電壓損失校驗、線損等計算公式

★為手填數(shù)據,☆為需調整數(shù)據,,,,,

,經濟電流密度選擇導線截面,,,,,

,經濟電流密度,,,,,

,3000小時以下,3000-5000小時,5000小時以上,,,

,1.65,1.15,0.9,,,

,,,,,,,

★,U,線路額定電壓,110,,,

★,PM,線路設計最大傳輸有功負荷(kw),49200,,,

★,功率因數(shù),,0.95,,,

★,J,經濟電流密度,1.2,,,

,,,,,,,

,經濟截面=,PM,=,226.5268462,mm2,

,,1.732*U*0.85*J,,,,

,允許電壓損失校驗導線截面,,,,,

★,D12,2,m,,,35kV一般取2、2、4

★,D23,2,m,16,,110kV一般取4、4、8

★,D31,4,m,,,

★,線路長度L=,11.55,公里,,,

☆,導線半徑=,9.44,mm,,,

☆,導線單位電阻=,0.1592,Ω/km,,,

★,功率因數(shù)=,0.9,,,,

★,有功功率=,10504,kw,,,

,視在功率=,11671.11111,kva,,,

,無功功率=,5087.319389,kar,,,

★,電壓等級,35,kV,,,

★,基準電壓,35,37,115,,

,基準電流,16.50,15.60,5.02,,

,基準電抗,1.225,1.369,13.225,,

★,基準容量,1000,MVA,,,

★,1#主變容量,40,MVA,,,

★,2#主變容量,40,MVA,,,

★,上級站110kV側母線阻抗XS*＝,0,,,,

★,,線路阻抗計算基準電壓,115,kV,,

,線路單位阻抗標幺值,＝X*(Sj/Uj2),0.028582231,,,

★,主變阻抗電壓百分數(shù)：,Ud1-2％=,10.5,,,

★,,Ud1-3％=,17,,,

★,,Ud2-3％=,6.5,,,

★,主變容量,損耗小時,負荷利用小時,,,

★,10504,4500,6000,,,

,DJ幾何間距=,2519.8421,mm,,,

,lg(DJ/r),2.426401333,,,,

,電抗計算公式,導線單位電抗=,0.145lg(DJ/r),=,0.367528193,Ω/Km

,導線單位電抗=,0.378,Ω/Km,,,

,線路電阻=,1.83876,Ω,,,

,線路電抗=,4.3659,Ω,,,

,,,,,,,

,電壓、功率、線損計算,,,,,

線路電壓損耗△U=,,1.186430365,kV,,,

,△U%=,3.389801042,%,,,

,,,,,,,

,有功損耗=,204.4623585,kw,,,

,無功損耗=,485.4696704,kar,,,

,,,,,,,

,線損=,1.182510309,%,,,

,,,,,,,

,短路計算（三卷變壓器）,,,,,

,110kV線路阻抗值,0.330124764,,,,

,1#主變參數(shù)：,,,,,

,1XT1-2*=,Ud1-2％×Sj/（100×Se）＝,8.75,,,

,1XT1-3*=,Ud1-3×Sj/（100×Se）=,4.25,,,

,1XT2-3*=,Ud2-3×SJ/（100×Se）=,1.625,,,

,1XT1*=,0.5×（XT1-2*+XT1-3*-XT2-3*）＝,5.6875,,,

,1XT2*=,0.5×（XT1-2*+XT2-3*-XT1-3*）=,3.0625,,,

,1XT3*=,0.5×（XT1-3*+XT2-3*-XT1-2*）=,-1.4375,,,

,1#主變參數(shù)：,,,,,

,1XT1-2*=,Ud1-2％×Sj/（100×Se）＝,2.625,,,

,1XT1-3*=,Ud1-3×Sj/（100×Se）=,4.250,,,

,1XT2-3*=,Ud2-3×SJ/（100×Se）=,1.625,,,

,1XT1*=,0.5×（XT1-2*+XT1-3*-XT2-3*）＝,2.625,,,

,1XT2*=,0.5×（XT1-2*+XT2-3*-XT1-3*）=,0.000,,,

,1XT3*=,0.5×（XT1-3*+XT2-3*-XT1-2*）=,1.625,,,

,1

當d1點發(fā)生短路時，即110kV母線發(fā)生短路時，各短路參數(shù)如下：,,,,,

,XΣ1*=,XS*+XL*=,0.3,,,

,I1*=,1/XΣ1*=,3.0,,,

,Id1（3）=,Ij/XΣ1*=,15.2,（短路電流周期分量始值）,,

,ich1=,1.8×√2×Id1（3）=,38.7,（短路電流沖擊值）,,

,Ich1=,1.509×Id1（3）=,22.9,（短路電流全電流最大有效值）,,

,Sd1=,Sj/XΣ1*=,3029.2,,,

,2

當d2點發(fā)生短路時，即35kV母線發(fā)生短路時，各短路參數(shù)如下：,,,,,

,XΣ2*=,XΣ1*+1XT1*//2XT1*=,2.1,,,

,I2*=,1/XΣ2*=,0.5,,,

,Id2（3）=,Ij/XΣ2*=,7.3,（短路電流周期分量始值）,,

,ich2=,1.8×√2×Id2（3）=,18.7,（短路電流沖擊值）,,

,Ich2=,1.509×Id2（3）=,11.1,（短路電流全電流最大有效值）,,

,Sd2,Sj/XΣ2*=,470.3,,,

,3

當d3點發(fā)生短路時，即10kV母線發(fā)生短路時，各短路參數(shù)如下：,,,,,

,XΣ3*=,XΣ2*+1XT3*//2XT3*=,-10.3,,,

,I3*=,1/XΣ3*=,-0.1,,,

,Id3（3）=,Ij/XΣ3*=,-1.6,（短路電流周期分量始值）,,

,ich3=,1.8×√2×Id3（3）=,-4.1,（短路電流沖擊值）,,

,Ich3=,1.509×Id3（3）=,-2.4,（短路電流全電流最大有效值）,,

,Sd3=,Sj/XΣ3*=,-96.8,,,

,,,,,,,

,,結果表(三卷變）,,,,

,,,,,,,

,,符號,單位,1,2,3

,短路點單位名稱,,,110kV側,35kV母線,10kV母線

,短路點編號,,,d1,d2,d3

,基準容量,Sj,MVA,1000,1000,1000

,基準電壓,Uj,,115,37,35

,基準電流,Ij,kA,5.02,15.60,16.50

,短路電流標么值,I*,,3.03,0.47,-0.10

,短路容量,S,MVA,3029.2,470.3,-96.8

,短路電流周期分量始值,Id3（3）,kA,15.2,7.3,-1.6

,短路電流全電流最大有效值,Ich3,kA,22.9,11.1,-2.4

,短路電流沖