珍藏大包期末故障分析第五章

故障分析五章一、思考題 序分量三角側(cè)電壓、電流較星形側(cè)k30；對于負(fù)序側(cè)分量剛好相反，即超前k30；負(fù)序分量都要乘以旋轉(zhuǎn)算子aa2，復(fù)合序網(wǎng)難以直接做出。B相發(fā)生單相短路接地故障，則對稱分量法的代表相也用B相，故障前正常工作電壓用B的。邊界條件：Ufb0Ifb0Ifc0U

U

U

U

0，

I

I

Ufb

F F a a(1 a b(1 1b a(2 b b(2F F c a(0 c b(0F a

c(1 b

c(2

c(0ABCBCACAB以單相短路故障為例，無論是否是A相發(fā)生短路接地，都按A相接地計算，序分量B相發(fā)生了短路接地，則將計算的結(jié)果的角標(biāo)進(jìn)行轉(zhuǎn)換：AB，B變A變?yōu)镃，B變?yōu)锳，C變?yōu)锽。向組(自己填寫(注意畫圖障障對稱分量法，9個電壓源加在故障點各序等效抗聯(lián)9個電源加在二、計算題求變壓器T2求變壓器T1和T3 G1=G2：15MVA

T1=T2=T3：15MVA

圖U Z B 881.6667，IB SBS

3xG1(1)xG2(1)xG1(2)xG2(2)xT1(1)xT2(1)xT3(1)xT1(2)xT2(2)xT3(2)

100

xG1(1)xT1(1)0.04540.1250.105 x(2)x(1) (xT1(0)xL(0))xT3(0)0.24110.105xx

xT

0.2411 IK(1)

x(0)

)IK0j7.6160.0753T2中性點的電壓就是零序網(wǎng)圖中CD

IK

x

xT

xT

j2.5387 0.2411

U2(0)IK(0)jx(0)j2.5387j0.0731U1(0)U2(0)I12(0)jxL(0)0.1856(j0.77)j0.1361有名值：U1(0) 變壓器T1、T3中性點中的電流是3倍的零序電I23(0)IK(0)I12(0)j2.5387j0.77j1.7687)Gcos

圖 U SIB1 B SB

3

B

GxG(1)xG(2)0.13125 Uk%SB10.5100T T T

xp 0.3025，則3x

30.3025

xl100

l

l

xl(0)3xl(1)30.3025

x(1)xG(1)xT(1)xl(1)0.1040.08750.3025x(2)x(1)x(0)xT(0)xl(0)3xp(0)0.90740.08750.9074

UKKjx(2) j0.494j0.494 jx(1) j0.494 I j1.1285 j0.8958K K (2) j0.494IK(0)IK(1)IK(2)j1.1285j0.8958j0.2327IKBIKC1.78740.50210.89KAIK3IK(0IB3j0.23270.5021IKUK(1)UK0jIK(1)x(1)1(j1.1285)j0.494UK(2)0jIK(2)x(2)0j0.8958j0.494UK(0)0jIK(0)x(0)0j0.23266j1.9025UM(1)UK(1)jIK(1)xl(1)0.4425(j1.1285)j0.3025UM(2)UK(2)jIK(2)xl(2) j0.8958j0.3025UM(0)UK(0)jIK(0)xl(0)0.442636j0.23266j0.9074UMAUM(1)UM(2)UM(0)0.783870.17150.2314M(1)M(1) (1 3)0.78387(1 3)0.1715 0.24625j0.5303MMMM(1 3)0.78387(1 3)0.1715 1.18677115U

0.5847115U

0.58471153IK(0)3j0.23270.502140 已知系統(tǒng)正序、負(fù)序和零序等值電抗為x1x2，且x03x1，求在系統(tǒng)同一故障點分別發(fā)生三相短路、單相接地短路、兩相短路和兩相短路接地時，各種短路電流的周期分量有效值之比I(3):I(1):I(2):I(1,1)?(3)Uf(3)Uf（2）f(1)：I(1)

3Uf 3Uf 3Ufj(x(1)x(2)x(0) j(2x(1)3x(1) 5（3）f(2)：I(2)IfbIfca2If(1)aIf

(a2a)If(1)

3If 3Uf 4Uf（4） ：I(1)

7

(1)

7 x x

7( a2 1(4a2