Talk:Power factor: Difference between revisions
m Archiving 2 discussion(s) to Talk:Power factor/Archive 4) (bot |
Constant314 (talk | contribs) m Reverted 1 edit by 103.89.26.28 (talk) to last revision by Qwerfjkl (bot) |
||
(18 intermediate revisions by 9 users not shown) | |||
Line 1: | Line 1: | ||
{{Talk header}} |
{{Talk header}} |
||
{{WikiProject banner shell| |
{{WikiProject banner shell|class=B| |
||
{{WikiProject Electrical engineering |
{{WikiProject Electrical engineering |importance=mid}} |
||
{{WikiProject Energy |
{{WikiProject Energy |importance=Low}} |
||
{{WikiProject Engineering |
{{WikiProject Engineering |importance=Low}} |
||
}} |
}} |
||
<!-- |
<!-- |
||
Line 23: | Line 23: | ||
a approx value of power factor which is acceptable in no energy losses <!-- Template:Unsigned IP --><small class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/115.248.112.54|115.248.112.54]] ([[User talk:115.248.112.54#top|talk]]) 13:33, 24 October 2017</small> |
a approx value of power factor which is acceptable in no energy losses <!-- Template:Unsigned IP --><small class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/115.248.112.54|115.248.112.54]] ([[User talk:115.248.112.54#top|talk]]) 13:33, 24 October 2017</small> |
||
⚫ | |||
== Specifying the circuits being discussed are LTI (of constant parameters) is not a leap too far == |
|||
⚫ | |||
Anonymous user of IP 86.129.19.88 reverted [https://en.wikipedia.org/enwiki/w/index.php?title=Power_factor&oldid=1028283002 my edit] to [https://en.wikipedia.org/enwiki/w/index.php?title=Power_factor&oldid=1029539014 this version]. Their reason: |
|||
⚫ | In this case, I'm looking at a power meter connected to a Dell R320 server with 2x350W PSUs connected to a 230V supply, and the power meter says the power factor is 36 while the server is turned off. What the hell is that supposed to tell me? This article doesn't answer the question at all. <!-- Template:Unsigned IP --><small class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/2A09:8E40:352B:D900:D16B:872B:FFD5:6B7D|2A09:8E40:352B:D900:D16B:872B:FFD5:6B7D]] ([[User talk:2A09:8E40:352B:D900:D16B:872B:FFD5:6B7D#top|talk]]) 05:01, 30 April 2022 (UTC)</small> <!--Autosigned by SineBot--> |
||
"This concept is a leap to far for an article of this nature. It only serves to obfuscate the issue being discussed. Simplicity is always better." |
|||
The next question is why do they make PSUs that have such a low power factor? Do the PSUs they put into servers suck? |
|||
In my edit, I clarified that it is linear time-invariant circuits (and not any linear circuit) that don't change the shape of applied volage in the resulting current. In other words, I fixed a mistake. There are linear circuits that produce harmonics: linear time-variant circuits. However, the user reverted my edit, making the article wrong again. |
|||
⚫ | |||
In my edit, I didn't go into much details of what was a time-invariant circuit. Instead, I just changed the words "linear" for "linear time-invariant", and I even added a short example of such a circuit: a circuit whose R, L and C are constants. |
|||
::What part of "the power factor of an AC power system is defined as the ratio of the real power absorbed by the load to the apparent power flowing in the circuit" is giving trouble? And "real power" and "apparent power" have links, in case those are troublesome. I admit, the article has been improved so much that it's nearly unreadable, but this one sentence seems to be still ok ( ignore the crap about "closed intervals", that's just Wikiwanking) Why are you measuring the power factor of something that's turned off? What did you expect to do with the measurement that you made? --[[User:Wtshymanski|Wtshymanski]] ([[User talk:Wtshymanski|talk]]) 04:11, 31 May 2022 (UTC) |
|||
== Improved, but edits still required. == |
|||
"It only serves to obfuscate the issue being discussed." // I don't think so. It serves to clarify what is being discussed: LTI circuits, not just any linear circuit. |
|||
Of course this isn't a question and answer forum, as pointed out, but the topic must correctly answer the question of precisely what the topic is, and go beyond dictionary level. |
|||
"Simplicity is always better." // Yes, simplicity is better, as long as it is correct, which was not the case. So that's why I corrected the article. |
|||
