Talk:Utility frequency/Archive 1

Archive 1

Tesla

The text around history of 50 vs 60 has been shortened over the past half year, so for reference below is what i originally compiled in August 2006. I have no real argument with the subsequent edits, but thought there might be some interest in some of the further details (and caveats) in the longer text. --Psm 21:40, 5 January 2007 (UTC)

Though many theories exist, and quite a few entertaining urban legends, there is little certitude in the details of the history of 60 Hz vs 50 Hz. What is known is that Westinghouse in the US decided on 60 Hz and AEG in Germany decided on 50 Hz, eventually leading to the world being mostly divided into two frequency camps. What is also well understood is why the frequencies ended up in the 50-60 range: direct current generators that came online in the late 1890:s were more stable at lower rotation speeds, and the flicker of lighting becomes noticeable somewhere below those levels. Westinghouse decided on 60 Hz before 1892 and AEG decided on 50 Hz by 1899. Tesla is believed to have had a key influence in the choice of 60 Hz by Westinghouse, but it may simply have been happenstance: Westinghouse won the World Fair in Chicago (1893) lighting contract, and after that the Niagara Falls project, both of which were 60 Hz. Maybe it simply "stuck" as corporate decisions are wont to do. AEGs choice of 50 Hz is by some thought to relate to a more "metric-friendly" number than 60, which would be peculiar since it is distinctly less efficient than 60Hz. It may also have been an intentional decision to be incompatible. In any case, a plethora of frequencies continued in broad use. For example, London in 1918 had 70 electric authorities with 24 different voltages and 10 different frequencies. It wasn't until after World War II with the advent of affordable electrical consumer goods that broader standards were enacted.

Niagara started off at 25 Hz, with a good explanation by Lamme in the 1918 article. The Edward Owen article in Dec. 1997 "IEEE Industry Applications" says Stillwell of Westinghouse decided on 60 Hz in 1890, because arc carbons in the US at the time didn't work well at 50 Hz and 60 Hz would be OK for induction motors. AEG was related to General Electric, and GE used 50 Hz for Mill Creek but soon switched to 60 Hz; the Owen article says they were losing market share to Westinghouse. The Owen article also says that AEG moved to 50 Hz because the 40 Hz of the Lauffen-Frankfurt transmission gave some light flicker (and by this time Europe would have been using 240 V metal-filament lamps which were more sensitive than 120 V or carbon-filament lamps).

I didn't find a link between Tesla and 60 Hz except indirectly since the induction motor didn't work well with the 133 Hz single phase power of 1880; to use Tesla's motor with the materials available at the time required a lower frequency. In 1890 the whole world was within an eyelash width of all being 50 Hz.

Someone in the Baltimore Amateur Radio Club transcribed the 1918 Lamme article and put it on-line as a .PDF file (at [1]); anyone editing this article should read the Lamme paper, and I'd also highly recommend the Hughes book, too. --Wtshymanski 16:44, 5 November 2007 (UTC)

Various

I heard a rumor that higher-frequency waves on the power lines would increase efficiency and decrease losses.

I'm skeptical, and Utility_frequency#400Hz seems to say the opposite. Which is true? — Omegatron 17:41, 16 September 2006 (UTC)

The History section is a bit repetitive. The second half of that section says pretty much the same as the first, only in slightly different words. Perhaps someone ought to tighten that up a bit. 203.191.193.38 06:38, 4 January 2007 (UTC)

Yeah, this article has incorporated historical frequency texts from different sources, and would certainly be helped by some editing. --Psm 21:40, 5 January 2007 (UTC)

How does it look now? --Wtshymanski 16:44, 5 November 2007 (UTC)

Because of capacitance between lines, and between lines and ground, a higher frequency means more losses in the transportation of the energy. Conversely, a higher frequency requires smaller transformers, that can be cheaper or more efficient than lower frequencies. So, you gain on one side, and lose on the other.

