) 23:25, 12 March 2011 (UTC) (PS. Why does it not work with 250 px?)[reply]

So how does it relate to the real world ?[edit]

This is meant to be an encyclopedia - accessible to the intelligent general public, not a showcase for flaunting familiarity with mathematical expressions. There is nothing here about why we need it, how/where/why/when it is used, who invented it and when and why, how it compares and contrasts to other forms of electricity etc. In other words, the context. Anybody who can understand the jargon here wouldn't be using Wikipedia for their research about electricity. Rcbutcher (talk) 09:03, 27 November 2012 (UTC)[reply]

That's why the hatnote says "This article is about the basic mathematics and principles of three-phase electricity. For information on where, how and why three-phase is used, see three-phase electric power." This article was meant to spin out minute picky mathematical details out of the main article. --Wtshymanski (talk) 14:56, 27 November 2012 (UTC)[reply]
D'oh - beats self about head and mutters "I should have read the intro". Sorry. Rcbutcher (talk) 01:48, 28 November 2012 (UTC)[reply]
It does show the problem with relying on hatnotes, though. We're conditioned to ignore 2/3rd of the text we see every day... --Wtshymanski (talk) 21:35, 29 November 2012 (UTC)[reply]

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