Đồ án nhà máy điện - Đại học Bách Khoa Hà Nội

Trng i hc bch khoa h ni

n mn hc: Phn in trong NM &TBA Ng c Vit - HT1-K46

Trng i Hc Bch Khoa H Ni

Khoa in B mn H Thng in

--- o0o ---

n mn hc : Phn in trong

nh my in & trm bin pGio vin hng dn : PGS-TS Phm Vn Ho

Sinh vin

: Ng c Vit Lp

: HTI K46

H Ni 11-2005 Li ni u

Nh my in v trm bin p l cc khu ch yu trong H Thng in . Do vy mi sinh vin ngnh H Thng in cn hiu r c nhim v , chc nng , cu to v nguyn l vn hnh ca chng. Mn hc Phn in trong nh my in v trm bin p cho sinh vin c nhng kin thc c bn nht ,tng quan nht . Tuy vy , ch l phn l thuyt v s tht l kh khn cho mi sinh vin khi ra trng khng bit cch vn dng c nhng kin thc hc ca mn hc vo thc t. n mn hc Phn in trong nh my in v trm bin p gii quyt vn . Qua nhim v thit k sinh vin s bit cch p dng nhng kin thc hc , nhng cng thc ,tnh ton mt cch thnh tho.Khng ch n gin l nhng kin thc ca mn Phn in trong nh my in v trm bin p m khi lm n ,sinh vin c dp n li kin thc ca nhiu mn hc c bn nh : Ngn mch , cao p , li in , bo v Rle Trong thi gian lm n vi s c gng ht sc ca bn thn, c s gip tn tnh ca cc thy c ca b mn. c bit l s gip v hng dn tn tnh ca PGS - TS Phm Vn Ho gip em hon thnh bn n. V thi gian c hn, vi kin thc cn hn ch do vy bn n ca em khng trnh nhng thiu st. V vy em rt mong nhn c s gp b xung ca cc thy c gio n ca em ngy cng hon thin hn.

Em xi Mt ln na em xin chn thnh cm n ! H Ni ,ngy 5 thng 11 nm 2005 Sinh vin:

Ng c Vit

Mc lc

Li ni u...1

Mc lc ...2 Chng 1: Tnh ton ph ti v cn bng cng sut 1.1. Chn my pht in .....41.2. Tnh ton ph ti cc cp in p......5

1.3. Cn bng cng sut ton nh my ...5 1.4. Nhn xt ...6 Chng 2: La chn s ni in ca nh my2.1. sut cc phng n.7 2.2. La chn MBA cho cc phng n.102.3. Phn b ph ti cho cc MBA.14

2.4. Kim tra kh nng qu ti ca cc MBA....10

2.5. Tnh tn tht in nng trong MBA....10

2.6. Tnh dng in cng bc ..23 Chng 3: Tnh dng in ngn mch3.1. Phng n 1.203.2. Phng n 2.....22 Chng 4: Tnh ton ch tiu Kinh t K thut La chn phng n ti u4.1. Chn my ct v dao cch ly cho tng phng n .25

4.2. La chn s thit b phn phi ...26

4.3. Tnh ton kinh t k thut .50Chng 5: Chn kh c in v dy dn 5.1. Chn thanh dn cng ...27

5.2. Chn thanh dn mm ...31Chng 6: S ni in v thit b t dng 6.1. Chn MBA t dng cp 1.....44

6.2. Chn MBA d tr cp 1 ...45

6.3. Chn MBA t dng cp 2.....47

6.4. Chn my ct pha mch 6,3 kV .60

6.5. Chn ptmt cho ph ti t dng cp 0,4 kV ....70 Chng 1 : tnh ton ph tI v cn bng cng sut Ti mi thi im in nng do nh my pht ra phi cn bng vi in nng tiu th ca ph ti k c cc tn tht ca ph ti.Trong thc t in nng tiu th ti cc h dng in lun thay i, v th vic tm c th ph ti l rt quan trng i vi vic thit k v vn hnh.

Da vo th ph ti ta c th chn c phng n ni in hp l, m bo cc ch tiu kinh t k thut. th ph ti cn cho ta chn ng cng sut ca cc my bin p (MBA) v phn b ti u cng sut gia cc t my vi nhau v gia cc nh my in vi nhau.

1.1. Chn my pht in. Theo yu cu thit k nh my c tng cng sut 4(60 MW = 240 MW. Chn 4 my pht in kiu TB(-60-2 c cc thng s nh bng 1-1 sau:

Bng 1-1

Sm(MW)Pm(MW)Um(KV) Im(KA)COS(mXdXdXd

756010,54,1250,80,1460,221,691

1.2. Tnh ton ph ti cc cp in p. Trong nhim v thit k cho th ph ti ca nh my v th ph ti ca cc cp in p di dng bng theo phn trm cng sut tc dng Pmax v h s cos(tb ca tng ph ti tng ng t ta tnh c ph ti ca cc cp in p theo cng sut biu kin nh cng thc sau :

(1.1) vi : .

Trong : S(t) : l cng sut biu kin ca ph ti ti thi im t (MVA).

cos(TB : l h s cng sut trung bnh ca tng ph ti.

P% :Cng sut tc dng ti thi im t tnh bng phn trm cng sut cc i.

Pmax : Cng sut ca ph ti cc i tnh bng, MW.

1.2.1. Ph ti cp in p my pht :Theo thit k : Pmax = 20 MWvi cos( = 0,85 . p dng cng thc (1.1).Ta c : Bng 1.2

T(h)0 - 88-1212-1414-1616-1818-2222-24

P %807080901009080

P(t) MW16141618201816

S(t) MW18,8216,4718,8221,1823,5321,1818,82

1.2.2. Ph ti cp in p trung (110 kV) : Vi Pmax = 80 MWvi cos( = 0,88 tng t ta c bng kt qu v th sau :

Bng 1.3

T(h)0 - 66-1010-1414-1616-2020-24

P %9080901009080

P(t) MW726472807264

S(t) MW81,8272,7381,8290,91 81,8272,73

1.2.3. Cng sut pht ca ton nh my Nh my gm 4 t my c: Pm = 60 MW, cos(m = 0,8 do

Tng cng sut t ca ton nh my l:

PNMm = 4(Pm = 4 ( 60 = 240 MW ( SNMm = 300 MW. T ta c phn b cng sut theo thi gian v th :

Bng 1.3

T(h)0 - 1010-1414-1818-2222-24

P %80901009080

P(t) MW192216240216192

S(t) MW240270300270240

1.2.4. Cng sut t dng ca nh my : Cng sut t dng ca ton nh my c xc nh theo cng thc sau :

(1.2)

Trong : STD : cng sut t dng ca nh my

: phn trm lng in t dung Pt : Cng sut NM pht ra ti thi im t Da vo bng kt qu (1.3) v cng thc (1.2) ta c kt qu sau :

Bng 1.4T(h)0 - 1010-1414-1818-2222-24

P(t) MW192216240216192

S(td) MW18,520,8223,1320,82 18,5

1.3. Cn bng cng sut ton nh my Phng trnh cn bng cng sut ton nh my:

Ta b qua tn tht (S(t) trong my bin p v SuC = 0(

T ta lp c kt qu tnh ton ph ti v cn bng cng sut ton nh my nh sau :

T(h)0-66-88-1010-1212-1414-1616-1818-2020-2222-24

SNM240240240270270300300270270240

S uf18,8218,8216,4716,4718,8221,1823,5321,1821,1818,82

SuT81,8272,7372,7381,8281,8290,9181,8281,8272,7372,73

STD18,518,518,520,8220,8223,1323,1320,8220,8218,5

SHT120,85129,94132,3150,89148,54164,78171,52146,2155,3129,9

1.4. Nhn xt : Tnh trng ph ti cc cp in p.

Ta thy ph ti phn b khng u cc cp in p. cp in p my pht ph ti Pmax= 20MW kh nh so vi cng sut mt my pht P = 60 MW Ph ti cp in p trung : Pmax= 80MW, tng i ln Ph ti cp in p cao khng c.

D tr ca h thng Ta c d tr ca h thng S = 100MVA, ln hn so vi cng sut mt my pht.

Cng sut ca h thng ln SHT= 2000MVA.Vi cng sut ca h thng ln nh vy th nh my khng c vai tr thc s quan trng . in p.

Nh my thit k ch c cc cp in p l:

Cp in p my pht Um= 10,5 KV. Cp in p trung c Um= 110KV. Khng c cp in p cao :220KV(ni h thng)Chng 2 : la chn s ni in ca nh my2.1. sut cc phng n : La chn s ni in chnh l mt trong nhng nhim v ht sc quan trng trong thit k nh my in. S ni in hp l khng nhng em li nhng li ch kinh t ln lao m cn phi p ng c cc yu cu k thut .

