{"id":3521,"date":"2018-12-09T23:40:47","date_gmt":"2018-12-09T22:40:47","guid":{"rendered":"https:\/\/onload.reinhausen.com\/de\/?p=3521"},"modified":"2023-05-30T17:51:32","modified_gmt":"2023-05-30T15:51:32","slug":"more-power-to-london","status":"publish","type":"post","link":"https:\/\/onload.reinhausen.com\/en\/12-2018\/more-power-to-london\/","title":{"rendered":"More Power to London"},"content":{"rendered":"
\n

D<\/span>ark\u00adness in front, dark\u00adness behind. Every few min\u00adutes, a rum\u00adbling tube train speeds along above his head. Then every\u00adthing becomes qui\u00adet again and every word dis\u00adap\u00adpears into the dark\u00adness, just like the light from the work lamps.<\/p>\n

Andreas Wein\u00adlein from the cable man\u00adu\u00adfac\u00adtur\u00ader S\u00fcd\u00adk\u00ada\u00adbel GmbH in Mannheim still can\u2019t help shud\u00adder\u00ading slight\u00adly when he recalls his time work\u00ading far below Lon\u00addon. As Head of Sys\u00adtem Engineer\u00ading, he was respon\u00adsi\u00adble for lay\u00ading and test\u00ading high-volt\u00adage cables over a dis\u00adtance of just under 32 kilo\u00adme\u00adters. 200 kilo\u00adme\u00adters of cabling were required in total, as there had to be enough for three phas\u00ades as well as the con\u00adnec\u00adtions to the pri\u00adma\u00adry sub\u00adsta\u00adtions. The work was car\u00adried out in three con\u00adstruc\u00adtion stages from 2010 to 2017. The cus\u00adtomer: Nation\u00adal Grid, the British trans\u00admis\u00adsion sys\u00adtem oper\u00ada\u00adtor.
\n<\/p>\n

Heading down under the Megacity<\/h2>\n

Lon\u00addon is a rav\u00aden\u00adous con\u00adsumer of pow\u00ader. The megac\u00adi\u00adty already devours 20 per\u00adcent of the total elec\u00adtric\u00adi\u00adty used in the Unit\u00aded King\u00addom. And each year it gets greed\u00adi\u00ader. Demand is ris\u00ading by three to five per\u00adcent per year on aver\u00adage \u2013 twice as much as in the rest of the coun\u00adtry. The city\u2019s pow\u00ader net\u00adwork is groan\u00ading under the strain and is start\u00ading to reach its capac\u00adi\u00adty lim\u00adits. Many of the cables below the city were laid 40 or 50 years ago and are based on the out\u00addat\u00aded tech\u00adnol\u00ado\u00adgy of oil-paper insu\u00adla\u00adtion. \u201cThese days, state-of-the-art cables have insu\u00adla\u00adtion made from cross-linked poly\u00adeth\u00adyl\u00adene,\u201d explains Wein\u00adlein.<\/p>\n

\u201cCon\u00adnect\u00ading high-volt\u00adage cables is a com\u00adplex process. They can\u00adnot be con\u00adnect\u00aded to the pow\u00ader net\u00adwork with\u00adout exten\u00adsive test\u00ading.\u201d Andreas Wein\u00adlein, Head of Sys\u00adtem Engi\u00adneer\u00ading at S\u00fcd\u00adk\u00ada\u00adbel GmbH<\/cite><\/p><\/blockquote>\n

These XLPE cables are safer, as they pre\u00advent oil get\u00adting into the ground\u00adwa\u00adter, and they are also cheap\u00ader to main\u00adtain. In one of the largest infra\u00adstruc\u00adture projects Lon\u00addon has seen for decades, Nation\u00adal Grid there\u00adfore decid\u00aded to replace the old 275 kV oil-filled cables with mod\u00adern XLPE cables which, at 400 kV, sig\u00adnif\u00adi\u00adcant\u00adly increase the trans\u00admis\u00adsion capac\u00adi\u00adty.<\/p>\n

