電力系統(tǒng)分析試題與答案

1、一.計算題計算題例26已知，試求出圖中變壓器不含勵磁支路的Ⅱ型等值電路。????)52.63j08.4(TZ1011011??k解：變壓器阻抗折算到高電壓側(cè)時，含理想變壓器的等值電路示于圖，因此圖中各支路阻抗為，??????)52.63j408.0(1052.63j08.4kZT????????).0587j453.0(10152.63j08.41kZT????????).7060j0453..0(1)10(1052.63j08.4)1

2、(kkZT例28試計算如圖所示輸電系數(shù)各元件電抗的標(biāo)幺值。已知各元件的參數(shù)如下，發(fā)電機(jī)SG(N)=30MVA，VG（N）=10.5kV，XG（N）=0.26；變壓器T1ST1(N)=31.5MVA，VS%=10.5，kT1=10.5121；變壓器T2ST2(N)=15MVA，VS%=10.5，kT2=1106.6；電抗器VR(N)=6kV，IR(N)=0.3kA，XR%=5；架空線路長80km，每公里電抗為0.4Ω；電纜線路長2.5km

3、，每公里電抗為0.08Ω。解：首先選擇基準(zhǔn)值，取全系統(tǒng)的基準(zhǔn)功率SB=100MVA。121kVkV1215.1015.101VV)ⅠⅠ(B)ⅠB()ⅠB(????k7.26kV(1106.6)1121kV)6.6110()1215.10(15.101V1VV)ⅠⅠ(B)ⅠⅠ(B)ⅠB()ⅠⅠ(B)ⅠB()ⅠB(?????????kkk各元件電抗的標(biāo)幺值為87.05.10100305.1026.0VSSVXX222)ⅠB(BG(N)2G(

4、N)G(B)G(B)1???????x33.05.101005.315.101005.10VSSV100%VX222)ⅠB(BT1(N2)2)ⅠT1(NST1(B)2????????x22.0121100804.0VSXX22)ⅠB(BLL(B)3??????x58.0211100155.101005.10VSSV100%VX222)ⅠB(BT2(N2)2)ⅠT2(NST2(B)4????????x09.126.71003.036100

5、5VS3V100%VX22)ⅠB(BR(N)R(N)RR(B)5?????????Ix，87.03010026.0SS26.0GNB1??????dxx33.05.311001005.10SS100%VT1(N)BS1T2??????xx，24.0115100804.0VSXx22)ⅠB(BL3??????7.0151001005.10SS100%VXT2BST24??????x，46.13.61003.0361005VS3V100%V

6、X22)ⅠB(BR(N)R(N)RR5?????????Ix504.03.61005.208.0VSXX22)ⅠB(BCC6??????x104.4504.046.17.024.033.087.0????????X，，15.105.10V10.5ⅠB????E244.0104.411I????XfkA24.23.63100104.41V3IIⅠ)(B?????BffS例32已知同步電機(jī)的參數(shù)為：，，。試求在額定滿載運行時的電勢和。0.1

7、d?x6.0q?x85.0cos??qEQE解：用標(biāo)幺值計算，額定滿載時V=1.0，I=1.0（1）先計算。由圖的相量圖可得QE41.1)85.06.0()53.06.01()cos()sinV(2222Q???????????IxIxEqq（2）確定的相位，相量和間的相角差?QE，EQ?V????????2153.06.0185.06.0sincosarctgIxVIxarctgqq???和的相位差為：，EQ?I???????5385

8、.06.053.0cossinarctgVIxVarctgq????(3)計算電流和電壓的兩個軸向分量，8.053sin)sin(?????IIId??6.053cos)cos(?????IIIq??，36.021sinsin????VVVd?93.021coscos????VnVVq?（4）計算空載電勢：qE73.18.0)6.01(41.1)(q????????dqdQIxxEE例41某電力系統(tǒng)的等值網(wǎng)絡(luò)示于。各元件阻抗、導(dǎo)納均以標(biāo)