C s xc nh cc phng n c th l s lng v cng sut my pht in , cng sut h thng in , s li v ph ti tng ng , trnh t xy dng nh my in v li in ... Theo nhim v thit k nh my c 4 t my pht, cng sut nh mc ca mi t my l 60 MW c nhim v cung cp in cho ph ti cc cp in p sau:

Ph ti a phng cp in p 10 kV c:

Sp max = 23,53 MVA Sp min = 16,47 MVA

Ph ti cp in p 110 kV c: S110 max = 90,91 MVA

S110 min = 72.73 MVA a v h thng cp in p 220kVS220 max = 171,52 MVA

S220 min = 120,85 MVA Cng sut d phng ca h thng Sdp= 100 MVA.Vy ta khng th ghp chung hai my pht vi mt my bin p v

(Sb = 2*75 = 150 MVA > Sdp ht = 100 MVA Ta c : >30% Vy cn phi c TG in p my pht.T nhng nhn xt trn y ta c th xut mt s phng n nh sau:

Phng n 1 :

Phng n 2:

Phng n 3:

Phng n 4 :

Nhn xt :

Phng n 4 : cc MBA lin lc lun phi ti cng sut t h sang trung nn ch lm vic kh nng n . Mc d tit kim c s lng MBA

Phng n 3 : ch khc i cht vi phng n 1 .Tuy nhin phng n 3 MBA 2 dy qun ch to vi UC =220 kV nn t tin hn.

T cc nhn xt trn ta thy hai phng n 1 v 2 l hai phng n tt nht .Ta s la chn hai phng n ny tnh ton tip theo.2.2. La chn my bin p cho cc phng n :a. Phng n 1 : MBA ni b : B3 & B4 MBA 3 pha 2 dy qun v ni theo s b ,cng sut c xc nh nh sau : SB SFm = 75 MVA . Ta chn MBA loi TPH 115/10,5 vi cc thng s sau :Sm (MVA)UCm(Kv)UHm(Kv)(PO(Kw)(PN (Kw)UN%IO%

8011510,57031010,50,6

MBA lin lc : B1 & B2 B1 & B2 l cc MBA t ngu ni vo thanh gp in my pht nn cng sut c xc nh nh sau :

Trong : : h s c li ca MBA t ngu ;

Stha = SFm Sufmin - STDmax = 2*75 16,47 23,13*0,5 = 121,97 (MVA) Vy ta chn MBA loi ATTH vi cc thng s sau : Sm (MVA)UCm(Kv)UTm(Kv)UHm(Kv)(PO(Kw)(PN (Kw)UN%IO%

C-TC-HT-H

12523012111752901131190,6

b. Phng n 2 :

MBA ni b : B3 Ta la chn tng t nh vi phng n 1

MBA lin lc : B1 & B2 cng ging nh phng n 1 ta c :

Stha = SFm Sufmin - STDmax

= 3*75 16,47 23,13*3/4 = 191,18 (MVA)

Vy ta chn MBA loi ATTH vi cc thng s sau :

Sm (MVA)UCm(Kv)UTm(Kv)UHm(Kv)(PO(Kw)(PN (Kw)UN%IO%

C-TC-HT-H

200230121111054301132200,5

2.3. Phn b ph ti cho cc MBA

a. Phng n 1 :

Vi MBA 2 dy qun B3 & B4 thun tin cho vic vn hnh ta cho th ph ti bng phng trong sut c nm

SB1=SB2= SFm Stdmax = 75 23,13/4 = 69,22 MVA < SmB = 80MVA

Vy iu kin lm vic bnh thng MBA B3&B4 khng b qu ti MBA t ngu B1&B2 :ta cn phn b cng sut cho tng cun dy Ta nhn thy : SBT > SUT do vy cng sut c chuyn t : T C

H C Cao :

Trung :

H : SH = SC ST MVA Da vo cc cng thc trn ta c bng phn b cng sut cho tng cun dy ca MBA lin lc nh sau :

T(h)0-66-88-1010-1212-1414-1616-1818-2020-2222-24

SC(MVA)60.4364.9766.1575.4574.2782.3985.7673.0977.6464.97

ST(MVA)28.3132.8632.8628.3128.3123.7728.3128.3132.8632.86

SH(MVA)32.1232.1233.2947.1445.9658.6357.4544.7844.7832.12

Qua bng phn b trn ta c: SCmax=85,76 MVA < SmBtn=125 MVA

STmax=32,86 MVA < Stt =* SmBtn = 0,5*125 = 62,5 MVA

SHmax=58,63 MVA < Stt = * SmBtn = 62,5 MVA

Vy iu kin lm vic bnh thng MBA B1&B2 khng b qu tib. Phng n 2 :

Vi MBA 2 dy qun B3 thun tin cho vic vn hnh ta cho th ph ti bng phng trong sut c nm

SB3= SFm Std = 75 23,13/4

= 69,22 MVA < SmB = 80MVA

Vy iu kin lm vic bnh thng MBA B3 khng b qu ti MBA t ngu B1&B2 :ta cn phn b cng sut cho tng cun dy

Ta nhn thy : SBT < SUT do vy cng sut c chuyn t : H T

H C Cao :

Trung :

H : SH = ST + SC Da vo cc cng thc trn ta c bng phn b cng sut cho tng cun dy ca MBA lin lc nh sau :

T(h)0-66-88-1010-1212-1414-1616-1818-2020-2222-24

SC(MVA)60.4364.9766.1575.4574.2782.3985.7673.0977.6464.97

ST(MVA)6.301.751.756.306.3010.846.306.301.751.75

SH(MVA)66.7366.7367.9081.7580.5793.2492.0679.3979.3966.73

Qua bng phn b trn ta c:

SCmax=85,76 MVA < SmBtn=200 MVA

STmax= 10,84 MVA < Stt =* SmBtn = 0,5*200 = 100 MVA

SHmax=93,24 MVA < Stt =* SmBtn = 100 MVA Vy iu kin lm vic bnh thng MBA B1&B2 khng b qu ti2.4. Kim tra kh nng qu ti ca cc MBAa. Phng n 1 : S c 1 b bn trung : Khi c s c mt b bn trung th cng sut thiu l :Sthiu= SUTmax - SBT = 90,91 69,22 = 21,69 MVA

Lng cng sut thiu ny c ti t MBA t ngu sang . Mi MBA t ngu cn ti 1 cng sut l :

Hai MBA t ngu lm vic trong ch : H T H C Trong ch truyn ti ny SH l ln nht nn ta ch cn kim tra cun h.

SH = 0,5*( Smf 0,5*Std SUf ) = 0,5*(2*75 0.5*23,13-21,18) = 58,63 MVA Stt = *SmB = 0,5*125 = 62,5 MVA Nh vy : SH < Stt MBA khng b qu ti .Lng cng sut ton b nh my pht ln thanh gp cao p l :

Lc ny h thng thiu mt lng cng sut :

SHTthiu=SHT STG220 = 164,78 94,91 = 69,21 MVA

Lng cng sut ny nh hn d tr ca h thng : 100 MVA S c 1 MBA lin lc :

Gi s hng MBA B1. Cng sut tha t bn trung l : Stha = SBT - SuTmin = 2*(75-23,13/4) 72,73

= 65,71 MVA

MBA B2 phi lm vic trong ch ti : H C

T C

Kh nng ti ca MBA lc s c l : Sttsc = kqtsc**SmB = 1,4*0,5*125 = 87,5 MVA Ta c cng sut pht ln ca cc MF pha h p lc ny l :

SfH = (Smf - Stdmax ) SUf

= 3*69,22 16,47 = 191,19 MVA

SfH > Sttsc Trong trng hp ny cc MF ni vo pha h ca MBA lin lc khng pht vi cng sut nh mc m ch pht lng cng sut ph hp vi kh nng ti ca MBA lin lc. Sttsc > Stha MBA ti ht c lng cng sut thaSo vi khi bnh thng cng sut nh my pht ln h thng thiu mt lng l:

SHTthiu=SHTmax SC2 = 132,3 87,5 = 44,8 MVALng cng sut ny nh hn d tr ca h thng : 100 MVA

b. Phng n 2 : Xt cc trng hp nh ca phng n 1 ta c S c 1 b bn trung :

Khi c s c mt b bn trung th cng sut thiu l :

Sthiu= SUTmax = 90,91 MVA

Lng cng sut thiu ny c ti t MBA t ngu sang . Mi MBA t ngu cn ti 1 cng sut l :

Hai MBA t ngu lm vic trong ch : H C

H T

Trong ch truyn ti ny SH l ln nht nn ta ch cn kim tra cun h.

