Transcript

n mn hc li inLI NI U Nc ta ang trong qu trnh cng nghip ho, hin i ho xy dng CNXH. c bit qu trnh m ca ngy cang su rng, ra nhp WTO cng lm kinh t nc ta pht trin ngy cng mnh m hn, rt nhiu cc nh my, khu cng nghip mi c xy dng. Nng lng ni chung v in nng ni ring lun phi m bo i trc mt bc nhm chun b cho xy dng cc nh my sn xut cng nghip. iu i hi chng ta phi xy dng cc nh my in, mng li in sn xut, truyn ti in nng cho cc ph ti ny. Vic thit k cc mng li in khu vc cung cp cho cc nh my cng nghip l mt l mt nhim v rt quan trng i vi cc k s h thng in. n mn hc thit k mng li in khu vc gip chng ta vn dng nhng kin thc hc vo thc t cng vic, n gip chng ta c nhng k nng c bn phc v cho lm n cng nh thc t cng vic sau ny. Qa trnh lm n s khng th trnh khi khim khuyt do kin thc bn thn cn hn ch, v vy em knh mong cc thy c ch bo gip tn tnh bn n hon thin hn. Em xin chn thnh cm n!

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n mn hc li inCHNG I: PHN TCH NGUN V PH TI 1.1 S mt bng T l:1 n v =10 km15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Ngun cung cp cho cc ph ti l nh my in hoc trm bin p khu vc c cng sut m bo cung cp cho cc ph ti theo yu cu. 1.2 Bng s liu ph ti Cc s liu Ph ti cc i(MW) H s cng sut cos Mc m bo cung cp in Yu cu iu chnh in p in p danh nh li in th cp(kV) 1 38 1 Cc h tiu th 2 3 4 5 18 38 29 18 0,9 1 1 1 1 Khc thng 10 6 29 1

CHNG II. CN BNG CNG SUT TC DNG V PHN KHNG TRONG H THNG2

n mn hc li in2.1 Bng s liu ph ti Cc s liu Ph ti cc i(MW) H s cng sut cos Mc m bo cung cp in Yu cu iu chnh in p in p danh nh li in th cp(kV) 1 38 1 Cc h tiu th 2 3 4 5 18 38 29 18 0,90 1 1 1 1 Khc thng 10 6 29 1

2.2 Cn bng cng sut tc dng Mt c im quan trng ca h thng in l truyn ti tc thi in nng t ngun in n cc h tiu th m khng th tch lu c. Tnh cht ny th hin s ng b trong qu trnh sn xut in nng. Ti mi thi im trong ch xc lp ca h thng, cc nh my pht in trong h thng phi pht cng sut in ng bng cng sut tiu th ca cc ph ti trong h thng ng thi cng thm cc tn tht pht sinh trong qu trnh truyn ti. Ngoi ra m bo h thng vn hnh n nh trong cc iu kin khc nhau, h thng pht in ca nh my phi c d tr cng sut tc dng nht nh. Mc d tr cng sut tu thuc vo yu cu ca h thng v mc pht trin sau ny. PF =PYC = mPpt +P +Ptd+Pdt (1.21) Ta c phng trnh cn bng cng sut tc dng trong h thng: Trong : PF:Tng cng sut tc dng pht ra t ngun pht. Ppt:Tng cng sut tc dng ca cc ph ti trong ch ph ti P :Tng tn tht cng sut tc dng trong mng in, khi tnh s b c th ly P = 5%.Pmax Ptd :Tng cng sut t dng ca nh my in Pdt :Tng cng sut d tr trong mng in,khi cn bng s b c th ly : Pdt = 10%.Pmax m : h s ng thi xut hin cc ph ti cc i3

n mn hc li inMt cch gn ng ta c th thay bng cng thc: PF = Ppt + 15%Ppt. (1.2.2) Theo bng s liu v ph ti cho trn ta c : PF =Pyc = 1,15.(38+28+38+29+18+29) = 178,5 (MW) Vic cn bng cng sut tc dng gip cho tn s ca li in lun c gi n nh.2.3 Cn bng cng sut phn khng trong h thng.

Cn bng cng sut phn khng c quan h ti in p.H thng khng cn bng cng sut phn khng s dn ti thay i in p trong h thng in. Nu cng sut phn khng pht ra ln hn cng sut phn khng tiu th th in p trong h thng s tng, ngc li nu cng sut phn khng pht ra nh hn cng sut phn khng tiu th th s dn ti s sut p. V vy m bo cht lng ca h thng in ta cn phi cn bng cng sut phn khng trong h thng. Phng trnh cn bng cng sut phn khng trong h thng: QF = Qyc =mQpt +Qb +QL -Qc +Qtd +Qdt (1.3.1) Trong : QF :Tng cng sut phn khng do ngun in pht ra Qyc: Tng cng sut yu cu ca h thng Qpt :Tng cng sut phn khng ca cc ph ti ch cc i QL :Tng cng sut phn khng trong cm khng ca cc ng dy trong mng in. Qc : tng cng sut phn khng do in dung ca cc ng dy sinh ra,khi tnh s b ly : Qc = QL Qb : tng tn tht cng sut phn khng trong cc trm bin p ,khi tnh s b c th ly Qb = 15%Qmax Qtd: tng cng sut phn khng t dng trong nh my in. Qdt : Tng cng sut phn khng d tr trong h thng. m :h s ng thi Trong tnh ton s b ta c th tnh tng cng sut phn khng yu cu trong h thng bng cng thc sau y:4

n mn hc li inQyc = Qpt + 15%Qpt (1.3.2) Cng sut phn khng ca cc ph ti c tnh theo cng thc sau Qpt =Ppt. tg (1.3.3) T cos= 0,9 ta suy ra tg= 0,484 Ta c bng s liu sau: Cc h ph ti 1 2 3 4 Q(MVAr) 18,404 8,718 18,404 14,045 Bng 2.1:cng sut phn khng ca cc ph ti p dng cng thc 1.3.2 ta c Qyc= 1,15.(18,404+8,718+18,404+14,045+8,718+14,045)= = 94,685 MVAr T cos= 0,85 ta suy ra tg= 0,62 Ta li c : QF = PF .tg = 178,5 .0,62 = 110,624 MVAr > Qyc = 94,685 MVAr Nh vy cng sut phn khng pht ra ln cng sut phn khng tiu th ca h thng do vy ta khng phi b cng sut phn khng. KT LUN Sau khi tnh ton ta c s liu ca cc ph ti c cho trong bng 1.3.2 Cc h tiu th Pmax(MW) Qmax(MVAr) Smax(MVA) cos 1 38 18,404 42,222 0,9 2 18 8,718 20,000 0,9 3 38 18,404 42,222 0,9 4 29 14,045 32,222 0,9 5 18 8,718 20,000 0,9 6 29 14,045 32,222 0,9 5 8,718 6 14,045

Bng 2.2 S liu tnh ton ca cc h ph ti

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n mn hc li inCHNG III D KIN CC PHNG N NI DY CA MNG IN V SO SNH CC CH TIU K THUT 3.1 M u Cc ch tiu kinh t k thut ph thuc rt nhiu vo s ni dy ca n.V vy ta phi c cc phng n ni dy khc nhau trong mng li in t so snh tm ra phng n ti u nht:va bo m cc ch tiu k thut ng thi bo m chi ph nh nht, tin cy cn thit, thun li cho vn hnh, sa cha, ng thi bo m kh nng pht trin tng lai tip nhn thm ph ti mi. T s mt bng ngun in v cc ph ti cho ta c th a ra cc phng n ni dy cho mng li in trn. Sau y l 5 phng n v tnh ton nh gi cc ch tiu k thut ca cc phng n ny. 3.2 D kin cc phng n 3.2.1 Phng n I15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.1:S ni dy phng n I

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n mn hc li in3.2.2 Phng n II15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.2 : S ni dy phng n II 3.2.3 Phng n III15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.3 : S ni dy phng n III

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n mn hc li in3.2.4 Phng n IV15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.4 : S ni dy phng n IV 3.2.5 Phng n V15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.5 : S ni dy phng n V

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n mn hc li in3.3 Phng n ni dy 1 3.3.1 S ni dy15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.6 : S ni dy phng n I 3.3.2 Tnh in p vn hnh ca mng in in p vn hnh nh hng n cc c trng k thut, cc ch tiu k thut ca mng li in. in p nh mc ca mng li in ph thuc vo nhiu yu t: cng sut ca ph ti, khong cch t ngun n cc ph ti, v tr tng i gia cc ph ti trong mng li in p nh mc c th c chn ng thi vi s cung cp in. in p nh mc s b ca mng in c th xc nh theo gi tr cng sut trn mi on ng dy in. in p nh mc trn ca ng dy c th c tnh theo cng thc kinh nghim sau: Uvhi = 4,34. li + 16. P i (2.1)

