第11章 电力系统潮流计算-手算.ppt

第11章电力系统潮流计算－手算,,电力系统潮流计算在给定的稳态运行条件下确定电力系统的运行状态（包括母线电压相量，网络中的功率分布和功率损耗）,第11章电力系统潮流计－手算,,如何计算电力系统的潮流传统方法－手算11-1,11-2计算机计算11-3,11-4,11-5,,,11.1开式网的潮流计算,第1步做简化的等值电路及其相应的运算负荷或运算功率,第11章电力系统潮流计－手算,A,b,c,d,,,,,,,,,用额定电压计算运算负荷或运算功率,,,11.1开式网的潮流计算,第11章电力系统潮流计－手算,,第1步做简化的等值电路及其相应的运算负荷或运算功率,,11.1开式网的潮流计算,第11章电力系统潮流计－手算,,第2步在简化的等值电路上选用两类过程之一进行潮流计算,,两类过程简单辐射形网络的潮流计算有两类基本过程。过程1已知同一端的功率和电压，求另一端功率和电压；过程2已知始端电压、末端功率，求始端功率、末端电压（以此居多）；或已知末端电压、始端功率，求末端功率、始端电压。,,两类过程简单辐射形网络的潮流计算有两类基本过程。过程1已知同一端的功率和电压，求另一端功率和电压；过程2已知始端电压、末端功率，求始端功率、末端电压（以此居多）；或已知末端电压、始端功率，求末端功率、始端电压。,,11.1开式网的潮流计算,第11章电力系统潮流计－手算,,第2步在简化的等值电路上选用两类过程之一进行潮流计算,,过程1总结为从已知功率、电压端，用第十章中适当的公式齐头并进逐段求解功率和电压。,,,求功率,求电压,求功率,求电压,求功率,求电压,计算起点,计算终点,S4已知,V1已知,3,2,1,4,图已知一点电压、另一点功率求辐射形网络潮流,过程2总结为“一来、二去”共两步，一来即设所有未知电压节点的电压为线路额定电压，用第十章中适当的公式从已知功率端开始逐段求功率，直到推得已知电压点的功率；二去即从已知电压点开始，用推得的功率和已知电压点的电压，选用第十章中适当的公式，往回逐段向未知电压点求电压。,,两类过程简单辐射形网络的潮流计算有两类基本过程。过程1已知同一端的功率和电压，求另一端功率和电压；过程2已知始端电压、末端功率，求始端功率、末端电压（以此居多）；或已知末端电压、始端功率，求末端功率、始端电压。,,11.1开式网的潮流计算,第11章电力系统潮流计－手算,,第2步在简化的等值电路上选用两类过程之一进行潮流计算,,,,,11.1开式网的潮流计算,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,,,环网,两端供电网,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,A,b,c,d,,,,,,,,,,jΔQB3,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,,第1步做简化的等值电路及其相应的运算负荷或运算功率,A,c,d,,,,,第2步忽略功率损耗，计算初步功率分布,,a,2,b,2,1,Za1,Zb2,Z12,S2,S1,,,Sa1,,S12,,Sb2,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,A,c,d,,,,,a,2,b,2,1,Za1,Zb2,Z12,S2,S1,,,Sa1,,S12,,,,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,,第2步忽略功率损耗，计算初步功率分布,A,c,d,,,,,a,2,b,2,1,Za1,Zb2,Z12,S2,S1,,,Sa1,,S12,,Sb2,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,,第2步忽略功率损耗，计算初步功率分布,A,c,d,,,,,a,2,b,2,1,Za1,Zb2,Z12,S2,S1,,,Sa1,,S12,,Sb2,,即初步功率分布基本功率分布循环功率,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,,第2步忽略功率损耗，计算初步功率分布,A,c,d,,,,,Fundamentalpowerrelatestoloadpowerandgridconfigurationandisirrelevanttothepowersourcevoltage.,,a,2,b,2,1,Za1,Zb2,Z12,S2,S1,,,Sa1,,S12,,Sb2,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,,即初步功率分布基本功率分布循环功率,A,c,d,,,,,Whereascirculatepowerrelatestothedifferenceofpowersourcevoltageandisirrelevanttotheloadpowerandgridconfiguration.,,a,2,b,2,1,Za1,Zb2,Z12,S2,S1,,,Sa1,,S12,,Sb2,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,,即初步功率分布基本功率分布循环功率,A,c,d,,,,,Step2Neglectthepowerloss,calculatethepreliminarypower,,a,2,b,2,1,Za1,Zb2,Z12,S2,S1,,,Sa1,,S12,,Sb2,,Inthecaseofunigrid均一网,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,A,c,d,,,,,Step3Findthepowerconvergencepointaccordingtothepreliminarypower.Markthepointby“▼”or“▽”.,,a,2,b,2,1,Za1,Zb2,Z12,S26j6,S13j3,,,Sa15j5,,S122j2,,Sb24j4,“▼”or“▽”,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,A,c,d,,,,,Step3Findthepowerconvergencepointaccordingtothepreliminarypower.Markthepointby“▼”or“▽”.Thenseparatethetwo-endsuppliedgridintotwoopen-endedgrids.,,a,2,b,2,1,Za1,Zb2,Z12,S26j6,S13j3,,,Sa15j5,,S122j2,,Sb24j4,“▼”or“▽”,,,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,A,c,d,,,,,Step4Calculatethepowerflowo-endedgrids.,,a,2,b,2,1,Za1,Zb2,Z12,S26j6,S13j3,,,Sa15j5,,S122j2,,Sb24j4,“▼”or“▽”,,,,第11章电力系统潮流计－手算,11.2闭式网的潮流计算,例习题集例2-5110KV简单环网示于题，导线型号均为LGJ-95，已知线路AB段为40KM，AC段30KM，BC段30KM；变电所负荷为SB＝20＋j15MVA，SC＝10j10MVA。电源点A点电压为115KV。求电压最低点和此网络的最大电压损耗和有功总损耗；导线参数LGJ-95r＝0.33Ω/km,x0.429Ω/km,b2.65X10-6s/km,,,Chapter11ThePowerSystemsPowerFlowCalculation,,11.2ThePowerFlowCalculationofclose-endedGrid,,*Thepowerflowcalculationofmulti-voltagelevelgrid,,,,,Chapter11ThePowerSystemsPowerFlowCalculation,,11.2ThePowerFlowCalculationofclose-endedGrid,,*Thepowerflowcalculationofmulti-voltagelevelgrid,,,,,Chapter11ThePowerSystemsPowerFlowCalculation,,11.2ThePowerFlowCalculationofclose-endedGrid,,*Thepowerflowcalculationofmulti-voltagelevelgrid,,,,,,,,,,,,,,Chapter11ThePowerSystemsPowerFlowCalculation,,11.2ThePowerFlowCalculationofclose-endedGrid,,*Thepowerflowcalculationofmulti-voltagelevelgrid,,,,,,,,,,,,,,,,,,Chapter11ThePowerSystemsPowerFlowCalculation,,11.2ThePowerFlowCalculationofclose-endedGrid,,*Thepowerflowcalculationofmulti-voltagelevelgrid,,,,,,,,,,,,,,,,,,where,,,11.2ThePowerFlowCalculationofclose-endedGrid,*Thepowerflowcalculationofmulti-voltagelevelgrid,Chapter11ThePowerSystemsPowerFlowCalculation,where,,,,,Chapter11ThePowerSystemsPowerFlowCalculation,,11.2ThePowerFlowCalculationofclose-endedGrid,,*Thepowerflowcalculationofmulti-voltagelevelgrid,,,,,,,,,,,,,,,,,,例（习题集例2-7）两台型号相同的降压变压器并联运行，已知每台容量为5.6MVA，额定变比为35/10.5，归算到35KV侧的阻抗为2.22＋j16.4Ω，10KV侧的总负荷为8.5＋j5.27MVA，高压侧电压为35KV。不计变压器内部损耗，试计算１．两台变压器变比相同时，各变压器输出的有功功率和低压侧电压；２．