SH = 0,5*( Smf 0,5*Std SUf )

= 0,5*(3*75 0.75*23,13-21,18) = 93,24 MVA

Stt = *SmB = 0,5*200 = 100 MVA Nh vy : SH < Stt MBA khng b qu ti .Lc ny h thng thiu mt lng cng sut :

SHTthiu=SHT 2*SCB = 164,78 2*(93,24- 45,46) = 69,22 MVA

Lng cng sut ny nh hn d tr ca h thng : 100 MVA S c 1 MBA lin lc :

Gi s hng MBA B1. Cng sut thiu ca bn trung l :

Sthiu = SUTmax - SBT = 90,91 69,22 = 21,69 MVA

MBA B2 phi lm vic trong ch ti : H T H C

Cng sut ca cc MF pht pha h ln l : SH = Smf 0,75*Std SUf

= 3*75 0.75*23,13 - 21,18 = 186,48 MVA

Sttcs = kqtsc**SmB =1,4* 0,5*200 = 140 MVA

SH > Sttcs Trong trng hp ny cc MF ni vo pha h ca MBA lin lc khng pht vi cng sut nh mc m ch pht lng cng sut ph hp vi kh nng ti ca MBA lin lc.Do vy s ch kim tra xem vi cng sut ti lc s c ca MBA lin lc c cung cp cho lng cng sut thiu bn trung khng : Sthiu = 21,91 MVA < Sttcs = 140 MVA Tho mn

Lc ny h thng thiu mt lng cng sut :

SHTthiu=SHTmax SC = 164,78 (140-21,91)= 46,69 MVA

Lng cng sut ny nh hn d tr ca h thng : 100 MVA2.5. Tnh tn tht in nng trong cc MBAa. Phng n 1 :

MBA 2 dy qun :

Khi c n my bin p vn hnh song song th ta c cng thc tnh tn tht in nng:

Trong :

SBm: Cng sut nh mc ca my bin p

Sb : Cng sut qua my bin p

(P0 : Tn tht cng sut khng ti

(Pn : Tn tht cng sut ngt mch ca my bin p T : S gi trong 1 nm ; T = 8760 h

Theo cc s liu ca MBA 2 dy qun chn ta c :

MBA t ngu :

Vi (PnC ,(PnT ,(PnH : tn tht cng sut ngn mch trong cun dy C,T,H ca MBA t ngu. SiC , SiT ,SiH : cng sut ti qua cc cun C,T,H ca MBA t ngu ti thi im t Ta c:

( = 0,5 l h s li dng ca my bin p t ngu.

Do thng s MBA ch cho (PnCT nn ta c th coi (PNCH = (PNTH =

Thay s ta c:

(PNCH = (PNTH = = = 145 KW Vy

Thay s vo cng thc ta tnh c :

Vi : (P0 = 75 KW

n (P0t = 75*8760 = 657 MWh

t = 0h ( 6h(A0-6 =

Tnh ton tng t cho cc thi im khc ta c kt qu

T0-66-88-1010-1212-1414-1616-1818-2020-2222-24

A(kWh)415,6154160,9242,7233,3326,8333,6224,2241,5153,7

T tnh c :

Tng tn tht cng sut trong my bin p t ngu

= 657 + 907,39 = 1564,39 MWh( Tng tn tht cng sut trong my bin p

(A1 = 2*(Atn +2* (AB =2*( 2646,25 + 1564,39) = 8421,28 MWh

b. Phng n 2 :

Tnh ton tng t nh vi phng n 1 ta c :

MBA 2 dy qun :

MBA t ngu :

Vi : (PNCH = (PNTH = = = 215 KW Vy

Thay s vo cng thc ta tnh c :

Vi : (P0 = 105 KW

(P0t = 105*8760 = 919800 KWh = 919,8 MWh

t = 0h ( 6h(A0-6 =

Tnh ton tng t cho cc thi im khc ta c kt qu

T0-66-88-1010-1212-1414-1616-1818-2020-2222-24

A(kWh)549.8189195.8277.1269.1354.6352.8261.1268.1189

T tnh c :

Tng tn tht cng sut trong my bin p t ngu

= 919,8 + 1060,82 = 1980,62 MWh( Tng tn tht cng sut trong my bin p

(A1 = (Atn + (AB = 2646,25 + 2*1980,62 = 6607,49 MWh2.6. Tnh dng in cng bc

a. Phng n 1 :

Ta s tnh dng cng bc ti cc im nh trn hnh v

Cp in p cao (220kV) :

ng dy kp ni vo h thng :

Pha cao p MBA t ngu : Ch bnh thng : SCmax= 79,96 MVA Ch s c B3(hoc B4) : SCB1= SCB1= 46,28 MVA

Ch s c B1(hoc B2) : SC= 161,56 MVA

Vy :

Cp trung (110kV) :

ng dy kp ph ti trung p :

B MF - MBA 2 dy qun :

Pha trung p MBA lin lc :

Ch bnh thng : STmax= 33,36 MVA Ch s c B3(hoc B4) : STB1= STB1= 10,955 MVA

Ch s c B1(hoc B2) : ST= 47,09 MVA

Vy

Cp in p my pht (10,5kV) :

Mch h p MBA lin lc :

Mch MF :

Mch khng phn on :Dng cng bc qua khng phn on c xt theo 2 trng hp : Khi s c 1 my pht F1(hoc F2):

Dng cng sut chy qua khng : SquaK = SquaB + 0,5*SUf = 22,735 + 0,5*22,53 = 34 MVA Khi s c 1 MBA lin lc :

Dng cng sut chy qua khng :

SquaK = SquaB + 0,5*SUf +0,25*Stdmax-SmF = 87,5 + 0,5*22,53 +0,25*24-75 = 30,265 MVA Vy dng cng bc qua khng :

Chn khng in phn on :

Khng in phn on c chn theo iu kin sau :

UmK > Umng = 10,5 kV

ImK IcbK = 1,87 kA

Tra Thit k nh my in ta chn c khng nh sau :

Loi PbA_10_2000_10

Um= 10,5 kV

ImK= 2 kA

XK% = 10%b. Phng n 2 :

Tng t nh vi phng n 1 ta c :

Cp in p cao (220kV) :

ng dy kp ni vo h thng :

Pha cao p MBA t ngu :

Ch bnh thng : SCmax= 79,96 MVA

Ch s c B3(hoc B4) : SCB1= SCB1= 46,28 MVA

Ch s c B1(hoc B2) : SC= 135,91 MVA

Vy :

Cp trung (110kV) :

ng dy kp ph ti trung p :

B MF - MBA 2 dy qun :

Pha trung p MBA lin lc :

Ch bnh thng : STmax= 19,91 MVA

Ch s c B3(hoc B4) : STB1= STB1= 45,46 MVA

Ch s c B1(hoc B2) : ST= 19,91 MVA

Vy

Cp in p my pht (10,5kV) :

Mch h p MBA lin lc :

Mch MF :

Mch khng phn on :

Dng cng bc qua khng phn on c xt theo 2 trng hp :

Khi s c 1 my pht F1(hoc F2):

Phn b cng sut trn phn on 1 ca TG :


SquaK = SquaB + SI = 57,235 + 9,41 = 66,645 MVA

Khi s c 1 MBA lin lc :


SquaK = kqtsc**SmB + S I+0,25*Stdmax-SmF = 1,4*0,5*200 + 9,41 + 0,25*23,53 - 75 = 80,29 MVA

Vy dng cng bc qua khng :

Chn khng in phn on :

Khng in phn on c chn theo iu kin sau :

UmK > Umng = 10,5 kV

ImK IcbK = 4,41 kA

Tra Thit k nh my in ta chn c khng nh sau :

Loi PbA_10_5000_12 Um= 10,5 kV

ImK= 5 kA

XK% = 12%Chng 3 : Tnh dng in ngn mch

3.1. Phng n 1 : Chn cc im tnh ngn mch :

im N1 : chn kh c in pha 220 kVc ngun cung cp l NM v HT im N2 : chn kh c in pha 110 kVc ngun cung cp l NM v HT im N3 : chn kh c in mch h p ca MBA lin lc c ngun cung cp l cc MF v h thng vi gi thit MBA lin lc B1 ngh tc l cc my ct in pha cao v trung ca MBA u ct ra.

im N4 : chn kh c in trn mch phn on TG in p MF c ngun cung cp l cc MF v h thng .Gi thit MF1 v MBA1 khng lm vic.

