H BCH KHOA H NI

Li M u *******in nng l mt ngun nng lng quan trng ca h thng nng lng quc gia, n c s dng rng ri trn hu ht cc lnh vc nh: sn xut kinh t, i sng sinh hot, nghin cu khoa hc Hin nay nc ta ang pht trin theo hng cng nghip ha, hin i ha, nn nhu cu v in nng i hi ngy cng cao v s lng cng nh cht lng. p ng c v s lng th ngnh in ni chung phi c k hoch tm v khai thc tt cc ngun nng lng c th bin i chng thnh in nng.Mt khc, m bo v cht lng c in nng cn phi xy dng h thng truyn ti, phn phi in nng hin i, c phng thc vn hnh ti u nht m bo cc yu cu v k thut cng nh kinh t. Xut pht t iu , bn cnh nhng kin thc ging dy trn ging ng, mi sinh vin ngnh H thng in u c giao n mn hc v thit k in cho mng in khu vc. Qu trnh thc hin n gip chng ta hiu bit tng quan nht v mng li in khu vc, hiu bit hn v nhng nguyn tc ch yu xy dng h thng in nh xc nh hng v cc thng s ca cc ng dy, chn h thng in p cho mng in chnhnhng nguyn tc t chc v iu khin h thng, tng vn u t v cc ngun nguyn vt liu pht trin nng lng Chng em xin chn thnh cm n n thy Xun Khi, cng ton th cc thy c trong khoa H thng in tn tnh hng dn chng em hon thnh bn n. H Ni, ngy 11 thng 11 nm 2011. SINH VIN Bi Xun Hong

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H BCH KHOA H NI

THIT K MNG LI IN KHU VC GM MT NGUN IN V MT S PH TI KHU VC CHNG I: PHN TCH NGUN V PH TI ********* I S A L:16 15 14 1 13 12 N 3 11 10 2 9 8 4 7 5 6 5 4 6 3 2 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1.1. Nhng s liu ngun cung cp. Ngun c cng sut v cng ln. 1.2. Nhng s liu v ph ti. Trong h thng in thit k gm 6 ph ti ( t ph ti 1 n ph ti 6). + Trong c ph ti 2,3,4,5,6 thuc h loi I chim 83,3%. + Ph ti 1 l h loi III chim 16,7%.

2

H BCH KHOA H NI

S liu tnh ton ca cc ph ti cho trong bng di y

Ph ti

Thuc h loi III I I I I I

Smax (MVA)

Smin (MVA)

Pmax (MW)

Pmin (MW)

Qmax (MVAr)

Qmin (MVAr)

yu cu cos ca T KT KT KT KT T

UH (kV)

1 2 3 4 5 6 Tng

42 30 43 49 46 37

21 20 30 24 28 22

24 30 32 30 32 20 168

17,85 17 25,5 20,4 23,8 18,7 123,25

22,26 15,9 22,79 25,97 24,38 19,61

11,13 10,6 15,9 12,72 14,84 11,66

0,85 0,85 0,85 0,85 0,85 0,85

22 22 22 22 22 22

Trong : Cng sut tiu th ca cc ph ti khc nhau, cng sut tiu th cc tiu bng 58,7% ph ti cc i. Pmin = 58,7% Pmax. Smax = Pmax+ jQmax. Smin= Pmin+jQmin. Tmax= 5000h (thi gian s dng cng sut cc i). II- Phn tch ngun v ph ti 2.1 Ngun in Trong thit k li in, vic phn tch ngun in nm vng c im v s liu ca ngun, thun li cho vic tnh ton. Ta s dng ngun c cng sut v cng ln: - Ngun cng sut v cng ln l ngun c in p u cc khng thay i v bin d c xy ra s c g sau n - Cng sut ngun ln (57) ln cng sut ti. 2.2 Ph ti3

H BCH KHOA H NI

- Cc h ph ti loi I l nhng h quan trng, v vy phi d phng chc chn. Mi ph ti phi c cp in bng mt l ng dy kp v hai my bin p lm vic song song m bo cp in lin tc cng nh m bo cht lng in nng mt ch vn hnh. Khi ngng cp in c th lm hng sn phm, h hi thit b gy nh hng ln n hot ng ca ph ti. - Cc h ph ti loi III l cc h ph ti t quan trng hn nn gim chi ph u t ta ch cn cp in bng mt ng dy n v mt my bin p. - Yu cu iu chnh in p. Trong mng in thit k cc h 2,3,4,5 c yu cu iu chnh in p khc thng. phng php ny lch in p phi tha mn cc ch nh sau: Ch ph ti cc i: du% 5% Um. Ch ph ti cc tiu: du% 0% Um. Ch s c: 0% du% 5% Um. Cc ph ti 1 v 6 c yu cu iu chnh in p thng nn phm vi chnh in p ch cc i, cc tiu, s c l: -2,5% Um. du% +10% Um. - Tt c cc ph ti u c in p h nh nhau l 22 kV, h s cng sut ca cc h u cos = 0.85. Trong bai ta a co cng sut tac dung cc ai t o ta co cng sut phan khang c tinh theo cng thc sau : Qimax = Pimax . tg (1.1) = 0,9 Trong o : cos = arcos 0,9 Suy ra T o ta co bang s liu cua cac phu tai Bang 2.1 Cac s liu Phu tai cc ai (MW) H s cng sut cos 1 24 2 30 Cac h tiu thu 3 4 32 30 0.9 5 32 6 20

Cng sut phan khang 10,66 15,5 16,47 14,53 14,53 9,69 cc ai (MVAr) III- Cn bng cng sut trong h thng in

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H BCH KHOA H NI

c im c bit ca ngnh sn xut in nng l in nng do cc nh my in trong h thng sn xut v cn bng vi in nng tiu th ca cc ph ti.Do vy cn bng cng sut nhm n nh ch vn hnh ca h thng. Do y ta s dng ngun c cng sut v cng ln nn c th p ng vi cng sut v cht lng in p cho cc ph ti.Ta khng cn cn bng cng sut. Gia thit cng sut tac dung do ngun cung cp ap ng u cho yu cu phu tai Cng sut tac dung do ngun phat ra va cng sut tac dung do ngun yu cu c tinh theo cng thc sau :P P =F Y C

P P = m. PPTi + P + TD + DTi= 1

6

(1.2)

Trong o :P P F Y C

: Tng cng sut tac dung phat ra do ngun phat ra : Tng cng sut tac dung yu cu cua cac h tiu thu : Tng cng sut tac dung cc ai cua cac h tiu thu

Pi= 1

6

PTi

P

: Tng tn tht cng sut tac dung trn ng dy va may bin ap. P TD : Tng cng sut tc dng t dung cua cac nha may in P DT : Tng cng sut d tr m : H s ng thiP Khi tinh toan s b ta co : TD = 0 P P + DT

=5%.6

Pi= 1

6

PTi

Theo s liu bai ra ta co : m=1 Vy ta co :P F

=

P YC

= PPTii= 1 6 i= 1

6

+ 0,05. PPTii= 1

= 1,05. PPTi =1,05.( 24+30+32+30+32+20 ) =175,35MW PYC = =175,35MW

Kt lun :

P

F

IV.CN BNG CNG SUT PHN KHNG : 1.Cng sut phan khang do ngun phat ra :

5

H BCH KHOA H NIQ P = .tg FF F

(1.3) Trong o :

: Tng cng sut phan khang phat ra cua ngun. cos F : H s cng sut trung binh trn thanh gop cao ap cua nha may in khu vc. F = 0,85 Ta co : cos Suy ra : F = arcos 0,85 Q P Do o : F = F .tg ( arcos 0,85 ) = 175,35. tg ( arcos 0,85 ) = 108,67 MVArF

Q

2.Cng sut phan khang cua phu tai yu cu :

Q

Y C

= m. Q PTi + Q B + Q L Q C + Q TD + Q DT (1.4)i =1

6

Trong o :6

Q

Y C

: Tng cng sut phan khang yu cu cua cac h tiu thu. : Tng cng sut phan khang cc ai cua cac h tiu thu .

Qi =1

PTi

.

Q : Tng tn tht cng sut phan khang . Q , Q : L tng tn tht cng sut phn khng do in cm vB L C

Q Qm

TD D T

in dung ca ng dy gy ra. : Tng cng sut phn khng t dng cua cac nha may in . : Tng cng sut phn khng d tr. : H s ng thi .

Khi tinh toan s b ta co : Q TD = 0

Q BTheo s liu bai ra ta co : m=1 Vy ta c : Q YC =6 i =1

+

Q DT=0

=15%. Q PTii =1

6

Q L Q C6

Q PTi + 0,15. Q PTii =1 6 i =1

= 1,15. Q PTi = 1,15.(14,53+15,5+16,95+14,53+9,69+9,69) = 93,0235 MVAr

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H BCH KHOA H NI

3.B cng sut phn khng cho h thng : Q Theo phn trc ta c: F > Q YC Do ta khng cn b cng sut phn khng cho h thng

CHNG II: D KIN CC PHNG N, TNH TON S B LA CHN PHNG N ********* 2.1 Chn in p nh mc cho li in La chn cp in p nh mc cho mng in l nhim v rt quan trng, v tr s in p nh hng trc tip n cc chi ph kinh t, k thut ca mng in. chn c cp in p hp l phi tha mn cc yu cu sau: - Phi p ng c yu cu m rng ph ti sau ny. - m bo tn tht in p t ngun n ph ti. - Khi in p cng cao th tn tht cng sut cng b, s dng t kim loi mu (I nh). Nhng in p cng tng cao th chi ph xy dng mng in cng ln v gi thnh thit b cng tng. V vy phi chn in p nh mc nh th no cho ph hp v kinh t v k thut. Chn in p ti u theo cng thc kinh nghim: Ui = 4,34. li +16 P ( kW, km, MW). Trong : Ui - in p ng dy th i (kV). li - khong cch t ngun n ph ti th i ( km). Pi - cng sut ln nht trn ng dy th i(MW). Ta c bng s liu:

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H BCH KHOA H NI

Ph ti 1 2 3 4 5 6

Smax (MVA) 24+j22,26 30+j15,9 32+j22,79 30+j25,97 32+j24,38 20+j19,61

Pmax (MW) 24 30 32 30 32 20

li (km) 45,35 79,32 44,00 46,67 45,35 49,19

Ui (kV) 107,76 95,81 108,83 115,89 112,42 102,00

U m (kV)

110

T bng s liu trn ta thy rng in p ti in trong khong (95,81115,89) chn in p nh mc cho mng in l Um = 110kV.

