差动保护-1课件

Klicken Sie,um das Format des Titel-Masters zu bearbeiten.,Klicken Sie,um die Textformatierung des Masters zu bearbeiten.,Zweite Ebene,Dritte Ebene,Vierte Ebene,Fnfte Ebene,Principles Transf.Diff,*,西门子能源自动化,-,让您永争第一,变压器差动保护原理,基本原理,:,基尔霍夫电流定律,I,1,I,2,I,3,I,4,I,1,+,I,2,+,I,3,+,I,4,=0,I,=0,差动保护基础：,定义：,电流流入节点,(,保护对象,),，方向为正,电流流出节点,(,保护对象,),，,方向为负,保护对象：,线路，变压器，发电机,/,电动机，母线,基本原理：,比较电流,I,F,I,I,Diff,=,I,1,+,I,2,I,P1,I,S1,I,S2,I,P2,外部故障或负载,保护对象,保护对象,I,Diff,=,I,1,+,I,2,I,S1,I,S2,I,P1,I,S1,I,S2,I,P2,内部故障,I,I,1F,I,2F,假定：,CT-ratio:1/1,I,P1,=,I,1F,I,P2,=,I,2F,I,Diff,=,I,P1,+,I,P2,=,I,1F,+,I,2F,跳闸,假定：,CT-ratio:1/1,I,P1,=,I,F,I,P2,=-,I,F,I,Diff,=,I,P1,+,I,P2,=,I,F,-,I,F,=0,不跳闸,差动保护要求,:,1),内部故障,(,故障落在两个,CT,之间,),跳闸,2),外部故障 不跳闸,基本原理：制动电流比较,(1/2),假定,:CT,变比为,1/1,I,Diff,=,I,S1,+,I,S2,=(1+,1,),I,P1,+(1+,2,),I,P2,=0.95,I,P1,1.05,I,P1,=0.1I,P1,正常运行,:,I,P1,=,I,N,I,Diff,=0.1I,P1,=,0.1I,N,外部故障,:,设定,:,I,P1,=10,I,N,I,Diff,=0.1I,P1,=,1I,N,I,F,I,Diff,=0.1,I,P1,I,P1,I,S1,=0.95,I,P1,I,S2,=1.05I,P2,I,P2,=-,I,P1,例：,外部故障，,CT,为线性误差,保护对象,I,Ct 2:,2,=+5%,Ct 1:,1,=-5%,由于通常情况下定值,I,Diff,小于额定电流，,在外部故障电流很大的情况下将产生误跳,!,抑制特性就必不可少！,基本原理,:,制动电流比较,(2/2),在如下假定条件下：,1,=,2,and I,1,=I,2,传统的差动保护特性应该是：,I,Diff,=,I,Diff,+,1,I,1,+,2,I,2,=I,Diff,+2,1,I,1,with,I,Diff,=setting,I,Diff,I,Diff,=,I,S1,+,I,S2,I,Rest,=,I,S1,+,I,S2,I,N,综合特性,Block,Trip,由于,CT,变比不同产生的线性误差,定值设定，考虑磁化电流或充电电流影响,2,10,I,Rest,I,F,I,Diff,=,I,S1,+,I,S2,I,Diff,=0.1,I,P1,I,P1,I,S1,=0.95,I,P1,I,S2,=1.05I,P2,I,P2,=-,I,P1,例,:,外部故障，,CT,为线性误差,保护对象,I,Diff,CT 2:,2,=+5%,CT 1:,1,=-5%,I,Rest,=,I,S1,+,I,S2,I,Rest,=2,I,P1,基本原理,:,3,相系统的测量回路,制动电流,差流,传统差动保护,L1,L2,L3,3,相系统的基本回路,:,发电机,/,电动机,/,电抗,变压器差动保护特性,对于,3,相变压器，由于矢量组变换的原因产生了,N30,的相移,(,0 N 11),高压侧和低压侧,CT,一次电流值不同,外部故障时的零序电流也会产生差动电流,要考虑变压器分接头的改变，,以及励磁电流,暂态电流涌流,CT,饱和,3,相变压器,:,一次值,I1,L1,I1,L2,I1,L3,I2,*,L1,=-,I1,L1,k,u,/3+,I1,L2,k,u,/3,I2,L1,I2,L3,I1,L1,容量：,100MVA,，,矢量组：,Yd5,低压侧,:,20kV,2887A,高压侧,:,110kV,525A,1L1,1L2,1L3,2L1,2L2,2L3,I1,L2,I2,L2,I1,L3,I2,*,L1,I2,*,L3,I2,*,L2,750/1A,3000/1A,k,U,=U,1N,/U,2N,=110kV/20kV=5.5,k,Winding,=w1/w2=k,U,/,3,I2,*,L3,I2,*,L2,530,I2,*,L1,I1,L1,k,u,/3,-,I1,L1,k,u,/3,I1,L2,k,u,/3,3,相变压器,:,二次值,I2,L1sec,=0.96A,-150,I1,L1sec,=0.7A,0,I,Diff L1,=,I1,L1sec,+,I2,L1sec,=0.5A,传统的变压器差动保护矢量组和电流值的匹配,(1/2),额定负载,(,无故障,):,0.70A 23Wdg=0.555A 