im N5 : chn kh c in trn mch MF c ngun cung cp l cc MF v h thng tr MF1.

im N5 : chn kh c in trn mch MF c ngun cung cp l cc MF v h thng tr MF1.

im N6 : chn kh c in trn mch phn on TG in p MF c ngun cung cp l cc MF v h thng .Gi thit MF1 v MBA1 khng lm vic. IN6 =IN5+IN5 Chn cc i lng c bn : Scb = 100 MVA Ucb = Utbm Dng in c bn cp 10,5 kV :

Dng in c bn cp 110 kV :

Dng in c bn cp 220 kV :

Tnh cc in khng cc phn t :

H thng :

ng dy kp (220kV) :

X1 = XHT + Xd = 0,05 + 0,03 = 0,08 MF :

X6 = X7 = X8 = X9 = XF = 0,195 MBA 2 dy qun :

X10 = X11 = XB = 0,131

MBA t ngu :

Xc = X2 = 0,092

XH = X3 = 0,156

Khng in :

XK = X5 = 0,275

Tnh ton dng NM :

a. im N1 : Ta c s thay th :

Vi : X1= 0,08 ; X2= 0,092 ; X3= 0,156 ; X5= 0,275 ;

X6= X7=X8= X9= 0,195 ; X10= X11= 0,131 ;

( X8 + X10 )// ( X9 + X11 )

S trn i xng vi im NM ta s dng phng php gp i s :

Bin i tip ta c :

X16 = X14 + X15 = 0,078 + 0,0975 = 0,1755

Ghp E12 & E34 :

X17= X16// X12

X18 = X13 + X17 = 0,046 + 0,0845 = 0,1305

S rt gn cui cng :

Dng in ngn mch ti N1 thi im t = 0 :

Dng in xung kch ti N1 :

Trong : kxk l h s xung kch . Ly kxk = 1,8

b. im N2:

Bin i s ging nh vi im N1 ta c : X1= 0, 08 X13= 0, 046 X12= 0, 163

X16 = X1+ X13 = 0, 08 + 0,046 = 0,126 X17 = X14+ X15

= 0, 078 + 0,108 = 0,186

X16 = X12// X17

S rt gn cui cng :



c. im N3:

X1= 0, 08 ; X2= 0, 092 ; X3= 0, 156

X5= 0,275 ; X6= X7= 0,195 ; X12= 0,163

Bin i tip ta c :

X6= X1 + X2 = 0,172

Bin i Y(X8 , X3 , X12) (X9 , X10)

Kt qu sau khi bin i : Ghp E2 vi E34 ta c :

Bin i Y(X5 , X9 , X11) thiu (X13,X14) S c rt gn tip l : Nhp E1 vi E34 :

Ta c s rt gn cui cng l :



d. im N5: Ta c s tnh im NM :



e. im N4: Theo nguyn l xp chng ta c dng NM ti N4 thi im t=0 l :


f. im N5 :

S thay th :

X1= 0, 08; X2= 0, 092 ; X3= 0, 156 ; X5= 0,275; X7= X8= X9= 0,195

X10= X11= 0,131; X12= 0,163 X14= X1 + X13= 0,08+0,046 = 0,126

S c rt gn li :

Bin i (X3 , X3 , X5) Y(X15 ,X16 ,X17)

X17 = X16= 0,073S cn li : Bin i Y(X14 , X12 , X15) thiu (X18,X19)

X20=X17+X7 = 0,073+0,195 = 0,268

Ghp E34 vi E2 :

Bin i Y(X18, X16, X21) thiu (X22,X23)

S rt gn cui cng :



g. im N6:

Theo nguyn l xp chng ta c dng NM ti N6 thi im t=0 l :


3.2. Phng n 2 : Chn cc im tnh ngn mch : tng t nh vi phng n 1

Chn cc i lng c bn : tng t

Scb = 100 MVA Ucb = Utbm Dng in c bn cp 10,5 kV : Icb1= 5,5 kA

Dng in c bn cp 110 kV : Icb2= 0,552 kA

Dng in c bn cp 220 kV : Icb3= 0,251 kA Tnh cc in khng cc phn t :

H thng v ng dy kp : X1 = XHT + Xd = 0,05 + 0,03 = 0,08 MF : X6 = X7 = X8 = X9 = XF = 0,195 MBA 2 dy qun : X10 = XB = 0,131

MBA t ngu :

Cun cao :

Cun trung :

Cun h :

Khng in :

Tnh ton dng NM :

a. im N1 :

Ta c s thay th :

Vi : X1= 0,08 ; X2= 0,0575 ; X3= 0,1025 ; X5= 0,132 ;

X6= X7=X8= X9= 0,195 ; X10= 0,131 ;

S trn i xng vi im NM ta s dng phng php gp i s :

X15 = X10 + X9 = 0,195 + 0,131 = 0,326

Bin i tip ta c :

X16 = X7 + X13 = 0,195 + 0,066 = 0,261

X17= X16// X14

X18 = X17 + X12 = 0,071 + 0,0513 = 0,122

X19= X18// X15

X20 = X19 + X11 = 0,089 + 0,02875 = 0,118

S rt gn cui cng :



b. im N2 :

Bin i s ging nh vi im N1 ta c : X11= 0, 02875 ; X12= 0, 0513 ; X13= 0,066

X14= 0, 0975 ; X15= 0,326 ; X16= 0,261

X17= 0, 071 ; X18 = 0,122

X19 = X1+ X11 = 0, 08 + 0,02875 = 0,10875S cn li l :

Bin i tip :

X20= X18// X15

S rt gn cui cng :



c. im N3 :

X1= 0, 08 ; X2= 0,0575 ; X3= 0,1025

X5= 0,132 ; X6= X7= X8= X9= 0,195 X10= 0,131

Bin i tip ta c :

X11= X1 + X2 = 0,08 + 0,0575 = 0,1375

X20= X9 + X10 = 0,195 + 0,131 = 0,326 Bin i (X7 , X5, X8) Y(X12 , X13 , X14)

Kt qu sau khi bin i : Ta c tip :

X15= X12 + X5 = 0,049 + 0,132 = 0,181

X16= X3 + X13 = 0,1025 + 0,049 = 0,1515

Bin i (X6 , X15, X14) Y(X17 , X18 , X19)

X21= X18 + X13+ X3 = 0,0294 + 0,049+0,1025 = 0,1809 S c rt gn tip l : Bin i Y(X11, X21, X20) thiu (X22,X23)

Ta c :

Ta c s l : Bin i tip :Y(X22, X17, X24) thiu (X25,X26)

Ta c s rt gn cui cng l :



d. im N5 :

Kt qu ging nh vi phng n 1 :

ixk= 71,79 kAe. im N4:

Theo nguyn l xp chng ta c dng NM ti N4 thi im t=0 l :


f. im N5 :

S thay th : X1= 0, 08; X2= 0,0575 ;

X3= 0,1025 ; X5= 0,132;

X6= X7= X8= X9= 0,195

X10= 0,131; X14= 0,073

X12= X13= 0,049 X15= X12 + X5 = 0,181

X16= X13 + X3 = 0,1515

X20= X9 + X10 = 0,326

S c rt gn li :

Bin i (X3 , X16 , X15) Y(X17 ,X18 ,X19)

X22 = X19 +X14=0,063 + 0,073 = 0,136

S cn li : Bin i Y(X18 , X21 , X20) thiu (X23,X24)

Ghp E34 vi E2 :

S :

Bin i Y(X17, X23, X25) thiu (X26,X27)

S rt gn cui cng :



g. im N6 : Theo nguyn l xp chng ta c dng NM ti N6 thi im t=0 l :


Bng tng kt tnh ton ngn mch ca cc phng n

Cp in p

kVim

ngn mchPhng n 1Phng n 2

I(kA)ixk(kA)I(kA)ixk(kA)

220N15,0412,885,2713,41

110N210,91327,7811,2828,6

10,5N342,71108,7254,74139,34

10,5N414,5136,9426,5467,56

10,5N528,271,7928,271,79

10,5N536,0691,852,24132,99

10,5N664,26163,5880,44204,77

Chng 4 : So snh kinh t k thut v

La chn phng n ti u4.1. Chn my ct v dao cch ly cho tng phng n :My ct in c chon theo cc iu kin sau :

in p nh mc : UmMC UmMng Dng in nh mc : ImMC Ilvbt iu kin n nh nhit : I2nh.tnh BN iu kin n nh lc in ng : idd ixk iu kin ct : Ict m I4.1.1. Phng n 1: Theo kt qu tnh ton dng cng bc v dng NM ti chng 2 v 3 ta chn my ct in cho phng n 1 c cc thng s nh sau :im