2.2 D kin cc phng n ni dy. Mng in thit k gm 1 ngun in v 6 ph ti, trong c 5 ph ti loi I, 1 ph ti loi III. Cc phng n ni dy d vo cc yu t sau: + V tr ngun v ph ti. + m bo cht lng in nng, kinh t. + m bo vn hnh an ton, tin cy v linh hot. Ta c th a ra cc phng n nh sau:

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H BCH KHOA H NI

1 N 2 4 5 3

1 N 2 4 5 3

6

6

1

Phuong n 1N 3

Phuong n 21 N 2 3

2 4 5

4 5

6

6

Phuong n 31 N 2 4 5 3

Phuong n 4

6

Phuong n 5

2.3 Tnh ton chn tit din dy dn Do mng in thit k c Um =110kV. Tit din dy dn thng c chn theo phng php mt kinh t ca dng in Jkt. Fkt = J . (*) kt Vi Imax l dng in cc i trn ng dy trong ch lm vic bnh thng, c xc nh theo cng thc:I max

9

H BCH KHOA H NI

Imax = n 3.U = dm

S max i

Pi 2 + Qi 2 n 3.U dm

Trong : Jkt - mt kinh t ca dng in. Um - in p nh mc ca dng in. (kV) Smaxi - cng sut trn ng dy th i khi ph ti cc i.(MVA) n - s l ng dy. Ta s dng dy nhm li thp truyn ti vi thi gian s dng cng sut cc i ca ph ti l 5000h. Jkt c tra theo bng trang 295_Thit k cc mng v h thng in_NXB khoa hc k thut 2008, ta c mt kinh t ca dng in Jkt = 1,1 A/mm2 . Da vo tit din dy dn tnh theo cng thc (*), tit hnh chn tit din tiu chun gn nht v kim tra cc iu kin v s to thnh vng quang. bn c v ng dy v iu kin php nng ca dy dn. * Kim tra iu kin vng quang. Theo iu kin, tit din dy dn khng c nh hn tr s cho php i vi mi cp in p. Vi cp in p 110kV, khng xut hin vng quang tit din dy dn ti thiu c php l 70mm2 . * Kim tra pht nng dy dn. Theo iu kin: Isc max < k. Icp. Trong : Icp - dng in cho php ca dy dn, n ph thuc vo bn cht v tit din ca dy. k - h s quy i theo nhit Khc = 0.8 ng vi nhit l 25oc. i vi ng dy kp : Isc max = 2.Ibt max < 0.8 Icp. i vi ng dy n khi c s c s dn n mt in. 2.4 Tiu chun tn tht in p Cc mng in 1 cp in p t tiu chun k thut nu trong ch ph ti cc i cc tn tht in p ln nht trong ch lm vic bnh thng v ch s c nm trong khong sau y:

10

H BCH KHOA H NIU max bt = 10% 15% U max sc = 15% 20%

i vi nhng mng in phc tp (mng in kn), c th chp nhn tn tht in p ln nht trong ch ph ti cc i v ch s c nm trong khong:U max bt = 15% 20%

U max sc = 20% 25%

Trong Ubt Max , Usc Max l tn tht in p lc bnh thng v lc s c nng n nht. Ta tnh tn tht theo cng thc:

Ui (%) =

Pi.Ri + Qi.XiU 2d m

1 0 % 0

Pi ,Qi l cng sut tc dng v cng sut phn khng trn ng dy th i (MW, MVAr). Ri, Xi l in tr tc dng v in khng ca ng dy th i( ). 2.5 Tnh ton c th tng phng n Phng n I 1. S :1 N 2 4 5 3

6

2. La chn tit din dy dn

a - on ng dy N-1 Chn tit din dy dn.11

H BCH KHOA H NI

Imax N-1 =I max

S max 1 n 3.U dm1 0 ,2 1 2

=

35,72 + 22,262 2 3.110

.103= 110,22 (A)

Fkt = J = 1,1 = 100,2 kt Chn dy dn loi AC- 95,c tit din chun l 95mm2 v dng in cho php Icp=330A. - Kim tra theo iu kin vng quang: dy dn chn c: Ftc=95mm2 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng: v on N-1 l ng dy kp nn khi hng mt l th l cn li vn phi lm vic bnh thng. Do dng in trong ch s c phi nh hn h s k nhn vi dng in cho php ca dy dn: Isc = 2.Ibt max = 2.110,22 = 220,44 (A) Isc < 0,8.Icp = 330A ( tha mn iu kin ). Kim tra tn tht in p trn ng dy. Vi loi ng dy AC- 95 ta c: ro=0.33 /km, xo=0.429 /km in tr v in khng ng dy : R= 2 . ro.l = 2 . 0,33.45,35=7,48 ( ). X = 2 . xo .l = 2 . 0,429.45,35=9,73( ). - Tn tht in p ch bnh thng : U1bt % =1 1

1

1

P .R + Q .X

35 ,7.7,48 + 22 ,26 .9,73 100 = 4 % 110 2

1 1 1 1 1 0 0 = U 2 m

- Tn tht in p ch s c : U1sc % =2. U1bt % = 2. 4 % = 8 % b - on ng dy N-6 Chn tit din dy dn: Imax =S max n 3.U dmI max

=

31,452 +19,612 1 3.110

.103 =194,2(A)

Fkt = J = 1,1 =176,55 kt Chn dy dn loi AC-185 c tit din chun l 185mm2 v dng in cho php Icp= 510 A.12

1 4 ,2 9

H BCH KHOA H NI

- Kim tra theo iu kin vng quang: dy dn chn c: Ftc=185mm2 > 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : v on N-6 l ng dy n nn khi xy ra s c s dn n mt in, khng tnh n Isc. Kim tra tn tht in p trn ng dy. Vi loi ng dy AC- 185 ta c: ro=0.17 /km, xo=0.409 /km in tr v in khng ng dy : R= n . ro.l =1.0,17.49,19=8,36 ( ). X = n xo .l = 1 .0,409.49,19=20,12( ).. - Tn tht in p ch bnh thng U1bt % =1

1

P .R + Q .X

25 ,5.8,36 +15 ,81 .20 ,12 100 = 4,39% 110 2

1 1 1 1 1 0 0 = U 2 m

Khng tnh n tn tht in p ch s c . Cc on dy cn li tnh tng t, ta c cc bng s liu tnh ton.-

Bng chn tit din dy dn

13

H BCH KHOA H NIro ( km ) 0,33 0,45 0,33 0,27 0,27 0,17 xo ( km ) 0,429 0,44 0,429 0,423 0,423 0,409

on ng dy N-1 N-2 N-3 N-4 N-5 2

s l

l (km)

Smax (MVA)

Imax (A)

Fkt

Loi dy

2 2 2 2 1 1

45,35 70,32 44 46,67 45,35 49,19

30+j22,26 32+j15,9 35+j22,79 30+j25,97 20+j24,38 20+j19,61

110,22 78,73 112,85 128,59 120,72 194,2

100,2 71,57 102,59 116,9 109,75 176,55

AC-95 AC-70 AC-95 AC-120 AC-120 AC-185

Bng kim tra iu kin pht nng ca dy dnon ng dy N-1 N-2 N-3 N-4 N-5 N-6 Imax 110,2 78,73 112,9 128,6 120,7 194,2 Isc 220,4 157,5 225,7 257,2 241,4 k,Icp(A) 264 212 264 304 304 408

Theo s liu tnh ton bng trn,cc dy dn chn tha mn iu kin pht nng. Bng tnh tn tht in p

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H BCH KHOA H NI

on ng dy N-1 N-2 N-3 N-4 N-5 N-6

R( ) 7,48 17,85 7,26 6,30 6,12 8,36

X( ) 9,73 17,45 9,44 9,87 9,59 20,12

Ubt% 4 6,05 3,97 4,29 3,91 5,43

Usc% 8 12,1 7,94 8,57 7,82

Theo bng trn ta thy: Ubt max%= 6.05 < 10% Uscmax% = 12.1 < 20% (tha mn iu kin) Vy phng n I t yu cu k thut. Phng n II 1. S :

15

H BCH KHOA H NI1 N 2 4 5 3

6

2-La chn tit din dy dn a- on ng dy 3-4 Chn tit din dy dn. . . S 3-4 = S 4= 41,65+ j25,97 (MVA). Imax 3-4 = Fkt =S max 3 4 = n 3.U dm2 2 41,65 + 25,97 .10 3 2 3.110

=128,59 (A)

I max3 4 J kt

. =

1 8 ,5 2 9 1,1

= 116,9

Chn dy dn loi AC- 120 ,c tit din chun l 120mm2 v dng in cho php Icp=380A. - Kim tra theo iu kin vng quang: dy dn chn c : Ftc=120mm2 > 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : on 5-4 l ng dy kp nn khi hng mt l th l cn li vn phi lm vic bnh thng . Isc = 2.Ibt max = 2.128,59 = 257,18 (A) Isc < 0,8.Icp = 304 A ( tha mn iu kin ) Kim tra tn tht in p trn ng dy. Vi loi ng dy AC- 120 ta c: ro=0,27 /km, xo=0.423 /km in tr v in khng ng dy :

R= n . ro.l = 2 .0,27.45,35=6,12 ( ). X = n xo .l = 2 .0,423.45,35=9,59( ). - Tn tht in p ch bnh thngP1 1

1

1

U3-4 bt % =

. +Q .X 3 4 R3 4 3 4 3 4U2m

100 =

41,65 .6,12 + 25 ,97 .9,59 100 = 4,11% 110 2

16

H BCH KHOA H NI

- Tn tht in p ch s c : U5-4sc % 2. U5-4bt % = 2. 4,11% = 8,22%. b- on ng dy N-3 Chn tit din dy dn. . . . S N-5= S 5+ S 4 =(39.1+j24.38)+(41.65+j25.97)=80.75+j50.35 (MVA). Imax N-5 = Fkt =80 ,75 2 + 50 ,35 2 .10 3 2 3.110 2 9 ,3 4 1 . = 1,1

= 249,31 (A)

I max N 5 J kt

= 26,65

Chn dy dn loi AC- 240 ,c tit din chun l 240mm2 v dng in cho php Icp=610A. - Kim tra theo iu kin vng quang: dy dn chn c: Ftc=240mm2 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : Isc = 2.Ibt max = 2.249,31 = 498,62 (A) Isc > 0,8.Icp =488 A (khng tha mn iu kin ). Chn li dy dn loi AC-300 ,tit din chun 300 mm2 v dng in cho php l 690A - Kim tra theo iu kin vng quang: dy dn chn c: Ftc=300mm2 > 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng: Isc = 2.Ibt max = 2.249,31 = 498,62 (A) Isc < 0,8.Icp =552 A(tha mn iu kin) Tnh tn tht in p trn ng dy. Vi loi ng dy AC-300 ta c: ro=0,108 /km, xo=0,392 /km in tr v in khng ng dy : R= n . ro.l = 2 .0,108.45,35=2,45 ( ). X = n xo .l = 2 .0,392.45,35=8,89( ). - Tn tht in p ch bnh thng1 1

1

1

17

H BCH KHOA H NI

UN-5 bt % =

p N 5.R N 5+ QN 5.X N 5 U 2 m

1 0 0=

39 ,1.2,45 + 24 ,38 .8,89 100 = 2,58% 110 2

- Tn tht in p ch s c : UN-5sc % 2. UN-5bt % = 2.2,58% =5,16%. Cc on ng dy cn li tnh phng n I, ta c cc bng s liu: Bng chn tit din dy dnon ng dy ro ( km ) 0,33 0,45 0,33 0,27 0,27 0,17 xo ( km ) 0,429 0,44 0,429 0,423 0,423 0,409

s l

l (km)

Smax (MVA)

Imax (A)

Fkt

Loi dy

N-1 N-2 N-3 1-4 N-5 N-6

2 2 2 2 1 2

45,35 70,32 44 45,35 45,35 49,19

30+j22,26 32+j15,9 35+j22,79 30+j25,97 20+j24,38 20+j19,61

110,22 78,73 112,85 128,59 120,72 194,2

100,2 71,57 102,59 116,9 109,75 176,55

AC-95 AC-70 AC-95 AC-120 AC-120 AC-185

Bng kim tra iu kin pht nng ca dy dnon ng dy N-1 N-2 N-3 5-4 N-5 N-6 Imax 110,22 78,73 112,85 128,59 249,31 194,2 Isc 220,44 157,46 225,7 257,18 498,62 k,Icp(A) 264 212 264 304 552 408