Trong : li : khong cch truyn ti trn on ng dy th i (km) Pi :Cng sut truyn ti trn on ng dy th i (MW)9

n mn hc li inDa vo s mt bng ca cc ngun in v cc ph ti ta c in p vn hnh trn cc on ng dy nh sau: in p nh Cng sut Chiu di on ng in p vn mc ca c truyn ti on ng dy hnh, kV mng in, ,MVA dy, km kV N-1 38+ j18,404 56,57 81,31 N-2 18+ j8,718 63,25 61,79 N-3 38+ j18,404 76,16 83,55 N-4 29+ j14,045 125,30 81,20 110 N-5 18+ j8,718 82,46 64,66 N-6 29+ j14,045 111,80 79,62 Bng 3.1: in p vn hnh trn cc on ng dy v in p vn hnh ca c mng in in p vn hnh tnh trong phng n ny c th dng lm in p vn hnh chung cho cc phng n tip theo. 3.3.3 La chn tit din dy dn trn mi on ng dy ca phng n chn. Cc mng in 110 kV ch yu c thc hin bng cc ng dy trn khng, cc dy dn ch yu c dng l dy nhm li thp ( dy AC). i vi cc mng in khu vc tit din dy dn c chn theo mt dng kinh t ca dng in:

Fkt =

I max J kt

(2.2)

Trong : Imax : dng in chy trn ng dy ch ph ti cc i(A); Jkt : mt kinh t ca dng in,A/mm2 Vi dy AC v Tmax = 5500h ta tra bng c c : Jkt = 1,1A/mm2 Dng in chy trn ng dy trong ch ph ti cc i c tnh bng cng thc :

I max =

S max .103 A (2.3) nU dm 3 .

Trong : n: s mch ca ng dy10

n mn hc li inUm : in p nh mc ca mng in , kV Smax : cng sut chy trn ng dy khi ph ti cc i,MVA i vi cc ng dy trn khng , khng xut hin vng quang cc dy nhm li thp cn phi c tit din F 70 mm2 Sau y ta s tnh ton trn tng on ng dy trong phng n 1 on N-1S = 38 + j18,404 MVA 42, 222.103 I max = = 110,80 kA 2. 3.110 110,80 2 Fkt = 1,1 = 110,80 mm

Ta chn theo tit din tiu chun gn nht : AC- 120 Isc = 2.Imax = 2.110,80 = 221,61A < Icp = 380 A (tha mn iu kin pht nng) Tnh ton tng t cho cc on cn li ta c kt qu cho bng 3.2 3.3.4 Tnh tn tht in p trong mng in trong cc trng hp vn hnh bnh thng v ch s c Tn tht in p trn mi on ng dy trong ch d vn hnh bnh thng c tnh bng cng thc

U ibt =Trong

P .R + Q .Xi i i

i

U

2

.100(%)

(2.4)

dm

Uibt : tn tht in p trn on ng dy th i,% Pi, Qi : Cng sut tc dng v cng sut phn khng chy trn on ng dy th i Ri, Xi : in tr v in khng ca on ng dy th i Trong ch s c , i vi mng in ng dy 2 mch tn tht in p trong ch s c (t mt on ng dy ) c tnh theo cng thc : Uisc =2.Uibt i vi on ng dy N-1U N 1bt = 38.8, 212 + 18, 404.12,865 = 4,536 % 1102 11

(2.5)

n mn hc li inTrong trng hp ngng mt mch trn on ng dy N-1 ,ta c: U N-1sc= 2.4,536 = 9,071 % Tnh ton tng t i vi cc on ng dy cn li ta c bng s liu sau: ng dy N-1 N-2 N-3 N-4 N-5 N-6 Ubt% Usc% 4,536 9,071 5,155 10,309 7,604 15,209 3,470 6,941 4,616 9,232 3,222 6,444

Bng 3.3 Tn tht in p trn cc on ng dy trong mng in T cc kt qu trn nhn thy rng ,tn tht in p ln nht trong ch vn hnh bnh thng l: Umax bt = 7,604 % Tn tht in p trong ch s c bng : Umax sc= 15,209 %

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n mn hc li inBng 3.2. Thng s ca cc ng dy trong mng in phng n I

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n mn hc li in

n g dy

Chiu di

S l song song

Smax MVA

Imax (A)

Ftt

Ftc

Isc (A)

Icp (A)

Ro /k m

Xo /k m 0,42 3 0,44 0,42 3 0,42 9 0,44 0,42 9

Bo /km 2,6 9 2,5 8 2,6 9 2,6 5 2,5 8 2,6 5

R ()

X ()

B/2

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

60,83 102,96 101,98 53,85 92,20 50,00

2 2 2 2 2 2

42,22 2 20,00 0 42,22 2 32,22 2 20,00 0 32,22 2

110,8 0 52,49 110,8 0 84,56 52,49 84,56

110,80 52,49 110,80 84,56 52,49 84,56

120 70 120 95 70 95

221,61 104,97 221,61 169,12 104,97 169,12

380 265 380 330 265 330

0,27 0,46 0,27 0,33 0,46 0,33

8,212 23,68 0 13,76 7 8,886 21,20 5 8,250

12,86 5 22,65 0 21,56 9 11,55 1 20,28 3 10,72 5

1,63 6 2,65 6 2,74 3 1,42 7 2,37 9 1,32 5

3.4 Phng n ni dy 2. 3.4.1 S ni dy15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.7 S ni dy phng n II14

n mn hc li in y ch : Dng cng sut chy trn ng dy N-1 c gi tr:S max(N-1) = S max1 + S max2 = 56+j27,122 (MVA)

Dng cng sut chy trn ng dy 1-6 bng:S max(1-6) = 18+j8,718 (MVA)

Kt qu tnh in p trn cc on ng dy v chn in p nh mc ca mng in cho bng 3.4 Bng 3.4.in p tnh ton v in p nh mc ca mng in in p nh Cng sut Chiu di on ng in p vn mc ca c truyn ti on ng dy hnh, kV mng in, ,MVA dy, km kV N-1 56+j27,122 60,83 134,25 1-2 18+j8,718 50,00 79,79 N-3 38+j18,404 101,98 115,64 N-4 29+j14,045 53,85 98,76 110 N-5 18+j8,718 92,20 84,62 N-6 29+j14,045 50,00 98,39

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n mn hc li in3.4.2 La chn tit din dy dn Tnh ton tng t nh i vi phng n 1, ta c thng s cc ng dy trong mng in phng n II c cho trong bng 3.5: 3.4.3 Tnh tn tht in p ca cc on ng dy trong mng in Tnh ton tng t nh i vi phng n I ta c bng s liu sau: ng dy Ubt% N-1 5,792 1-2 2,503 N-3 7,604 N-4 3,470 N-5 4,616 9,232 N-6 3,222 6,444

Usc% 11,584 5,007 15,209 6,941 Bng 3.6.Tn tht in p trn cc ng dy Tn tht in p trn ng dy N-1-2:

Umax bt% = UN-1bt% + U1-2bt% = 5,792 % + 2,503 % = 8,30 % T cc kt qu bng trn ta nhn thy, tn tht in p lc lm vic bnh thng v khi s c c gi tr ln nht l: Umax bt% = 8,30 % Trong ch s c khng xt s c xp chng m ch xt s c n gin (t mt dy) nn: Umax sc% = UN -1-2 sc% = UN -1bt% + U1-2 sc% = 14,09 %

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n mn hc li inBng 3.5.Thng s ca cc ng dy trong mng in phng n IIS l song song 2 2 2 2 2 2 Bo /k m 2,74 2,58 2,69 2,65 2,58 2,65

ng dy

Chiu di

Smax MVA

Imax (A)

Ftt

Ftc

Isc (A)

Icp (A)

Ro /km

Xo /km

R ()

X ()

B/2, 10-4S

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

60,83 50,00 101,98 53,85 92,20 50,00

62,222 20,000 42,222 32,222 20,000 32,222

163,29 52,49 110,80 84,56 52,49 84,56

163,29 52,49 110,80 84,56 52,49 84,56

150 70 120 95 70 95

326,58 104,97 221,61 169,12 104,97 169,12

445 265 380 330 265 330

0,21 0,46 0,27 0,33 0,46 0,33

0,416 0,44 0,423 0,429 0,44 0,429

6,387 11,500 13,767 8,886 21,205 8,250

12,652 11,000 21,569 11,551 20,283 10,725

1,667 1,290 2,743 1,427 2,379 1,325

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n mn hc li in3.5 Phng n ni dy 3 S mng in phng n III cho trn hnh 3.815 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.8.S ni dy phng n III Kt qu tnh ton ca phng n III cho trong cc bng 3.7, 3.8, 3.9 Bng 3.7.in p tnh ton v in p nh mc ca mng in in p nh Cng sut Chiu di on ng in p vn mc ca c truyn ti on ng dy hnh, kV mng in, ,MVA dy, km kV N-6 47+j22,763 50,00 122,91 6-2 18+j8,718 60,83 81,06 N-1 38+j18,404 60,83 112,24 N-3 38+j18,404 101,98 115,64 110 N-4 58+j28,091 53,85 135,99 N-5 18+j8,718 92,20 84,62 Bng 3.8.Tn tht in p trn cc ng dy ng dy Ubt% N-6 3,996 6-2 3,045 N-1 4,536 9,071 N-3 7,604 15,209 N-4 4,751 9,502 N-5 4,616 9,232