NMTn mchThng s tnh tonLoi

MC

Um

(kV)Icb

(kA)I

(kA)Ixk

(kA)Um

(kV)Im

(A)Ict

(kA)I

(kA)

N1Cao2200,4475,0412,883AQ-2245400050125

N2Trung1100,41310,91327,783AQ-1125400040100

N3H TN10,54,81142,71108,728FG-10121250080225

N4Khng P10,51,8714,5136,948FG-10121250080225

N5MF10,54,3336,0691,88FG-10121250080225

N6T dng10,50,31864,26163,588FG-10121250080225

Trong : Icb ti N6 c xc nh khi ph ti t dng max :

4.1.2. Phng n 2 :Tng t ta c :im

NMTn mchThng s tnh tonLoi

MC

Um

(kV)Icb

(kA)I

(kA)Ixk

(kA)Um

(kV)Im

(A)Ict

(kA)I

(kA)

N1Cao2200,4475,2713,413AQ-2245400050125

N2Trung1100,41311,2828,63AQ-1125400040100

N3H TN10,57,754,74139,348FG-10121250080225

N4Khng P10,54,42126,5467,568FG-10121250080225

N5MF10,54,12452,24132,998FG-10121250080225

N6T dng10,50,31880,44204,778FG-10121250080225

4.2. La chn s thit b phn phi :4.2.1. Phng n 1 : Pha 220 kV : S mch vo l : 2 mch .

S mch ra l : 2 mch .

Tng s mch vo ra l 4 mch nn ta dng s h thng 2 TG

Pha 110 kV : S mch vo l : 4 mch .


Tng s mch vo ra l 6 mch nn ta dng s h thng 2 TG c TG vng

Pha 10,5 kV :

Ta dng TG in p MF v ph ti in p MF chim qu 15% cng sut ca b.

4.2.2. Phng n 2: Tng t nh vy : Pha 220 kV :

S mch vo l : 2 mch .


Tng s mch vo ra l 4 mch nn ta dng s h thng 2 TG

Pha 110 kV :

S mch vo l : 3 mch .


Tng s mch vo ra l 5 mch nn ta dng s h thng 2 TG c TG vng

Pha 10,5 kV :

Ta dng TG in p MF v ph ti in p MF chim qu 15% cng sut ca b.

4.3. Tnh ton kinh t k thut :4.3.1. Tnh vn u t thit b :

Ta xc mh theo cng thc sau :

Vi = VBi + VTBPPi

Trong :

VB : vn u t mua MBA .c xc nh theo biu thc :

VB = kB*vB kB : h s tnh n tin chuyn ch v xy lp MBA.H s ny ph thuc

vo in p nh mc cun cao p v cng sut nh mc MBA

vB : tin mua MBA

VTBPPi : Vn u t xy dng thit b phn phi . c xc nh nh sau :

VTBPP = n1* VTBPP1 + n2* VTBPP2 + nn* VTBPPn

n1 , n2 : s mch ca thit b phn phi ng vi cc cp in p

VTBPP1 ,VTBPP2 : Gi mi mch ca thit b phn phi tng ng vi cc

cp in p .Bao gm c tin mua , chuyn ch v xy lp.a) Phng n 1 :

Vn u t cho phng n 1 :VI = VB + VTBPP u t MBA :

MBA 3 pha 2 dy qun TPH-80 115/10,5 gi : 3,2.109 ng/my ; vi kB = 1,5

MBA t ngu ATTH-125 220/110 gi : 6,5.109 ng/my ; vi kB = 1,4

Tng vn u t cho MBA l :

VB = 2*1,4*6,5*109 +2*1,5*3,2*109 = 27,8.109 ng u t thit b phn phi :

Ta thy s ni in chnh ca 2 phng n la tng t nhau ch khc nhau v s lng my ct .V th khi tnh ton vn u t cho thit b phn phi ta ch tnh n gi ca cc my ct in .

Cp 220 kV : Gm 5 mch my ct mi mch l : 2,856.109 ng/mch. Cp 110 kV: Gm 6 mch my ct mi mch l : 1,4.109 ng/mch.

Cp 10,5 kV : Gm 5 mch my ct mi mch l : 0,84.109 ng/mch.


VTBPP = 5*2,856*109 +6*1,4*109 +5*0,84*109 = 26,88.109 ng Vy tng vn u t cho phng n 1 l :

VI = VB + VTBPP = 27,8.109 + 26,88.109 =54,68.109 ngb) Phng n 2:

Vn u t cho phng n 2 : VII = VB + VTBPP u t MBA :

MBA 3 pha 2 dy qun TPH-80 115/10,5 gi : 3,2.109 ng/my ; vi kB = 1,5

MBA t ngu ATTH-200 220/110 gi : 9.109 ng/my ; vi kB = 1,4


VB = 2*1,4*9*109 +1*1,5*3,2*109 = 30.109 ng u t thit b phn phi :

Cp 220 kV : Gm 5 mch my ct mi mch l : 2,856.109 ng/mch. Cp 110 kV: Gm 5 mch my ct mi mch l : 1,4.109 ng/mch.

Cp 10,5 kV : Gm 7 mch my ct mi mch l : 0,84.109 ng/mch.


VTBPP = 5*2,856*109 +5*1,4*109 +7*0,84*109 = 27,16.109 ng Vy tng vn u t cho phng n 2 l :

VII = VB + VTBPP = 30.109 + 27,16.109 =57,16.109 ng4.3.2. Ph tn vn hnh hng nm :Ph tn vn hnh hng nm ca mi phng n c xc nh nh sau :

P = Pk + Pp + Pt

Trong :

Pk :tin khu hao v vn u t v xa cha ln ,[ng/nm]

Vi : V: vn u t 1 phng n

a: nh mc khu hao %, tra bng ta c a = 8,4%

Pp : chi ph phc v thit b (xa cha thng xuyn v lng cng nhn).

Phn chi ph ny kh nh ng thi cng khc nhau rt t gia cc

phng n.Do vy ta c th b qua khi so snh kinh t.

Pt : chi ph do tn tht in nng hng nm trong cc thit b in.

Pt = *A

Vi : : gi thnh tin in nng tn tht ; = 500 ng/kWh

A :tn tht hng nm trong thit b in ; [kWh]

a. Phng n 1 :

Khu hao hng nm :

ng

Chi ph do tn tht in nng hng nm :

Pt1 = *A1 = 500*8421,28*103 = 4,21.109 ng

Chi ph vn hnh hng nm ca phng n 1 :

PI = Pk1 + Pt1 = 4,59.109 + 4,21.109 = 8,8.109 ngb. Phng n 2 :

Khu hao hng nm :

ng

Chi ph do tn tht in nng hng nm :

Pt1 = *A1 = 500*6607,49*102 = 3,3.109 ng

Chi ph vn hnh hng nm ca phng n 2 :

PII = Pk2 + Pt2 = 4,8.109 + 3,3.109 = 8,1.109 ng4.3.3. So snh chn phng n ti u :

Ta c bng tng kt v kinh t ca 2 phng n nh sau : Phng nVn u t (x109ng)Chi ph vn hnh (x109ng)

154,688,8

257,168,1

V hai phng n c tin cy cung cp in nh nhau m : V1< V2 v P1>P2 nn ta tnh thi gian thu hi vn du t chnh lch :

nm < 8 nm

Ta thy T= 3,54 nm cho nn phng n hp l v mt kinh t l phng n c vn u t ln tc l phng n 2.

Vy phng n 2 l phng n ti u .Chng 5 : chn kh c in v dy dn

5.1. Chn thanh dn cng :

5.1.1. Chn thit b theo dng cho php lu di :

Dng cho php lu di ca thanh dn Icp phi ln hn dng cng bc qua n.