18

H BCH KHOA H NI

Theo s liu tnh ton bng trn ,cc dy dn chn tha mn iu kin pht nng. Bng tnh tn tht in pR ( ) 7,48 17,85 7,26 6,12 2,45 8,36 X ( ) 9,73 17,45 9,44 9,59 8,87 20,12

on ng dy

Ubt %

Usc%

N-1 N-2 N-3 5-4 N-5 N-6

4 6,05 3,97 4,16 2,58 5,43

8 12,1 7,94 8,32 5,16

19

H BCH KHOA H NI

Theo bng trn ta tht tn tht in p ln nht trn on ng dy lin thng N-5-4: Ubt max%= 4,16+2,58 = 6,74 < 10% Usc max% = 8,32+5,16=13,48 < 20% (tha mn iu kin) Vy phng n II t yu cu k thut. Phng n III 1. S 1 N 2 4 5 3

6

2. La chn tit din dy dn a - on ng dy 5-6 Chn tit din dy dn. . . S 5-6 = S 6 =25,5+j15,9 (MVA). Imax 5-6 =S max 5 6 n 3.U dm7 ,7 8 3

=

25 ,5 2 +15 ,9 2 .10 3 2. 3.110

= 78,73

(A)

Fkt = J = 1,1 = 71,57 kt Chn dy dn loi AC- 70, c tit din chun l 70mm2 v dng in cho php Icp=265A. - Kim tra theo iu kin vng quang: dy dn chn c: Ftc=70mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng :

I max

20

H BCH KHOA H NI

Isc = 2.Ibt max = 2.78,73 = 157,46 (A) Isc < 0,8.Icp = 265A ( tha mn iu kin ). Kim tra tn tht in p trn ng dy. Vi loi ng dy AC-70 ta c: ro=0,45 /km, xo=0.44 /km in tr v in khng ng dy :

R= 2 . ro.l = 2 . 0,45.49,19=11,07( ). X = 2 . xo .l = 2 . 0,44.49.19= 10,82( ). - Tn tht in p ch bnh thng :P1 1

1

1

U5-6bt % =

5 6 56

.R

+Q

5 6

.X

U2 m

5 6 100

=

25 ,5.11,07 +15 ,9.10 ,82 100 = 110 2

3,75% - Tn tht in p ch s c : U1sc % 2. U1bt % = 2. 3,75 % = 7,51 % b - on ng dy N-5 Chn tit din dy dn: . . . S N-5 = S 5 + S 6 =(36,55+j22,79)+(25,5+j15,9)=62,05+j38,69 (MVA) Imax =S max N 5 = n 3.U dmI max1 ,5 91 862 ,05 2 + 38 ,69 2 .10 3 2. 3.110

=191,58(A)

Fkt = J = 1,1 =174,16 kt Chn dy dn loi AC-185 c tit din chun l 185mm2 v dng in cho php Icp= 510 A. - Kim tra theo iu kin vng quang: dy dn chn c: Ftc=185mm2 > 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : Isc = 2.Ibt max = 2.191,58 = 383,16 (A) Isc < 0,8.Icp = 510 (tha mn iu kin). Kim tra tn tht in p trn ng dy. Vi loi ng dy AC- 185 ta c: ro=0,17 /km, xo=0,409 /km in tr v in khng ng dy : R= n . ro.l = X = n xo .l1

1

1 . 0,17.44=3,74( ). 2 1 = 2 . 0,409.44=9( ).. 21

H BCH KHOA H NI

- Tn tht in p ch bnh thngP

UN-5bt % =

N 5 N 5

.R

+Q

N 5

.X

U2

N 5 100

=

m

62 ,05 .3,74 + 38 ,69 .9 100 = 4,8% 110 2

- Tn tht in p ch s c : UN-5sc % 2. UN-5bt % = 2. 4,8 % = 9,59 %. Cn li cc on ng dy N-1,N-2 tnh phng n I,cc on ng dy N-3,N-4c tnh phng n II. Ta c cc bng s liu sau: Bng chn tit din dy dnro ( km ) 0,33 0,45 0,17 0,27 0,108 0,17 xo ( km ) 0,429 0,44 0,409 0,423 0,391 0,409

on ng dy N-1 N-2 N-3 N-4 N-5 5-6

s l

l (km) 49,19 49,19 44 45,35 45,35 45,35

Smax (MVA)

Imax (A)

Fkt

Loi dy

1 2 2 2 2 2

35,7+j22,26 25,5+j15,9 62,05+j38,69 41,65+j25,97 80,75+j50,35 31,45+j19,61

110,22 78,73 191,58 128,59 249,31 194,2

100,20 71,57 174,16 116,90 226,65 176,55

AC-95 AC-70 AC-185 AC-120 AC-300 AC-185

Bng kim tra iu kin pht nng ca dy dn

22

H BCH KHOA H NIon ng dy N-1 N-2 N-3 N-4 N-5 5-6

Imax 110,22 78,73 191,58 128,59 249,31 194,2

Isc 220,44 157,46 383,16 257,18 498,62

k,Icp(A) 264 212 408 304 552 408

Theo s liu tnh ton bng trn ,cc dy dn chn tha mn iu kin pht nng. Bng tnh tn tht in pon ng dy R X Ubt % Usc%

( ) 7,48 11,07 3,74 6,12

( ) 9,73 10,82 9,00 9,59

N-1 3-2 N-3 5-4

4,00 3,75 4,80 4,17

7,99 7,51 9,59 8,33

23

H BCH KHOA H NI

N-5 N-6

2,45 8,36

8,87 20,12

5,32 5,43

10,65

Ta c tn tht in p ng dy lin thng N-3-2: Ubt %= 3,75+4,8=8,55% U sc% =7,51+9,59=17,46 Tn tht in p ng dy lin thng N-5-4: Ubt % = 6,74% Usc % =13,48% Vy tn tht in p ln nht l : Ubt max%= 8,55 < 10% Umax sc% = 17,46 < 20% (tha mn iu kin) Vy phng n III t yu cu k thut. Phng n IV 1. S 1 N 2 4 5 3

6

2. La chn tit din dy dn a - on ng dy1-2 Chn tit din dy dn. . . S 1-2= S 2=25,5+j15,9 (MVA). Imax 1-2 =S max 12 n 3.U dm

=

25 ,5 2 +15 ,9 2 .10 3 2. 3.110

= 78,73

(A)

Fkt = J . = 1,1 = 71,57 kt Chn dy dn loi AC- 70 ,c tit din chun l 70mm2 v dng in cho php Icp=265A. - Kim tra theo iu kin vng quang: dy dn chn c:24

I max

7 ,7 8 3

H BCH KHOA H NI

Ftc=70mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : Isc = 2.Ibt max = 2.78,73 = 157,46 (A) Isc < 0,8.Icp = 265A ( tha mn iu kin ). Kim tra tn tht in p trn ng dy. Vi loi ng dy AC-70 ta c: ro=0,45 /km, xo=0.44 /km in tr v in khng ng dy : R= 2 . ro.l = 2 . 0,45.55=12,38( ). X = 2 . xo .l = 2 . 0,44.55= 12,1( ). - Tn tht in p ch bnh thng : U1-2bt % =1 1

1

1

P .R1 2

+ Q1 2.X1 2 1 2U 2 m

100=

25 ,5.12 ,38 +15 ,9.12 ,1 100 =4,2% 110 2

- Tn tht in p ch s c : U1-2sc % =2.U1-2bt % = 2. 4,2 % = 8,4 % b - on ng dy N-1 Chn tit din dy dn: . . . S N-1= S 1+ S 2 =(35,5+j22,26)+ (25,5+j15,9)=61+j38,16(MVA) Imax =S max n 3.U dmI max

=

61 2 + 38 ,16 2 .10 3 2. 3.110

=188,95(A)

Fkt = J = 1,1 =171,77 kt Chn dy dn loi AC-185 c tit din chun l 185mm2 v dng in cho php Icp= 510 A. - Kim tra theo iu kin vng quang: dy dn chn c: Ftc=185mm2 > 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng: Isc = 2.Ibt max = 2.188,95 = 311,9 (A) Isc < 0,8.Icp = 510 (tha mn iu kin). - Kim tra tn tht in p trn ng dy. Vi loi ng dy AC- 185 ta c: ro=0,17 /km, xo=0,409 /km25

1 8 ,9 8 5

H BCH KHOA H NI

in tr v in khng ng dy : R= n . ro.l = X = n xo .l1

1

1 . 0,17.45,35=3,85( ). 2 1 = 2 . 0,409.45,35=9,27( )..

- Tn tht in p ch bnh thng

P

UN-1bt % =

.RN 1+ QN 1.X N 1 N1U 2 m

100=

61,2.3,85 + 38 ,16 .9,27 100 = 4,87% 110 2

-Tn tht in p ch s c: UN-3sc % =2. UN-3bt % = 2. 4,87 % = 9,74 %. c -on ng dy 4-3 Chn tit din dy dn. . . S 4-3 = S 3= 36,55+j22,79 (MVA). Imax 4-3 =S max 4 3 n 3.U dm

=

36 ,55 2 + 22 ,79 2 .10 3 2. 3.110

= 112,85

(A)

Fkt = J . = 1,1 = 102,59 kt Chn dy dn loi AC- 95 ,c tit din chun l 95mm2 v dng in cho php Icp=330A. - Kim tra theo iu kin vng quang: dy dn chn c: Ftc = 95mm2 > 70mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : Isc = 2.Ibt max = 2.112,85 = 225,7 (A) Isc < 0,8.Icp = 330 A ( tha mn iu kin ). Kim tra tn tht in p trn ng dy. Vi loi ng dy AC- 95 ta c: ro=0,33 /km, xo=0.429 /km in tr v in khng ng dy : R= 2 . ro.l = 2 . 0,33.34,79=5,74( ). X = 2 . xo .l = 2 . 0,429. 34,79 =7,46( ). - Tn tht in p ch bnh thng :1 1

I max

1 2 ,8 1 5

1

1

26

H BCH KHOA H NI

U4-3bt

P 4 3.R4 3+ Q4 3.X 4 3 = 36,55 .5,74 + 22,79 .7,46 100 = %= 1 0 0 110 2 m U2

3,14% - Tn tht in p ch s c : U1sc % =2. U1bt % = 2. 3,14% = 6,28 % d - on ng dy N-4 Chn tit din dy dn: . . . S N-4 = S 4 + S 3 =(41,65+j25,97)+(36,55+j22,79)=78,2+j48,76(MVA) Imax =S max n 3.U dmI max

=

78 ,2 2 + 48 ,76 2 .10 3 2. 3.110

=241,44(A)

Fkt = J = 1,1 =219,49 kt Chn dy dn loi AC-240 c tit din chun l 240mm2 v dng in cho php Icp= 610 A. - Kim tra theo iu kin vng quang: dy dn chn c Ftc=240mm2 > 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : Isc = 2.Ibt max = 2.241,44=482,88 (A) Isc < 0,8.Icp = 671(tha mn iu kin). kim tra tn tht in p trn ng dy. Vi loi ng dy AC- 240 ta c: ro=0,131 /km, xo=0,401 /km in tr v in khng ng dy :

241 ,44

R= n . ro.l = X = n xo .l1

1

1 . 0,131. 46,67=3,06( ). 2 1 = 2 . 0,401. 46,67= 9,36( )..

