Talk:High-voltage direct current

message: Right now, I think it doesn't get clear enough how the HVDC is put back to AC. An explanation would be great, especially see Static inverter plant - i think that would be a good reference. Thanks, --Abdull 09:22, 22 July 2005 (UTC)
thread_title:  Back from DC to AC 

message: Corona dicharge does not depend on an electromagnetic field neccessarily ( unless you are talking about RF corona when of course it does) So, to keep thing simple and improve accuracy, I ve changed electromagnetic to electric. Any comments. Please reply here initially. I watch this page. Light current 16:41, 5 August 2005 (UTC)
replies: text: FYI, static electric fields are electromagnetic fields, and so are static magnetic fields. There is no such thing as a pure magnetic or electric field for all observers. If you ever see what you think is a pure one, you should know that your view is only due to your unique point of view as an observer with a particular velocity. Change velocity and any "pure" magnetic field you were looking at, will now have an electric component, and any pure electric field picks up a magnetic component. So each one is just an aspect of the other, and will show both faces to another observer in a different reference frame. Which is why the one EM field that always has two aspects, is called electomagnetic. SBHarris 00:03, 27 April 2012 (UTC)
thread_title:  Corona discharge 

message: The additional copper in AC lines is used to transmit the reactive power due to inductance. Since DC lines are not subject to reactive power, you can use less copper.
Ac power lines act as a transmitting antenna, so there is significant 60 hertz electromagnetic energy lost, plus small skin effect losses. Three phase ac requires at least three conductors. HVDC monopole one conductor, bipolar two conductors. The voltage can be 140% or more higher without serious arcing, corona losses and environmental hazard. Higher voltage means less current and/or more power capacity.
Is HVDC more vulnerable to EMP = electromagnetic pulse than properly transposed ac power lines? Ccpoodle (talk) 01:39, 8 January 2009 (UTC)
thread_title:  Copper Losses 

message: This stuff is all irrelevant without cost informatn and comparison with AC.  Also what about losses? Cam;t see them anywhere yetEngineman 18:48, 8 April 2007 (UTC)
thread_title: lack of costing information

message: I’ve heard HVDC lines are better for long-distance transitions because the ac current reflects from the end points when the length of the line approaches 1/2 of the wavelength of the power. Given a 50 Hz line, the length is c/ν = (3e8 m/s) / (50 s-1) = 6e6 m = 6 thousand km, and if the line is exactly 3000 kilometers in length, the potential difference at the recipient’s end will be exactly zero. Is that true? Zero and double voltage is for a theoretical transmission line loaded at the characteristic impedance. The voltage is however different at the half wave length and quarter wave length points of ac power lines, but not by enough to cause serious problems in most cases. Ccpoodle (talk) 02:05, 8 January 2009 (UTC)
thread_title:  Wave effects 

message: "Between each" makes no sense.  I tried to correct the grammar of that section, and hope that in the process I didn't change the intended meaning.  Please, would somebody who is familiar with the subject verify that the rewording is accurate? D021317c 00:46, 10 June 2007 (UTC)
thread_title:  12-pulse system grammar 

message: I read  (e.g. 50 hz is used in Canada while 60 hz is used in the United States)  and was made very sad. I'd like to think that someone who's bold enough to edit an article can speak with some reliability about the topic he or she chooses to edit; but if you're missing on the fundamentals, it really undercuts the reliability and credibility of the whole process. --Wtshymanski (talk) 13:24, 21 May 2008 (UTC)
replies: text: Most of Canada uses 60 hertz. Parts of Quebec, or other locals far North may use 50 hertz. The phase likely is not synchronized everywhere. Ccpoodle (talk) 02:18, 8 January 2009 (UTC)
replies: text:  Sorry, completely incorrect. There are no 50 Hz grids in Canada, and the 25 Hz generation at Niagara Falls has been shut down. Quebec is its own synchronous grid, and Canadian regions are synchronous in the  NERC areas. Isolated communities in Canada are necessarily not on a grid, but are all 60 Hz. --Wtshymanski (talk) 14:38, 8 January 2009 (UTC)
thread_title: Credibility

message: Due to Texas wind farms now feeding presumably the USA EAST grid
is it correct to still list TEXAS as being a grid unto itself?  —Preceding unsigned comment added by 151.198.55.135 (talk) 18:20, 3 May 2009 (UTC)
thread_title:  TEXAS joins EAST grid? 