If "time invariance" is a present factor in determination of the accuracy of the calculation, it must be mentioned as such. In fact, no specification of time frames are present. RMS is barely mentioned. Where multiple waves exist, are offset, and aren't even sinusoidal, time frames must of course be measured, calculated or specified!!! If power factor is calculated on a per-cycle basis, which cycle is it? If it is NOT calculated on a per-cycle basis, what is the averaging basis? |
|||
Don't you prefer to have a specific but correct explanation than a shorter but wrong explanation? --[[User:Alej27|Alej27]] ([[User talk:Alej27|talk]]) 20:17, 20 June 2021 (UTC) |
|||
For some reason certain remarks ("the ratio of real power to apparent power") still exist over and over, but not in a problem / solution / proof format or presentation. In fact this wiki presently shows it is a collection of multiple, separate (and slightly conflicting!), pieces by multiple authors. |
|||
:In ordinary parlance, a resistor, capacitor, or inductor (or a linear amplifier) without further qualification is considered linear and time-invariant EVEN THOUGH there is always SOME voltage or current that can overload or destroy it, but that doesn't change its basic character. A VARIABLE R/C/L is considered to be linear on the timescale of the signal even though it changes when someone turns the knob. Yes, if a 100Hz signal is processed by an LTI circuit while someone turns the knob on millisecond time scales then you get new frequencies, but that doesn't justify changing our normal way of speaking. If the R/C/L is dependent on voltage or current then it obviously isn't linear, but you have different names for such components. There is always non-ideal behaviour that needn't be pointed out when it isn't dominant. Otherwise we could never talk about a resistor or capacitor without specifying its stray inductance, leakage, temperature dependence etc. These are a higher level of detail that shouldn't be introduced into the basic explanations. [[User:Interferometrist|Interferometrist]] ([[User talk:Interferometrist|talk]]) 21:10, 2 July 2021 (UTC) |
|||
I hold no degrees, only some licenses which required some schooling, so I don't speak, and can't contribute, on the level of the main contributors here. I don't feel comfortable or capable of tackling the needed editing at this point. I'd call on the authors to do a bit of that. [[User:Tranzz4md|Tranzz4md]] ([[User talk:Tranzz4md|talk]]) 18:03, 28 August 2022 (UTC) |
|||
:[https://en.wikipedia.org/enwiki/w/index.php?title=Power_factor&type=revision&diff=1029539014&oldid=1028283002 Here's the diff in dispute]. {{u|Alej27}}, I've added a link to [[Linear time-invariant system]] to help readers through this [[WP:JARGON|terminology]] you've introduced. I think it is a reasonable assumption that electrical parameters for the R, L and C devices are constant so stating that qualification is unnecessary. ~[[User:Kvng|Kvng]] ([[User talk:Kvng|talk]]) 14:10, 5 July 2021 (UTC) |
|||
:That is a valid complaint about this article. I will see if I can address it in the next few days. Also, most articles are a "collection of multiple, separate, pieces by multiple authors." [[User:Constant314|Constant<b style="color: #4400bb;">''314''</b>]] ([[User talk:Constant314|talk]]) 19:20, 28 August 2022 (UTC) |
|||
:: I think the [https://en.m.wikipedia.org/enwiki/w/index.php?title=Power_factor&oldid=1032095120 current version] as edited by {{u|Kvng}} is good. It doesn't say the R/L/C are constants (so I think it is in agreement with {{u|Interferometrist}}), but it also clarifies the ''wrong'' statement that linear circuits ''always'' produce sinusoidal outputs of same frequency to sinusoidal inputs (it's false, they don't, ''e.g.'' linear time-variant circuits). --[[User:Alej27|Alej27]] ([[User talk:Alej27|talk]]) 17:26, 5 July 2021 (UTC) |
|||
::I added the general case. I hope it answers the question. Everyone is invited to improve and edit. [[User:Constant314|Constant<b style="color: #4400bb;">''314''</b>]] ([[User talk:Constant314|talk]]) 20:52, 30 August 2022 (UTC) |
|||
::"...the higher currents increase the energy lost..." appears in the second paragraph. It would help me to know that this re-write is still correct: ...the higher currents increase ohmic heating (resistive loss)...". Energy is not "lost" to the electric field in a capacitor, or magnetic field in a motor. It's lost because efficiencies fall and stuff gets hot when I and V are not in phase. |
|||