Stability

The stability chapter on the main page claims that the line frequency is adjusted so that "at the end of the day" we are within reasonable accuracy. Another website claims that the power companies will run the frequency .01Hz fast or slow to bring it back so that there are exactly 216,000 cycles each hour. Which is right? Who controls the frequency, and how accurately do they keep it? Should I assume each hour has the right number of cycle, or each day? I suppose this needs to be answered on a per country or region basis. —Preceding unsigned comment added by 66.84.205.186 (talk) 23:45, 20 November 2007 (UTC)

I recently bought a Fluke digital multimeter which has a frequency counter built in, which resolves 0.01 Hz at 60 Hz. I've observed my local wall plug frequency (Manitoba, linked to the MAPP area of the North American electrical system) and I've seen as low as 59.98 Hz around suppertime during the week and up to 60.03 Hz on Sunday afternoons. This is consistent with lower frequency during heavy loads and trying to average out the frequency during the day, though I'm not checking nearly as often as necessary to verify the network's performance. --Wtshymanski (talk) 22:13, 14 February 2008 (UTC)

"System time", the integrated line frequency, is compared to real time by most operators. The UK system operator endeavours to keep system time and real time as close as possible, and to reduce accumulated errors through means of speed correction, though it does not do so on an hour-by-hour or even day-by-day basis. You can view real-time frequency data on their website. Operational limits for the UK are set at ±0.2 Hz, rather more than the ±0.02 Hz Wtshymanski has observed in Canada, though the North American (and, for example, continental European) systems have substantially more system inertia than the essentially islanded UK system. This acts to considerably stabilise the supply frequency. — BillC ^talk 02:21, 29 February 2008 (UTC)

Requesting color change in the world map

Hi, i'm new to editing Wikipedia and stuff so i apologise if i post this at the wrong place. I happen to be color blind and actually had to check the world map with paint shop to spot which countries had different shades of blue. Would be nice if a version with more different colors could be posted.. For ex not yellow/green, or blue/that other blue.. it really sucks being color blind ;( —Preceding unsigned comment added by 213.226.106.200 (talk) 03:54, 24 March 2008 (UTC)

25 Hz - Grids

Were the 25 Hz Grids also used for electric lighting purposes? Were the 25 Hz-grids not used for railway electrifications single phase or three phase grids? —Preceding unsigned comment added by 91.46.245.89 (talk) 10:10, 15 May 2009 (UTC)

AEG

AEG (Allgemeine Elektrizitäts-Gesellschaft) Was founded by Walter Rathenau (later foreign minister) and some other german "money people". The goal of the company was to introduce Edisons electricity patents in Germany. They purchased/rented a licence from Edison to do that. But the company was not founded by Edison. Nevertheless the AEG soon left the "DC party" to join the AC technology. —Preceding unsigned comment added by 93.221.240.67 (talk) 15:15, 2 November 2010 (UTC)

Frequency regulation experiment

Yes, the same AP story got picked up by a zillion Web outlets. But I can't find anything on the NERC Web site. The NERC June newsletter doesn't even mention this. I don't doubt Seth Borenstein at AP got his facts right, but it woudl be very interesting to see NERC's explanation of what is planned, how the specific drifts in time were estimated, and what savings might be obtained by letting long-term frequency regulation relax. --Wtshymanski (talk) 14:37, 6 July 2011 (UTC)

Sound files

The 50 and 60 hz sounds like an amplifier buzz. Waveform is square with lots of harmonics superimposed. I don't think it's accurate to generalize to the "hum" of a single type of device. Might it be better to post actual clean sinusoidal waves instead? Even the 400hz sound has lots of harmonics superimposed, pretty much drowning out the base 400hz wave. 66.114.93.6 (talk) 21:27, 13 March 2010 (UTC)

The entry on mains hum explains why this is mistaken reasoning regarding the frequency content of mains hum signatures. http://en.wikipedia.org/wiki/Mains_hum LVv8LBX6c6V8eqOS (talk) 13:57, 12 July 2012 (UTC)

droop speed control

Revision history of Utility frequency (cur) (prev) 15:27, 30 March 2010 Wtshymanski (talk | contribs) (26,438 bytes) (Please stop. This is just wrong and irrelevant. Undid revision 352963354 by Wdl1961 (talk)) (undo)

pls have some degreed electrical engheadline Subject/headline preview: (→droop speed control: new sectionrs stop this Wdl1961 (talk) 15:40, 30 March 2010 (UTC)