- Tn tht in p ch bnh thng UN-4bt

P N 4.RN 4 + QN 4.X N 4 = %= 1 0 0 U 2 m27

78 ,2.3,06 + 48 ,76 .9,36 100 = 5.75% 110 2

-Tn tht in p ch s c :

H BCH KHOA H NI

UN-4sc % 2. UN-4bt % = 2. 5.75% = 11,5 %. Cn li cc on ng dy N-5,N-6 tnh phng n I, ta c cc bng s liu sau: Bng chn tit din dy dnon ng dy N-1 N-2 N-3 1-4 N-5 3-6 s l Smax (MVA) Imax (A) Fkt Loi dy ro km ) ( 0,17 0,45 0,33 0,131 0,27 0,17 xo km ) ( 0,409 0,44 0,423 0,401 0,429 0,409

l (km) 49,19 55 34,79 46,67 45,35 49,19

2 2 2 2 1 2

61+j38,16 25,5+j15,9 36,55+j22,79 78,2+j48,76 39,1+24,38 31,45+j19,61

188,95 78,73 112,85 241,44 120,72 194,2

171,77 71,57 102,59 219,49 109,75 176,55

AC-185 AC-70 AC-95 AC-240 AC-120 AC-185

Bng kim tra iu kin pht nng ca dy dnon ng dy N-1 1-2 4-3 N-4 N-5 Imax 188,95 78,73 112,85 241,44 120,72 Isc 377,9 157,46 225,7 482,88 241,44 k,Icp(A) 408 212 264 488 304

28

H BCH KHOA H NIN-6 194,2 408

Theo s liu tnh ton bng trn ,cc dy dn chn tha mn iu kin pht nng. Bng tnh tn tht in pon ng dy N-1 1-2 4-3 N-4 N-5 N-6 R ( ) 3,85 12,38 5,74 3,06 6,12 8,36 X ( ) 9,27 12,10 7,46 9,36 9,59 20,12 Ubt % Usc%

4,87 4,20 3,14 5,75 3,91 5,43

9,75 8,40 6,28 11,5 7,82

Ta thy tn tht in p ng dy lin thng N-1-2: Ubt % = 4,87+4,2=9,07% Usc % =9,75+8,4=18,15% Tn tht in p ng dy lin thng N-4-3 Ubt % = 3,14+5,75=8,89 % Usc % =6,28+11,4=17,68 % Tn tht in p ln nht l : Ubt max%= 9,07 < 10% Umax sc% = 18,15 < 20% (tha mn iu kin) Vy phng n IV t yu cu k thut. Phng n V 1. S

29

H BCH KHOA H NI1 N 2 4 5 3

6

2. La chn tit din dy dn phng n ny cc ph ti 3 v 4 ni vi nhau thnh mch kn. Cc ph ti cn li c tnh ging phng n I. Ta ch tnh ton on mch kn N-3-4-N. * Tnh phn cng sut trn on ng dy. Gi s cc ng dy c cng tit din, mch in ng nht ,ta c : - Cng sut trn on N-4. . S N-4=S 4 ( L43 + LN 3 ) + S 3 L N 3 (41,65 + j.25,97 ).( 34,79 + 44 ) + (36,55 + j.22 ,79 ).44 = LN 4 + L N 3 + L43 46 ,67 + 34 ,79 + 44. .

= 38,98+j24,3 (MVA). Cng sut trn on N-3. . . . S N-3 = S 4+ S 3 - S N-4 = (41,65+j25,97)+(36,55+j22,79)-(38,98+j24,3) = 39,22+j24,46 (MVA)..

Cng sut trn on 3-4. . . S 3-4 = S N-3 S 3 = (39,22+j24,46) (36,55+j22,79) = 2,67+j1,67 (MVA). Vy im ph ti 4 l im phn cng sut..

a - on ng dyN-4 Chn tit din dy dn. Imax =S max 3.U dm

=

2 2 Pmax + Qmax

3.U m2 1 ,0 4 9 1,1

=

38 ,98 2 + 24 ,3 2 3.110

.103=241,09 (A)

Fkt = J . = kt

I max

= 219,17

30

H BCH KHOA H NI

Chn dy dn loi AC- 240 ,c tit din chun l 240mm2 v dng in cho php Icp=610A. - Kim tra theo iu kin vng quang: dy dn chn c: Ftc=240mm2 > 70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : i vi ng dy N-4 c 2 trng hp vn hnh s c : + trng hp s c on 4-3 + trng hp s c on N-3 Ta thy rng trng hp s c on N-3 nguy him hn v phi ti mt lng cng sut ti ph ti 3.Khi c s c on N-3,cng sut chy trn on cn li l . . . S N 3 = S 3 + S 4 =(36,55+j22,79)+(41,65+j25,97)=78,2+j48,76 (MVA) IscN-4 =S N 3 max 3.U dm

=

78 ,2 2 + 48 ,76 2 .10 3 3.110

=482,87 A

Isc N-4= 482,87A < 0,8Icp(tha mn iu kin) b- on ng dy N-3 Imax =39 ,22 2 + 24 ,46 2 3.110 .10 3 =242,87

A

Fkt = J . = 1,1 =220,79 kt Chn dy dn AC-240, Icp=610A - Kim tra theo iu kin vng quang: dy dn chn c: Ftc=240mm2 >70 mm2 ( tha mn iu kin). - Kim tra theo iu kin pht nng : i vi ng dy N-3 c 2 trng hp vn hnh s c : + trng hp s c on 4-3 + trng hp s c on N-4 Cng ging nh ng dy N-4,s c nguy him nht l on N-4 .Khi c s c . . on N-4,cng sut chy trn on cn li l S N 4 = S N 3 =78,2+j48,76 (MVA) IscN-3 = IscN-4 =482,87 A Isc N-3= 482,87A < 0,8 Icp(tha mn iu kin) c- on ng dy 3-4 Imax =2,67 2 +1,67 2 3.110 .10 3 =16,53

I max

2 2 ,8 4 7

A

Fkt = J . = kt

I max

1 ,5 6 3 1,1

=15,03

31

H BCH KHOA H NI

Tit din ti thiu cho cp in p 110 kV l 70 mm2 .Chn dy dn AC-70 tha mn iu kin vng quang vi Icp=610A Kim tra theo iu kin pht nng : vi ng dy ny c 2 TH vn hnh s c + trng hp s c on N-3 + trng hp s c on N-4 S c ng dy N-4 nguy him hn do ph ti ca n ln hn Isc =41 ,65 2 + 25 ,97 2 3.110 .10 3 =257,62A

>0,8Icp

Chn li tit din AC-95 vi Icp =330, Isc < 0,8Icp(tha mn). Cc on ng dy cn li c chn phng n I , ta c bng s liu sau

on ng dy N-1 N-2 N-3 N-4 4-6 N-5 N-6

s l

l (km) 45,35 70,32 44

Smax (MVA)

Imax (A)

Fkt

Loi dy

ro ( km ) 0,33 0,45 0,131 0,131 0,33 0,27 0,17

xo ( km ) 0,429 0,44 0,401 0,401 0,429 0,423 0,409

2 2 2 1 1 1 1

35,7+j22,26 25,5+j15,9 36,55+j22,79

110,22 78,73 242,6 241,09 16,53 120,72 194,2

100,2 71,57 220,55 219,7 15,03 109,75 176,55

AC-95 AC-70 AC-240 AC-240 AC-95 AC-120 AC-185

46,67 41,65+j25,97 34,79 45,35 2,67+j1,67 39,1+j24,38

49,19 31,45+j19,61

Bng kim tra iu kin pht nng ca dy dnon ng dy N-1 Imax 110,2 Isc 220,4 k,Icp(A) 264

32

H BCH KHOA H NIN-2 N-3 N-4 4-3 N-5 N-6 78,73 242,6 241,09 16,53 120,7 194,2 157,5 482,87 482,87 257,18 241,44 212 488 488 265 304 408

Theo s liu tnh ton bng trn ,cc dy dn chn tha mn iu kin pht nng. Kim tra tn tht in p trn ng dy Tnh tn tht in p trn on ng dy kn N-3-4-N Loi AC-240 c ro=0,131 /km, xo=0,401 /km - in tr in khng ng dy N-3

R= n . ro.l = 1. 0,131. 44=5,76( ). X = n xo .l =1. 0,401. 44= 17,64( ).. - in tr in khng ng dy N-4 R= n . ro.l = 1.0,131. 46,67=6,11( ). X = n xo .l =1. 0,401. 46,67= 18,72( ). Loi AC-95 c ro=0,33 /km, xo=0.429 /km - in tr in khng ng dy 3-4 R= n . ro.l = 1.0,33. 34,79=11,48( ). X = n xo .l =1. 0,429.34,79= 14,93( ). * Tn tht in p lc bnh thng: Xt on N-3:11 1

1

1

1

UbtN-3

P N 3.RN 3+ QN 3.X N 3 %= 1 0%0 U 2 m

= Trn on N-4:

39,22 .5,76 + 24,46 .17,64 .100 % = 2,22 % 110 2

33

H BCH KHOA H NI

UbtN-4

P N 4.RN 4 + QN 4.X N 4 %= 1 0%0 U 2 m P 3 4.R3 4 + Q3 4.X3 4 %= 1 0%0 U 2 m

= Xt on 3-4

38,98 .6,11 + 24,3.18,71 .100 % = 5,73 % 110 2

Ubt3-4

=

2,76 .11,48 + 1,67 .14 ,72 .100 % =0,47% 110 2

* Ch lm vic s c ch lm vic s c ch xt trng hp nng l nht , l s c on ng dy t ngun n im phn b cng sut Trng hp s c trn on N-3 : UscN-4-3% = =( P4 + P3 ).R N 4 + (Q4 + Q3 ). X N 4 U m2

.100% +

P3. R43 + Q3. X 43 U m2

.100%

(41,65 + 36 ,55 ). 6,11 + (25,97 + 22,79 ). 18,71 36 ,55 .11,48 + 22 ,79 .14 ,72 .100 % + .100 % 2 110 110 2

=14,72% Trng hp s c trn on N-4 : UscN-3-4% = =(36 ,55 + 41,65 ).5,76 + ( 22 ,79 + 25,97 ). 17 ,64 41,65 .11,48 + 25,97 .14 ,72 .100 % + .100 % 2 110 110 2

( P3 + P4 ).R N 3 + (Q3 + Q4 ). X N 3 P R +Q X .100% + 4. 3 4 2 4. 3 4 .100% 2 Um U m

=17,9%34

H BCH KHOA H NI

Bng tnh tn tht in pon ng dy N-1 N-2 N-3 3-4 N-4 N-5 N-6 R ( ) 3,85 12,38 5,76 11,48 6,11 6,12 8,36 X ( ) 9,27 12,1 17,64 14,93 18,71 9,59 20,12 Ubt % 4,87 4,2 2,22 0,47 5,73 3,91 5,43 17,9 7,82 Usc% 9,75 8,4 14,72

Theo bng trn ta tht tn tht in p ln nht trn on ng dy kn N-3-4 Ubt max%=5,73 < 10% Usc max% =17,9 < 20% (tha mn iu kin) Vy phng n 5 t yu cu k thut. Bng tng kt tn tht in p ca 5 phng nPhng n 1 2 3 4 5 Ubt % 6,05 6,74 8,55 9,07 5,73 Usc% 12,1 13,48 17,46 18,15 17,9