message: Can someone please make a photograph of the crossing of HVDC CU and Square Butte situated at ? It would be the unique chance to take a photograph showing 2 different HVDC lines!
:I have posted a request at Wikipedia talk:WikiProject North Dakota#photo request near Bismarck.  —EncMstr (talk) 16:26, 7 October 2009 (UTC)
replies: text: Done.  --Wtshymanski (talk) 02:41, 3 June 2010 (UTC)
thread_title:  Photo Request 

message: It is possible to go from one frequency to another without rectification. It is used in motor drives. Wdl1961 (talk) 15:18, 1 November 2009 (UTC)
replies: text: That's a cycloconverter and has nothing to do with HVDC transmission. --Wtshymanski (talk) 04:56, 19 January 2010 (UTC)
replies: text: Back to back  is not distance transmission , it is connection.Wdl1961 (talk) 18:06, 14 March 2010 (UTC)
thread_title:  Back to back  

message: Am I the only one who cannot parse this?:
"For an 8 GW 40 km link laid under the English Channel, the following are approximate primary equipment costs for a 2000 MW 500 kV bipolar conventional HVDC link... "
The cited reference cannot be "reasonably well relied upon" given that the quotation is pretty well garbled.  What is the point it is trying to make?  An anonymous reference is no reference at all, because it is unverifiable.
This section has nothing to say, except there is no reliably sourced data on HVDC costs. --Albany45 (talk) 13:14, 8 June 2010 (UTC)
replies: text: See above.  You know what to do. --Wtshymanski (talk) 20:48, 8 June 2010 (UTC)
replies: text: Deleted section. Info on commercial suppliers might be useful somewhere else. --Albany45 (talk) 02:47, 10 June 2010 (UTC)
thread_title:  Costs of high voltage DC transmission 

message: While trolling through the Web on a quest for cheap references, I found . It appears to rip off quote extensively from an earlier version of this article. We must be doing something right if it's worth putting on Governor Schwartzenegar's desk. Pity they garbled it somewhat. --Wtshymanski (talk) 20:48, 8 June 2010 (UTC)
thread_title:  Quoted by Lawrence Berkeley National Laboratory

message: There seems to be a mismatch between the descriptions to
http://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/HVDC_Europe.svg/350px-HVDC_Europe.svg.png   "On the main article"
and
http://upload.wikimedia.org/wikipedia/commons/thumb/5/51/HVDC_Europe_annotated.svg/400px-HVDC_Europe_annotated.svg.png   "Annotated version"
"Under construction" and "Under consideration" are switched. I think the annotated version has it right, but could someone more familiar with the article take a look at this?
Thanks,
Satan_Klaus  —Preceding unsigned comment added by 84.160.50.191 (talk) 11:08, 7 August 2010 (UTC)
replies: text: I've all ready changed it. BritNed is allmost finisched (the green line between Britan and the Netherlands. You can look at the website or the articles assosiated with the shown lines (which largely don't exist for the proposed projects): http://en.wikipedia.org/wiki/List_of_HVDC_projects#Europe Pcmadman (talk) 02:54, 20 September 2010 (UTC)
thread_title:  Graphics of HVDC in Europe 

message: The "AC network interconnections" section is missing citation, which makes it hard to veryfie, and is not usable as a reference.
81.225.97.154 (talk) 18:25, 31 October 2010 (UTC)
thread_title:  AC network interconnections 

message: Could someone who understands the subject rewrite "At such operation mode, it is possible that transmission can be continued, if one conductor fails, however with greater losses and possibly with less transmission capacity, if ground electrodes or lines are not designed for the load of both poles." This sentence does not make much sense, there are a few too many clauses that appear disjointed.
192.16.184.140 (talk) 10:49, 22 November 2010 (UTC)
replies: text: Fixed. --Wtshymanski (talk) 17:58, 9 March 2011 (UTC)
thread_title:  Rewrite sentence 