Icb Icp

Icp : l gi tr dng cho php lu di c hiu chnh theo nhit Thanh dn cng y dng ni t cc MF n MBA

Ta tnh c dng cng bc trong chng 3 :

Tra ti liu Thit k nh my in ta chn thanh dn hnh mng bng ng

c cc thng s sau :

h = 125 cm b = 55 cm c = 6,5 cm r = 10 cm

Tit din cc l : 1370 mm2

Momen tr khng : Wxx = 50 cm2 Wyy = 9,5 cm2 Wyoyo = 100 cm2 Dng in cho php : 5500 A Hiu chnh dng in cho php theo nhit mi trng MT = 250C ; nhit

mi trng xung quanh ni t thanh dn l xq = 350C ; nhit cho php vn hnh lu di ca thanh dn cp = 700C :

Vy dng cho php hiu chnh theo nhit l :

Ihccp = khc*Icp = 0,88*5500 = 4840 > icb = 4330 A

Tho mn iu kin 5.1.2. Kim tra n nh nhit khi ngn mch :

V thanh dn chn c Icp = 5500 A > 1000 A nn ta khng cn kim tra iu kin n nh nhit .5.1.3. Kim tra n nh ng :

iu kin kim tra n nh ng :

tt cp

cp : ng sut cho php ca thanh dn.Vi thanh dn ng ta c cp = 1400Kg/cm2 Xc nh ng sut do dng NM gia cc pha

Lc tnh ton Ftt tc dng ln thanh dn cc pha :

ixk : Dng NM xung kch (ti N5 ixk = 71,79 kA) L : khong cch gia 2 s lin nhau

a : khong cch gia cc pha

Vi cp in p 10,5 kV ly : L= 180 cm ; a = 45 cm

Mmen un M :

ng sut tnh ton trong vt liu thanh dn

Ta thy tt = 65,3 Kg/cm2 < cp = 1400 Kg/cm2 5.2. Chn thanh dn mm :

5.2.1. Mch in p 220kV :

iu kin : Icp Ilvcb

Tra bng : chn dy nhm li thp AC-240 vi

Icp = 610 A ; d = 21,6 mm Hiu chnh dng in theo nhit mi trng vi Khc = 0,88

IhcCP = 0,88*610 = 536,8 A > Icb = 450 A Kim tra iu kin vng quang :

Uvq Um = 220 kV

Uvq : in p ti hn pht sinh vng quang

Dy dn t trn mt phng nm ngang ta c :

m : h s xt ti b mt nhn ca dy dn , m = 0,85

r : bn knh ngoi ca dy dn r = 21,6/ 2 =10,8 mm = 1,08 cm

a: khong cch gia cc trc dy dn a= 500 cm

Kim tra iu kin n nh nhit :

Xung lng nhit khi ngn mch c xc nh theo biu thc :

Mt cch gn ng ta ly it l gi tr hiu dng tc thi ca dng ngn mch :

Ickt : Gi tr hiu dng tc thi dng NM thnh phn chu k

ikckt : Gi tr tc thi dng NM thnh phn khng chu k

BN = BNCK + BNKCK

BNCK : Xung lng nhit dng NM chu k

BNKCK : Xung lng nhit dng NM khng chu k

Xc nh BNCK dng phng php gii tch th : tm gi tr hiu dng dng NM thnh phn chu k ti cc thi im khc nhau : 0; 0,1; 0,2; 0,5;1s l cc gi tr I0 , I0,1 , I0,2, I0,5 , I1 .n thi im t Biu din trn th ta c din tch gii hn ca ng cong ny vi cc trc to chnh l BNCK . Mt cch gn ng din tch ny c th xc nh theo ng bc thang ho :

t : khong chia thi gian t khi NM cho n khi ct xong NM

Ti phn tnh NM im N1 ta c s :

Nhnh h thng : X1 = 0,08

Tra ng cong tnh ton ta c :

I0 = 0,64 I0,1 = 0,54 I0,2 = 0,515 I0,5 = 0,48 I1 = 0,478

Chuyn sang n v c tn :

Nhnh MF :


I0 = 2,8 I0,1 = 2,71 I0,2 = 2,6 I0,5 =2,5 I1 = 2,41


Vy dng NM ti im N1 do h thng c nh my cung cp :

I0N1= 3,21 + 2,11 = 5,32 kA I0,1N1= 2,71 + 2,03 = 4,74 kA I0,2N1=2,59 + 1,96 = 4,55 kA

I0,5N1= 2,4 + 1,88 = 4,28 kA

I1N1= 2,39 + 1,81 = 4,2 kA

Bnh phng cc tr s dng in :

I02N1= 5,322 = 28,3 kA2

I0,12N1= 4,742 = 22,47 kA2 I0,22N1= 4,552 = 20,7 kA2 I0,52N1= 4,282 = 18,32 kA2 I12N1= 4,22 = 17,64 kA2Cc tr s trung bnh bnh phng :

Xung lng nhit thnh phn chu k :

= 25,39*0,1 + 21,59*0,1 + 19,51*0,3 + 17,98*0,5 = 19,54.106 A2.s

Xung lng nhit ca dng in NM thnh phn khng chu k :

BNKCK = I. Ta

Ta : Hng s thi gian tng ng ca li . U 1 kV th Ta = 0,05s

BNKCK = 0,05*(5,27.103)2 =1,39.106 A2.s

Vy ta c xung lng nhit ton phn :

BN = BNCK + BNKCK = 19,54.106 + 1,39.106 =20,93.106 A2.s

m bo n nh nhit th dy dn chn phi c tit din nh nht l :

vi dy nhm li thp C = 88 A.s0,5/mm2

M ta chn dy AC-240 nn tho mn .5.2.2. Chn thanh cho cp 110 kV :a. iu kin pht nng lu di : Dng in cng bc : Icb = 0,413 kV Dy dn chn phi tho iu kin :

Ta chn dy AC-240 c Icp = 610 v ng knh dy : d = 21,6 mm Hiu chnh dng in theo nhit mi trng vi Khc = 0,88 Icphc = 0,88*610 = 536,8 A > 470 A tho mn iu kin pht nng cho php b. iu kin vng quang : Uvq Um Vi :

Uvq = 205,5 kV Um = 110 kV iu kin vng quang c tho mnc. iu kin n nh nhit : Xt tng t nh cp 220 kV

S thay th tnh ton NM ti im N2 :

Nhnh h thng : X19 = 0,10875


I0 = 0,465 I0,1 = 0,392 I0,2 = 0,36 I0,5 = 0,338 I1 = 0,31


Nhnh MF :


I0 = 4,3 I0,1 = 3,6 I0,2 = 3,2 I0,5 =2,8 I1 = 2,5


Vy dng NM ti im N1 do h thng c nh my cung cp :

I0N1= 4,67 + 6,48 = 11,15 kA I0,1N1= 3,94 + 5,42 = 9,36 kA

I0,2N1=3,62 + 4,82 = 8,44 kA

I0,5N1= 3,39 + 4,22 = 7,61 kA

I1N1= 3,11 + 3,77 = 6,88 kA

Bnh phng cc tr s dng in :

I02N1= 11,152 = 124,32 kA2

I0,12N1= 9,362 = 87,61 kA2 I0,22N1= 8,442 = 71,23 kA2 I0,52N1= 7,612 = 57,91 kA2 I12N1= 6,882 = 47,33 kA2Cc tr s trung bnh bnh phng :

Xung lng nhit thnh phn chu k :

= 105,97*0,1 + 79,42*0,1 + 64,57*0,3 + 52,62*0,5

= 64,22.106 A2.s

Xung lng nhit ca dng in NM thnh phn khng chu k :

BNKCK = I. Ta

Ta : Hng s thi gian tng ng ca li . U 1 kV th Ta = 0,05s

BNKCK = 0,05*(11,24.103)2 =6,32.106 A2.s

Vy ta c xung lng nhit ton phn :

BN = BNCK + BNKCK = 64,22.106 + 6,32.106 =70,54.106 A2.s

m bo n nh nhit th dy dn chn phi c tit din nh nht l :

vi dy nhm li thp C = 88 A.s0,5/mm2

M ta chn dy AC-240 nn tho mn .5.2.3. Chn s cho thanh dn : Loi s trong nh.

