đồ án nhà máy điện

1

LI NI U

in nng l mt dng nng lng ph bin v c tm quan trng khng th thiu c trong bt k mt lnh vc no ca nn kinh t quc dn ca mi t nc. Vi tc tng trng ngnh in trung bnh hng nm khong 15%, vn t ra cho chng ta l sn xut ra c in nng cung cp in cho cc ph ti mt cch hiu qu, tin cy. V vy, nhn v phng din quc gia th vic m bo cung cp in mt cch lin tc v tin cy cho ngnh cng nghip tc l m bo cho nn kinh t ca quc gia pht trin lin tc v kp vi s pht trin ca nn khoa hc cng ngh th gii.

Trong h thng in cc nh my in c nhimv bin i nng lng s cp nh: than, du, kh t, thu nng ... thnh in nng.Hin nay nc ta lng in nng c sn xut hng nm bi cc nh my nhitin khng cn chim t trng ln nh thp k 80. Tuy nhin, vi th mnh ngunnguyn liu nh nc ta, tnh cht ph ti y ca nh my nhit in th viccng c v xy dng mi cc nh my nhit in vn ang l mt nhu cu i vigiai on pht trin hin nay.

Xut pht t cc yu cu thc tin , vi cc kin thc c hc em nhn ti thit k phn in nh my in. n tt nghip thit k phn in nh my in l mt c hi mi sinh vin n luyn, trau di kin thc chuyn ngnh, phc v hu ch cho cng vic thc t sau ny. Trong n ny em thc hin cc nhim v: chn my pht in v cn bng cng sut, sut cc phng n v chon my bin p, tnh ton dng in ngn mch v la chn thit b chnh ca nh my, so snh chn phng n ti u, chn kh c in v dy dn, chn s ni in v thit b t dng.

n thit k gm c:

- Phn I: Thit k phn in nh my nhit in cng sut 130 MW

Mc d rt c gng song kin thc v kinh nghim bn thn cn hn ch nn bn n thit k tt nghip ca em kh trnh khi nhng thiu st, em rt mong nhn c s thng cm v ng gp kin t pha thy c.

Em xin chn thnh cm n thy cng cc thy c gio khc trong b mn in - in t nhit tnh hng dn em c th hon thnh n ny.

Hng Yn, thng nm 2015

Sinh vin thc hin

2

MC LC

LI NI U ................................................................................................................................ 1

MC LC ...................................................................................................................................... 2

PHN I ........................................................................................................................................... 4

THIT K PHN IN NH MY NHIT IN ................................................................. 4

CHNG 1:CHN MY PHT IN-TNH TON PH TI -CN BNG CNG SUT .............................................................................................................................................. 4

1.1. Chn my pht in. ......................................................................................................... 4

1.2. Tnh ton ph ti v cn bng cng sut ........................................................................... 4

1.2.1. th ph ti nh my .............................................................................................. 4

1.2.2. th ph ti t dng ca nh my. .......................................................................... 5

1.2.3. th ph ti a phng (10kV) ............................................................................. 6

1.2.4. th ph ti trung p (110kV) ................................................................................ 6

1.2.5. Cng sut pht v h thng (VHT) ............................................................................ 7

CHNG 2: XUT CC PHNG N V CHN MY BIN P ............................. 9

2.1. xut cc phng n ni dy. ........................................................................................ 9

2.1.1. Phng n ................................................................................................................ 10

2.2. Tnh ton chn my bin p. ........................................................................................ 10

CHNG 3: TNH TON NGN MCH .............................................................................. 17

3.1. Tnh in khng cc phn t trong s . .................................................................. 17

3.2. Xc nh im ngn mch tnh ton. .......................................................................... 18

3.2.1. im ngn mch N-1 ............................................................................................. 19

3.2.2. im ngn mch N-2 ............................................................................................. 21

3.2.3. im ngn mch N-3 ............................................................................................. 23

3.2.4. im ngn mch N-4 ............................................................................................. 26

3.2.5. im ngn mch N-5 ............................................................................................. 27

CHNG 4: TNH TON KINH T - K THUT CHN PHNG N TI U ........ 28

4.1. La chn s thit b phn phi (TBPP) ................................................................. 28

4.1.1. Phng n : ............................................................................................................ 28

4.2. Chn my ct in cho cc mch. ............................................................................... 29

CHNG 5: CHN KH C IN V DY DN ............................................................... 31

5.1. Chn thanh dn cng u cc my pht .................................................................... 31

5.1.1. Chn loi v tit din thanh dn .......................................................................... 31

5.1.2. Kim tra n nh ng .......................................................................................... 32

5.2. Chn s cho thanh dn cng .................................................................................. 34

5.3. Chn thanh gp v thanh dn mm ............................................................................ 36

3

5.3.1. Chn thanh dn mm lm thanh gp cp in p 220kV .................................. 36

5.3.2. Chn thanh dn mm lm thanh gp cp in p 110kV .................................. 36

5.4. Chn dao cch ly trong mch in chnh ................................................................... 37

5.5. Chn my bin dng in (BI) v my bin in p(BU) ......................................... 38

5.5.1. Chn my bin in p(BU) ................................................................................. 38

5.5.2. Chn my bin dng in (BI) ............................................................................. 41

5.6. Chn cp v khng ng dy cho ph ti a phng ........................................... 45

5.6.1. Chn cp cho ph ti a phng ........................................................................ 45

5.6.2. Chn khng ng dy cho ph ti a phng ................................................ 48

5.7. Chn my ct, dao cch ly cho ph ti a phng. .................................................. 51

5.7.1. Chn dao cch ly .................................................................................................... 51