Usc% 7,992 6,091 Umax bt% = UN-3bt% =7,604% Umax sc% = UN -3sc% = 15,209 %

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n mn hc li inBng 3.5.Thng s ca cc ng dy trong mng in phng n III

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n mn hc li in

n g dy

Chiu di

S l song song 2 2 2 2 2 2

Smax MVA

Imax (A)

Ftt

Ftc

Isc (A)

Icp (A)

Ro /k m 0,21 0,46 0,27 0,27 0,17 0,46

Xo /km

Bo /km 2,74 2,58 2,69 2,69 2,84 2,58

R ()

X ()

B/2, 10-4S

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

50,00 60,83 60,83 101,9 8 53,85 92,20

52,22 2 20,00 0 42,22 2 42,22 2 64,44 4 20,00 0

137,0 5 52,49 110,8 0 110,8 0 169,1 2 52,49

137,0 5 52,49 110,8 0 110,8 0 169,1 2 52,49

150 70 120 120 185 70

274,1 0 104,9 7 221,6 1 221,6 1 338,2 5 104,9 7

445 265 380 380 510 265

0,416 0,44 0,423 0,423 0,409 0,44

5,250 13,99 0 8,212 13,76 7 4,577 21,20 5

10,40 0 13,38 2 12,86 5 21,56 9 11,01 3 20,28 3

1,37 0 1,56 9 1,63 6 2,74 3 1,52 9 2,37 9

3.6 Phng n ni dy 4 S mng in phng n IV cho trn hnh 3.815 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.8.S ni dy phng n III Kt qu tnh ton ca phng n III cho trong cc bng 3.10, 3.11, 3.12 Bng 3.10.in p tnh ton v in p nh mc ca mng in

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n mn hc li inon ng dy N-1 1-2 N-3 N-4 4-5 N-6 Cng sut truyn ti ,MVA 56+j27,122 18+j8,718 38+j18,404 47+j22,763 18+j8,718 29+j14,045 Chiu di on ng dy, km 60,83 50,00 101,98 53,85 50,99 50,00 in p vn hnh, kV 134,25 79,79 115,64 123,20 79,91 98,39 in p nh mc ca c mng in, kV

110

Bng 3.11.Tn tht in p trn cc ng dy ng dy Ubt% N-1 5,792 1-2 2,503 N-3 7,604 15,209 N-4 4,304 8,607 4-5 2,553 5,106 N-6 3,222 6,444

Usc% 11,584 5,007 Umax bt% = UN-1-2bt% =8,30 % Umax sc% = UN -1-2sc = 14,087%

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n mn hc li inBng 3.12.Thng s ca cc ng dy trong mng in phng n IVS l song song 2 2 2 2 2 2 Bo /k m 2,74 2,58 2,69 2,74 2,58 2,65

ng dy

Chiu di

Smax MVA

Imax (A)

Ftt

Ftc

Isc (A)

Icp (A)

Ro /km

Xo /km

R ()

X ()

B/2, 10-4S

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

60,83 50,00 101,98 53,85 50,99 50,00

62,222 20,000 42,222 52,222 20,000 32,222

163,29 52,49 110,80 137,05 52,49 84,56

163,29 52,49 110,80 137,05 52,49 84,56

150 70 120 150 70 95

326,58 104,97 221,61 274,10 104,97 169,12

445 265 380 445 265 330

0,21 0,46 0,27 0,21 0,46 0,33

0,416 0,44 0,423 0,416 0,44 0,429

6,387 11,500 13,767 5,654 11,728 8,250

12,652 11,000 21,569 11,201 11,218 10,725

1,667 1,290 2,743 1,476 1,316 1,325

20

n mn hc li in3.7.Phng n ni dy 5 3.7.1.S ni dy15 13 11 9 7 5 3 1 0 2 4 6 8 10 12 14 16

2 6 N 1

3 4 5

Hnh 3.10.S ni dy phng n V 3.7.2 La chn tit din dy dn v kim tra iu kin pht nng Do trong s ni dy c mch vng nn ta phi tnh dng cng sut chy trong cc ng dy trong mch vng N-4-5-N. Gi thit mng in ng nht v tt c cc on ng dy u c cng mt tit din. Gi khong cch N-4 l l1, khong cch N-5 l l2, khong cch 4-5 l l, . (l1 = 82,462 km , l2 = 111,803 km, l = 56,569 km) Dng cng sut chy trn on N-4 l:S N 4 S 4 .(l2 + l ) + S 5 .l (29 + j14, 045).(92,195 + 60,828) + (18 + j8, 718).60,828 = = l1 + l2 + l 53,852 + 92,195 + 60,828* *

= 29,47+j14,27 MVA Do , Smax(N-4) = 32,743 MVAS max(4+5) = S maxN-4 - S 4 = (29,47+j14,27 ) (29+j14,045 )

= 0,47+j0,228 MVA; Smax(4-5) = 0,522 MVAS max(N-5) = S 5 - S max(4-5) = (18+j8,718) - (0,47+j0,228 )21

n mn hc li in= 17,53+j8,49 MVA; Smax(N-5) = 19,478 MVA Tit din cc on ng dy trong mch vng N-4-5-N: ImaxN-4 =32, 743 3 171,86 .10 = 171,86 A ; Fkt(N-4) = = 171,86 mm2 3.110 1

=> Chn dy AC-185 c Icp = 510 A Imax4-5=0,522 2, 74 .103 = 2,74 A ; Fkt(4-5) = = 2,74 mm2 3.110 1

=> Chn dy AC-70 c Icp = 265A ImaxN-5=19, 478 3 102, 23 .10 = 102,23 A ; Fkt(N-5) = = 102,23 mm2 3.110 1

=> Chn dy AC-95 c Icp = 330 A Kim tra s c : dng in chy trn on 4-5 ln nht khi c s c t N-4:I sc = 32, 222 3 .10 = 169,122 A 3.110 52, 222 3 .10 = 274, 095 A . 3.110

Khi , Isc(N-5) =

Khi s c t N-5 dng in chy trn on N-4 c gi tr : Isc(N-6) = Isc(N-5) = 274,095 A Vi cc on khc lm tng t nh cc phng n trn ta c bng 3.13on dy N-4 N-5 4-5 N-1 N-2 N-3 N-6 Kiu dy dn AC-185 AC-95 AC-70 AC-120 AC-70 AC-120 AC-95 Pmax (MW) 29,47 17,53 0,47 38 18 38 29 Qmax (MVAr) 14,270 8,490 0,228 18,404 8,718 18,404 14,045 Imax (A) 171,86 102,23 2,74 110,80 52,49 110,80 84,56 Isc (A) 171,86 102,23 2,74 221,61 104,97 221,61 169,12 Icp (A) 510 330 265 380 265 380 330 r0 (/m) 0,17 0,33 0,46 0,27 0,46 0,27 0,33 x0 (/m) 0,409 0,429 0,44 0,423 0,44 0,423 0,429 b0*10-6 (S/km) 2,84 2,65 2,58 2,69 2,58 2,69 2,65

Bng 3.13.Thng s ng dy phng n V22

n mn hc li inCc tit din dy dn c chn u tha mn iu kin pht nng khi s c Tnh tn tht in p trong mch vng xt Bi trong mch vng xt ch c mt im phn chia cng sut l nt 5 Do tn tht in p ln nht trong mng in trong ch vn hnh bnh thng l:U max % = U N 5 % = 17,53.30, 424 + 8, 490.38,552 .100% = 7,183% 1102

Khi ngng on N-4 - Tn tht in p trn on N-5 l:U N 5 sc % = 47.30, 424 + 22, 763.39,552 .100% = 19, 258% 1102

- Tn tht in p trn on 5-6 l:U 56 sc % = 18.27,981 + 8, 718.26, 764 .100% = 9,813% 1102

Khi ngng on ng dy N-6 - Tn tht in p trn on ng dy N-5 lU N 5 sc % = 47.9,155 + 22, 763.22, 025 .100% = 7, 699% 1102

- Tn tht in p trn on ng dy 5-6 l:U 56 sc % = 29.27,981 + 14, 045.26, 764 .100% = 6, 091% 1102

Vy tn tht in p ln nht trong ch s c l tn tht in p khi t on ng dy N-4 v bng: Umaxsc = 19,258+9,813=29,071 % Cc tn tht in p trn nhng on khc tnh tng t nh cc phng n trn ta c bng sau: ng dy Ubt% Usc% N-4 4,827 19,258 N-5 7,183 7,699 4-5 0,159 9,813 N-1 7,677 15,354 N-2 5,106 10,211 N-3 3,728 7,457 N-6 3,222 6,444