Ums Um mng = 10 kV

Ta chn loi s : 10-2000KPY3 c :

Um = 10 kV Fph = 2000 kg H = 235 mm = 23,5 cm

Kim tra n nh ng :

iu kin : Ftt < 0,6.Fph vi :

Ftt = 362,83 Kg h= 10 cm (chiu cao thanh dn)

H = H + h/2 = 23,5 + 5 = 28,5 cm

Ftt = 440,02 Kg < 0,6.Fph = 1200 Kg s chn t yu cu .5.2.4. Chn chng st van : Chng st van c dng gim qu in p ti mc in p d ca n m cch in ca thit b in c th chu c . Ta phi chn CSV cho cc TG v cc mch pha 110 kV v 220 kV cng nh trung tnh MBA . Ta chn cc loi CSV sau : FP 220

FP - 1105.2.5. Chon cp cho ph ti 10,5 kV : Ph ti cp in p 10,5kV bao gm : 4 kp P = 3MW ; cos = 0,85

4 n P = 2 MW ; cos = 0,85

Tit din ca khng c chn theo tiu chun mt dng in kinh t Jkt

Vi Ilvbt : l dng lm vic bnh thng

Chn tit din cp n : S = 2,35 MVADng in lm vic bnh thng l :

T th ph ti a phng ta tnh c thi gian s dng cng sut cc i :

Vi Tmax = 7226,5h ta c JKT = 2A/mm2Vy tit din cp l :

Ta chn loi cp 3 li bng ng v nhm cch in bng giy tm du nha thng v cht do khng chy , v ch :

F= 70mm2 Um = 10,5 kV Icp = 165 A

Kim tra cp theo iu kin pht nng lu di :

K1.K2.Icp Ilvbt Trong : K1 : h s hiu chnh theo nhit

cp : nhit pht nng cho php cp = 600C

0 : nhit thc t ni t cp 0 = 250C

0 : nhit tnh ton tiu chun 0 = 150C

K2 : h s hiu chnh theo s cp t song song vi cp n (chn bng 1)

0,88*1*165=145,2 > Ilvbt = 129

Vy cp chn tho mn iu kin pht nng cho php lu di. Chn tit din cp kp : Dng in lm vic bnh thng qua mi cp l :

Vi JKT = 2A/mm2 ta chn c tit din cp :

Ta chn loi cp 3 li bng ng v nhm cch in bng giy tm du nha thng v cht do khng chy , v ch :

F = 70mm2 Um = 10,5 kV Icp = 165 A

Kim tra cp theo iu kin pht nng lu di tng t nh trn .

K1.K2.Icp Ilvbt K2= 0,9 (do 2 cp t song song) 0,88*0,9*165=130,68 > Ilvbt = 97,5

Vy cp chn tho mn iu kin pht nng cho php lu di.

Kim tra cp theo iu kin pht nng lu di :

Khi lm vic bnh thng :

Nh vy khi lm vic bnh thng cp lm vic non ti .V th khi s c cho php cp lm vic qu ti 30% trong 5 ngy m.

Isc = kqt*Icb = 1,3*130,86 = 170,12 A < Icb = 194,1 A

Khng tho mn nn ta phi chn tit din cp tng ln 1 cp

Chn cp : F = 95 mm2 Um = 10 kV Icp = 200 A Icp = 0,88*0,9*200 = 158,4 A

Isc = 1,3*158,4 =205,92 A > Icb = 194,1 A

Vy cp F = 95 mm2 l tho mn. Chn khng in : Xc nh dng cng bc qua khng :Dng cng bc qua khng c gi thit khi s c 1 khng in. Lc cng

sut qua cc khng cho bi bng sau :

Cng sut qua khng (MVA)Khng 1Khng 2Khng 3

Bnh thng5,8811,765,88

S c khng 1015,295,88

S c khng 29,4109,41

Dng cng bc qua khng :

Tra bng ta chn loi khng kp loi PbAC -2(1000 c Imk = 1000A. Xc nh XK% ca khng :

Xk% c chn xut pht t hai iu kin sau:

Xk% phi hn ch dng ngn mch ti N5 chn my ct 1 v m bo n nh nhit cho cp 1 tc l:

IN5 ( min{ Ic1m, Inhc1}.

Xk% phi hn ch dng ngn mch ti N6 chn my ct 2 v m bo n nh nhit cho cp 2 tc l:

IN6 ( min{ Ic2m, Inhc2}.

Trong chng 3 ta tnh c dng NM ti im N6 : IN6 = 80,44 kA

in khng ca h thng tnh n im NM N6 l :

in khng ca cp 1 l :

Trong :

X0 : in khng n v ca cp . Vi cp S=95 mm2 chn ta c X0 = 0,083 /km

l : chiu di ca cp

Thay s vo ta c :

Dng n nh nhit ca cp 1 l :

S1 : tit din cp S1 = 95 mm2

C1 : h s cp ng C = 90 A.s1/2/s

t1 : thi gian ct ca MC1

t1 = t2 +t = 0,7 + 0,2 = 0,9 sec

Dng n nh nhit ca cp 2 :

Ta la chn cc MC du cho ng dy .Cc MC c chn cng loi , dng cng bc qua MC c tnh ton cho ng dy kp khi 1 ng dy b s c.

Theo tnh ton trn ta c : Icb = 194,1 A

Chn MC Kim tra khng va chn :

5.2.6. Chn thit b o lng :a. Chn my bin in p BU :

Chn BU cho cp in p 10,5 kV : S ni dy v kiu ni dy phi chn ph hp vi nhim v ca n. cp cho cng t ta dng 2 BU mt pha ni V/V ; kim tra cch in trn thanh gp 10,5 kV ta dng loi my bin in p 3 pha 5 tr Y0/Y0/ .

iu kin :

UmBU = Umng Cp chnh xc : chn ph hp vi nhim v ca BU

Cng sut nh mc tng ph ti ni vo bin in p cng sut nh mc ca bin in p vi cp chnh xc chn. S2 SmBU Chn dy dn ni gia BU v cc dng c o :

Tit din dy c chn sao cho tn tht in p khng qu 0,5%Um th cp khi c cng t v 3% khi khng c cng t.

Theo iu kin bn c tit din ti thiu l 1,5 mm2 ddoois vi dy ng v 2,5 mm2 vi dy nhm.

Cn c vo cc iu kin trn v s b tr thit b o lng ta chn BU

Chn dy ni t BU n cc ng h o :

Chn BU cho cp in p 110 kV v 220 kV :

b. Chn my bin dng in BI :

My bin dng in c chn theo cc iu kin sau :

S ni dy v kiu my : ph thuc vo nhim v ca BI v v tr t UmBI Umng ImBI Icb Cp chnh xc chn ph hp vi yu cu ca dng c o Ph ti th cp tng ng vi mi cp chnh xc c 1 ph ti nh mc Z2 = Zdc + Zdd ZmBI Trong : Zdc tng tr cc dng c o

Zdd tng tr ca dy dn ni t BI n cc dng c o

Chn BI cho cp in p MF 10,5 kV : Chn BI cho cp in p 110 v 220 kV : Vi cp 110 kV : Icb = 0,413 kA

Vi cp 110 kV : Icb = 0,447 kA

Ta chn BI c thng s sau :

Umng

(kV)Loi

BIUm(kV)Bi s n nh ngBi s n nh nhitIm (A)Cp CXPh ti

()Iidd(kA)Inh/

tnh

S cpTh cp

110TH_110M11015043,3/360050,51,2145

220TH_220T2207560/160050,51,25420,4

Chng 6 : chn s ni in v thit b t dng

in t dng l mt phn in nng khng ln nhng li d mt phn quan trng trong qu trnh vn hnh nh my in.

in t dng nh my in c th chia lm hai phn:

( Mt phn cung cp cho cc my cng tc m bo ca cc l v cc tuabin ca cc t my.

( Phn kia cung cp cho cc my cng tc phc v chung, khng lin quan trc tip n l hi v cc tuabin nhng li cn thit cho s lm vic ca nh my.

Ta chn s t dng theo nguyn tc kinh t v m bo cung cp in lin tc.

i vi nh my in thit k dng hai cp in p t dng 6kv v 0.4kv ni theo s bin p ni tip, vi mt bin p d tr ly in t pha cun h v pha trn my pht.

6.1. Chn MBA t dng cp 1 : Cc MBA t dng cp 1 c nhim v nhn in t thanh gp 10,5 kV cung cp cho cc ph ti t dng cp in p 6 kV, cn li cung cp tip cho ph ti cp in p 0,4 kV. T cng sut ca chng cn phi chn ph hp vi ph ti cc i ca cc ng c cp in p 6 kV v tng cng sut ca cc MBA cp 2 ni tip vi n .

Trong :

SBm cng sut nh mc ca MBA cng tc bc mt , kVA

K1 h s ng thi c tnh n s khng y ti ca cc my cng tc ca c 6 kV

P1 tng cng sut tnh ton ca cc my cng tc vi ng c 6 kV ni vo phn on xt , kW

1 v cos hiu sut v h s cng sut ca ng c 6 kV S2 tng cng sut nh mc ca MBA bc 2 ni vo phn on xt

K2 h s ng thi ca nhm MBA bc 2.