35

H BCH KHOA H NI

Theo bng s liu trn,ta chn 2 phng n c tn tht nh nht tnh ton v mt kinh t l : Phng n 1 vi : Ubt max%= 6,05 % Uscmax% = 12,1 % Phng n 2 vi : Ubt max%= 6,74 % Usc max% = 13,48 % 2.6 Tnh ton so snh cc phng n v kinh t Khi tnh ton, thit k mng li in cn phi m bo yu cu v kinh t v k thut.Mc d trn thc t hai yu cu kinh t v k thut thng mu thun nhau, mt li in c ch tiu k thut tt, vn u t v chi ph vn hnh cao. Ngc li, li in c vn u t, chi ph vn hnh nh th tn tht cao, cu trc li in phc tp, vn hnh km linh hot, an ton thp.V vy vic nh gi tnh ton ch tiu kinh t ,k thut ca mt li in s m bo cho vic t ch tiu v k thut, hp l v kinh t. so snh v mt kinh t ta s dng hm chi ph tinh ton hng nm: Z = (atc + avh).K + A.C (1) Trong : Z: l hm chi ph tn tht hng nm (ng). atc : h s thu hi vn tiu chun,atc = 1 Ttc 1 8

=

= 0,125

Ttc: thi gian tiu chun thu hi vn u t avh: h s khu hao hao mn thit b , y ly avh = 4% =0,04 K: vn u t xy dng ng dy K = x. K0i.li = Ki K0i: chi ph cho 1 ng dy nhnh th i, tit din Fi. li: chiu di chuyn ti th i ,(km) Vi ng dy n x= 1, ng dy kp x=1,6 A: tn tht in nng , (kWh)( Pi max 2 + Qi2 max) .Ri . A = Pmax. = 2 U m i =16

P: tn tht cng sut ton h thng khi ph ti cc i, (kW)36

H BCH KHOA H NI

: thi gian tn tht ln nht ph thuc vo ph ti v tnh cht ca ph ti c tnh bng cng thc: = (0,124 + Tmax.10-4)2.8760 (h) Vi Tmax: thi gian s dng ph ti ln nht v ly bng Tmax = 5000 h = (0,124 + 5000.10-4)2.8760 = 3411 (h) C: gi in nng tn tht, C = 500/1kWh. Gi dy dn:Loi dy Gi (106 / km) AC-70 208 AC-95 283 AC-120 354 AC-150 403 AC-185 441 AC-240 500 AC-300 600

Tnh ton c th nh sau: a. Phng n 1 T phng php tnh trn ta lp c bng s liu sau:ng S l dy N-1 N-2 N-3 N-4 N-5 N-6 Tng 2 2 2 2 2 1 li (km) 45,35 79,32 44 45,35 45,35 49,19 Koi (106) 283 208 283 354 354 441 Ki (106 ) 20534,48 26397,7 19923,2 25686,24 25686,24 21692,79 139920,6 Pi (MV) 35,7 25,5 36,55 41,65 39,1 31,45 Qi (MVr) 22,26 15,9 22,79 25,97 24,38 19,61 Ri ( ) 7,48 17,85 7,26 6,12 2,45 8,36 Pi (MV) 1,0942 1,3322 1,1132 1,2185 0,4299 0,9491 6,1370

Loi dy AC-95 AC-70 AC-95 AC-120 AC-120 AC-185

x 1,6 1,6 1,6 1,6 1,6 1

Tng vn u t xy dng ng dy : Ki = 139920,6 .106() Tng tn tht cng sut ton h thng :37

H BCH KHOA H NI

Pmax =6,1370 (MW) Tng tn tht in nng : A = Pmax . = 6,1370. 3411 =20933,07(MWh)ng S l dy N-1 N-2 N-3 4-5 N-5 N-6 Tng 2 2 2 2 2 1 li (km) 45,35 79,32 44 45,35 45,35 49,19 Loi dy AC-95 AC-70 AC-95 AC-120 AC-300 AC-185 x Koi (106) 285 208 283 354 600 441 Ki (106 ) 20679,6 26397,7 19923,2 25686,24 43536 21692,79 157915,5 Pi (MV) 61,2 25,5 36,55 41,65 80,75 31,45 Qi (MVr) 38,16 15,9 22,79 25,97 50,35 19,61 Ri Pi (MV) 3,216 1,332 1,113 1,219 1,834 0,949 9,662

( ) 7,48 17,85 7,26 6,12 2,45 8,36

1,6 1,6 1,6 1,6 1,6 1

Theo cng thc (1) hm chi ph tnh ton: Z=(0,125+0,04). 139920,6.106 +20933,07.500.103 =3,36.1010() b. Phng n 2 bng s liu tnh ton

Tng vn u t xy dng ng dy Ki = 157915,5.106 () Tng tn tht cng sut ton h thng : Pmax =9,6621(MW) Tng tn tht in nng: A = Pmax . = 9,6621. 3411 =32957,42(MWh) Theo cng thc (1) hm chi ph tnh ton: Z=(0,125+0,04). 157915,5.106+32957,42.500.103 =4,25.1010().

38

H BCH KHOA H NI

Bng tng kt tnh ton cc ch tiu kinh t, k thut ca cc phng nK Phng n I II Ubt% 6,05 6,74 Usc % 12,1 13,48 (106 ) 139920,6 157915,5 Z (1010) 3,36 4,25

Kt lun: phng n I l phng n ti u nht m bo v kinh t v k thut.mt khc phng n l phng n n gin c v s ni dy cng nh v b tr thit b bo v rle,my bin p, my ctcc ph ti khng lin quan n nhau,nn khi c s c mt ph ti s khng nh hng n cc ph ti khc,V vy phng n I l phng n ti u nht.

39

H BCH KHOA H NI

CHNG III : TNH TON LA CHN MY BIN P B TR KH C V THIT B TRN S NI IN CHNH ********* 3.1 Tnh ton chn cng sut, s lng ,loi my bin p Trm bin p l mt phn t rt quan trng ca h thng in, n c nhim v tip nhn in nng t h thng, bin i t cp in p ny sang cp in p khc v phn phi cho cc mng in tng ng.v vy vic la chn cc my bin p cn m bo tnh cht cung cp in lin tc v yu cu v kinh t ,k thut. 3.1.1 Tnh ton chn cng sut nh mc, s lng my bin p cho ph ti Tt c cc ph ti trong h thng bao gm h loi I v h loi III v vy m bo cung cp in cho cc ph ti ny ta cn t 2 my bin p i vi h loi I v 1 my bin p i vi h loi III . Trong n phng n ti u c chn phn trn gm 5 ph ti loi I (1,2,3,4,5) v 1 ph ti loi III(6).Nh vy cng sut ca my bin p trong trm c th xc nh theo cng thc sau: i vi ph ti loi III, TBA(trm bin p) c 1 MBA(my bin p) SmB Smax Ph ti loi I, TBA c 2 MBA lm vic song song SmB S max k

Vi k: h s qu ti s c, ly k =1,4. a- Ph ti 1 Ta c : P1= 35,7 (MW) , cos 1= 0,851 S1max= COS = 0,85 = 42 (MVA) 1

P

35 ,7

S1B

4 2 1,4

= 30 (MVA)

Chn 2 MBA c cng sut nh mc l Sm =32(MVA). b- Ph ti 6 P1= 31,45 (MW) , cos 1= 0,856 S1max= COS = 0,85 = 37 (MVA) 1

P

31,45

40

H BCH KHOA H NI

S1B 37 (MVA) Chn 1 MBA c cng sut nh mc l Sm =40(MVA).

Cc ph ti 2,3,4,5 tnh v chn tng t nh ph ti 1,ta c bng s liu sauPh ti 1 2 3 4 5 6 Thuc h loi I I I I I III Simax (MW) 35,70 25,50 36,55 41,65 39,10 31,45 cos 0,85 0,85 0,85 0,85 0,85 0,85 Simax (MVA) 42,00 30,00 43,00 49,00 46,00 37,00 SimB (MVA) 32 25 32 40 40 40

3.1.2 Chn loi MBA Ta chn MBA cho tng ph ti ,nu ph ti yu cu iu chnh in p thng th chn MBA 3 pha c u phn p c nh. Nu ph ti yu cu iu chnh in p khc thng th chon MBA c b iu chnh in p di ti . Trong n c 2 ph ti yu cu iu chnh in p T (ph ti 1 v 6).cn li l ph ti yu cu iu chnh in p KT.Ta c bng thng s MBA chn:

41

H BCH KHOA H NIph ti 1 2 3 4 5 6 s l 2 2 2 2 2 1 Loi my Bin p TPD 32000/110 TPDH 25000/110 TPDH 32000/110 TPDH 40000/110 TPDH 40000/110 TPD 40000/110 S liu k thut Um (kV) Cao H 115 115 115 115 115 115 22 22 22 22 22 22 Un (%) 10,5 10,5 10,5 10,5 10,5 10,5 Pn (kW) 145 120 145 175 175 175 P0 (kW) 35 29 35 42 42 42 I0 (%) 0,75 0,8 075 0,7 0,7 0,7 S liu tnh ton R X Qo ( ) ( ) kVAr 1,87 2,54 1,87 1,44 1,44 1,44 43,5 55,9 43,5 34,8 34,8 34,8 240 200 240 280 280 280

3.2 B tr thit b v kh c in trn s ni in chnh. Do a phn ph ti l cc h tiu th loi I nn m bo cung cp in an ton v lin tc ta s dng s h thng hai thanh gp l vic song song.Khi vn hnh mt thanh gp vn hnh cn mt thanh gp d tr.

MCLL

S h thng 2 thanh gp i vi cc trm cui ta c 2 trng hp: - Ph ti loi III : Ta dng s b ng dy-my bin

42

H BCH KHOA H NI

MC1 D

MBA

MC2

S b ng dy my bin p

- Ph ti loi I :ta dng s cu

S cu trong Ta c th chn s cu theo 2 k sau:43

S cu ngoi

H BCH KHOA H NI

- Chn theo cng sut ca MBA,tnh cng sut gii hn thay i 2 sang 1 MBA lm vic : Sgh = SmB .n.( n 1). P0 PN

= SmB .

2.P0 PN

.

Nu Spt min Sgh s dng s cu ngoi. Nu Spt min > Sgh s dng s cu trong. - Chn theo ng dy,s cu thng c phi hp vi ng dy: S cu ngoi phi hp vi ng dy c l < 70 km S cu trong phi hp vi ng dy c l 70 km. Do thao tc bn MBA quan trng hn ng dy,nn ta chn s cu trong, ngoi theo Sgh. a- Ph ti 1 L ph ti loi I , ta dng s cu: Sgh1= SmB1 .2.P0 PN

= 32.

2.35 145

=22,234(MVA)

Spt min= 21< Sgh1 ta chn s cu ngoi.

b- Ph ti 6 L ph ti loi III nn ta dng s b ng dy-my bin p. Cc ph ti cn li l ph ti loi I tnh tng t nh ph ti 1 bng chn s cu:Ph ti Sm min (MVA) 21 20 30 24 28 SmB (MVA) 32 25 32 40 40

Pn (kW)145 120 145 175 175

Po (kW)35 29 35 42 42

Sgh (MVA) 22,234 17,381 22,234 27,713 27,713

Chn

1 2 3 4 5

s cu ngoi s cu trong s cu trong s cu ngoi s cu trong

44

H BCH KHOA H NI6 -

Theo bng s liu tnh ph ti 1 v 4 ta dng s cu ngoi,ph ti 2,3,5 ta dng s cu trong .

CHNG IV : TNH TON CH XC LP CA LI IN . ********* Vic tnh ton ch xc lp ca mng in c ngha ht sc quan trng i vi vic tnh ton , thit k v vn hnh mng in. chng ny ta xc nh thng s ch xc lp trong cc trng thi ph ti cc i , cc tiu, v sau s c khi ph ti cc i. Khi xc nh cc dng cng sut v cc tn tht cng sut, ta ly in p tt c cc nt trong mng in bng in p nh mc l Ui = Um = 110 kV. 4.1 Ch ph ti cc i. a. on N-1: * S nguyn l :N 45,35 km 2xAC-95 1 2TPD-32000/110 2

S 1 =35.7+j22.26

.