The old oil-filled cables are locat\u00aded direct\u00adly below the road sur\u00adface. Lay\u00ading new cables in the same place would have meant tear\u00ading up the roads, result\u00ading in nev\u00ader-end\u00ading con\u00adges\u00adtion through\u00adout the already traf\u00adfic-plagued city. Nation\u00adal Grid there\u00adfore decid\u00aded to head fur\u00adther down and dig tun\u00adnels.<\/p>\n

But the city is grow\u00ading under\u00adground as well, with net\u00adworks of shafts from the tube sys\u00adtem, sew\u00ader lines, and a war\u00adren of road and pedes\u00adtri\u00adan tun\u00adnels. Nation\u00adal Grid there\u00adfore had to go even deep\u00ader: 12 to 60 meters into the earth. This is where they drilled the cable tun\u00adnels, which have a diam\u00ade\u00adter of three to four meters and have been designed to accom\u00admo\u00addate more cables in the future if required. There are shafts at reg\u00adu\u00adlar inter\u00advals which lead to day\u00adlight and con\u00adnect the under\u00adground line to the pri\u00adma\u00adry sub\u00adsta\u00adtions.<\/p>\n

\n
<\/div>

The Pow\u00ader Tun\u00adnel Project in Lon\u00addon: The tun\u00adnel sys\u00adtem for the 400 kV cables is just under 32 kilo\u00adme\u00adters long in total. Shafts con\u00adnect the line to the pri\u00adma\u00adry sub\u00adsta\u00adtions on the sur\u00adface. (\u00a9 shut\u00adter\u00adstock)<\/p><\/div>\n

<\/div>

Lay\u00ading the cables at a depth of up to 60 meters requires a huge amount of spe\u00adcial\u00adist knowl\u00adedge from the tech\u00adni\u00adcians. (\u00a9 S\u00fcd\u00adk\u00ada\u00adbel GmbH)<\/p><\/div>\n<\/div>\n

Highly Accurate Assembly<\/h2>\n

How\u00adev\u00ader, before the first meter of cable could dis\u00adappear down into the depths of the city, the mate\u00adr\u00adi\u00adal had to get to Lon\u00addon first. Fol\u00adlow\u00ading comple\u00adtion and final inspec\u00adtion at the fac\u00adto\u00adry in Mannheim, S\u00fcd\u00adk\u00ada\u00adbel trans\u00adport\u00aded 200 kilo\u00adme\u00adters of cabling in total along the Rhine and over the North Sea to the British cap\u00adi\u00adtal. The cabling was trans\u00adport\u00aded on 182 drums, each weigh\u00ading 40 met\u00adric tons. In\u00adstalling the cables on site was the next chal\u00adlenge. \u201cCon\u00adnect\u00ading high-volt\u00adage cables of this nature is a com\u00adplex process \u2013 they can\u00adnot sim\u00adply be assem\u00adbled like a nor\u00admal exten\u00adsion cable,\u201d says Wein\u00adlein.<\/p>\n

S\u00fcdkabel\u2019s tech\u00adni\u00adcians con\u00adnect\u00aded the cables using spe\u00adcial sleeves. As it is a three-phase sys\u00adtem, they had to fit three sleeves at every sin\u00adgle con\u00adnec\u00adtion point. The process took a week and a half for just one set. \u201cEvery mil\u00adlime\u00adter counts. You won\u2019t find this infor\u00adma\u00adtion in any text\u00adbook \u2013 it requires a huge amount of expe\u00adri\u00adence.\u201d The tech\u00adni\u00adcians fol\u00adlowed the con\u00adstruc\u00adtion draw\u00adings to the let\u00adter and made sure that noth\u00ading was con\u00adt\u00ada\u00adm\u00adi\u00adnat\u00aded \u2013 all while work\u00ading in a nar\u00adrow tube dozens of meters under the hus\u00adtle and bus\u00adtle of the city.<\/p>\n