T cc kt qu bng trn ta nhn thy, tn tht in p lc lm vic bnh thng v khi s c c gi tr ln nht l:23

n mn hc li in Umax bt% = UN -3bt% = 7,677 % Trong ch s c khng xt s c xp chng m ch xt s c n gin (t mt dy) nn: Umax sc% = 29,071% l trng hp ngng N-4 trong mch vng. KT LUN Khi chn s b cc phng n cung cp in c th nh gi cht lng in nng theo cc gi tr ca tn tht in p. Ta c th chp nhn l ph hp nu trong ch ph ti cc i cc tn tht in p ln nht ca mng in mt cp in p khng vt qu 10 15% trong ch lm vic bnh thng, cn trong ch sau s c cc tn tht in p ln nht khng vt qu 15 20% . y ta xt vi trng hp: Umaxbt % 10% Umaxsc % 20% thun tin cho vic so snh v k thut cc gi tr v tn tht ca cc phng n c tng hp bng sau: Tn tht in p Umaxbt % Umaxsc % 1 2 Phng n 3 4 5

7,604 15,209

8,295 15,209

7,604 15,209

8,295 15,209

7,677 29,071

Nh vy sau khi tnh ton so snh cc ch tiu k thut ta thy phng n 1,2,3 m bo yu cu k thut. Do so snh kinh t ,k thut ta chn cc phng n 1,2,3,4

CHNG IV SO SNH KINH T CC PHNG N

24

n mn hc li in4.1 t vn V cc phng n so snh ca mng in c cng in p nh mc ,do n gin ta khng cn tnh vn u t vo cc trm h p. Ch tiu kinh t c s dng so snh cc phng n l cc chi ph tnh ton hng nm, c xc nh theo cng thc: Z=(atc+ avh) K + A.c Trong : Z:hm chi ph tnh ton hng nm atc:h s hiu qu ca vn u t .atc=0,125 avh:h s vn hnh i vi cc ng dy trong mng in. avh=0,04 (Dng ct btng ct thp) A:Tng tn tht in nng hng nm C : gi 1kWh in nng tn tht :c = 1000 /kW.h) K : tng cc vn u t v ng dy -Tnh K i vi cc ng dy trn khng 2 mch t trn cng mt ct,tng vn u t xy dng cc ng dy c th xc nh theo cng thc sau: K= 1,6.k0i.li Trong : k0i : gi thnh 1 km ng dy th i , /km li : chiu di on ng dy th i ,km Vi ng dy 1 mch :K= k0i.li -Tn tht in nng trong mng in c tnh theo cng thc : A = Pimax. Trong : : thi gian tn tht cng sut ln nht ,h ti cc i .Ta c cng thc: Pimax :tn tht cng sut trn on ng dy th i khi cng ph

25

n mn hc li inPi max =Trong : Pimax ,Qimax : cng sut tc dng v phn khng chy trn ng dy ch ph ti cc i Ri: in tr tc dng ca on ng dy th i Udm: in p nh mc ca mng in - Thi gian tn tht cng sut ln nht c th c tnh theo cng thc: = (0,124+ Tmax .10-4)2 .8760 Trong : Tmax l thi gian s dng ph ti cc i trong nm Vi Tmax = 5500 h ta c = 3979,458 h Sau y ta s tnh ton hm chi ph tnh ton hng nm i vi tng phng n 4.2 Tnh ton cc phong n 4.2.1 Phng n 1 Tnh K cho mi on ng dy on ng dy N-1(AC-120) K1= 1,6.ko1.l1 Tra bng 8.39 sch Thit k cc mng v h thng in Ta c ko1= 354.106 /km Suy ra K1= 1,6.354.106.60,83 = 34452,767.106 Tn tht cng sut:382 + 18, 4042 P = .8, 212 = 1,210 MW 1 1102

Pi 2 + Qi2max max2 U dm

* Ri

Tnh ton tng t ta c bng sau:

ng dy

Chiu di (km)

S l song

Loi dy

Gi tin VN/km

Thnh tin VN26

P (MW)

n mn hc li inN-1 N-2 N-3 N-4 N-5 N-6 Tng 60,83 102,96 101,98 53,85 92,20 50,00 song 2 2 2 2 2 2 AC-120 AC-70 AC-120 AC-95 AC-70 AC-95 354 208 354 283 208 283 34452,767 34263,857 57761,693 24384,026 30682,644 22640,000 204184,987 1,210 0,783 2,028 0,762 0,701 0,708 6,192

Tng vn u t ng dy l: K= 204184,987. VN) Tn tht in nng :A=P. = 6192.3979,458 = 24,642. (kWh) Vy chi ph tnh ton cho phng n I l: Z=(0,125+0,04).204184,987. + 24,642. .1000 = 58,332. (VN) 4.2.2 Phng n 2 Tnh ton tng t nh i vi phng n trn ta c bng s liu sau: ng dy Chiu di (km) S l song song 2 2 2 2 2 2 Loi dy Gi tin VN/km Thnh tin VN P (MW) 2,044 0,380 2,028 0,762 0,701 0,708 6,623

N-1 60,83 AC-150 403 39221,653 1-2 50,00 AC-70 208 16640,000 N-3 101,98 AC-120 354 57761,693 N-4 53,85 AC-95 283 24384,026 N-5 92,20 AC-70 208 30682,644 N-6 50,00 AC-95 283 22640,000 Tng 191330,016 Tng vn u t ng dy l: K= 191330,016. VN) Tn tht in nng :A=P. = 6623.3979,458 = 26,358. (kWh) Vy chi ph tnh ton cho phng n I l: Z=(0,125+0,04).191330,016. + 26,358. .1000 = 57,927. (VN) 4.2.3 Phng n 3 Tnh ton tng t nh trn ta c bng sau: ng Chiu di S l Loi Gi tin Thnh tin27

P

n mn hc li indy (km) song song 2 2 2 2 2 2 dy VN/km VN (MW) 1,183 0,462 1,210 2,028 1,571 0,701 7,156

N-6 50,00 AC-150 403 32240,000 6-2 60,83 AC-70 208 20243,434 N-1 60,83 AC-120 354 34452,767 N-3 101,98 AC-120 354 57761,693 N-4 53,85 AC-185 441 37997,723 N-5 92,20 AC-70 208 30682,644 Tng 213378,261 Tng vn u t ng dy l: K= 213378,261. VN) Tn tht in nng :A=P. = 7156.3979,458 = 28,477. (kWh) Vy chi ph tnh ton cho phng n I l: Z=(0,125+0,04).213378,261. + 28,477. .1000 = 63,685. (VN) 4.2.4 Phng n 4 Tnh ton tng t nh trn ta c bng sau: ng dy Chiu di (km) S l song song 2 2 2 2 2 2 Loi dy Gi tin VN/km Thnh tin VN

P (MW) 2,044 0,380 2,028 1,274 0,388 0,708 6,822

N-1 60,83 AC-150 403 39221,653 1-2 50,00 AC-70 208 16640,000 N-3 101,98 AC-120 354 57761,693 N-4 53,85 AC-150 403 34723,543 4-5 50,99 AC-70 208 16969,537 N-6 50,00 AC-95 283 22640,000 Tng 187956,425 Tng vn u t ng dy l: K=187956,425. VN) Tn tht in nng :A=P. = 6822.3979,458 = 24,642. (kWh) Vy chi ph tnh ton cho phng n I l: Z=(0,125+0,04).187956,425. + 24,642. .1000 = 58,161. (VN)

28

n mn hc li in

Phng n Z(.109 )

Phng n 1 58,333

Phng n 2 57,927

Phng n 3 63,685

Phng n 4 58,161

T kt qu trn ta nhn thy phng n 2 l phng n ti u Nh vy sau khi a ra cc phong n tho mn v mt k thut ,chng ta tin hnh so snh v mt kinh t cc phng n v la chn phng n 2 l phng n ti u .T chng sau tr i ta ch tin hnh tnh ton cho phong n ny.