• Please post comments more intelligibly. The reference which was added by User:Wdl1961 was to a website which had anonymous postings and apparently no editorial supervision for accuracy of the postings. The person who posted there about "Droop speed control" did mention some possible references. As such it does not constitute a reliable source and should not be added to an article, especially when the article is a highly technical one already linked to numerous reliable sources, and when there are journal articles, textbooks and handbooks which address the issue of speed control and generator dispatch theory. The same ref appears in the Droop speed control article and does not belong there either. Is "droop speed control" really that common of a term? It barely gets mentioned in Fink and Beatty's "Standard Handbook for Electrical Engineers (11th ed). Edison (talk) 17:17, 30 March 2010 (UTC)

Droop speed control is a very common term amongst those electrical engineers and operators who design, maintain, and operate large marine power generation systems.LVv8LBX6c6V8eqOS (talk) 14:10, 12 July 2012 (UTC)

pls see droop speed conrol fro refs. how much discussion do you need for x=x0+kf?Wdl1961 (talk) 17:36, 30 March 2010 (UTC)

For a more useful discussion of this subject, see [2], starting at Slide 18. This is a training presentation from the PJM Interconnect, the power grid for the Eastern US, and it's aimed at the people who actually run the generators. "Droop control" is discussed in detail, and watching that presentation should clarify the issue. --John Nagle (talk) 20:31, 30 March 2010 (UTC)

Incompatibility between 50Hz and 60Hz?

Is is really true to say that "Unless specified by the manufacturer to operate on both 50 and 60 Hz, appliances may not operate efficiently or even safely if used on anything other than the intended frequency."? Fair enough if it's something specifically designed to use AC, there could be a problem, but at a consumer level most electronic devices rectify and smooth the current before it reaches anything sensitive, so would it really be such an issue? AlexGordovani (talk) 21:43, 1 February 2013 (UTC)

Well, yes, consumer stuff is made in enough volume that it's an economic win to idiot proof it; and any power tool you can lift with one hand probably doesn't care much about frequency. But the sentence visualizes a world beyond that of consumer goods. I wouldn't light-heartedly power up a 5000 HP mine hoist on a 60 Hz supply unless I had some really good indication that it would be something the manufacturer had thought (carefully) about. And even in the consumer area, not every portable appliance made would have been happy changing power frequencies; we must beware of recentism. --Wtshymanski (talk) 16:17, 2 February 2013 (UTC)

Frequency Control

Added a small section in the Stability section outlining how the frequency of the system is restored after a load mismatch occurs. — Preceding unsigned comment added by Acidmagic (talk • contribs) 04:20, 27 November 2013 (UTC)

I removed the unreferenced addition because some of the statements seemed counterfactual, such as the generator governor adjusting the system load. It also stated that the frequency is restored in minutes, which is, sadly, not always the case. Some utilities hate to drop or to sever interconnections, and on high-load days I have seen a slightly droopy frequency persist for quite a while. The integrated time error, shown by a synchronous clock dropping many seconds behind official time, might persist until the load drops in the wee hours of the morning. Perhaps you are stating how it works for some individual utility, or how you think it should work. A reference to a reliable source is needed, so others can verify the accuracy of the text. Edison (talk) 23:38, 27 November 2013 (UTC)

History

The history section states "Though many theories exist, and quite a few entertaining urban legends...", yet does not specify what any of these may be. Does anyone have the source that the writer quotes? I've tried to access the article via the institutional account we have at work, but our online access doesn't cover as far back as 1997. 197.87.229.61 (talk) 16:31, 20 August 2015 (UTC)

Tables

The tables have a column labled "cycles", a terminology that's been obsolete for more than 50 years. The description is "frequency", the unit of measure is "hertz", and the symbol for hertz is "Hz". Cycles doesn't belong in an encyclopedia except in an article about obsolete terminology. — Preceding unsigned comment added by 108.7.62.214 (talk) 00:30, 11 March 2015 (UTC)

Yes, but if you take a look at the tables, the most recent one dates from 1945. In all likelihood, the column is labelled "Cycles" because that's the terminology used in the original tables from which the writer was copying. If the documents used as sources in this section were created during the time periods when "cycles" would have been the correct terminology, then it's still an acceptable use of the term. Perhaps we could just add a footnote to the effect that the original tables use dated terminology, and that the term has since been replaced by "frequency". Bird Tiger (talk) —Preceding undated comment added 16:41, 20 August 2015 (UTC)