::Before arriving at this Wikipedia article, I did consult Quora as suggested above. Quora now seems to count ChatGPT among its experts. After a bit of prompting, Mr GPT came back with "I apologize..." and agreed that "...it is accurate to state that a low power factor '''inevitably '''increases ohmic heating in electrical systems. Thank you for pointing out the ambiguity." (Emphasis mine.) |
|||
::If ChatGPT and I are correct, that 2nd paragraph might be revised slightly. I'm not all that confident in either of us (me and Mr GPT) so I'm not going to change anything.[[User:Captain Puget|Captain Puget]] ([[User talk:Captain Puget|talk]]) 18:43, 28 October 2023 (UTC) |
|||
:::Neither Quora nor ChatGPT are reliable sources. [[User:Constant314|<b style="color: #4400bb;">''Constant314''</b>]] ([[User talk:Constant314|talk]]) 20:16, 28 October 2023 (UTC) |
|||
:::The second paragraph looks correct to me. [[User:Constant314|<b style="color: #4400bb;">''Constant314''</b>]] ([[User talk:Constant314|talk]]) 23:15, 28 October 2023 (UTC) |
|||
:::I am neither claiming that Quora or ChatGPT is a valid source of anything, nor am I saying that paragraph is incorrect. I am asking if the loss is due to ohmic heating (which I believe to be the case), and not something else (I cannot imagine what that might be). Being explicit about the loss mechanism would seem a useful addition. [[User:Captain Puget|Captain Puget]] ([[User talk:Captain Puget|talk]]) 20:32, 30 October 2023 (UTC) |
|||
::::Yes, the loss is ohmic heating of the wires in that bring the electrical energy to the load. [[User:Constant314|<b style="color: #4400bb;">''Constant314''</b>]] ([[User talk:Constant314|talk]]) 20:36, 30 October 2023 (UTC) |
|||
== When was Power Factor first understood/detected/measured? == |
|||
::: Thinking back, long ago to my university lectures, it seems that in each class that the professor would say, once, near the beginning of the semester, that the math applied to linear time-invariant circuits. He did not elaborate. He was being rigorous, but not tedious. One time, I asked if a certain result always applied and the professor replied, “yes, for linear time-invariant circuits.” I suppose hearing it often enough drummed it into my consciousness. I think that is what we should do in this article. Mention it once, with a wiki-link, without elaboration and move on. [[User:Constant314|Constant<b style="color: #1100cc;">''314''</b>]] ([[User talk:Constant314|talk]]) 18:06, 5 July 2021 (UTC) |
|||
It would be useful for the article to discuss the origins and "finding/discovery" of Power Factor. It might also be worth including in this Power Factor topic a write up of how scam companies use Power Factor to sell devices claimed to reduce your residential electric bill by up to 50% with a $40 device that contains nothing more than a less-than-$1 capacitor, and a less-than-$1 green LED in a $2 plastic housing that plugs-in to an electrical outlet. [[Special:Contributions/2601:648:8100:C83:55A8:670F:C635:3E13|2601:648:8100:C83:55A8:670F:C635:3E13]] ([[User talk:2601:648:8100:C83:55A8:670F:C635:3E13|talk]]) 20:12, 24 April 2023 (UTC) |
|||
:::: {{ping|Constant314}} So in section ''Linear time-invariant circuits'' we should say something like "Linear time-invariant circuits ''(referred to simply as linear circuits for the rest of this article)'', for example, circuits consisting of combinations of resistors, inductors and capacitors have a sinusoidal response to the sinusoidal line voltage"? That'd be a good idea, since in the current version of the article, loads are still called as linear even though they are actually linear time-invariant (e.g. the power triangle doesn't hold true for linear time-variant loads). --[[User:Alej27|Alej27]] ([[User talk:Alej27|talk]]) 07:54, 21 July 2021 (UTC)← |
|||
:Scam avoidance and consumer warnings are outside the charter of Wikipedia. [[User:Constant314|<b style="color: #4400bb;">''Constant314''</b>]] ([[User talk:Constant314|talk]]) 20:33, 24 April 2023 (UTC) |
|||
::::: Sure, put in that parenthetical remark if it helps. When you don't specify otherwise, time-invariance is almost always assumed. You have to go to a lot of trouble to make an actual physical system that is not time-invariant, and even further to find an actual use for it. And in cases when something is labelled non-time-variant (like the "examples" I removed from the to-be-deleted "time-variant" page), there isn't any clear distinction between saying that and saying that it's a non-linear system with two inputs. So I don't know about any "time-varying loads", but perhaps you're referring to a motor under differing back torque, in which case you could just as well call that torque an additional input in a nonlinear system. So although "time-invariant" is a useful and correct qualifier, it hardly ever needs to be pointed out when you just say "linear system" or linear component. [[User:Interferometrist|Interferometrist]] ([[User talk:Interferometrist|talk]]) 15:34, 21 July 2021 (UTC) |