29

n mn hc li inCHNG V LA CHN MY BIN P V S NI DY CHI TIT 5.1 Chn s lng v cng sut my bin p trong cc trm h p. Trong h thng in c 6 ph ti loi I,v vy m bo cung cp in cho cc h ph ti ny cn t hai my bin p lm vic song song trong mi trm. Khi chn cng sut ca my bin p cn phi xt n kh nng qu ti ca my bin p cn li sau s c .Xut pht t iu kin qu ti cho php bng 40% trong thi gian ph ti cc i.Cng sut ca mi my bin p lm vic trong trm c n my bin p c xc nh theo cng thc :

S dm

S max k (n 1)

Trong : Smax :ph ti cc i ca trm k: h s qu ti ca my bin p trong ch sau s c , k=1,4 n : s my bin p trong trm i vi trm c hai my bin p ,cng sut ca mi my bin p bng:

Sdm

Smax 1.4

Sau y chng ta tin hnh la chn my bin p cho cc h ph ti phn trn chng ta la chn in p vn hnh ca mng in l 110kV,do chng ta la chn my bin p c Um= 110 kV T cc cng thc trn ta tnh chn c cc MBA trong bng sau: H ph ti 1 2 3 4 5 6 Smax (MVA) 42,222 20,000 42,222 32,222 20,000 32,222 Sm(MVA) 30,159 14,286 30,159 23,016 14,286 23,016 Loi my bin p TPDH-32000/110 TPDH-16000/110 TPDH-32000/110 TPDH-25000/110 TPDH-16000/110 TPDH-25000/110

Bng thng s my bin p:

30

n mn hc li inCc s liu k thut My bin p TPDH16000/110 TPDH25000/110 TPDH32000/110 TPDH40000/110 Udm(kV) Cao h 115 115 115 115 11 11 11 11 Un (%) 10,5 10,5 10,5 10,5 Pn kW 85 120 145 175 P0 kW 21 29 35 42 I0 (%) 0,85 0,8 0,75 0,7 Cc s liu tnh ton R () 4,38 2,54 1,87 1,44 X () 86,7 55,9 43,5 34,8 Q (kVAr) 10,5 200 240 280

5.2 S ni dy chi tit 5.2.1 Trm ngun Do trong mng in c 6 ph ti loi I nn m bo cung cp in an ton v lin tc ta s dng s hai thanh gp c my ct lin lc. Khi vn hnh mt h thng thanh gp vn hnh cn mt h thng thanh gp d tr.

5.2.2 Trm trung gian m bo tin cy ta cng s dng s 2 h thng thanh gp:

31

n mn hc li in

5.2.3 Trm cui trm cui c cc trng hp xy ra nh sau:

Nu ng dy di (l 70 km) v trn ng dy hay xy ra s c. Khi cc my ct t cui ng dy (s cu trong):

- Nu ng dy ngn (l < 70 km) v t xy ra s c th my ct t pha my bin p. Mc ch thao tc ng ct my bin p theo ch cng sut ca trm (ph ti cc i, ph ti cc tiu ca trm). Khi ta s dng s cu ngoi :

Sp tL70km32

n mn hc li inCHNG VI TNH TON CHNH XC CH VN HNH CA LI IN nh gi cc ch tiu kinh t-k thut ca mng in thit k ,cn xc nh cc thng s ch xc lp trong cc ch 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 Ui = Udm= 110 kV. tnh tn tht cng sut chy trn mt on ng dy ta s dng cng thc:

P2 + Q2 S = P + jQ = * ( R + jX ) MVA U2 tnh tn tht in p ta s dng cng thc:

U =

P*R + Q* X ( kV ) UP2 + Q2 .Z d 2 U dm

tnh tn tht cng sut trong my bin p ta s dng cng thc:Sb =

Trong : S :cng sut ca ph ti Sdm:cng sut nh mc ca my bin p m:s my bin p vn hnh trong trm Tn tht in p trong my bin p:

U b =

Pb * Rb + Qb * X b U

6.1 Ch ph ti cc i. Trong ch ph ti cc i ta ly UN= 110%.110=121 kV 6.1.1 Xt on ng dy N-3

33

n mn hc li inS ni dy ca on N-3101,98 kmN

TPDH-32000/110

S3 = 38+j18,404AC-120

.

S thay th ca mng in :

N

S N3

S' 3 Z N3 S" 3-jQ Cd3

1

S C3 S B3 Z B3S0

S3

-jQ Cc3

Ta c cc thng s ca s thay th: + i vi ng dy N-3:

z N3 = 13,77+j21,57 ();

BN3 / 2 = 2,743.10-4 (S) + i vi MBA trm 3: S 03 = 2(P03+ j Q03) = 2.(35+j240).30-3 = 0,07 + j0,48 MVA - Tn tht cng sut trong my bin p l: Sb1 = Pb1 + Q b1 =.

P2 + Q 2 38 2 + 18, 404 2 .Z b = .(0,935+ j21, 75) 2 U dm 110 2

= 0,138 + j3,204 MVA - Cng sut trc tng tr ca my bin p l:S b3 = S 3+ S b3= (38+j18,404)+(0,138+j3,204)= 38,138 + j21,608 MVA

- Cng sut truyn vo thanh gp cao p ca trm 3 bng:S c3 = S b3 + S 03 = (38,138 + j21,608) +(0,07 + j0,48) S c3 = 38,208 + j22,088 MVA

- Cng sut phn khng do in dung cui ng dy 3 sinh ra l: -jQcc3= -j(BN3 / 2) .Udm2 = - j2,743.10-4 .1102 = - j3,32 MVAr - Dng cng sut chy trn on ng dy sau tng tr Z3 ca ng dy l:34

n mn hc li in S 3 = S c3 jQcc3 = (38,208 + j22,088) j3,32 = 38,208+j18,768 MVA

- Tn tht cng sut trn on N-3 l:S N 1 = 38, 2082 + 18, 7682 .(13, 77 + j21,57) = 2,062 + j3,230 MVA 1102

- Cng sut trc tng tr Z3 ca ng dy l: S 3 = S 3 + S N3 = (38,208+j18,768 ) +(2,062 + j3,230)

= 40,27 +j21,998 MVA - Cng sut phn khng do in dung u on N-3 sinh ra l: -jQcd3 = -jQcc3 =-j3,32 MVAr - Dng cng sut chy vo on N-3 l: S N3 = S 3 jQcd3 = 40,27 +j21,998 j3,32 = 40,27 + j18,678 MVA

6.1.2 Xt on ng dy N-1-2 S ni dy ca on N-1-2:2 60,83 km 50 km TPDH-16000/110

N 2xAC-1501 TPDH-32000/110

2xAC-70

S2 = 29+j14,045

.

S1 = 38+j18,404

.

S thay th ca mng in: N S N1 S'N1 Z N1 S"1 S cN1 N S 12SC3 -jQcdN3 -jQccN31 S'12 Z 12 S"2

S 12 Z 12

2

S2

S B11

S 01

-jQCd12

-jQCc12

S 02

ZB1

S135

n mn hc li inTa c cc thng s ca s thay th: + i vi ng dy N-1:

z N1 = 11,50 + j11 ();BN1 / 2 = 1,290.10-4 (S)

+ i vi ng dy 1-2:

z 12 = 6,39 + j12,65 (); B12/ 2 = 1,667.10-4 (S)

+ i vi MBA trm 1 v 2: S 03 = 0,07 + j0,48 (MVA) S 05 = 0,042 + j0,272 (MVA) - Tn tht ng trong my bin p trm 2 l:P2 + Q2 .Zb Sb= 2 U dm 182 + 8,7182 . (2,19+j43,35 ) = 110 2

= 0,072 + j1,433 (MVA) - Cng sut trc tng tr ca trm bin p 2 l:S b2= S 2+ S b2= 18,072 + j10,151 MVA

- Cng sut truyn vo thanh gp cao p ca trm 2 bng:S c2 = S b2 + S 02 = 18,114 +j10,423 MVA

- Cng sut phn khng do in dung cui ng dy 1-2 sinh ra l: -jQcc12= -j(B12/2) . Udm2 = -j1,56 MVAr - Dng cng sut chy trn on ng dy sau tng tr Z12 ca ng dy l: S 12 = S c2 jQcc12 = 18,114 + j8,863 MVA - Tn tht cng sut trn on 1-2 l:

S12 =

18,114 2 + 8,863 2 .(6,39 + j12,65)= 0,387+ j0,370 MVA 110 2

- Cng sut trc tng tr Z12 ca ng dy l: S 12 = S 12 + S 12 = 18,501+j9,233 MVA - Cng sut phn khng do in dung u on 1-2 sinh ra l: -jQcd35 = -jQcc35 = -j1,56MVAr - Dng cng sut chy vo on 1-2 l: S 12 = S 12 jQcd12 = 18,501+j7,673 MVA - Tn tht ng trong my bin p trm 1 l:

P2 + Q2 382 + 18, 4042 .Zb = . (0,935 + j21,75 ) = 0,138+j3,204 (MVA) Sb= 2 U dm 1102

- Cng sut trc tng tr ca trm bin p 1 l:36

n mn hc li inS b1= S 1+ S b1 = 38,138+j21,608 MVA

- Cng sut truyn vo thanh gp cao p ca trm 1 bng: S c1= S b1 + S 01 = 38,208+j21,608 MVA - Cng sut cui on N-1 l: S cN1 = S 12+ S c1 = 56,709+j29,761 MVA - Cng sut phn khng do in dung cui ng dy N-1 sinh ra l: -jQccN1 = -j(BN1/ 2) . Udm2 = -j2,02 MVAr - Dng cng sut chy trn on ng dy sau tng tr ZN1 ca ng dy l: S N1 = S cN1 jQccN1 = 56,709+j27,741 MVA - Tn tht cng sut trn on N-1 l:

56,7092 + 27,7412 SN 1 = .(11,50 + j11) = 2,105 + j 4,167 MVA 1102

- Cng sut trc tng tr ZN1ca ng dy l: S N1 = S N1 + S N1 = 58,814+j31,908 MVA - Cng sut phn khng do in dung u on N-1sinh ra l: -jQcdN2 = -jQccN2 = -j2,02 MVAr - Dng cng sut chy vo on N-3 l: S N3 = S N3 jQcdN3 = 58,814+j29,888 MVA Tnh ton tng t cho cc ng dy cn li .Thng s ca cc ng dy c cho trong bng sau: B/2 Zd So Zb S=P+jQ ng dy () (MVA) () (MVA) N-1 6,39+j12,65 1,667 0,07+j0,48 0,935+j21,75 38+j18,404 1-2 11,50+j11,00 1,290 0,042+j0,272 2,19+j43,35 18+j8,718 N-3 13,77+j21,57 2,743 0,07+j0,48 0,935+j21,75 38+j18,404 N-4 8,89+j11,55 1,427 0,058+j0,4 1,27+j27,95 29+j14,045 N-5 21,20+j20,28 2,379 0,042+j0,272 2,19+j43,35 18+j8,718 N-6 8,25+j10,73 1,325 0,058+j0,4 1,27+j27,95 29+j14,045

Kt qu tnh cc dng cng sut v tn tht cng sut trn ng dy c cho trong bng sau:

37

n mn hc li inBng kt qu tnh dng cng sut v tn tht cng sut trn cc nhnh ca ng dy trong ch ph ti cc i

38

n mn hc li inTng cng sut trong ch ph ti cc i : S = D Smax (MVA) 38+j18,4 04 18+j8,71 8 38+j18,4 04 29+j14,0 45 18+j8,71 8 29+j14,0 45 So (MVA) Sb (MVA) Sb (MVA) Qc M VA r 2,0 2 1,5 6 3,3 2 1,7 3 2,8 8 1,6 0 S (MVA) Sd (MVA) S (MVA) SN(MVA)

N1 12 N3 N4 N5 N6

0,07+j0,4 0,138+j3,20 38,138+j21,6 8 4 08 0,042+j0, 0,072+j1,43 18,072+j10,1 272 3 51 0,07+j0,4 0,138+j3,20 38,138+j21,6 8 4 08 0,058+j0, 0,109+j2,39 29,109+j16,4 4 8 43 0,042+j0, 0,072+j1,43 18,072+j10,1 272 3 51 0,058+j0, 0,109+j2,39 29,109+j16,4 4 8 43

56,709+j27,7 2,105+j4,1 58,814+j31,9 58,814+j29,8 41 67 08 88 18,114+j8,86 0,387+j0,3 18,501+j9,23 18,501+j7,67 3 70 3 3 38,208+j18,7 2,062+j3,2 40,27+j21,99 40,27+j18,67 68 30 8 8 29,167+j15,1 0,793+j1,0 29,96+j16,14 29,96+j14,41 13 30 3 3 18,114+j7,54 0,675+j0,6 18,789+j8,18 18,789+j5,30 3 45 8 8 29,167+j15,2 0,738+j0,9 29,905+j16,2 29,905+j14,6 43 60 03 03

= 196,239+j90,563 (MVA) m bo iu kin cn bng cng sut trong h thng th cng sut ca cc ngun cung cp phi m bo yu cu cng sut ca ph ti.T tng cng sut tc dng yu cu ca ngun in yu cu Pcc = 196,239 MW Vi h s cos =0,85 trn thanh gp cao p ca ngun in th cng sut phn khng yu cu cn cung cp cho mch in: Qcc = Pcc.tg = 196,239x 0,62 = 121,618 MVAr T ta thy rng cng sut phn khng do ngun cung cp ln hn cng sut phn khng yu cu ca ph ti,do ta khng cn b cng sut phn khng cho h thng trong ch ph ti cc i. 6.2 Tnh ton trong ch ph ti cc tiu Trong ch ph ti cc tiu ta la chn: UN = 105%*110=115,5 kV Ph ti cc tiu bng 50% ph ti cc i. Cng sut ca cc ph ti trong ch ph ti cc tiu cho trong bng sau:39

n mn hc li inPh ti 1 2 3 4 5 6S min = Pmin +j Qmin (MVA)

Smin (MVA)21,11 10,00 21,11 16,11 10,00 16,11

19+j9,202 9+j4,359 19+j9,202 14,5+j7,0225 9+j4,359 14,5+j7,0225

Trong ch ph ti cc tiu c th xt cho ngh 1 my bin p (MBA) trong cc trm 2 MBA ,nhng cn tha mn iu kin:

S pt < S gh = S dm

m(m 1).P 0 Pn

y: m l s my bin p trong trm. Vi trm c 2 MBA th:

S gh =S dm

2.P0 Pn

Kt qu tnh cc gi tr cng sut ph ti Spt v cng sut gii hn Sgh c ghi trong bng: Ph ti 1 2 3 4 5 6 Spt 22,234 11,247 22,234 17,381 11,247 17,381 Sgh 21,111 10,000 21,111 16,111 10,000 16,111 Cc kt qu tnh ton trong bng cho thy trong ch ph ti cc tiu cc trm u vn hnh 1 MBA Vic tnh ton ch mng in khi ph ti cc tiu c tin hnh tng t nh ch cc i vi thng s ng dy cho trong bng sau Zd () 6,39+j12,65 11,50+j11,00 13,77+j21,57 B/2 1,667 1,290 2,743 So (MVA) 0,035+j0,24 0,021+j0,136 0,035+j0,24 Zb () 1,87+j43,5 4,38+j86,7 1,87+j43,540

ng dy N-1 1-2 N-3

S=P+jQ (MVA) 19+j9,202 9+j4,359 19+j9,202

n mn hc li inN-4 N-5 N-6 8,89+j11,55 21,20+j20,28 8,25+j10,73 1,427 2,379 1,325 0,029+j0,2 0,021+j0,136 0,029+j0,2 2,54+j55,9 4,38+j86,7 2,54+j55,9 14,5+j7,0225 9+j4,359 14,5+j7,0225

Kt qu tnh ton cho trng hp ph ti cc tiu cho trong bng sau:

41

n mn hc li inBng kt qu tnh dng cng sut v tn tht cng sut trn cc nhnh ca ng dy trong ch ph ti cc tiu

42

n mn hc li in6.3 Xt ch sau s c Trong khi xt ch s c: D N1 12 N3 Sm n (MVA) 19+j9,20 2 9+j4,359 19+j9,20 2 So (MVA) 0,035+j0, 24 0,021+j0, 136 0,035+j0, 24 0,029+j0, 2 0,021+j0, 136 0,029+j0, 2 Sb (MVA) 0,069+j1, 602 0,036+j0, 717 0,069+j1, 602 0,054+j1, 199 0,036+j0, 717 0,054+j1, 199 Sb (MVA) 19,069+j10, 804 9,036+j5,07 6 19,069+j10, 804 14,554+j8,2 215 9,036+j5,07 6 14,554+j8,2 215 Qc MVA r 2,02 S (MVA) 28,252+j11, 203 9,057+j3,65 2 19,104+j7,7 24 14,583+j6,6 915 9,057+j2,33 2 14,583+j6,8 215 Sd (MVA) 0,488+j0,9 66 0,091+j0,0 87 0,483+j0,7 57 0,189+j0,2 46 0,153+j0,1 47 0,177+j0,2 30 S (MVA) 28,74+j12,1 69 9,148+j3,73 9 19,587+j8,4 81 14,772+j6,9 375 SN(MVA) 28,74+j10,1 49 9,148+j2,17 9 19,587+j5,1 61 14,772+j5,2 075

1,56

3,32

N- 14,5+j7,0 4 225 N9+j4,359 5 N- 14,5+j7,0 6 225

1,73

2,88

9,21+j2,479 14,76+j7,05 15

9,21-j0,401 14,76+j5,45 15

1,60

- Ta gi thit ngng mt mch ca ng dy hai mch, ng thi xt trng hp nguy him nht ta gi thit s ngng mt mch on ng dy ni trc tip vi ngun. - Ta khng gi thit s c xp chng - S c xy ra ch cc i. - UN = 121 kV Vy cc thng s s thay th ca l ng dy trong ch s c ch c thng s v ng dy ni trc tip vi ngun l thay i cn cc thng s khc l khng thay i so vi ch ph ti cc i. Thng s ca cc ng dy c cho trong bng sau: ng dy Zd () B/2 So (MVA) Zb ()43

S=P+jQ (MVA)

n mn hc li inN-1 1-2 N-3 N-4 N-5 N-6 12,78+j25,3 23+j22 27,54+j43,14 17,78+j23,1 42,4+j40,56 16,5+j21,46 0,833 0,645 1,372 0,714 1,189 0,663 0,07+j0,48 0,042+j0,272 0,07+j0,48 0,058+j0,4 0,042+j0,272 0,058+j0,4 0,935+j21,75 2,19+j43,35 0,935+j21,75 1,27+j27,95 2,19+j43,35 1,27+j27,95 38+j18,404 18+j8,718 38+j18,404 29+j14,045 18+j8,718 29+j14,045