T s : K1/1*cos lc lm vic bnh thng chim khong 0,9 ; K2 cng gn bng 0,9 . Do cng thc trn c th vit li nh sau :

SBm (P1 + S2)*0,9

Ta s chn MBA t dng cp 1 theo cng sut t dng theo cng sut t dng cc i ca nh my : Stdmax = 23,53 MVA

Cng sut ca MBA t dng cp 1 c chn l :

Tra bng ta chn MBA TMHC 6300/10,5 vi :

Sm = 6300 kVA UCm= 10,5 kV UHm = 6,3 kV P0 = 8 kW

PN = 46,5 kW UN% = 8% I0% = 0,9 % 6.2. Chn MBA d tr cp 1 :

Cng sut ca MBA d tr cp 1 c chn ph hp vi mc ch ca chng .Do nh my c TG in p my pht nn MBA d tr ch lm chc nng thay th cho cc MBA khc khi sa cha vy MBA ny c chn cng loi vi MBA cp 1 nh trn.6.3. Chn MBA t dng cp 2 :

Cc MBA t dng cp 2 dng cung cp in cho cc ph ti cp in p 380/220 V v chiu sng .Cng sut ca cc loi ph ti ny thng nh nn cc MBA cng sut 630 kVA v 1000 kVA c s dng ph bin . Cng sut ca MBA t dng cp 2 c chn nh sau :

Tra bng ta chn loi MBA TC3C-1000/10 vi :

Sm = 1000 kVA UCm = 6,3 kV UHm = 0,4 kV P0 = 3 kW

PN = 12 kW UN% = 8% I0% = 2 % 6.4. Chn my ct pha mch 6,3 kV :

Tnh ton dng NM ti TG phn on 6,3 kV chn MC Theo kt qu tnh ton NM ti chng 3 ta c : IN6=80,44 kV

in khng h thng tnh n im N6 l :

in khng ca MBA cp 1 :

X = XHT + XB1 = 0,068 + 1,27 = 1,338

Dng NM siu qu thnh phn chu k ti N7 l :

T ta chn MC 8FG-10 c cc thng s :

Um = 7,2 kV Im = 12500 A Icm = 80 kA Iidd = 225 kV6.5. Chn tmt cho ph ti t dng cp 0,4 kV :

ptmt c chn theo cc iu kin : Um Ummng = 0,4 kV

Im Ilvmax Ict m IN

chn dng ct nh mc ca Aptomat ta tnh NM ti thanh ci 0,4 kV , lc ny c th coi MBA t dng cp 2 l ngun d phng cho im NM .

Ta c s thay th :

ZB = 1,92 +j 12,8 m

Dng NM ti N8 l :

T ta chn c loi : M12 vi

Um=690 V Im=1250 A s cc : 3-4 Ict N = 40 kA

N

- th cng sut t dng ca nh my-

- th ph ti ton nh my-

- th ph ti cp in p trung-

- th ph ti cp in p my pht-

PAGE 50Trng i Hc Bch Khoa H Ni

_1190132279.unknown

_1191219846.unknown

_1191323627.unknown

_1191669638.unknown

_1191670683.unknown

_1191671188.unknown

_1191671578.unknown

_1191689085.unknown

_1191689307.unknown

_1191689317.unknown

_1191689101.unknown

_1191671771.unknown

_1191671783.unknown

_1191671923.unknown

_1191671700.unknown

_1191671337.unknown

_1191671369.unknown

_1191671210.unknown

_1191670777.unknown

_1191671141.unknown

_1191670761.unknown

_1191670488.unknown

_1191670615.unknown

_1191670670.unknown

_1191670595.unknown

_1191670150.unknown

_1191670169.unknown

_1191669783.unknown

_1191413344.unknown

_1191582259.unknown

_1191605430.unknown

_1191605827.unknown

_1191606646.unknown

_1191606747.unknown

_1191606314.unknown

_1191605591.unknown

_1191605092.unknown

_1191605138.unknown

_1191583228.unknown

_1191517294.unknown

_1191518727.unknown

_1191518917.unknown

_1191518383.unknown

_1191414860.unknown

_1191516736.unknown

_1191414547.unknown

_1191414000.unknown

_1191324216.unknown

_1191324496.unknown

_1191413162.unknown

_1191324293.unknown

_1191323681.unknown

_1191324150.unknown

_1191323834.unknown

_1191323650.unknown

_1191257717.unknown

_1191322677.unknown

_1191322949.unknown

_1191323111.unknown

_1191323600.unknown

_1191322981.unknown

_1191322877.unknown

_1191322906.unknown

_1191322692.unknown

_1191322428.unknown

_1191322638.unknown

_1191322660.unknown

_1191322511.unknown

_1191322562.unknown

_1191322607.unknown

_1191322537.unknown

_1191322485.unknown

_1191264713.unknown

_1191265903.unknown

_1191266280.unknown

_1191266567.unknown

_1191265532.unknown

_1191264718.unknown

_1191258397.unknown

_1191258405.unknown

_1191258186.unknown

_1191255935.unknown

_1191256814.unknown

_1191256869.unknown

_1191256926.unknown

_1191256841.unknown

_1191256717.unknown

_1191256780.unknown

_1191256300.unknown

_1191219885.unknown

_1191221686.unknown

_1191254722.unknown

_1191255375.unknown

_1191255896.unknown

_1191220857.unknown

_1191219864.unknown

_1191219875.unknown

_1191219855.unknown

_1191065003.unknown

_1191170929.unknown

_1191171679.unknown

_1191172476.unknown

_1191172826.unknown

_1191173863.unknown

_1191172385.unknown

_1191171594.unknown

_1191171613.unknown

_1191171260.unknown

_1191067838.unknown

_1191169812.unknown

_1191170322.unknown

_1191067953.unknown

_1191068096.unknown

_1191067939.unknown

_1191067109.unknown

_1191067239.unknown

_1191065160.unknown

_1190220101.unknown

_1190221419.unknown

_1190222153.unknown

_1190807470.unknown

_1190957854.unknown

_1190978445.unknown

_1191003547.unknown

_1191004260.unknown

_1190978918.unknown

_1190958355.unknown

_1190957150.unknown

_1190806991.unknown

_1190807044.unknown

_1190222215.unknown

_1190805739.unknown

_1190222192.unknown

_1190221917.unknown

_1190222110.unknown

_1190221739.unknown

_1190220802.unknown

_1190221041.unknown

_1190221081.unknown

_1190220932.unknown

_1190220597.unknown

_1190220663.unknown

_1190220434.unknown

_1190200687.unknown

_1190201744.unknown

_1190219751.unknown

_1190201428.unknown

_1190201602.unknown

_1190199263.unknown

_1190199317.unknown

_1190200122.unknown

_1190200277.unknown

_1190199298.unknown

_1190134195.unknown

_1190134214.unknown

_1190133549.unknown

_1190134148.unknown

_1190132280.unknown

_1189527921.unknown

_1189968561.unknown

_1190054793.unknown

_1190131776.unknown

_1190132098.unknown

_1190132121.unknown

_1190131828.unknown

_1190130743.unknown

_1190130972.unknown

_1190130661.unknown

_1189969746.unknown

_1190053139.unknown

_1190054649.unknown

_1189969912.unknown

_1189969605.unknown

_1189969614.unknown

_1189969293.unknown

_1189796225.unknown

_1189854502.unknown

_1189968190.unknown

_1189968399.unknown

_1189855409.unknown

_1189853774.unknown

_1189854343.unknown

_1189796242.unknown

_1189790527.unknown

_1189790615.unknown

_1189795815.unknown

_1189796196.unknown

_1189790536.unknown

_1189790315.unknown

_1189790388.unknown

_1189790305.unknown

_1188384877.unknown

_1188386553.unknown

_1188387330.unknown

_1189443509.unknown

_1189443602.unknown

_1189445056.unknown

_1189445218.unknown

_1189450128.unknown

_1189451302.unknown

_1189451606.unknown

_1189450508.unknown

_1189445278.unknown

_1189445177.unknown

_1189443954.unknown

_1189444376.unknown

_1189443740.unknown

_1189357955.unknown

_1189358237.unknown

_1188838810.unknown

_1189357654.unknown

_1189357852.unknown

_1188758269.unknown

_1188387280.unknown

_1188387311.unknown

_1188387255.unknown

_1188384896.unknown

_1188384985.unknown

_1188385442.unknown

_1188384898.unknown

_1188384893.unknown

_1188148188.unknown

_1188327051.unknown

_1188384490.unknown

_1188384750.unknown

_1188384770.unknown

_1188384693.unknown

_1188234055.unknown

_1188234843.unknown

_1188326989.unknown

_1188151466.unknown

_1187457882.unknown

_1187463010.unknown

_1187631790.unknown

_1188064582.unknown

_1187462821.unknown

_1080801707.unknown

_1187456281.unknown

_1080801702.unknown

_976666008.unknown

Documents

Đồ án nhà máy điện - Đại học Bách Khoa Hà Nội