|||
::Would it not accomplish much the same thing to say somewhere that "unless a residential consumer is running a 100hp electric motor, it is unlikely that they would have a power factor small enough to impact the grid or their electric bill." [[User:Captain Puget|Captain Puget]] ([[User talk:Captain Puget|talk]]) 19:03, 28 October 2023 (UTC) |
|||
::: |
:::You would need a reliable source and it probably would not be notable. [[User:Constant314|<b style="color: #4400bb;">''Constant314''</b>]] ([[User talk:Constant314|talk]]) 20:14, 28 October 2023 (UTC) |
||
== Typos == |
|||
Seems like every page ought to have a section for just typographical errors. Anyway, this |
|||
"''The power factor...or equivalently the angle by which the voltage''" |
|||
seems to be missing a word. It should be "''...equivalently the '''sine''' of the angle...''". |
|||
The whole sentence seems unnecessarily long, though. I would suggest |
|||
''The power factor '''is''' the cosine of the angle θ ...'' |
|||
[[User:Captain Puget|Captain Puget]] ([[User talk:Captain Puget|talk]]) 22:41, 19 November 2021 (UTC) |
|||
:[[WP:BOLD|Go for it!]] You might as well fix the article as comment on it on the talk page, especially for stuff like this. --[[User:Wtshymanski|Wtshymanski]] ([[User talk:Wtshymanski|talk]]) 21:57, 22 November 2021 (UTC) |
|||
::No. Because it is the same angle. It is still the phase angle between current and voltage whichever way around you express it. Why we actually need to express it the other way around is another matter. [[Special:Contributions/86.188.36.150|86.188.36.150]] ([[User talk:86.188.36.150|talk]]) 18:05, 6 December 2021 (UTC) |
|||
⚫ | |||
⚫ | |||
⚫ | In this case, I'm looking at a power meter connected to a Dell R320 server with 2x350W PSUs connected to a 230V supply, and the power meter says the power factor is 36 while the server is turned off. What the hell is that supposed to tell me? This article doesn't answer the question at all. |
||
⚫ |
Latest revision as of 11:45, 22 August 2024
This is the talk page for discussing improvements to the Power factor article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google (books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
Archives: 1, 2, 3, 4Auto-archiving period: 3 months |
This article is rated B-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | |||||||||||||||||||||||||||||||
|
what is the approx value of power factor which is maintain by factory
[edit]a approx value of power factor which is acceptable in no energy losses — Preceding unsigned comment added by 115.248.112.54 (talk) 13:33, 24 October 2017
not understandable
[edit]This article doesn't make understandable what this power factor means or is supposed to be. It seems to indicate that "power" (whatever that means) somehow magically disappears because more current is being drawn from a supply than the device connected to the power supply receives.
In this case, I'm looking at a power meter connected to a Dell R320 server with 2x350W PSUs connected to a 230V supply, and the power meter says the power factor is 36 while the server is turned off. What the hell is that supposed to tell me? This article doesn't answer the question at all. — Preceding unsigned comment added by 2A09:8E40:352B:D900:D16B:872B:FFD5:6B7D (talk) 05:01, 30 April 2022 (UTC)
The next question is why do they make PSUs that have such a low power factor? Do the PSUs they put into servers suck?
- Sorry, this is not a question and answer forum. Try Quora. Constant314 (talk) 05:24, 30 April 2022 (UTC)
- What part of "the power factor of an AC power system is defined as the ratio of the real power absorbed by the load to the apparent power flowing in the circuit" is giving trouble? And "real power" and "apparent power" have links, in case those are troublesome. I admit, the article has been improved so much that it's nearly unreadable, but this one sentence seems to be still ok ( ignore the crap about "closed intervals", that's just Wikiwanking) Why are you measuring the power factor of something that's turned off? What did you expect to do with the measurement that you made? --Wtshymanski (talk) 04:11, 31 May 2022 (UTC)
Improved, but edits still required.