Kt qu tnh cc dng cng sut v tn tht cng sut trn ng dy c cho trong bng sau:

44

n mn hc li inBng kt qu tnh dng cng sut v tn tht cng sut trn cc nhnh ca ng dy trong ch sau s c

45

n mn hc li in

D

Sssc (MVA)

So (MVA) 0,07+j0,4 8 0,042+j0, 272 0,07+j0,4 8 0,058+j0, 4 0,042+j0, 272 0,058+j0, 4

Sb (MVA) 0,138+j3, 204 0,072+j1, 433 0,138+j3, 204 0,109+j2, 398 0,072+j1, 433 0,109+j2, 398

Sb (MVA) 38,138+j21, 608 18,072+j10, 151 38,138+j21, 608 29,109+j16, 443 18,072+j10, 151 29,109+j16, 443

Qc MV Ar 1,01

S (MVA) 57,122+j30, 707 18,114+j9,6 43 38,208+j20, 428 29,167+j15, 983 18,114+j8,9 83 29,167+j16, 043

Sd (MVA) 4,442+j8,79 4 0,800+j0,76 6 4,272+j6,69 3 1,625+j2,11 2 1,433+j1,37 0 1,511+j1,96 5

S (MVA) 61,564+j39, 501 18,914+j10, 409 42,48+j27,1 21 30,792+j18, 095 19,547+j10, 353 30,678+j18, 008

SN(MVA) 61,564+j38, 491 18,914+j9,6 29 42,48+j25,4 61 30,792+j17, 235 19,547+j8,9 13 30,678+j17, 208

N- 38+j18,4 1 04 12 18+j8,71 8

0,78

N- 38+j18,4 3 04 N4 29+j14, 045

1,66

0,86

N- 18+j8,71 5 8 N6 29+j14, 045

1,44

0,80

CHNG VII LA CHN PHNG THC IU CHNH IN P TRONG MNG IN 7.1 Xc nh in p ti cc nt ca mng in Trong mc ny, ta s dng cc s liu v tnh ton chnh xc phn b cng sut trong mng in chng trc tnh in p ti cc nt. Phng php chung tnh in p ti cc nt l cng sut u th ly in p . Trong n mn hc cho trc in p vn hnh ti thanh ci cao p ca nh my in trong cc trng thi vn hnh nn ta s tnh in p ti cc nt trong mng in theo cng sut u ng dy trong c 3 trng thi: ph ti cc i, ph ti cc tiu v s c.

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n mn hc li in7.1.1 Ch ph ti cc i Trong ch ph ti cc i in p trn thanh ci ca ngun in l: UN = 110%Um = 121kV Xt ng dy N-1 in p trn thanh gp cao p trm 1 bng:U1 = U N ' ' PN 1.RN 1 + QN 1. X N 1 58,814.6,39 + 31,908.12, 65 = 121 = 114,56 kV UN 121

in p trn thanh gp h p trm 1 quy v cao p bng:U1q = U1 Pb'1.Rb1 + Qb' 1. X b1 38,138.0,935 + 21, 608.21, 75 = 114,56 = 110,14 kV U1 114,56

i vi cc ng dy cn li,vic tnh in p trn cc ng dy ny c thc hin tng t nh i vi ng dy N-1 mc trn. Kt qu tnh ton in p c ghi trong bng sau : Trm bin p Uq, kV 1 110,14 2 114,35 3 108,00 4 113,02 5 112,21 6 113,30

7.1.2 Ch ph ti cc tiu Trong ch ny in p trn thanh gp cao p ca ngun in l: UN = 105%Um= 115kV Da vo bng 6.2 v tnh ton tng t nh trong ch ph ti cc i ta c bng sau: Trm bin p Uq, kV 1 107,55 2 109,51 3 106,51 4 108,77 5 108,62 6 108,90

7.1.3 Ch sau s c Trong ch s c in p trn thanh gp cao p ca ngun in : UN = 110%Um = 121kV. Trong ch ny ta khng xt s c xp chng m ch xt s c t mt mch trn ng dy ni trc tip vi ngun in khng xt s c t dy ni gia trm trung gian v ph ti. Da vo bng 6.3 ta c :47

n mn hc li inKt qu tnh ton in p ca mng in trong ch sau s c cho trong bng sau : Trm bin p Uq, kV 1 101,48 2 111,36 3 96,69 4 108,63 5 106,35 6 109,25

7.2 La chn u phn p Cc ph ti trong mng in thit k (5 ph ti loi I v 1 ph ti loi III) v c yu cu iu chnh in p khc thng . ng thi cc gi tr in p trn thanh gp h p quy v cao p ca cc trm trong ch ph ti cc i ,cc tiu v sau s c khc nhau tng i nhiu . Do m bo cht lng in p cung cp cho cc h tiu th cn s dng cc my bin p iu chnh in p di ti. Tt c cc my bin p dng trong cc trm bin p ca mng in thit k u l cc my bin p iu chnh in p di ti v c phm vi iu chnh 9 . 1,78% , Ucdm = 115 kV,Uhdm = 11 kV i vi trm c yu cu iu chnh in p khc thng , lch in p trn thanh gp h p ca trm c quy nh nh sau: Trong ch d ph ti cc i dUmax% = +5% Trong ch ph ti cc tiu dUmin% = 0% Trong ch sau s c thc sau: Uyc = Udm + dU%*Udm Trong Udm l in p nh mc ca mng in h p i vi mng in thit k Udm =10 kV.V vy in p yu cu trn thanh gp h p ca trm trong cc ch nh sau: *Ph ti cc i: Uycmax = 10 +5%.10 = 10,5 kV *Ph ti cc tiu Uycmin = 10+ 0%.10 = 10 kV *Ch sau s c Uycsc = 10+5%.10 = 10,5 kV dUsc% = 05% in p yu cu trn thanh gp h p ca trm c xc inh theo cng

48

n mn hc li inKt qu tnh in p trn thanh gp h p ca cc trm ,quy i v pha in p cao trong cc ch ph ti cc i ,cc tiu v sau s c cho trong bng sau : TBA Uqmax kV Uqmin kV Uqsc kV 1 110,14 107,55 101,48 2 114,35 109,51 111,36 3 108,00 106,51 96,69 4 113,02 108,77 108,63 5 112,21 108,62 106,35 6 113,30 108,90 109,25

S dng cc my bin p iu chnh in p di ti cho php thay i cc u iu chnh khng cn ct cc my bin p .Do cn chn u iu chnh ring cho ch ph ti cc i ,cc tiu v sau s c. 7.2.1 Chn cc u iu chnh in p trong MBA trm 1 *Ch ph ti cc i in p tnh ton ca u iu chnh ca my bin p c xc nh theo cng thc:U dc max = U q max.Uhm U yc max = 110,14.11 = 115,39 kV 10,5

Da theo bng 8.36 trong sch Thit k cc mng v h thng in ca tc gi Nguyn Vn m ta chn u iu chnh tiu chun n = 9, khi in p ca u iu chnh tiu chun Utcmax = 115 kV in p thc trn thanh gp h p bng:U t max = U q max.Uhm U tc max = 115,39.11 =10,536 kV 115

lch in p trn thanh gp h p bngU dc max = U tm U max U m .100 = 10,536 10 .100 = 5,36 % 10

*Ch ph ti cc tiu in p tnh ton ca u iu chnh ca my bin p c xc nh theo cng thc:U dc min = U q min x.Uhm U yc min = 107,55.11 = 118,31 kV 10

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n mn hc li inDa theo bng 8.36 trong sch Thit k cc mng v h thng in ca tc gi Nguyn Vn m ta chn u iu chnh tiu chun n = 8, khi in p ca u iu chnh tiu chun Utcmin = 119,1 kV in p thc trn thanh gp h p bng:U t min = U q min.Uhm U tc min = 118,31.11 = 9,93 kV 119,1

lch in p trn thanh gp h p bngU min % = U tm U min U m .100 = 9,93 10 .100 = -0,67 % 10

*Trong ch sau s c in p tnh ton ca u iu chnh ca my bin p bng:U d csc = U qsc.Uhm U y csc = 101, 48.11 = 106,31 kV 10,5

Vy ta chn u iu chnh in p tiu chun n = 14 vi Utcsc = 106,8 kV in p thc trn thanh gp h p bng:U tsc = U qsc.Uhm U t csc = 106,31.11 = 10,45 kV 106,8

lch thc ca in p trn thanh gp h p c gi tr bng:U min % = U tscm U U m .100 = 10, 45 10 .100 = 4,52 % 10