message: Now that the second cable from the south of the UK has been opened, perhaps the images should be updated.  Esn (talk) 05:25, 4 May 2011 (UTC)
thread_title: Update image

message: BBC is mentioned, but after a a short confusion about what BBC has to do with high voltage, a quick check reveals the current name of that company is ABB. Article aslo meantions ASEA a lot, that too is now ABB. Is this article really the right place for a history lesson? 83.227.1.122 (talk) 08:59, 8 September 2011 (UTC)
replies: text: Well...yes. Anyone who wants to know what happened to Brown Boveri or ASEA only has to click on the link to eventually get the ABB story; we should report HVDC projects with the manufacturer's names as they were at the time the project was built. It's confusing to refer to a congolomerate that didn't exist until decades after the project was built. --Wtshymanski (talk) 13:15, 8 September 2011 (UTC)
thread_title: BBC?

message: I am not an expert in this area, but found further detailed info (in pretty much this format) at http://www.energy.siemens.com/fi/pool/hq/power-transmission/HVDC/HVDC_Proven_Technology.pdf some of which may be added whist avoiding copyright infringement. Particularly thought that the figures were informative 1-1, 1-2 and section 4. Would an expert in this area be able to compare and see if useful additions may be made to improve the quality of this article. Thanks --DrSteveEllis (talk) 11:22, 26 September 2012 (UTC)
thread_title:  Siemens info from 

message: I have just made quite a large number of text changes to improve clarity, but could not help noticing that the section "Applications" right at the very end seems to be in the wrong place.  Shouldn't it be moved to somewhere near the start of the article? Clampower (talk) 20:13, 3 October 2012 (UTC)
replies: text: Applications are discussed throughout the article. If you're talking about real world PROJECTS there's a list of them which I've put in as a section, rather than just a "see also". It's at List of HVDC projects. When you check it out you'll see why we didn't shoehorn it into the article, as it's large and rather amazing. The current "applications" section is really a little section on theory of future applications, so I've retitled it. And no, since this is an article about the technology itself, we don't discuss this stuff till the end. Just as an article on automobiles would discuss particular models of automobiles (as examples) until near the end, and certainly wouldn't contain a list of them, as it's too long. And future automobile plan and theory goes at the end, since it's the future and isn't yet real. SBHarris 02:26, 4 October 2012 (UTC)

text: Agree. Okay, go ahead and add the ability to connect grids of differing frequencies up toward the front. I think it should be even mentioned in the lede as a neat "feature." The "applications" section as it was, really looked forward to a time when all grids of the world would be connected in some way by HVDC links. SBHarris 19:53, 4 October 2012 (UTC)
replies: text:  The entire Applications section could be removed, with a selection of the most relevant content relocated into the sections earlier in the article about "Advantages".  The specific applications of HVDC that are described in the current Applications section are all instances where HVDC has been chosen because of the benefits it provides.  I think this re-arrangement would be an improvement, and eliminate the current duplication of content. Marshelec (talk) 05:19, 14 October 2012 (UTC)
thread_title:  Applications 

message: If you are knowledgeable about HVDC, please take a look at the electrode line article which needs a hand (expansion and references). Katana (talk) 20:41, 30 October 2012 (UTC)
replies: text: The Electrode Line article has had exactly 1 edit since I wrote this, and it is an excellent large and referenced expansion by Clampower - good job and case closed. Katana (talk) 14:43, 12 April 2013 (UTC)
thread_title:  Electrode line article needs a hand 

message: Sunrise Powerlink is an AC line!  — Preceding unsigned comment added by 91.46.154.156 (talk) 18:31, 9 December 2012 (UTC)
replies: text: If anyone has any clue where to look for a citable reference on this point, per WP:V, please join in the discussion at Talk:Sunrise Powerlink#AC or DC?, and eventually help fix the {cn} tag I just added here. --Nigelj (talk) 20:15, 9 December 2012 (UTC)
thread_title:  Sunrise Powerlink 