A sin\u00adgle error dur\u00ading assem\u00adbly could lead to a cat\u00ada\u00adstro\u00adphe: \u201cIf there were an error and the line were con\u00adnect\u00aded to the pow\u00ader net\u00adwork, it would cause break\u00addowns and large parts of Lon\u00addon would go dark.\u201d To make sure this doesn\u2019t hap\u00adpen, the cables are test\u00aded pri\u00ador to com\u00admis\u00adsion\u00ading so that any prob\u00adlems can be rec\u00adti\u00adfied before\u00adhand. \u201cAfter assem\u00adbly we can\u2019t see into the cable sys\u00adtem; it\u2019s not trans\u00adpar\u00adent. We can only detect errors by apply\u00ading a test volt\u00adage and tak\u00ading a par\u00adtial dis\u00adcharge mea\u00adsure\u00adment at the same time,\u201d says Wein\u00adlein. The par\u00adtial dis\u00adcharge mea\u00adsure\u00adment detects dis\u00adcharges in the cable which could cause a sparkover in the equip\u00adment.<\/p>\n

On-Site Testing<\/h2>\n

The glob\u00adal mar\u00adket leader for such test sys\u00adtems is HIGHVOLT in Dres\u00adden. Since 2002, the com\u00adpa\u00adny has been part of the Rein\u00adhausen Group. HIGHVOLT is a pio\u00adneer when it comes to test\u00ading XLPE cables in high-volt\u00adage appli\u00adca\u00adtions. The com\u00adpa\u00adny pro\u00adduced the world\u2019s first mobile test sys\u00adtem for 400 kV cables for a project in Berlin in the 1990s (see \u201cCable Unifica\u00adtion\u201d box). It was at this time that XLPE was tak\u00ading over as the pre\u00adferred insu\u00adla\u00adtion mate\u00adr\u00adi\u00adal for high-volt\u00adage appli\u00adca\u00adtions. Pre\u00advi\u00adous\u00adly, the oil-filled or gas-filled cables that were used for under\u00adground instal\u00adla\u00adtion had been test\u00aded by test\u00ading insti\u00adtutes using direct cur\u00adrent. How\u00adev\u00ader, it soon became clear that this method was not suit\u00adable for XLPE cables.<\/p>\n

Michael Hensel, Area Sales Man\u00adag\u00ader at HIGHVOLT, explains: \u201cThere were cas\u00ades where test\u00ading with DC volt\u00adage would always pro\u00adduce pos\u00adi\u00adtive results, but then we would see cable defects on a reg\u00adu\u00adlar basis dur\u00ading oper\u00ada\u00adtion\u201d. This is because, as a high\u00adly insu\u00adlat\u00ading mate\u00adr\u00adi\u00adal, crosslinked poly\u00adeth\u00adyl\u00adene can hold charges for days. When the cable is then con\u00adnect\u00aded to the pow\u00ader net\u00adwork, the inter\u00adnal and exter\u00adnal fields are added togeth\u00ader, caus\u00ading local\u00adized over\u00adload\u00ading of the insu\u00adla\u00adtion.<\/p>\n

\n
\n
Cable Unification in Berlin<\/h5>\n

After the fall of the Berlin Wall and the polit\u00adi\u00adcal reuni\u00adfi\u00adca\u00adtion of Ger\u00admany, anoth\u00ader area that required uni\u00adfi\u00adca\u00adtion between East and West was that of their ener\u00adgy sup\u00adplies. In the mid-1990s, the Berlin-based ener\u00adgy provider BEWAG decid\u00aded that the new con\u00adnect\u00ading line between the Tier\u00adgarten dis\u00adtrict in the West and Friedrichshain in the East should be laid under\u00adground for space rea\u00adsons.<\/p>\n

