A21.6+ j33.84-j1.3-j1.32-j0.96-j0.96-j0.8116.5+j21.453ST2?B19.8+j25.74ST1??-j0.81?SYT2?0.049?j0.46??SYT1?0.081?j1.05?4.75+|j63.53??20?j15S3?3.44+j42.35??20?j15S2
二，计算运算负荷
（1） 计算2点的运算负荷
2P22?Q2202?152~?SZT1?(RT1?jXT1)?(3.44?j42.35)?0.18?j2.2MVA 22UN110~~~ST1?S2???SZT1?20?j15?0.18?j2.2?20.18?j17.2MVA
~~~~~~S2?S2???SZT1??SYT1??SYL1??SYL2?20?j15?0.18?j2.2?0.081?j1.05?j1.3?j0.96?20.26?j15.99MVA（2） 计算3点的运算负荷
?2P3?2?Q3152?122~?SZT1?(RT2?jXT2)?(4.75?j63.53)?0.15?j1.97MVA 22UN110~~~ST2?S3???SZT3?15?j15?0.15?j1.97?15.15?j13.97MVA
~~~~~~S3?S3???SZT2??SYT2??SYL2??SYL3?15?j12?0.15?j1.97?0.049?j0.46?j0.96?j0.81?15.2?j12.66MVA电力网络的简化等值电路如图：
A-j1.321.6+j33.842?Sa?19.8+j25.743?S23?16.5+j21.45?Sb?B-j0.81
20.26+j15.99三，计算近似功率分布
15.2+j12.66~Sa??~?~?S2(Z23?Z3B)?S3Z2B???ZA2?Z23?Z2B(20.26?j1.99)?(36.3?j47.2)?(15.2?j12.66)?(16.5?j21.45) ?
57.9?j81 ?15.79?j13.57MVA~[计算 Sb??~?~?S2ZA2?S3(ZA2?Z23)ZA2?Z23?Z3B????19.6?j15.08MVA，校Sa?Sb?S2?S3]?UdU110?(117?112)??U? U?存在循环功率 SC?N???3.21?j4.5MVAAB59.7?j81Z???Sa?Sc?15.79?j13.57?3.21?j4.5?19?j18.07MVA SaSb??Sb?Sc?19.67?j15.08?3.21?j4.5?16.46?j10.58MVA ??Sa??S2?19?j18.07?20.26?j15.99??1.26?j2.08MVA S23由近似功率分布计算可见：P23??1.26MW?0 有功功率从节点3流向节点2，所以有功功率的分布为2节点；Q23?2.08MVar?0 无功功率从节点2流向节点3，因此在电压最低点将电网拆分为两个：
2??21.6+j33.84 ASS1A?3?19.8+j25.74S2?16.5+j21.45S4?SB?B-j1.3S1????20.26+j15.99四，计算功率分布和电压分布
S?23??1.26?j2.08Sb?16.46?j10.58??-j0.81
1， 左侧电网A?2?3 已知：首端电压UA?117kv，末端功率
???1.26?j2.08MVA S23（1） 计算功率分布
?2?Q?2P23~~??S???S23(R23?jX23)2UN ??1.26?j2.08?1.26?2.08(19.8?j25.74)??1.25?j2.09MVA211022
???S2??1.25?j2.09?20.26?j15.99?19?j18.08MVA S1??S222~~P1??Q1?S1?S1??(RA2?jXA2)2UN ?19?j18.08?19?18.08(21.6?j33.84)?20.23?j20MVA211022
SA?S1?(?j1.3)?20.23?j20?j1.3?20.23?j18.7MVA
（2） 计算电压分布
U2?UA?P1RA2?Q1XA220.23?21.6?20?33.84?117??107.49kv
UA117??X23P2??RA2?Q2?1.25?19.8?2.09?25.74?107.49??107.22kv
U2107.49U3?U2?2， 右侧电网B?3 已知：始端电压UB?112kv，末端功率Sb??16.46?j10.58MVA
（1） 计算功率分布
~~P??Q?S4?Sb??b2b(R3B?jX3B)UN ?16.46?j10.58?16.46?10.58(16.5?j21.45)?16.98?j11.26MVA11022222
SB?S4?(?j0.81)?16.98?j11.26?j0.81?16.98?j10.45MVA
（2） 计算电压分布 U3?UB?P4R3B?Q4X3B16.98?16.5?11.26?21.45?112??107.34kv
UB112五，计算变电所低压母线电压（根据电力网络的等值电路图）
??U2?U2PT1RT1?QT1XT1U2?107.49? 变电所Ⅰ 20.18?3.44?17.2?42.35?100.07kv
107.49U?100.07实际电压为: 2??10kvKT1110/11 变电所Ⅱ
107.22?107.34?107.28kv2PR?QT2XT215.15?4.75?13.97?63.53??U3?T2T2U3?107.28??98.34kv
U3107.28U?98.34实际电压为: 3??9.83kvKT2110/11U3?电力网络的潮流分布图
A19+j18.08-1.25+j2.09107.49kV-1.26+j2.0816.46+j10.58107.28kVIIB20.23+j18.7I16.98+j10.4510kV20+j15MVA9.83kV15+j12MVA
例3-5: 由钢芯铝绞线架设的35KV网络，其线路公里数，导线型号以及负荷兆伏安数和功率因数均已示于图中。线路参数如下 LGJ—35：
r1?0.91?/kmx1?0.442?/kmr1?0.33?/kmx1?0..40?/km
LGJ—95：
求网络的最大电压损耗。