message: Cross Channel is still considered a "bipole" even though ground return is not possible, because each end (of each bipole) contains two completely independent converters.  A fault in one converter does not shut down the entire bipole (as would happen for NorNed) because the bipole can still operate with the faulted converter bypassed and its HV cable used as the neutral return.
Clampower (talk) 19:29, 14 December 2012 (UTC)
thread_title:  Symmetrical Monopole 

message: Hi there. I am completely new to wikipedia, but I found a dead link (currently referece 25 to a pdf of ABB) and I think I found the new location of the reference. I don't know how the procedure is to fix that, but I wanted to let you know, in case someone has the time to fix that. the new location is 
http://new.abb.com/docs/default-source/default-document-library/hybrid-hvdc-breaker---an-innovation-breakthrough-for-reliable-hvdc-gridsnov2012finmc20121210_clean.pdf?sfvrsn=2  — Preceding unsigned comment added by 129.132.125.221 (talk) 09:17, 13 January 2014 (UTC)
replies: text: Thank you ... I have updated the link.  Dwpaul Talk    17:29, 13 January 2014 (UTC)
thread_title:  Dead link 

message: Per this edit, Wikipedia is not a reliable source and the claim that this was the "AC system of George Westinghouse and Nikola Tesla" is incorrect. The Westinghouse AC system was based on the work of many engineers, not just Tesla, including the early work of Lucien Gaulard, John Dixon Gibbs and the developments of Westinghouse engineers William Stanley (who developed the first AC transformer), Vladimir Zworykin, Oliver B. Shallenberger, Stephen Timoshenko, and Benjamin Garver Lamme. Westinghouse started installing AC systems in 1886, two full years before Tesla got into the business and the company was eating Edison lunch by 1887, that led into the War of Currents (given a start date of December 1887 (Empires Of Light By Jill Jonnes, page 419). The "War" was a battle of lighting businesses, AC Arc vs DC incandescent (The 100 Most Significant Events in American Business: An Encyclopedia By Quentin R. Skrabec, page 86) so Tesla's July 1888 licensing of his induction motor patents to Westinghouse didn't come into it. The "War" was over by either: 1890 (Edison Machine entered AC biz), or the 1891 International Electro-Technical Exhibition, or the 1892 merger of Edison Electric into GE and the ouster of Edison...... take your pick. Tesla's AC motor was still on the back burner at Westinghouse at that point (George Westinghouse: Gentle Genius By Quentin R. Skrabec page 127). The Tesla induction motor patent did become important to the Westinghouse system in later patent battles but that was after the "War" and a motor is only one quarter of a system, you also have to have lighting, generators, and transformers - none of which were invented by Tesla. Fountains of Bryn Mawr (talk) 04:14, 5 February 2015 (UTC)
thread_title:  Correctly summarizing material 

message: I add on one more important applications especially for now and the future, which is the integration of renewable resources such as wind into the main transmission grid. One of the challenges of renewable power generation like wind and solar power is that it can be interrupted, and this variability affects the stability of the power produced. HVDC is so far the best technology for integrating more intermittent forms of renewable energy into the local power grid, particularly over long distances. This is especially significant for large scale offshore wind projects, or large scale solar power production.  — Preceding unsigned comment added by (talk) Shenyawang (talk) 01:42, 28 April 2015 (UTC)
thread_title:  Applications of HVDC transmission technology 

message: This article's lead contains some misleading and out-of-date information. Here is the link from which I get my information:http://www.santoantonioenergia.com.br/energia/energia1/ (as of June 14, 2015) there are 32 of the total planned 50 turbines operational. (Each with 71.5 MW capacity ...doing the math...) that's 2288 MW (so far, that dam is scheduled for completion in Nov 2016). There are also 3 other hydroelectric dams planned, only one of which is in construction. (I don't know if the others will contribute to the HVDC transmission, based on the claim that a total of over 6000 MW will be transmitted, I assume so -but the total MW claimed seems a bit high to me). The lede needs to change to reflect this information. That is the lede states "which consists of two bipoles of ±600 kV, 3150 MW each..." which is clearly not correct. I know almost nothing about HVDC transmission, but I'm guessing that only one bipole is operational. (No idea about whether both have been constructed).FWIW216.96.78.101 (talk) 17:34, 14 June 2015 (UTC)
thread_title:  Rio Madeira line 