29Wdg,I,R,=0.5553=0.96A,匹配变压器,-,向量组自适应,-,电流值自适应,-,零序电流处理,传统差动保护,L1,制动电流,差流,L2,L3,容量,:,100MVA,矢量组,:,YNd5,低压侧,:,20kV,高压侧,:,110kV,750/1A,3000/1A,I,Load,=525A,0.7A,0.96A,29,Wdg,.,23,Wdg,.,2887A,I,R,传统的变压器差动保护矢量组和电流值的匹配,(,2,/2),高压侧单相故障,:,5.73A 23Wdg=4.550A 29Wdg,I,R,=4.55A,匹配变压器,-,向量组自适应,-,电流值自适应,-,零序电流处理,传统差动保护,L1,制动电流,差流,L2,L3,容量,:,100MVA,矢量组,:,YNd5,低压侧,:,20kV,高压侧,:,110kV,750/1A,3000/1A,I,P,=4300A,3I,0,5.73A,4.55A,29,Wdg,.,23,Wdg,.,13655A,I,R,数字式变压器差动保护矢量组和电流值的匹配,(,1,/2),I1,B,I1,C,I1,A,I2,L1P,I2,L2P,I1,L1P,1L1,1L2,1L3,2L1,2L2,2L3,comparison,I,Io handling,I2,L2S,I2,L1S,I2,L3S,I2,B,I2,C,I2,A,Vectorgroupadaptation,Current value adaptationCT 1,Io handling,I1,L2S,I1,L1S,I1,L3S,I2,L3P,Current value adaptationCT 2,I1,L2P,I1,L3P,容量,:,100MVA,矢量组,:,YNd5,低压侧,:,20kV,高压侧,:,110kV,数字式变压器差动保护,CT 1750/1A,CT 23000/1A,数字式变压器差动保护矢量组和电流值的匹配,(,2,/2),7UT6,差动保护装置中变压器和,CT,数据的参数设定,变压器差动保护的跳闸特性,CT,误差，,变压器分接头的改变，磁化电流,CT-,误差,因变压器分接头改变引起的误差,变压器励磁电流,I,Diff,=f(I,Rest,),I,Rest,=|,I,1,|+|,I,2,|,2.0,8.0,9.0,3.0,7.0,2.5,slope 1,slope 2,I,Diff,0,1.0,4.0,5.0,3.0,6.0,0,1.0,0.5,2.0,1.5,跳闸区域,闭锁区域,总误差,45,特性：,InO=,保护对象的额定电流,暂态电流,(,包含谐波,)-,变压器涌流,(1 of 2),2,次谐波,.,2,次谐波,.,3,次和,5,次,谐波,.,i,1,t,i,Diff,=i,1,i,Diff,=i,1,t,i,1,涌流,i,1,i,2,=0,Y,Y,t=0,涌流,i,1,I,2,=0,Y,t=0,i,1,i,2,-T1,-T2,合上,T2,，与,T1,并列运行,t=0T2,涌流,i,Diff,=i,1,+,i,2,t=0,i,1,涌流，交叉闭锁，过激磁,V/Hz (2 of 2),区分涌流条件判据：为评估二次谐波,I,2har,相对于基波,I,Diff,的比率。,交叉闭锁的时间限制。,交叉闭锁涌流条件的可靠反应。在整定延时之后跳闸。,区分过激磁判据,V/Hz,：为评估,3,次谐波或,5,次谐 波相对于基波的比率。,交叉闭锁,=Yes,(,全相闭锁,),O R,1,L1-block,L2-block,L3-block,I,Diff,跳闸闭锁 闭锁时间可整定,滤波窗口,1,周波,t,1P,2P,3P,i,RUSH,=,i,Diff,单相涌流,定值,t,15%,不闭锁,闭锁,0,0,L1-block,L2-block,L3-block,交叉闭锁,=No,(,分相闭锁,),I,Diff,L1,跳闸闭锁,I,Diff,L2,跳闸闭锁,I,Diff,L3,跳闸闭锁,3 cyclesCross Blocking,涌流,内部故障,I,Diff,I,Diff,变压器发展性故障时的涌流示意图,暂态电流,(,包含谐波,)(1/2)-,过激磁 和,CT,饱和,5,次谐波,偶次和奇,次谐波,过激磁,(U/f),U,Tr,U,N,i,1,i,2,内部故障：,高压侧,CT,饱和,i,1,I,2,0,LV,HV,外部故障：,低压侧,CT,饱和,i,1,i,2,LV,HV,i,Diff,=i,1,+,i,2,i,Diff,=i,1,+,i,2,i,Diff,=i,1,偶次和奇,次谐波,暂态电流,(,包含谐波,)(,2,/2)-,过激磁 和,CT,饱和,0,A,2,4,8,10,6,12,0,2,1,4,3,7UT6,的跳闸特性,跳闸区域,6,7,16,I,Diff,14,5,I,Diff,附加稳定区,45,闭锁区域,饱和起始点,B,D,C,外部故障时的，,Add-on,附加稳定区的工作原理,add-on,附加稳定区示意图,附加稳定区,45,闭锁,跳闸,变压器差动保护的应用,某一侧,1,断路器,7UT6137UT633,三卷变,单相或三相,7UT6137UT633,两卷变,单相或三相,7UT6127UM62,双侧,1,断路器,7UT635,发变组单元接线,Y,G3,7UT635,