45

H BCH KHOA H NI

*S thay th:N SN-1 S'N-1 SB1 S' N-1 ' SB1

ZN-1

1

S 1 S0 1

B

ZB2 2

S1

-jQ C1

-jQ1 C

*Tnh thng s: +Dy dn: 6 Dy dn AC-95 c ro=0,33 /km, xo=0,429 /km,bo=2,65.10 S. RN-1= 2 . ro.lN-1 = 2 . 0,33.45,35=7,48 ( ). XN-1 = 2 . xo .lN-1 = 2 . 0,429.45,35=9,73( ).6 BN-1 = n.Bo.lN-1 = 2. 2,65.10 .45,35 = 2,404. 10-4 (S).

1

1

1

1

+TBA: MBA- 32000/110 c

UN%= 10,5% P0 =35 kW UC m=115 kV

Pn = 145 kW Io% = 0,75% Sm = 32 MVA

UH m = 22 kV . in tr, in khng ca MBA:2 PN .U Cdm 145 .115 2 .10 3 =1,872 ( ). R1B = = 2 2 S m 32 2 U %.U cdm 1 ,5.1 5 2 0 1 X1B = N = 100 .32 =43,395 ( ). 100 .S m

Z1B = n .( R1B +jX1B) = 2 .(1,872 =0,936+j21,7( ). +Ph ti:S 1 =35.7+j22.26(MVA)..

1

1

+j43,395)

*Tnh ch xc lp: Ta c UN = 1,1.Um= 121 kV. - Cng sut sau tng tr ca MBA46

H BCH KHOA H NI'' S B1 = S 1 = 35.7+j22.26(MVA)

.

- Tn tht cng sut trn tng tr TBA

/ S1 / .Z1B = S B1 = 2 U m.' S B1

'' 2

35,7 2 + 22 ,26 2 110 2

.(0,936+j21,698) =0,137 + j3,174(MVA).

- Cng sut trc tng tr TBA . '' = S B1 + S B1 = (35,7+22,26) + (0,137 + j3,174) = 35,837 +j25,434(MVA). - Tn tht cng sut lc khng ti0 dmBA -3 S 01 = n( S 01 +j . 100 ) =2.(35.10 +j 100 (MVA). - Cng sut trn thanh gp cao p ca MBA

.

.1 B

I %.S

0,75 .32

)= 0,07+j0,48

S

.

B1

' = S B1 + S 01 = (35,837 +j25,434) +(0,07+j0,48) = 35,907+j25,914(MVA). - Cng sut phn khng do dung dn ca ng dy N-1 sinh ra

.

jQcc = j 2 Um2. B N-1=j 2 .1102.2,404.10-4 = j1,454( MVAr) - Cng sut sau tng tr ng dy'' SN 1

1

1

= S B1 - jQcc =(35,907+j25,914)- j1,454 =35,907 +24,46 (MVA)

.

- Tn tht cng sut trn tng tr ng dy : N S 1

/S / = 12 .ZN-1 = U m

'' 2

35 ,907 2 + 24 ,460 2 110 2

.(7,48+j9,73) =1,167 +

j1,518(MVA). - Cng sut trc tng tr dy dn : ' '' S N 1 = S N 1 + S N 1 =(35,907 +24,46)+ (1,167 + j1,518)= 37,074+j25,978(MVA). - Cng sut phn khng do dung dn u ng dy sinh ra jQcc = j 2 UN2. B N-1=j 2 .1212.2,404.10-4 = j1,76( MVAr) - Cng sut u ngunS.

1

1

N-1

= S 'N - jQcc =(37,074+j25,978)- j1,76 = 37,074 +j24,218(MVA). 1

-Tn tht in p trn ng dy N-1

47

H BCH KHOA H NI

UN-1 =

P' N 1.R N 1+ Q'N 1.X N 1 UN

= 100

37 ,074 .7,48 + 25 ,978 .9,73 121

=4,381(kV) - in p ti nt 1 U1 = UN - UN-1 = 121-4,381 =116,619 (kV) - Tn tht in p trn MBA

UB1

35 ,837 .0,936 + 25 ,434 .21 ,698 116 ,619

P' B1.R B1+ Q'B1.X B1 = 1 0 0= UN=5,020 (kV)

- in p nt quy i v pha cao p U2 = U1- UB1 = 116,619- 5,020 = 111,599 (kV) - in p thc nt 2 U2 =U '2 kU HdmCdn

= U2 . U

= 111,599. 115 =21,349 (kV).

22

- Tn tht in nng trn ng dy: AN-1 = PN-1. = 35,7.3411.10-3 = 121,772 (MWh) - Tn tht in nng trn trm bin p: AB1S max pt 1 = n. P0.t + .Pn . 2 . n S dmB2

= (2.35.8670+

4 2 1 .1 5 . 4 2 3 2

2 2

. 3411).

10-3 =1032,909(MWh) - Tng tn tht in nng: AN-1 = AN-1 + Ab1 = 121,772 + 1032,909= 1154,681 (MWh) b. on N-6. * S nguyn l :

48

H BCH KHOA H NI

N 49,19 km

6 S6 =31,45+j 19,61 TPD-40000/110

*S thay th:N S N-6 S'N-1 ZN-6 S' N-6 ' SB6

6

SB 6

ZB

SB6

1

-jQ C6

C -jQ6

S0

*Tnh thng s: +Dy dn: 6 Dy dn AC-185 c ro=0,17 /km, xo=0,409 /km,bo=2,82.10 S. RN-6= 2 . ro.lN-6 =0,17.49,19=7,48 ( ). XN-1 = 2 . xo .lN-1 =0,409. 49,19=9,73( ).6 BN-1 = n.Bo.lN-1 = 2,65.10 .49,19= 1,39. 10-4 (S).

1

1

+TBA: MBA- 40000/110 c

UN%= 10,5% P0 =42kW UC m=115 kV

Pn = 175 kW Io% = 0,7% Sm = 40 MVA

UH m =22kV . in tr, in khng ca MBA:2 PN .U Cdm 175 .115 2 .10 3 =1,446 ( ). R6B = = 2 S m 40 2 2 U N %.U cdm 1 ,5.1 5 2 0 1 X6B = = 100 .40 =34,72 ( ). 100 .S m

Z1B = n .( R1B +jX1B) =1,446+j34,72( ). +Ph ti:49

1

H BCH KHOA H NI S 1 =31,45+j19,61(MVA)..

* Tnh ch xc lp: Ta c UN = 1,1.Um= 121 kV. - Cng sut sau tng tr ca MBA'' S B6

= S 6 = 31,45+j19,61 (MVA)

.

- Tn tht cng sut trn tng tr TBA

/ S6 / . = .Z6B = S B6 2 U m

'' 2

31,45 2 +19 ,61 2 110 2

.(1,446+j34,72) =0,164 + j3,942(MVA).

- Cng sut trc tng tr TBA . ' '' S B6 = S B6 + S B 6 = (31,45+j19,61) + (0,164 + j3,942)= 31,614 +j23,552(MVA). - Tn tht cng sut lc khng ti0 dmBA ) =(42.10-3+j 100 S 06 = n( S 06 +j . 100 - Cng sut trn thanh gp cao p ca MBA

.

.B

I %.S

0,7.40

)= 0,042+j0,28 (MVA).

' = S B 6 + S 06 = (31,614 +j23,552)+(0,042+j0,28) = 31,656+j23,832(MVA). - Cng sut phn khng do dung dn ca ng dy N-1 sinh ra

S

.

.

B6

jQcc = j 2 Um2. B N-6=j 2 1102. 1,39.10-4 = j0,841( MVAr) - Cng sut sau tng tr ng dy'' S N 6

1

1

= S B6 - jQcc =(31,656+j23,832)- j0,841=31,656+j23,005(MVA)'' 2

.

- Tn tht cng sut trn tng tr ng dy : N 6 S

/ S6 / = .ZN-6 = 2 U m

31,656 2 + 23,005 2 110 2

.(7,48+9,73 ) =1,058 +

j2,545(MVA). - Cng sut trc tng tr dy dn : ' '' S N 6 = S N 6 + S N 6 =(31,656+j23,832)+( 1,058 +j2,545)=32,714+26,377(MVA). - Cng sut phn khng do dung dn u ng dy sinh ra

50

H BCH KHOA H NI

jQcc = j 2 UN2. B N-6=j 2 .1212.1,39.10-4 = j1,015( MVAr) - Cng sut u ngunS.

1

1

N-6

= S 'N 6 - jQcc =(32,714+26,377)- j1,015= 32.714+j24.522 (MVA).

-Tn tht in p trn ng dy N-1

UN-6 =

P' N 6.R N 6+ Q'N 6.X N 6 UN

= 100

32 ,714 .7,48 + 24 ,522 .9,73 121

=6,507(kV) - in p ti nt 1 U1 = UN - UN-1 = 121-3,994 =114,493 (kV) - Tn tht in p trn MBA

UB6

35 ,837 .0,936 + 25 ,434 .21 ,698 116 ,619

P' B6.R B6+ Q'B6.X B6 = 1 0 0= UN=3,77 (kV)\

- in p nt quy i v pha cao p U2 = U6- UB6 = 116,619- 5,020 = 110,723 (kV) - in p thc nt 2 U2 =U '2 kU HdmCdn

= U2 . U

= 111,599. 115 =21,182 (kV)

22

- Tn tht in nng trn ng dy: AN-6 = PN-6. = 31,45.3411.10-3 = 107,276 (MWh) - Tn tht in nng trn trm bin p: AB1= P0.t+ Pn . =(42.8670+175.3411). =961,065(MWh) - Tng tn tht in nng: AN-6 = AN-6 + Ab6 = 107,276 + 961,065= 1068,341 (MWh)51

10-3

H BCH KHOA H NI

Ta c bng thng s ng dy

Ph ti

l (km)

Pmax (MW)

Qmax (MVAr)

ro ( km ) 0,33 0,45 0,33 0,27 0,27 0,17

xo ( km ) 0,429 0,44 0,429 0,423 0,423 0,409

bo 106(S)

R ( )

X ( )

B/2 106(S)

1 2 3 4 5 6

45,35 79,32 44 46,67 45,35 49,19

35,7 25,5 36,55 41,65 39,1 31,45

22,26 15,9 22,79 25,97 24,38 19,61

2,65 2,58 2,65 2,69 2,69 2,82

7,48 17,85 7,26 6,30 6,12 8,36

9,73 17,45 9,44 9,87 9,59 20,12

120,18 409,29 233,20 251,08 243,98 69,36

Thng s my bin p c ly bng muc 3.1.2 phn chn my bin p. Bng tnh ton in p cc nt (kV) v tn tht in pPh ti

