計及護套環(huán)流和電流分布的多回電纜線路溫度場及載流量研究
本文選題:多回電纜線路 + 同相多根并聯(lián); 參考:《重慶大學》2014年碩士論文
【摘要】:受到城市地形、地下空間限制,,為了滿足大中城市電力供應(yīng)越來越多采用多回電纜線路同相多根并聯(lián)運行。但是,對于多回電纜線路同相多根并聯(lián)運行參數(shù)的計算,現(xiàn)有的設(shè)計規(guī)程、規(guī)范不再適用。而目前對于多回電纜線路同相多根并聯(lián)運行的設(shè)計、施工并無相關(guān)規(guī)程、規(guī)范。并且,以往研究中常常將多回電纜線路同相多根并聯(lián)的護套環(huán)流、同相并聯(lián)多根電纜的電流分布的不均勻與溫度場及載流量計算完全獨立成不相關(guān)的領(lǐng)域,大部分文獻中僅僅涉及到其中之一,而不是將其聯(lián)系起來組成系統(tǒng)工程進行研究。與此同時,在傳統(tǒng)的多回電纜線路溫度場及載流量計算中,各參數(shù)的取值一般均采用IEC-60287標準中的推薦值,而這與工程實際中電纜線路運行參數(shù)存在明顯差異,導(dǎo)致電纜線路載流量的理論值與實際值不符。 本文打破以往慣用思路,嘗試建立了計及護套環(huán)流和電流分布的多回電纜線路同相多根并聯(lián)的溫度場計算的精細化模型,并結(jié)合220kV坪江線等六回線路工程實際情況進行研究。本文取得的主要成果如下: ①首先,將電力電纜分別按照絕緣材料、電壓等級、結(jié)構(gòu)特征、敷設(shè)條件等指標加以分類。并以截面積2000mm2的YJLW02-127/220kV交聯(lián)聚乙烯電纜為例,對其基本結(jié)構(gòu)進行闡述。然后,詳細介紹了電纜線路四種常用敷設(shè)方式,即直埋敷設(shè)、排管敷設(shè)、電纜溝敷設(shè)和隧道敷設(shè)各自優(yōu)缺點及適用范圍。最后,建立了涵蓋可靠性、經(jīng)濟型、可監(jiān)測性、載流量等指標的敷設(shè)方式選擇評價體系。 ②建立了多回電纜線路護套環(huán)流、同相并聯(lián)電纜電流分布的等值計算模型,推導(dǎo)了多回電纜線路同相多根并聯(lián)時護套環(huán)流、同相并聯(lián)電纜的電流分布計算方法,并編程求解。結(jié)合220kV坪江線等六回線路工程實際,建模計算了其在兩種不同排列方式下電纜線路按照四種相序排列加載電流時1~24號電纜護套環(huán)流、同相并聯(lián)兩根電纜的電流分布,并進行了對比研究。為建立計及護套環(huán)流和電流分布的220kV坪江線等六回線路溫度場計算的精細化模型打下基礎(chǔ)。 ③根據(jù)220kV坪江線等六回線路的具體參數(shù)以及敷設(shè)方式,首先分段建立了其溫度場計算的截面物理模型;緊接著,根據(jù)傳熱學原理建立了電纜群及其周圍敷設(shè)區(qū)域內(nèi)的穩(wěn)態(tài)導(dǎo)熱微分方程,并結(jié)合②中內(nèi)容分別對初始條件、內(nèi)部熱源損耗值以及各熱力學參數(shù)進行計算和取值,從而建立計及護套環(huán)流和電流分布的220kV坪江線等六回線路溫度場計算的精細化模型。將求解區(qū)域用三角形網(wǎng)格進行自動劃分并對穩(wěn)態(tài)導(dǎo)熱微分方程進行求解,得到在100%額定負荷電流和120%額定負荷電流下電纜群及其周圍敷設(shè)區(qū)域的溫度分布;最后,利用雙點弦截法對各分段電纜線路的載流量進行計算和分析。 ④針對目前地下電纜線路的敷設(shè)條件和外界環(huán)境等情況日益復(fù)雜的現(xiàn)狀,以電纜溝敷設(shè)下220kV坪江一線和二線為例進行仿真計算,分析了電纜線路的敷設(shè)條件如電纜溝深度、電纜層間距等以及外界環(huán)境因素如空氣溫度、土壤熱阻系數(shù)等的因素的變化對220kV坪江一線和二線同相并聯(lián)兩根電纜載流量的影響,并進行規(guī)律性總結(jié)。
[Abstract]:In order to meet the demand of urban terrain and underground space limitation , in order to meet the increasing power supply of large and medium - sized cities , many parallel operation modes are adopted . However , the existing design rules and specifications are no longer applicable to the calculation of multiple parallel operation parameters of multi - circuit cables .