<\/p>\n

A 6.3\u2011kilometer-long tun\u00adnel was drilled to house the cables. This was the first time that a com\u00adpa\u00adny had dared to use 400 kV cables insu\u00adlat\u00aded with crosslinked poly\u00adeth\u00adyl\u00adene (XLPE). How\u00adev\u00ader, there was no suit\u00adable test sys\u00adtem avail\u00adable for this volt\u00adage lev\u00adel and cable tech\u00adnol\u00ado\u00adgy.<\/p>\n

HIGHVOLT was there\u00adfore com\u00admis\u00adsioned to devel\u00adop an appro\u00adpri\u00adate test sys\u00adtem. The engi\u00adneers drew on ideas devel\u00adoped in col\u00adlab\u00ado\u00adra\u00adtion with the Fachkom\u00admis\u00adsion f\u00fcr Hochspan\u00adnungs\u00adfra\u00adgen (High Volt\u00adage Test\u00ading and Engi\u00adneer\u00ading Com\u00admis\u00adsion; FKH) in Zurich dur\u00ading the project. Since then, the test\u00ading method has become stan\u00addard for com\u00admis\u00adsion\u00ading tests per\u00adformed on extrud\u00aded high-volt\u00adage cables.<\/p>\n<\/div>\n<\/div>\n

A dif\u00adfer\u00adent type of test\u00ading tech\u00adnol\u00ado\u00adgy was there\u00adfore required. The chal\u00adlenge is that, as the test volt\u00adage is high\u00ader than the oper\u00adat\u00ading volt\u00adage, the test sys\u00adtem needs to be designed so that pow\u00ader can also be sup\u00adplied on site. \u201cWe have to work with mobile gen\u00ader\u00ada\u00adtors \u2013 we can\u2019t sim\u00adply set a pow\u00ader plant next to the test sys\u00adtem,\u201d explains Hensel. HIGHVOLT there\u00adfore decid\u00aded to base its solu\u00adtion on a sys\u00adtem that was already in use for on-site test\u00ading of gasin\u00adsu\u00adlat\u00aded switchgears: res\u00ado\u00adnance test\u00ading with AC volt\u00adage and vari\u00adable fre\u00adquen\u00adcy. \u201cOur test sys\u00adtems work in the range of 20 to 300 hertz, so rel\u00ada\u00adtive\u00adly small gen\u00ader\u00ada\u00adtors are enough to sup\u00adply the pow\u00ader we need,\u201d says Hensel. To keep the test sys\u00adtem mobile, the HIGHVOLT engi\u00adneers designed it to fit on a truck trail\u00ader.<\/p>\n

The test sys\u00adtem fits on a truck trail\u00ader and com\u00adpris\u00ades a fre\u00adquen\u00adcy con\u00advert\u00ader (1), which also con\u00adtrols the test sys\u00adtem; an exciter trans\u00adformer (2); a res\u00ado\u00adnance reac\u00adtor (3) with fixed induc\u00adtance; and a capac\u00adi\u00adtive volt\u00adage divider for mea\u00adsur\u00ading the test volt\u00adage (4). The engi\u00adneers can observe the mea\u00adsure\u00adments from the test cab\u00adin (5). An indi\u00advid\u00adual test sys\u00adtem is designed for tests up to 260 kV and 83 A and can be used to test high-volt\u00adage cables with a length of sev\u00ader\u00adal kilo\u00adme\u00adters. If high\u00ader test volt\u00adages are required or cables with lengths of up to a hun\u00addred kilo\u00adme\u00adters are to be test\u00aded, mul\u00adti\u00adple test sys\u00adtems can sim\u00adply be con\u00adnect\u00aded in series or par\u00adal\u00adlel. (\u00a9 HIGHVOLT)<\/figcaption><\/figure>\n

If the test sys\u00adtem reg\u00adis\u00adters a flashover, it shuts down with\u00adin microsec\u00adonds. As only a small amount of ener\u00adgy is intro\u00adduced at the defect point via the res\u00ado\u00adnance effect, the dam\u00adage is less dra\u00admat\u00adic and defects can be iden\u00adti\u00adfied more eas\u00adi\u00adly and repaired more quick\u00adly.<\/p>\n