变压器1工作在＋2.5％抽头，变压器二工作在0抽头时，各变压器输出的有功功率；此时变压器运行有什么问题,,,,,,,,,,,,,,,,,,,,Chapter11ThePowerSystemsPowerFlowCalculation,11.2ThePowerFlowCalculationofclose-endedGrid,*Thepowerflowcontrolofclose-endedgrid,,,,Thefundamentalpower,alsocalledasnaturalpower,isuncontrollableandininverseproportiontotheconjugateimpedance.,,,,Chapter11ThePowerSystemsPowerFlowCalculation,11.2ThePowerFlowCalculationofclose-endedGrid,*Thepowerflowcontrolofclose-endedgrid,,,,,Howtocontrolthepowerflowsothatthegridpowerlossistheminimum.,Andthepowerflowwiththeminimumpowerlossisreferredtoasoptimumpowerflow.,,,Chapter11ThePowerSystemsPowerFlowCalculation,11.2ThePowerFlowCalculationofclose-endedGrid,*Thepowerflowcontrolofclose-endedgrid,,,,,Howtocontrolthepowerflowsothatthegridpowerlossistheminimum.,Andthepowerflowwiththeminimumpowerlossisreferredtoasoptimumpowerflow.,,or,,,,Chapter11ThePowerSystemsPowerFlowCalculation,11.2ThePowerFlowCalculationofclose-endedGrid,*Thepowerflowcontrolofclose-endedgrid,,,,Thegridpowerlossreachestheminimumwhenthepowerflowisinreverseproportiontotheresistance,orinotherwords,theoptimumpowerflowisinreverseproportiontotheresistance.,,Chapter11ThePowerSystemsPowerFlowCalculation,11.2ThePowerFlowCalculationofclose-endedGrid,*Thepowerflowcontrolofclose-endedgrid,,,,,,,Chapter11ThePowerSystemsPowerFlowCalculation,11.2ThePowerFlowCalculationofclose-endedGrid,*Thepowerflowcontrolofclose-endedgrid,,,,,,,Chapter11ThePowerSystemsPowerFlowCalculation,11.2ThePowerFlowCalculationofclose-endedGrid,*Thepowerflowcontrolofclose-endedgrid,,,,,,,,,,,,,,,,,,,,11.2ThePowerFlowCalculationofclose-endedGrid,Chapter11ThePowerSystemsPowerFlowCalculation,seriestranser,excitingtranser,Regulatingtranser,seriestranser,,excitingtranser,Regulatingtranser,,*Thepowerflowcontrolofclose-endedgrid,11.2ThePowerFlowCalculationofclose-endedGrid,Chapter11ThePowerSystemsPowerFlowCalculation,seriestranser,,Directregulatingtranser,,*Thepowerflowcontrolofclose-endedgrid,excitingtranser,,Directregulatingtranserismainlyusedtocontrolreactivepower,11.2ThePowerFlowCalculationofclose-endedGrid,Chapter11ThePowerSystemsPowerFlowCalculation,seriestranser,,excitingtranser,Quadratureregulatingtranser,,*Thepowerflowcontrolofclose-endedgrid,,,Quadratureregulatingtranserismainlyusedtocontrolactivepower,11.2ThePowerFlowCalculationofclose-endedGrid,Chapter11ThePowerSystemsPowerFlowCalculation,seriestranser,,Hybridregulatingtranser,,*Thepowerflowcontrolofclose-endedgrid,,excitingtranser,11.2ThePowerFlowCalculationofclose-endedGrid,Chapter11ThePowerSystemsPowerFlowCalculation,,AnotherwayofcontrollingthepowerflowisusingFACTSFlexibleACTransmissionSystem.SeePage5052,,*Thepowerflowcontrolofclose-endedgrid,,