第三章作业1输电系统如题图2所示。已知:每台变压器SN=100MVA,P0=450kW,Q0=3500kvar,Pk=1000kW,Uk%=12.5%,工作在-5%的分接头;每回线路长250km,r1=0.08Ω/km,x1=0.4Ω/km,b1=2.810-6S/kmP=150MW85.0cos×10-6S/km;负荷PLD=150MW,85.0cos。线路首端电压UA=245kV,试分别计算:1.输电线路,变压器以及输电系统的电压降落和电压损耗;2.输电线路首端功率和输电效率;3.线路首端A,末端B以及变压器低压侧C的电压偏移。第三章作业1第三章作业1(1)作出等值电路图,归算到220kv侧计算相应的参数SAABC'ASZL'BS'BSZTSLDBB双回输电线:1164111()(0.080.4)2501050221122.81025071022ZrjxljjBblS2Bj2BjSTY第三章作业1变压器:221222211110002202.42()2100021000100%11112.522030.25()221002100100SNTNSNNPURSUUBS负荷:(arccos(cos))150(arccos(cos0.85))92.96LDLDQPtgtgMVA15092.96()LDLDLDSPjQjMVA第三章作业1(2)设220ABCUUUkv,计算各分段及元件分布功率:22222215092.96()(2.4230.25)2201.5619.46()TLDLDZTTCPQSRjXjUjMVA004503500220.97()10001000TYPjQjSjMVA222222152.4685.54()(1050)2206.3131.57()LBBZLLNPQSRjXjUjMVA242/271022033.88(var)2BBBQUM第三章作业1输电系统首端的功率为:/2215092.961.5619.460.97233.886.3131.57158.7783.23()TTLALDZYBZSSSSQSjjjjjjMVA输电效率为:21150100%100%94.48%158.77PP第三章作业1(3)用已知的首端电压和已求出的功率分布计算此网络各电压'/2158.7783.2333.88158.77117.11()AABSSQjjjMVA''158.7710117.115030.38245ALALLAPRQXUkvU''''158.7750117.111027.62245ALALLAPXQRUkvU2222()()(24530.38)(27.62)216.39BALLUUUUkv输电线的电压降落为:30.3827.62LUjkv电压损耗为:245216.39100%100%13.0%220ABNUUU第三章作业1'15092.96(1.5619.46)151.56112.42()TBLDZSSSjjjMVA''151.562.42112.4230.2517.41216.39BTBTTBPRQXUkvU''151.5630.25112.422.4219.93216.39BTBTTBPXQRUkvU'2222()()(216.3917.41)19.93199.98CBTTUUUUkv'199.9810.532200.9511CCUUkvk第三章作业1变压器电压降落:17.4119.93TUjkv电压损耗:'216.39199.98100%100%7.46%220BCNUUU输电系统的电压降落为:输电系统的电压降落为:30.3827.6217.4119.9347.7947.55LTUUUjjjkv输电系统电压损耗为:'245199.98100%100%20.46%220ACNUUU第三章作业1A,B,C的电压偏移分别为:245220100%100%11.36%220ANNUUU216.39220100%100%1.64%220BNNUUU10.5310100%100%5.3%10CNNUUU