\u201cUnder oper\u00adat\u00ading con\u00addi\u00adtions, the repair costs would be sig\u00adnif\u00adi\u00adcant\u00adly high\u00ader as the pow\u00ader plant would just keep going.\u201d 300 test trail\u00aders are now in use all over the world \u2013 in Amer\u00adi\u00adca, Europe, Asia, and Aus\u00adtralia. \u201cThere is def\u00adi\u00adnite\u00adly a trend toward plac\u00ading high\u00ader and high\u00ader volt\u00adage lev\u00adels under\u00adground. No one wants to have trans\u00admis\u00adsion tow\u00aders right in front of their door, plus they take up a lot of space. And space is hard to find in large cities,\u201d stress\u00ades Hensel.<\/p>\n

Royal Seal of Approval<\/h2>\n

Wein\u00adlein con\u00adfirms this trend. \u201cS\u00fcd\u00adk\u00ada\u00adbel is car\u00adry\u00ading out cable projects like this in many major cities. In addi\u00adtion to Lon\u00addon, we have also recent\u00adly installed cables in Moscow.\u201d The expert often per\u00adforms the final inspec\u00adtions togeth\u00ader with the test\u00ading insti\u00adtutes who pro\u00advide the HIGHVOLT sys\u00adtems for the tests. \u201cWith these sorts of tests, there are so many things that need to be decid\u00aded on the spot, and you might need to replace a sleeve some\u00adwhere as well. The par\u00adtial dis\u00adcharge mea\u00adsure\u00adment in par\u00adtic\u00adu\u00adlar is very com\u00adplex and it is incred\u00adi\u00adbly impor\u00adtant to draw the right con\u00adclu\u00adsions from the val\u00adues.\u201d In Lon\u00addon, two test trail\u00aders were used as the longest sec\u00adtion to be test\u00aded mea\u00adsured over 12 kilo\u00adme\u00adters. \u201cIn this case, the sys\u00adtems are sim\u00adply con\u00adnect\u00aded in par\u00adal\u00adlel.\u201d In total, the com\u00admis\u00adsion\u00ading tests took a week to com\u00adplete.<\/p>\n

The tun\u00adnel was offi\u00adcial\u00adly opened at the start of 2018 with a bit of roy\u00adal assis\u00adtance: Prince Charles and Camil\u00adla pressed the start but\u00adton as the song \u201cI\u2019ve got the pow\u00ader\u201d played out. Thanks to the new cable sys\u00adtem, the megacity\u2019s appetite for pow\u00ader can now be sat\u00adis\u00adfied for anoth\u00ader forty years.<\/p>\n","protected":false},"excerpt":{"rendered":"

Lon\u00addon needs more and more ener\u00adgy, but it is run\u00adning out of space. The city has there\u00adfore con\u00adstruct\u00aded an elec\u00adtric\u00adi\u00adty tun\u00adnel deep under\u00adground. To elim\u00adi\u00adnate the risk of a cat\u00ada\u00adstroph\u00adic black\u00adout, mobile test sys\u00adtems checked every sin\u00adgle sec\u00adtion of cable.<\/p>\n","protected":false},"author":8,"featured_media":3703,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"wp_typography_post_enhancements_disabled":false,"footnotes":""},"categories":[5],"tags":[],"class_list":["post-3521","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-12-2018"],"acf":[],"_links":{"self":[{"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/posts\/3521","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/comments?post=3521"}],"version-history":[{"count":2,"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/posts\/3521\/revisions"}],"predecessor-version":[{"id":8421,"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/posts\/3521\/revisions\/8421"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/media\/3703"}],"wp:attachment":[{"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/media?parent=3521"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/categories?post=3521"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/onload.reinhausen.com\/en\/wp-json\/wp\/v2\/tags?post=3521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}