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thread_title:  External links modified 

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thread_title:  External links modified 

message: In the article, one should make a comparision on the effiency of HVDC converters and inverters using mercury arc valves, thyristors and IGBTs. Which percentage of the transmitted power is required to steer these different valve types? How depends the amount of steering power from the load current? What is their lose, when the valve is conducting?  — Preceding unsigned comment added by 93.236.153.175 (talk) 22:30, 27 September 2018 (UTC)
thread_title:  Effiency of different technologies 

message: Hi Wtshmansky, I was slightly worked up in my last revert on the "late completion date" question.  Sorry about that.  Maybe we can discuss here. 98.216.244.217 (talk) 09:04, 27 January 2019 (UTC)
thread_title:  What late completion date? 

message: Which HVDC schemes use Capacitor-commutated converters (CCC)?  — Preceding unsigned comment added by 2003:DF:1F25:7650:D7B:5B87:6F99:D1FE (talk) 20:41, 4 November 2020 (UTC)
thread_title:  Capacitor-commutated converters (CCC) 

message: The first sentence of the lead says, "A high-voltage, direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for the controlled bulk transmission of electrical power, in contrast with the more common alternating current (AC) systems." It is unclear to me what we're trying to accompliish with the "controlled bulk" qualifiers here.  recently added "controlled". It would seem that we could make things easier for readers by leaving out these qualifiers. If they need to remain, there needs to be some further explaination of this jargon. ~Kvng (talk) 13:47, 1 October 2021 (UTC)
replies: text: HVDC systems are controlled, unlike AC interconnectors. And that's a crucial difference. For example, historically the USA's Eastern and Western interconnections were AC linked. This made the overall system horribly unstable. When they were replaced with HVDC in 1975, or so, the system immediately stabilised. And that's because the generators were hunting trying to stabilise the phaze, and the interconnection was giving variable power based on the phase angle. With HVDC they can just set it to some value, and either side will stabilize itself around it. GliderMaven (talk) 17:31, 1 October 2021 (UTC)
replies: text: OK, I now see this is connected to the 3rd paragraph of the lead. But controlled in the first sentence of the lead is a forward reference and is not helping readers. I have removed it. ~Kvng (talk) 18:00, 4 October 2021 (UTC)
thread_title:  Qualifiers 

message: The ABB Power Grid unit (originally part of ASEA) was sold to Hitachi two years ago. Should we switch all references to ABB to Hitachi instead? jax (talk) 10:22, 9 September 2022 (UTC)
replies: text: No, becauase ABB was the company name at the time. Thei article is about high voltage direct current transmission, not what company owns what other company. --Wtshymanski (talk) 00:18, 17 September 2022 (UTC)
thread_title:  Change ABB to Hitachi? 

message: An overhead line strung with a bundle of stranded conductors (or indeed any stranded cable) behaves in the same way as a solid conductor of equivalent cross sectional area. The varying magnetic field of alternating current forces the current to the outside of the strands or solid conductor if it is larger in diameter than twice the skin depth . The advantage of stranded cables is solely that they are easier to handle, transport  and install because they are much more flexible (and possibly cheaper to make).
If more current capacity is required compared with a single cable (stranded or otherwise) that can carry the current without significantly exhibiting the skin effect (roughly 27 mm or so for the normally encountered utility frequencies in copper conductors), then separate multiple conductors are employed.
Although not relevant to this case, Litz wire does carry the current distributed in all the strands of the bundle, but only because the strands are insulated from each other which changes everything. The magnetic field cannot force the current through the insulation (though, of course, it will try). 109.152.150.247 (talk) 18:28, 14 February 2023 (UTC)
replies: text: Note: This was posted in response to a revert that was made in error. The post can remain for information to anyone interested. 109.152.150.247 (talk) 13:28, 17 February 2023 (UTC)
thread_title:  Bundling of conductors.