UN4,381 6,076 4,246 4,611 4,165 6,507

Ui

UB5,020 4,626 5,148 4,648 4,317 3,770

U'2

U2

1 2 3 4 5 6

116,619 114,924 116,754 116,389 116,835 114,493

111,599 110,298 111,606 111,741 112,517 110,723

21,349 21,101 21,351 21,376 21,525 21,182

52

H BCH KHOA H NI

Bng tnh ton ch xc lp

53

H BCH KHOA H NIPh ti S''B 1 35,7+j22,26 0,137+j3,174 35,837+j25,434 0,07+j0,48 35,907+j25,924 j1,454 35,907+j24,46 1,167+j1,517 37,074+j25,977 j1,76 37,074+j24,218 2 25,5+j15,9 0,095+j2,073 25,595+j17,973 0,058+j0,4 25,653+j18,373 j4,952 25,653+j13,42 1,236+j1,209 26,889+j14,629 j5,992 26,889+j8,637 3 36,55+j22,79 0,144+j3,327 36,694+j26,117 0,07+j0,48 36,764+j26,597 j2,822 36,764+j23,775 1,15+j1,495 37,914+j25,27 j3,414 37,914+j21,856 4 41,65+j25,97 0,144+j3,456 41,794+j29,426 0,084+j0,56 41,878+j29,986 j3,038 41,878+j26,948 1,291+j2,023 43,169+j28,971 j3,676 43,169+j25,295 5 39,1+j24,38 0,127+j3,046 39,227+j27,426 0,084+j0,56 39,311+j27,986 j2,952 39,311+j25,03 1,099+j1,722 40,41+j26,755 j3,572 40,41+j23,183 6 31,45+j19,61 0,164+j3,941 31,614+j23,551 0,042+j0,28 31,656+j23,831 j0,83 31,656+j24,034 1,058+j2,545 32,714+j24,522 j1,015 32,714+j23,507

SBiS'Bi

S0iSBi jQ''i S''Ni

SNiS'Ni jQ'i SNi

Bng tnh ton tn tht in nngS Ph ti MBA (MVA) (MV) (MVA) (kW) (kW) (MWh) 1039,209 802,790 1059,736 1183,720 1130,557 878,664 6094,676 (MWh) 3732,316 4544,134 3797,125 4156,304 1466,389 3237,380 20933,648 (MWh) 4771,525 5346,925 4856,861 5340,024 2596,946 4116,044 27028,324 Smmax Pi SmB PN P0 AB Add

A

1 2 3 4 5 6 Tng

2 2 2 2 2 1

42 30 43 49 46 37

1,0942 1,3322 1,1132 1,2185 0,4299 0,9491 6,137

32 25 32 40 40 40

145 120 145 175 175 175

35 29 35 42 42 42

4.2 Ch ph ti cc tiu.54

H BCH KHOA H NI

Ch ph ti cc tiu tnh tng t nh ch ph ti cc i vn hnh kinh t cc TBA, ti cc trm gim p c 2 MBA vn hnh song song ,trong ch cc tiu ta c th ct bt 1 MBA nu tha mn iu kin : S < Sgh = Sm .2.P0 PN

Vi Sgh c tnh phn 3.2 ,bng tnh ton sau:Ph ti 1 2 3 4 5 6 SMin (MVA) 21 20 30 24 28 22 Sgh (MVA) 22,234 17,381 22,234 27,713 27,713 27,713 Nhn xt Ct 1 MBA Khng ct Khng ct Ct 1 MBA Khng ct Khng ct MBA 1 32000/110 2 25000/110 2 32000/110 2 40000/110 1 1 40000/110

40000/110

55

H BCH KHOA H NI

Theo bng tnh ton trn ta thy ph ti 1 v 4 ct 1 MBA, cn li khng ct MBA Khi tnh ton ch xc lp ta ly: UN= 105%. 110 = 115,5(kV). Bng tnh ton ch xc lp

56

H BCH KHOA H NI

Bng tnh ton in p cc nt v tn tht in pPh ti ph ti S''Bi 1 1 17,85+j11,13 0,068+j1,587 2 3

UN (kV)2,181 2 3,847

Ui (kV) 113,319 3 111,653

UB(kV) 5,166 3,060 4

U'2 (kV) 108,153 108,593

U2 (kV) 20,690 5 20,774 6 18,7+j11,66 0,058+j1,393 18,758+j13,053 0,042+j0,28 18,8+j13,333 j0,83 18,8+j12,494 0,352+j0,847 19,152+j13,341 j1,015 19,152+j12,326

SBi

S'Bi

Soi SBi

4 17,918+j12,717 5 0,035+j0,24 6 17,953+j12,957 j1,454 17,953+j11,503 0,281+j0,366 18,235+j11,868 j1,76 18,235+j10,109

25,5+j15,9 36,55+j22,79 20,4+j12,72 23,8+j14,84 2,942 112,558 3,590 108,968 20,846 0,042+j0,921 0,07+j1,619 0,069+j1,658 0,047+j1,128 2,166 113,334 4,665 108,668 20,789 17,042+j11,521 25,570+j17,519 20,469+j14,378 23,847+j15,968 2,466 113,034 2,605 110,429 21,126 0,058+j0,4 0,07+j0,48 0,042+j0,28 0,084+j0,56 3,711 111,789 4,296 107,493 20,564 17,1+j11,921 j4,952 17,1+j6,969 0,503+j0,492 17,603+j7,461 j5,992 17,6+j1,468 25,64+j17,999 j2,822 25,64+j15,178 0,533+j0,692 26,173+j15,87 j3,414 26,173+j12,456 20,511+j14,658 23,931+j16,528 j3,038 20,511+j11,62 0,289+j0,453 20,8+j12,073 j3,676 10,8+j8,397 j2,952 23,931+j13,576 0,383+j0,6 24,314+j14,176 j3,572 24,314+j10,604

jQ'' S''Ni

SNi

S'Ni jQ'i Sni

57

H BCH KHOA H NI

CHNG V : TNH TON IU CHNH IN P ********* Cc ph ti ca mng in thit k l cc h tiu th loi I (ph ti 1,2,3,4,5), h ph ti loi III (ph ti 6).C yu cu iu chnh in p thng (ph ti 1,6)v khc thng (ph ti 2,3,4,5). iu chnh in p trong HT ta c th c nhiu bin php. i vi MBA c th ca bng cch thay i u phn p ca MBA nh thay i t s bin i in p,thay i thng s ng dy,thay i dng cng sut phn khng ph ti trong mng in Cc ph ti c yu cu iu chnh in p khc thng , ta s dng MBA c b iu chnh di ti v tin hnh chn u phn p cho cc ph ti vi phm vi iu chnh : Upatc = 115 9.1,78%.115. Cc ph ti c yu cu iu chnh in p thng ta s dng MBA c u phn p c nh vi phm vi iu chnh l: Upatc= 115 2.2,5%.115. Yu cu iu chnh cht lng in p bao gm : + Yu cu iu chnh in p khc thng, lch in p cho php Trong ch ph ti cc tiu :dU1% = 0 % Trong ch ph ti cc i : dU2% = +5 % + Yu cu iu chnh in p thng Ch ph ti cc tiu : dU1% +7.5% Ch ph ti cc i: dU2% +2.5% Quy c: K hiu 1 dng cho ch ph ti min. K hiu 2 dng cho ch ph ti max Phng php chn nh sau: - in p yu cu trn thanh ci h p ca trm c xc nh theo cng thc58

H BCH KHOA H NI

Uyc = UHm + dU%.UHm Trong UHm l in p nh mc ca mng in h p + Vi h iu chnh in p khc thng : i vi mng in ny UHm = 22 kV. V vy in p yu cu trn thanh ci h p ca trm khi ph ti cc tiu ,cc i l : Uyc1 = UHm + dU1%. UHm = 22 +0 %.22 = 22 (kV). Uyc2 = UHm + dU1%. UHm = 22 +5 %.22 = 23,1 (kV). + Vi h iu chnh in p thng : Uyc1 = UHm + du1%. UHm = 22 +7.5 %.22 = 23,65(kV). Uyc2 = UHm + du1%. UHm = 22 +2.5 %.22 = 22,55(kV).-

T s bin i in p ca MBA k = U

UCH

=

U pa U kt

Vi Upa gi tr in p tng ng vi u phn p c chn Ukt gi tr in p khng ti pha h p. Ukt =1,1.UHm =1,1.22= 24,2 (kV) - gi tr in p trn thanh ci h p quy i v pha cao p UH = k UH =(UC - UB).U pa U kt

+ MBA c b iu chnh in p di ti(Vi h iu chnh in p khc thng ). mi ch ph ti c mt u phn p tng ng Upa1=(UC1 - UB1).U kt U Hyc 1 U kt U Hyc 2

Upa2 =(UC2 - UB2).

in p ca u iu chnh tiu chun l : Upatc = 115 9.1,78%.115. Upa1 chn Upatc1 Upa2 chn Upatc2 Tnh li gi tr in p thc trn thanh ci h p ca MBA UH1 =(UC1 - UB1). UH2 =(UC2 - UB2). Kim tra iu kin :U kt U patc 1 U kt U patc 2

59

H BCH KHOA H NI

dU1%= dU2%=

U H 1 U dm .100% = 0% U Hdm U H 2 U dm .100% = 5% U Hdm

+ MBA c u phn p c nh (dng cho yu cu iu chnh in p thng). c hai ch ph ti min v ph ti max ch dng chung mt u phn p tiu chun : Upatb = (U1pa+U2 pa) (chn u phn p tiu chun gn nht vi gi tri Upatc) in p ca u iu chnh tiu chun l : Tnh li gi tr in p thc trn thanh ci h p ca MBA UH1 =(UC1 - UB1). UH2 =(UC2 - UB2). Kim tra iu kin : dU1%= dU2%=U H 1 U dm .100% 7,5% U Hdm U H 2 U dm .100% 2,5%. U HdmU kt U patc 1 U kt U patc 2

Bng s liu in p trn thanh ci h p quy i v pha cao pTrm bin p U2 max (kV) U2 min (kV) 1 111.599 108.153 2 110.298 108.593 3 111.606 108.968 4 111.741 108.668 5 112.517 110.429 6 110.723 107.493

Bng s liu cc u phn p tiu chun i vi MBA c yu cu ca khc thng

60

H BCH KHOA H NI

Nc Upatc (kV) Nc Upatc (kV)

-9 96,577 0 115

-8 98,624 1 117,047

-7 100,671 2 119,094

-6 102,718 3 121,141

-5 104,765 4 123,188

-4 106,812 5 125,235

-3 108,859 6 127,282

-2 110,906 7 129,329

-1 112,953 8 131,376

0 115 9 133,423

Bng s liu cc u phn p tiu chun i vi MBA yu cu ca thngNc Upatc (kV) -2 109,25 -1 112,125 0 115 1 117,875 2 120,75

5.1 Chn u phn p cho MBA trm 1. in p trn thanh ci h p quy i v pha cao p ' U 1 = 108,153kV U '2 = 111,599 kV y l h loi I, yu cu iu chnh in p thng nn ta c cc gi tr in p yu cu trn thanh ci ca TBA : Uyc1 = Um + du1%.Um = 22 +7.5 %.22 = 23,65(kV). Uyc2 = Um + du1%.Um = 22 +2.5 %.22 = 22,55(kV). Tnh u iu chnh trong MBA khi ph ti cc tiu v cc i: Vi Ukt = 24,2(kV)' Upa1 = U 1 . U

U kt1 yc

= 108,153. 23 ,65 = 110,668 (kV) = 111,599. 22 ,55 = 119,765 (kV)2 ,2 4

2 ,2 4

Upa2 = U '2 . U

U kt2 yc

c hai ch ph ti min v ph ti max ch dng chung mt u phn p tiu chun : Upatb = (U1pa+U2 pa) = (110,668+119,765) =115,217 (kV) Da vo bng ta chn Upatc =115kV ng vi n=0 Tnh li gi tr in p thc trn thanh ci h p ca MBA : UH1 =(UC1 - UB1).U kt U patc 1

= 108,153.