[edit]Of course this isn't a question and answer forum, as pointed out, but the topic must correctly answer the question of precisely what the topic is, and go beyond dictionary level.
If "time invariance" is a present factor in determination of the accuracy of the calculation, it must be mentioned as such. In fact, no specification of time frames are present. RMS is barely mentioned. Where multiple waves exist, are offset, and aren't even sinusoidal, time frames must of course be measured, calculated or specified!!! If power factor is calculated on a per-cycle basis, which cycle is it? If it is NOT calculated on a per-cycle basis, what is the averaging basis?
For some reason certain remarks ("the ratio of real power to apparent power") still exist over and over, but not in a problem / solution / proof format or presentation. In fact this wiki presently shows it is a collection of multiple, separate (and slightly conflicting!), pieces by multiple authors.
I hold no degrees, only some licenses which required some schooling, so I don't speak, and can't contribute, on the level of the main contributors here. I don't feel comfortable or capable of tackling the needed editing at this point. I'd call on the authors to do a bit of that. Tranzz4md (talk) 18:03, 28 August 2022 (UTC)
- That is a valid complaint about this article. I will see if I can address it in the next few days. Also, most articles are a "collection of multiple, separate, pieces by multiple authors." Constant314 (talk) 19:20, 28 August 2022 (UTC)
- I added the general case. I hope it answers the question. Everyone is invited to improve and edit. Constant314 (talk) 20:52, 30 August 2022 (UTC)
- "...the higher currents increase the energy lost..." appears in the second paragraph. It would help me to know that this re-write is still correct: ...the higher currents increase ohmic heating (resistive loss)...". Energy is not "lost" to the electric field in a capacitor, or magnetic field in a motor. It's lost because efficiencies fall and stuff gets hot when I and V are not in phase.
- Before arriving at this Wikipedia article, I did consult Quora as suggested above. Quora now seems to count ChatGPT among its experts. After a bit of prompting, Mr GPT came back with "I apologize..." and agreed that "...it is accurate to state that a low power factor inevitably increases ohmic heating in electrical systems. Thank you for pointing out the ambiguity." (Emphasis mine.)
- If ChatGPT and I are correct, that 2nd paragraph might be revised slightly. I'm not all that confident in either of us (me and Mr GPT) so I'm not going to change anything.Captain Puget (talk) 18:43, 28 October 2023 (UTC)
- Neither Quora nor ChatGPT are reliable sources. Constant314 (talk) 20:16, 28 October 2023 (UTC)
- The second paragraph looks correct to me. Constant314 (talk) 23:15, 28 October 2023 (UTC)
- I am neither claiming that Quora or ChatGPT is a valid source of anything, nor am I saying that paragraph is incorrect. I am asking if the loss is due to ohmic heating (which I believe to be the case), and not something else (I cannot imagine what that might be). Being explicit about the loss mechanism would seem a useful addition. Captain Puget (talk) 20:32, 30 October 2023 (UTC)
- Yes, the loss is ohmic heating of the wires in that bring the electrical energy to the load. Constant314 (talk) 20:36, 30 October 2023 (UTC)
When was Power Factor first understood/detected/measured?
[edit]It would be useful for the article to discuss the origins and "finding/discovery" of Power Factor. It might also be worth including in this Power Factor topic a write up of how scam companies use Power Factor to sell devices claimed to reduce your residential electric bill by up to 50% with a $40 device that contains nothing more than a less-than-$1 capacitor, and a less-than-$1 green LED in a $2 plastic housing that plugs-in to an electrical outlet. 2601:648:8100:C83:55A8:670F:C635:3E13 (talk) 20:12, 24 April 2023 (UTC)
- Scam avoidance and consumer warnings are outside the charter of Wikipedia. Constant314 (talk) 20:33, 24 April 2023 (UTC)
- Would it not accomplish much the same thing to say somewhere that "unless a residential consumer is running a 100hp electric motor, it is unlikely that they would have a power factor small enough to impact the grid or their electric bill." Captain Puget (talk) 19:03, 28 October 2023 (UTC)
- You would need a reliable source and it probably would not be notable. Constant314 (talk) 20:14, 28 October 2023 (UTC)
- Would it not accomplish much the same thing to say somewhere that "unless a residential consumer is running a 100hp electric motor, it is unlikely that they would have a power factor small enough to impact the grid or their electric bill." Captain Puget (talk) 19:03, 28 October 2023 (UTC)