Cycles should at least be cycles per second or CPS as it used be indicated. It is not wrong to recreate the tables as they were in the original source. However, it is also completely acceptable to modernize it to Hz.Constant314 (talk) 20:49, 20 August 2015 (UTC)

Load Frequency Control

The article says "The general control algorithm for LFC was developed by N. Cohn in 1971.[31]" Nonsense. The mechanics of LFC (as well as economic dispatch ED), including area control error ACE, were the subject of a noted book. https://www.amazon.com/Economic-Control-Interconnected-Systems-Kirchmayer/dp/B007CPV5W8 Economic Control of Interconnected Systems by L K Kirchmayer, Publisher: John Wiley and Sons (1959) ASIN: B007CPV5W8 Anorlunda (talk) 20:26, 28 July 2016 (UTC)

I don’t know anything about it, but the wording is “general control algorithm for LFC was developed”. Developed doesn’t mean invented or even defined. And algorithm suggests a computer program. Is it possible that Kirchmayer did the theoretical work and possibly disclosed a quasi-optimal strategy based on non-general simplifying assumptions while Cohn reduced the general algorithm to practice? Constant314 (talk) 22:52, 28 July 2016 (UTC)

I won't comment on any of the above other than to say that an algorithm is certainly not necessarily a computer program. As a word, 'algorithm' is well over a thousand years old, and the practice is over a thousand years older. The Sieve of Eratosthenes is an algorithm and dates from around 200 BC. —BillC ^talk 23:27, 28 July 2016 (UTC)

Time error correction: US Regulations

I've reverted the removal of a secondary source and addition of this statement: "reducing the manual correction would reduce clock error overall, not increase it." The source doesn't say that, and I don't believe it's true. What it does say is that eliminating manual TEC will "not adversely affect frequency." The NERC proposal sacrifices long term clock error in favor of improving short term frequency swings. MSNBC accurately describes the situation and has the advantage of being a secondary source. Kendall-K1 (talk) 15:46, 16 October 2018 (UTC)

No technical reason to prefer one (frequency) over the other

No authoritative source is given for the claim that there is no technical reason to prefer one frequency over another. Without such a reference, the claim can't be interpreted as anything beyond an opinion or original research, neither of which are acceptable in Wikipedia articles.

While I don't have an authoritative source to the contrary at hand, it is self-evident that if different frequencies didn't have any advantages or disadvantages, utilities and equipment vendors would simply have all followed a defacto standard established by the first, rather than making a lot of different choices. The article even gives examples of reasons to prefer one or another frequency, such as the size of the required transformers, and lighting flicker.

The "citation needed" tag should not be removed until and unless the claim can be backed up by an authoritative reference. That's standard Wikipedia policy. It is NOT policy for editors to remove "citation needed" tags because of their personal opinions. --Brouhaha (talk) 06:23, 15 July 2012 (UTC)

Find a cite that says there's a technical reason to prefer one frequency to another. Find a cite that says there's a worldwide effort to standardize on one frequency or the other. You can't cite a negative. Nobody is wrting scholarly texts with chapters titled "60 Hz is just fine, thank you". Unlike Wikipedians, scholars have limited time to spend on such things. --Wtshymanski (talk) 13:12, 16 July 2012 (UTC)

I don't need to "find a cite that says there's a technical reason to prefer one frequency to another", because that's not the claim made in the article. The article claims that there is no reason, so that's what needs a cite. The fact that it's stating a negative doesn't mean that it doesn't need a cite. You can't prove a universal negative, but what's at issue here isn't proof, but rather cited references. Certainly you can and should cite a reference if you make a negative claim in Wikipedia. Someone could put in the article a claim that the utility frequency was not determined by invisible pink unicorns, and while that is undoubtedly true, it would need a citation to be appropriate for the article. --Brouhaha (talk) 15:51, 18 July 2012 (UTC)

The reason for the existence of 50 and 60Hz systems is mainly because they were independently developed on both sides of the atlantic ocean. They could just as easily have occured the other way around. The US standardised on 60Hz probably because this was the most common frequency in use (25Hz being runner up). Similarly, Europe standardised on 50Hz for much the same reason (in the UK at least, 33Hz was the runner up). There is no real advantage of one choice over the other. Having said that, all marine based power generating schemes have standardised on 60Hz.