7.2.2 Chn cc u iu chnh trong cc my bin p ca cc trm cn li Chn cc u iu chnh ca cc my bin p cn li c tin hnh tng t nhu trn Cc kt qu tnh ton iu chnh in p trong mng in cho bngTrm bin p 1 2 3 4 5 Utcma x (kV) 115 119,1 112,95 119,1 117,05 Utmax Umax Utcmin (kV) (%) (kV) 10,54 10,56 10,52 10,44 10,55 5,36 5,61 5,18 4,39 5,45 119,1 121,15 117,05 119,1 119,1 Utmin (kV) 9,93 9,94 10,01 10,05 10,03 Umin ( %) -0,67 -0,57 0,10 0,46 0,32 Utcsc (kV) 106,8 117,05 102,7 115 112,95 Utsc (kV) 10,45 10,47 10,36 10,39 10,3650

Usc ( %) 4,52 4,65 3,56 3,90 3,57

n mn hc li in6 119,1 10,46 4,64 119,1 10,06 0,58 115 10,45 4,50

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n mn hc li inCHNG VIII TNH TON CC CH TIU KINH T - K THUT CA MNG IN 8.1.Tnh tn tht in p ln nht trong mng in T kt qu tnh ton Chng 3 ta c : ng dy Ubt% Usc% N-1 5,792 11,584 1-2 2,503 5,007 N-3 7,604 15,209 N-4 3,470 6,941 N-5 4,616 9,232 N-6 3,222 6,444

Ta nhn thy: Tn tht in p ln nht trong ch vn hnh bnh thng l : Umaxbt % = 8,30 % Tn tht in p ln nht trong ch s c l : Umax sc % = 14,09 % 8.2 Tng chiu di ng dy Tng chiu di ng dy trong mng in thit k l: L = 2.(lN-1 + l1-2+ + lN-3 + l5-4 + lN-5+ lN-6 ) = 408,855 km Cc dy dn dng trong mng in u l dy nhm li thp 8.3 Tng cng sut yu cu ca ph ti Pyc = 38+18+38+29+18+29 = 170 MW 8.4 Tng cng sut ca cc trm bin p h p Sb = 2.( Sba1 +Sba2+ Sba3+Sba4 + Sba5 + Sba6 ) = 2.(32+16+32+25+16+25) = 292 MVA 8.5 Tng tn tht cng sut tc dng Tn tht cng sut trong mng in bao gm tn tht trn ng dy v trong cc trm bin p ch ph ti cc i. T kt qu tnh ton bng 6.1 ta c: Tng tn tht cng sut tc dng trn ng dy bng: Pd = 6,62 MW Tng tn tht cng sut tc dng trong cc cun dy my bin p bng: Pb = 0,638 MW Tng tn tht trong li thp cc my bin p bng: Po = Poi = 0,34 MW52

n mn hc li inTng tn tht trong mng bng: P = Pd + Pb + Po = 6,62+0,638+0,34 = 7,60 MW Tng tn tht tc dng trong mng in tnh theo phn trm:P % = P 7, 60 .100 = .100 = 4,471 % 170 Pmax

8.6 Tng in nng cc ph ti tiu th A = Pmax .Tmax = 170.5500 = 935.103 (MW.h) = 935.106 (kW.h) 8.7 Tng tn tht in nng Tng tn tht in nng trong mng in c th xc nh theo cng thc sau: A = (Pd + Pb). + Po. t Trong : :thi gian tn tht cng sut ln nht t: thi gian cc my bin p lm vic trong nm Bi v cc my bin p vn hnh song song trong c nm cho nn t = 8760h. A = (Pd + Pb). + Po. t = (6,62+0,638).3797+0,34.8760 = 31875,165 MW.h Tng tn tht in nng trong mng in tnh theo phn trm bng :A% = A 31875,165 .100 = .100 = 3, 409% A 935.103

8.8 Tng vn u t xy dng mng in Tng cc vn u t xy dng mng in c xc nh theo cng thc K= Kd + Kt Trong : Kd: vn u t cho ng dy Kt: Vn u t cho trm bin p chng 3 ta tnh c vn u t ng dy l:53

n mn hc li inKd = 191330,02.106 = 191,330.10 9 Da vo bng 8.40 (trang 256) sch Thit k cc mng v h thng in-NGUYN VN M ta c : Vn u t cho cc trm h p trong mng in thit k l: Kt = 2.1,8.13.109 +2.1,8.19.109 +2.1,8.22.109 = 216.109 Do tng vn u t xy dng mng in l: K = Kd + Kt = 191,330.10 9 +216.109 = 407,330.109 8.9 Chi ph vn hnh hng nm Chi ph vn hnh hng nm trong mng in c xc nh theo cng thc : Y = avhd.Kd + avht.Kt + A.c Trong : avhd : H s vn hnh ng dy avhd = 0,04 avht : H s vn hnh cc thit b trong cc trm bin p (avht = 0,10) c Ta c: Y = 0,04.191,330.10 9 + 0,10.216.109 + 31875,165.103.1000 = 46,785.10 9 8.10 Chi ph tnh ton hng nm Chi ph tnh ton hng nm c tnh theo cng thc: Z = atc.K + Y Trong : atc l h s nh mc hiu qu ca cc vn u t atc = 0,125 Ta c: Z = 0,125.407,330+ 46,785 = 97,701.109 8.11 Gi thnh truyn ti in nng Gi thnh truyn ti in nng c tnh theo cng thc:=Y 46, 785.109 = = 50,037 / kW.h A 935.106

: Gi thnh 1 kW.h in nng tn tht 1000 .

54

n mn hc li in8.12 Gi thnh xy dng 1 MW cng sut ph ti trong ch ph ti cc i Gi thnh xy dng 1 MW cng sut ph ti c xc nh nh sau:K 407,330.109 = K0 = P = 2,396.109 170 max

Kt qu ca cc ch tiu kinh t k thut ca h thng in c tng hp trong bng sau: Cc ch tiu 1. Tng cng sut yu cu ca ph ti 2. Tng chiu di ng dy 3. Tng cng sut ca cc TBA h p 4. Tng tn tht cng sut tc dng 5. Tng tn tht cng sut tc dng 6. Umaxbt 7. Umaxsc 8. Tng in nng cc ph ti tiu th A 9. Tng tn tht in nng A 10. Tng tn tht in nng A 11. Tng vn u t xy dng mng in K 12. Chi ph vn hnh hng nm Y 13.Gi thnh truyn ti in nng 14. Gi thnh xy dng 1MW cng sut ph ti khi cc i P P n v MW km MVA MW % % % MW.h MW.h % 109 ng 109 ng ng 109 /MW Gi tr 170 408,855 292 7,60 4,471 4,536 9,071 935 31875,165 3,409 407,330 46,785 50,037 2,396

55

n mn hc li inMC LCLI NI U.................................................................................................................................1 CHNG I: PHN TCH NGUN V PH TI......................................................................2 CHNG II. CN BNG CNG SUT TC DNG...............................................................2 2.1 Bng s liu ph ti...............................................................................................................3 2.2 Cn bng cng sut tc dng.................................................................................................3 CHNG III...................................................................................................................................6 3.1 M u..............................................................................................................................6 3.2 D kin cc phng n..........................................................................................................6 3.3 Phng n ni dy 1 ..........................................................................................................9 3.4 Phng n ni dy 2............................................................................................................14 3.5 Phng n ni dy 3............................................................................................................17 3.6 Phng n ni dy 4............................................................................................................19 3.7.Phng n ni dy 5............................................................................................................21 KT LUN....................................................................................................................................24 CHNG IV.................................................................................................................................24 4.1 t vn ............................................................................................................................25 4.2 Tnh ton cc phong n.....................................................................................................26 CHNG V..................................................................................................................................30 5.1 Chn s lng v cng sut my bin p trong cc trm h p.........................................30 5.2 S ni dy chi tit...........................................................................................................31 CHNG VI.................................................................................................................................33 6.1 Ch ph ti cc i.........................................................................................................33 6.2 Tnh ton trong ch ph ti cc tiu..............................................................................39 6.3 Xt ch sau s c ...........................................................................................................43 CHNG VII................................................................................................................................46 7.1 Xc nh in p ti cc nt ca mng in.......................................................................46 7.1.1 Ch ph ti cc i................................................................................................47 7.1.2 Ch ph ti cc tiu..............................................................................................47 7.1.3 Ch sau s c.........................................................................................................47 7.2 La chn u phn p.........................................................................................................48 8.1.Tnh tn tht in p ln nht trong mng in................................................................52 8.2 Tng chiu di ng dy...................................................................................................52 8.3 Tng cng sut yu cu ca ph ti ................................................................................52 8.4 Tng cng sut ca cc trm bin p h p........................................................................52 8.5 Tng tn tht cng sut tc dng........................................................................................52 8.6 Tng in nng cc ph ti tiu th...................................................................................53 8.7 Tng tn tht in nng.......................................................................................................53 8.8 Tng vn u t xy dng mng in...............................................................................53 8.9 Chi ph vn hnh hng nm.................................................................................................54 8.10 Chi ph tnh ton hng nm...............................................................................................54 8.11 Gi thnh truyn ti in nng..........................................................................................54 8.12 Gi thnh xy dng 1 MW cng sut ph ti trong ch ph ti cc i.....................55

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