In this paper , we attempt to establish a refined model of the temperature field calculation of the multi - return cable line in parallel with a plurality of parallel cables with the circulation and current distribution of the sheath and sheath , and study the practical situation of the six return line projects , such as 220 kV Pingjiang Line . The main results are as follows :
Firstly , the electric cables are classified according to the indexes such as insulation material , voltage class , structural characteristics , laying conditions , etc . The basic structure of YJLW02 - 127 / 220 kV XLPE cable with a cross - sectional area of 2000mm2 is described . Then , four common laying methods of cable line , i.e . , direct - buried laying , pipe laying , cable trench laying and tunnel laying , are introduced in detail . Finally , a selection evaluation system covering reliability , economical type , monitorable property and current carrying capacity is established .
( 2 ) The current distribution method of the sheath circulation and the in - phase parallel cable is deduced and the current distribution of the two cables in the same phase is calculated , and the current distribution of the two cables in the same phase is calculated and the comparison study is carried out . The basis of the refined model for the calculation of the temperature field of the six return lines , such as the 220kV Pingjiang line , which is the circulation and current distribution of the sheath , is calculated .
( 3 ) according to the specific parameters of the six return lines such as 220 kV Pingjiang line and the laying mode , the section physical model of the temperature field calculation is firstly established ;
Then , according to the principle of heat transfer , the steady - state heat - conduction differential equation in the cable group and its surrounding lay - up area is established , and the calculation and value of the temperature field of the six - return line , such as the initial condition , the loss value of internal heat source and the thermodynamic parameters are calculated and taken according to the contents of 2 . The solution region is automatically divided by triangular meshes and solved by the steady - state heat conduction differential equation , so that the temperature distribution of the cable group and the surrounding laying area is obtained under the rated load current of 100 % and the rated load current of 120 % ;
Finally , the current carrying capacity of each segment cable line is calculated and analyzed by means of double - point chord cutting method .
In this paper , the influence of cable laying condition , such as depth of cable trench , spacing of cable layer and external environmental factors such as air temperature , coefficient of thermal resistance of soil and external environmental factors such as air temperature and soil thermal resistance coefficient are analyzed .
【學位授予單位】:重慶大學
【學位級別】:碩士
【學位授予年份】:2014
【分類號】:TM75
【參考文獻】
相關(guān)期刊論文 前10條
1 梁永春;李彥明;柴進愛;王正剛;李忠魁;;地下電纜群穩(wěn)態(tài)溫度場和載流量計算新方法[J];電工技術(shù)學報;2007年08期
2 王有元;陳仁剛;陳偉根;袁園;;電纜溝敷設(shè)方式下電纜載流量計算及其影響因素分析[J];電力自動化設(shè)備;2010年11期
3 付永長;張文斌;陳濤;羅曉初;魏志連;楊帆;;不規(guī)則排列電纜溫度場及載流量計算[J];電網(wǎng)技術(shù);2010年04期
4 王育學;張哲;尹項根;孔祥平;鄧星;蒙紹新;趙健康;;平行多回電纜序阻抗參數(shù)的計算與分析[J];電網(wǎng)技術(shù);2011年08期
5 唐慶華;劉寶成;楊洪;史磊;李叢林;呂紅開;;高壓電纜金屬護套的接地方式對線路參數(shù)的影響[J];電線電纜;2009年02期
6 胡志堅,陳允平,張承學,張翅飛;長距離高壓電纜線路互感參數(shù)測量[J];高電壓技術(shù);2002年05期
7 李志堅,張東斐,曹慧玲,郝文霞;地下埋設(shè)電纜溫度場和載流量的數(shù)值計算[J];高電壓技術(shù);2004年S1期
8 王曉兵,蟻澤沛;管道內(nèi)填充介質(zhì)提高電纜載流量的研究[J];高電壓技術(shù);2005年01期
9 張全勝;王和亮;周作春;;110 kV XLPE電纜金屬護套交叉互聯(lián)接地探討[J];高電壓技術(shù);2005年11期
10 蘇巍;明安持;;多回路電纜布置優(yōu)化的研究[J];高電壓技術(shù);2006年11期
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