I am reminded of a friend who received a substantial refund of his electricity bills for the last 50 years when it was discovered that the electric meter in his business premises was a 33Hz device and had thus been reading 50% fast since the supply was changed to 50Hz. The 11kV to 398/230 volt transformer in his basement was also rated at 33Hz but seemed to operate OK on 50Hz. DieSwartzPunkt (talk) 13:45, 16 July 2012 (UTC)

The situation is far more complicated that "independently developed on both sides of the atlantic"; that simplification suggests that the parties weren't aware of other efforts of that they were choosing different frequencies, which was not the case. The different frequencies were not chosen entirely arbitrarily, but for technical reasons, which is contrary to the claim that there are not technical reasons to prefer one frequency over another. This is exactly why a claim that there are no technical reasons to prefer one frequency over another needs a supporting citation. Without a citation, it is just opinion. --Brouhaha (talk) 15:56, 18 July 2012 (UTC)

Utility frequency became more of an issue with the introduction of CRT based television. Early TV broadcasters usually synchronised their field rate to that of line current for convenience and because early TV designs tended to be very susceptible to "hum bars" which were subjectively less obtrusive when stationary. Therefore most countries choice of broadcast standard was defined (in part) by whichever mains frequency was more widespread locally. A field rate of 50 Hz (rather than 60 Hz) was significantly more economical in terms of bandwidth utilisation but at the expense of some viewers noticing slightly worse flicker. 2A00:23C6:7F93:1A00:E9FA:AC85:3B3D:E0F3 (talk) 10:56, 7 June 2019 (UTC)

16+2⁄3 Hz?

No mention of 16+2⁄3 Hz?, or the close-but-no-cigar 16.7 Hz? These were, and still are, widely used for electric railways, to avoid the difficulties of making powerful motors work with the higher frequencies of 50 or 60 Hz in the early days. See railway electrification systems. Distribution for these low-frequency systems was difficult and mostly avoided in favour of more local generation, but they're important systems and within scope here. Andy Dingley (talk) 01:48, 19 June 2019 (UTC)

It didn't make it into the article until this edit [3] - there is now a section called "Railways" that mentions these systems. --Wtshymanski (talk)

"60 Hz" listed at Redirects for discussion

A discussion is taking place to address the redirect 60 Hz. The discussion will occur at Wikipedia:Redirects for discussion/Log/2021 March 21#60 Hz until a consensus is reached, and readers of this page are welcome to contribute to the discussion. 𝟙𝟤𝟯𝟺𝐪𝑤𝒆𝓇𝟷𝟮𝟥𝟜𝓺𝔴𝕖𝖗𝟰 (𝗍𝗮𝘭𝙠) 14:37, 21 March 2021 (UTC)

How?

"This is used by some clocks to accurately maintain their time." How is time accurately maintained when frequency is variable? 122.151.210.84 (talk) 12:26, 19 July 2023 (UTC)

Frequency is steered to keep the clocks on time. In older days, the powerhouse had a clock with a synchronous motor. They tweaked the frequency up or down as needed to keep that clock synced with some reliable time reference such as radio signals from the National Bureau of Standards. Today if the clocks get more than ten seconds behind, the grid is heavily overloaded. Constant314 (talk) 13:51, 19 July 2023 (UTC)

This also speaks to the variability of the term "accurate". In a typical residential home, there is (largely), no need for a clock to be precise to milliseconds - or even seconds. As long as a wall clock - frequently without a seconds hand - is within a minute or so of the correct time, the average person is very unlikely to notice. Grid frequency is more than adequate as a synchronizer in such day-to-day usage. cheers. anastrophe, an editor he is. 18:09, 19 July 2023 (UTC)

The glorious details are in Time control (electrical grid) Викидим (talk) 19:26, 19 July 2023 (UTC)

Invention of the load-frequency control

The current text states, The general control algorithm for LFC was developed by Nathan Cohn in 1971, referencing just the Cohn's work. However, the LFC with ACE was known well before that (it is easy to find the descriptions that date to early 1960s). So a reliable third party source is needed to credit Cohn with this invention. Викидим (talk) 22:45, 25 March 2023 (UTC)

Many months, still without a proper source. Removing the statement. Викидим (talk) 00:52, 20 July 2023 (UTC)