2 ,2 4 11 5

= 22,759 (kV)

61

H BCH KHOA H NI

UH2 =(UC2 - UB2). Kim tra iu kin : dU1%= dU2%=22 ,759 22 22

U kt U patc 2

=111,599.

24 ,2 11 5

=23,484 (kV)

.100% = 3,45% 7,5% .100% = 6,745% 2,5% (tha mn iu kin)

23 ,484 22 22

5.2 Chn u phn p cho MBA trm 2. in p trn thanh ci h p quy i v pha cao p ' U 1 = 108,593 (kV) U '2 = 110,298 (kV) y l h loi I, yu cu iu chnh in p khc thng nn ta c cc gi tr in p yu cu trn thanh ci ca TBA : Uyc1 = UHm + dU1%. UHm = 22 +0 %.22 = 22 (kV) Uyc2 = UHm + dU1%. UHm = 22 +5 %.22 = 23,1 (kV) Tnh u iu chnh trong MBA khi ph ti cc tiu v cc i:' Upa1 = U 1 . U

U kt1 yc

=108,593.

24 ,2 22

= 119,452(kV)

Upatc1 =119,094 ng vi n=2

Upa2 = U '2

U kt .U 2 yc

24,2 =110,298. 23,1 = 115,55(kV)

Upatc2=115 ng vi n =0

Tnh li gi tr in p thc trn thanh ci h p ca MBA : UH1 =(UC1 - UB1).U kt U patc 1 U kt U patc 2

= 108,593 . 119 ,094 = 22,066 (kV) =110,298.2 ,2 4 11 5

2 ,2 4

UH2 =(UC2 - UB2). Kim tra iu kin : dU1%=22 ,066 22 22

=23,211(kV)

.100% = 0%62

H BCH KHOA H NI

dU2%=

23 ,211 22 22

.100% = 5,5% (tha mn iu kin)

5.3 Cc MBA ca cc trm cn li i vi MBA ca trm 6 chn tng t nh trm 1, MBA trm 3,4,5 chn tng t nh trm 2, ta c bng thng s chnNc chn Trm bin p Ch Min 1 2 3 4 5 6 0 2 2 2 3 0 Ch Max 0 0 1 1 1 0

63

H BCH KHOA H NI

CHNG VI: B CNG SUT PHN KHNG TRONG LI IN. ********* Gim tn tht cng sut v in nng trong cc mng in l mt trong nhng bin php quan trng tit kim nhin liu v tng ngun in cho ph ti. Mt trong nhng bin php thng c p dng gim tn tht cng sut v in nng trong h thng in l b cng sut phn khng trong li in . Phng php b cng sut phn khng trong li in : Da vo hm chi ph tnh ton ti u ha dung lng thit b b bao gm: - Vn u t cho thit b b. - Tn tht in nng do thit b b gy ra. - Tn tht in nng trn li in sau khi t thit b b. Xt cho mt ph ti ta c hm chi ph tnh ton l : Z = Z1 + Z2 + Z3 () Z1 :l vn u t v chi ph lp t thit b b: Z1 = k0.Qb () k0 :sut u t cho thit b b (/ kVAr) ,k0= 150 106 / MVAr Qb :tng dung lng b Z2 :chi ph tn tht in nng do thit b b gy ra : Z2 = P0. Qb .C.t () P0 :tn tht cng sut tc dng ca thit b b ,(kW/kVAr)

P0=0,005 MW/MVAr C :gi tin 1 n v tn tht in nng t :thi gian vn hnh thit b b, t= 8760 h Z3 : tn tht in nng trong li in sau khi lp t thit b bZ3 = A.C = Pmax . .C

64

H BCH KHOA H NI

Vi

P max =

(Q Q )Ub 2 dm

2

.R

(MW)

Trong C :gi tin 1 n v tn tht in nng, C = 500.103/1MWh.

:thi gian tn tht cng sut ln nht, = 3411 h xc nh dung lng b kinh t ca cc h tiu th,chng ta o hm hm ch ph theo cng thc : Z =0 Zmin Qb

Trong qu trnh tnh ton b phn khng chng ta phi gi thit rng: - in p ti cc nt trong mng in bng in p danh nh ca mng in . - Khng xt nh hng ca cc thit b b n ch in p. - Co ly c nh. - gi ca cc thit b b c ly t l thun vi cng sut ca chng. Tnh ton b cho 1 ph ti in hnh theo hm chi ph tnh ton (Z): a - on ng dy N-1. * S thay th: 0 1 Q1- Qb Rd1 Rb1 Qb1 Rd1=7,48 ( ). Rb1=1,87 ( ). Hm chi ph tnh ton hng nm : Vi Z = (ko+ P0 .C.t )Qb1+ Ta c : Zmin Z =0 Qb2 U m 2.C . ( Rd 1 + Rb1 ) .( ko+ P0 .C.t)

C. .[( Q1 Qb

)

2

.( Rd 1 + Rb1 )

2 U dm

Qb = Q1-

65

H BCH KHOA H NI

= 22,26 8760)

110 2 2.500 .10 3.3411 .( 7,48 +1,87 )

.(150.106+ 0,005 .500.103

.

=-42,958 (MVAr). Vy Qb =0 khng phi b.

Cc ph ti cn li tnh tng t, ta c bng tng kt sauon ng dy N-1 N-2 N-3 N-4 N-5 N-6 Rdi ( ) 7,48 17,85 7,26 6,3 6,12 8,36 Rb1 ( ) 1,87 2,54 1,87 1,44 1,44 1,44 Qi (MVAr) 22,26 15,9 22,79 25,97 24,38 19,61 Qb (MVAr) -42,958 -14,006 -44,000 -52,814 -56,280 -42,613 nhn xt khng phi b khng phi b khng phi b khng phi b khng phi b khng phi b

Theo bng s liu tnh ton ta thy,khng cn b phn khng i vi tt c cc h tiu th.

66

H BCH KHOA H NI

CHNG VII : TNH TON GI THNH TI IN ********* Gi thnh truyn ti in ca li in c xc nh theo cng thcY = Att

(/kWh)

Trong : Y : chi ph vn hnh hng nm trong mng in () Att : tng in nng m cc ph ti in nhn c, (MWh) . 1. Tnh tng in nng ph ti nhn c Att c tnh theo ch ph ti cc i vi Tmax = 5000h. Ta c : Att = P i.Tmax =209,95.5000 = 1049,75.103 (MWh) .2. Chi ph vn hnh hng nm Y .

Y = avhd.kd + avht.kt + A.C () Trong avhd : h s vn hnh ng y , avhd= 0,04. avht : h s vn hnh thit b trong TBA , avht= 0,1. kd :vn u t xy dng ng y. kt : vn u t xy dng TBA. A :tng tn tht in nng (bao gm tn tht in nng trn ng y v MBA) , (MWh) C : gi in 1kWh ,C = 500/1kWh. a. Vn u t xy dng ng y: kd = 139920,6 .106 ()67

H BCH KHOA H NI

b. Vn u t xy dng TBA : Vi trm c 2 MBA, gi s bng 1,8 ln trm c 1 MBA 2 trm c 2 MBA cng sut 40 MVA, 2 trm c 2 MBA cng sut 32 MVA, 1 trm c 2 MBA cng sut 25 MVA V 1 trm c 1 my bin p cng sut 40 MVA.

Bng gi MBA 110/220 (106/MBA)Sm (MVA) Kt(106 ) 16 13000 25 19000 32 22000 40 25000 63 35000 80 42000

Ta c vn u t xy dng TBA l: kt=1,8.(2.25000.106+2.22000.106+ 19000. 106 )+25000.106 =2,284. 1011() Tng tn tht in nng trn ng dy ( tnh chng II). Ad=20933,07(MWh) Tng tn tht in nng trn MBA( tnh chng II). AB = 6094,676 (MWh) A = Ad+ AB =20933,07 + 6094,676 = 27027,746 (MWh) Tn tht in nng tnh theo % in nng ca ph ti:Att A% = = =2,575% Chi ph vn hnh hng nm l: Y = avhd.kd + avht.kt + A.C = 0,04. 139920,6 .106+ 0,1. 2,284. 1011+27027,746.500.103 = 4,195. 1010 ()

A.100

27027 ,746 1049 ,74 .10 3

* Vy gi thnh ti inK P

Y = : Att

=

4,195 .10 10 1049 ,75 .10 6

= 39,963 (/kWh).

* Gi thnh xy dng mng in cho 1 MW cng sut ph ti: k= =139920,6.1 0 6 + 2,284 .10 10 209,95

= 775,235.106 /MW.

68

H BCH KHOA H NI

Bng tng kt ch tiu kinh t- k thut ca mng in

69

H BCH KHOA H NI

TT 1 2

Cc ch tiu Utb Usc L n

Tr s 6,05 12,1 49,19 241,69 290,88 998 1,399 2,284 3,195 209,95 1049,75 6,1370 27027,74 6 2,575 4,195 39,963 775,235

n v % % km km km MVA 1011 1011 1011 MW 103 MWh MW MWh % 1010 / kWh 106 MW

3

di ng y

L kp Tng

4

Tng cng sut TBA ng dy

5

Vn u t

Trm bin p Tng vn u t

6 7 8 9 10 11 12 13

Tng cng sut ph ti max in nng ti hng nm Tng tn tht cng sut Tng tn tht in nng Tng tn tht in nng Chi ph vn hnh hng nm Gi thnh ti in Gi thnh xy dng cho 1 MW

TI LIU THAM KHO

70

H BCH KHOA H NI

1. 2.

3.

Nguyn Vn m. Mng li in. Nh xut bn Khoa hc v K thut H Ni , 2001. Nguyn Vn m. Mng li in.( Tnh ch xc lp ca cc mng in v h thng phc tp). Nh xut bn Khoa Hc va K thut H Ni, 2000. Nguyn Vn m. Thit k cc mng v h thng in. Nh xut bn Khoa hc v K thut H Ni, 2008.

MC LC Li m u

71

H BCH KHOA H NI

Chng 1. Phn tch ngun v ph ti I.S a l 1 1.1. Nhng s liu ngun cung cp 2 1.2. Nhng s liu ph ti 2 II. Phn tch ngun v ph ti 3 2.1. Ngun in 3 2.2. Ph ti 4 III. Cn bng cng sut trong h thng in 4 Chng 2. D kin cc phng n, tnh ton s b la chn phng n 2.1. Chn in p nh mc cho li in 5 2.2. D kin cc phng n ni dy 6 2.3. Tnh ton chn tit din dy dn 8 2.4. Tiu chun tn tht in p 9 2.5. Tnh ton c th tng phng n 10 2.6. Tnh ton so snh cc phng n v kinh t 33 Chng 3. Tnh ton la chn my bin p, b tr kh c v thit b trn s ni in chnh 3.1. Tnh ton chn cng sut, s lng, loi my bin p 37 3.1.1 Tnh ton chn cng sut nh mc, s lng my bin p cho ph ti 37 3.1.2 Chn my bin p 38 3.2. B tr thit b v kh c in trn s ni in chnh 39 Chng 4. Tnh ton ch xc lp ca li in 4.1. Ch ph ti cc i 42 4.2. Ch ph ti cc tiu 50 Chng 5. Tnh ton iu chnh in p 5.1. Chn u phn p cho my bin p trm 1 56 5.2. Chn u phn p cho my bin p trm 2 57 5.3. Chn u phn p cho my bin p trm cn li 58 Chng 6. B cng sut phn khng trong li in Chng 7. Tnh ton gi thnh ti in Ti liu tham kho 65 Mc lc 66

72