5.8. Chn chng st van cho cc cp in p ..................................................................... 53

5.8.1. Chn chng st van cho thanh gp ...................................................................... 53

5.8.2. Chn chng st van cho my bin p ................................................................... 54

CHNG 6: CHN S NI IN V THIT B T DNG ..................................... 56

6.1. Chn s t dng. ...................................................................................................... 56

6.2. Chn cc thit b in v kh c in t dng ............................................................ 56

6.2.1. Chn my bin p t dng 10,5/6,3kV ................................................................ 56

6.2.2. Chn my bin p t dng 6,3/0,4kV .................................................................. 57

6.2.3. Chn my ct 10,5 kV ........................................................................................... 58

6.2.4. Chn dao cch ly 10,5KV ...................................................................................... 58

6.2.5. Chn my ct pha h ca my bin p t dng cp 1 (6,3kV)........................ 59

6.2.6. Chn aptomat ......................................................................................................... 60

TI LIU THAM KHO ........................................................................................................... 62

4

PHN I

THIT K PHN IN NH MY NHIT IN CHNG 1:CHN MY PHT IN-TNH TON PH TI -

CN BNG CNG SUT

Tnh ton ph ti v cn bng cng sut l mt phn rt quan trng trong nhim v thit k n nh my in. N quyt nh tnh ng, sai ca ton b qu trnh tnh ton sau. Ta s tin hnh tnh ton cn bng cng sut theo cng sut biu kin S v da vo th ph ti cc cp in p hng ngy v h s cng sut cc cp khng ging nhau v do tnh ton cn bng theo cng sut biu kin S vi sai s cho php trong khi thit k.

1.1. Chn my pht in.

Theo nhim v thit k,nh my nhit in gm 2 t my, mi t my c cng sut 65MW cung cp cho ph ti a phng cp 10kV, ph ti trung p 110kV, ph ti cao p 220kVv ni vi h thng cp 220kV, cng sut t dng bng 6% cng sut nh mc ca nh my vi h s cng sut ca ph ti t dng l 0,85. thun tin cho vic xy dng v vn hnh ta chn cc my pht in cng loi. Cn c vo cc yu cu trn ta chn 3 my pht loi

TB -65-2T vi cc thng s k thut c ghi trong bng sau: (Tra PL trang 100 sch thit knh my in v trm binp PGS-TS Nguyn Hu Khi)

Bng 1.1 Thng s my pht in.

Loi my pht

Thng s nh mc in khng tng i

S

(MVA)

P

(MW)

U

(kV) Cos

I

(kA)

''

dX '

dX dX

TB -65-2T 76,47 65 10,5 0,85 3,78 0,1361 0,202 1,5131

1.2. Tnh ton ph ti v cn bng cng sut

in nng l mt dng nng lng c bit, t c kh nng tch ly vi cng sut ln bi vy in nng sn xut ra n u phi tiu th ht n . Lng in nng do cc nh my in pht ra phi cn bng vi lng in nng tiu th ca ph ti ti mi thi im.

Trong thc t mc tiu th in nng ca ph ti lun thay i theo thi gian. Do vic tm th ph ti l mt vic rt quan trng vi ngi thit k v vn hnh, v nh c th ph ti ta c th la chn c phng n, s ni in ph hp m bo cc ch tiu kinh t k thut, nng cao tin cy cung cp in. Ngoi ra t th ph ti cn cho php chn ng dung lng ca my bin p, phn b c cng sut ti u gia cc nh my in hoc gia cc t my trong mt nh my. chn ng dung lng v v tnh ton tn tht in nng trong my bin p, cn thit lp s ph ti ngy ca nh my. My bin p c chn theo cng

sut biu kin, mt khc h s cos ca cc cp in p khc nhau khng nhiu nn cn bng cng sut c th tnh ton dng cng sut biu kin cc cp in p ca nh my thit k.

1.2.1. th ph ti nh my

Nh my nhit in gm 3 t my, mi t my c cng sut nh mc l 55 MW vi h

s cng sut nh mc 0,85.FCos Cng sut t ca nh my:

. 2.65152,94

0,85

dmFdmNM

F

n PS

Cos (MVA)

Trong :

5

- dmFP : Cng sut nh mc ca mi 1 t my pht.(MW)

- n : S t my pht (n=3)

Cng sut pht ca nh my ti cc thi im t trong ch lm vic bnh thng c tnh theo cng thc sau:

%( )( ) .

100

NMNM dmNM

P tS t S (MVA)

Trong :

- ( )NMS t : cng sut biu kin ca ph ti nh my ti thi im t.(MVA).

- %( )NMP t : phn trm cng sut pht ca ton nh my ti thiim t.(MW)

- FCos : h s cng sut nh mc ca my pht. 0,85FCos

Ph ti nh my ti cc thi im t c tng kt trong bng sau:

t(h) 0-8 8--12 12--14 14-20 20-24

P(%) 70 90 85 100 75

SNM (MVA)

107.058 137.646 130 152.94 114.71

1.2.2. th ph ti t dng ca nh my.

Theo nhim v thit k, ta c cng sut t dng cc i bng 6% cng sut nh mc ca

nh my vi h s cng sut 0,85TDCos .

Cng sut t dng theo thi gian ca nh my:

. ( )%( ) . 0,4 0,6

100

dmF NMTD

TD dmNM

n P S tS t

Cos S

(MVA)

Trong :

- ( )TDS t : cng sut biu kin ca ph ti t dng ti thi im t.(MVA)

- dmFP : cng sut tc dng ca mt t my pht. ( dmFP )

- dmNMS : cng sut t ca nh my. ( dmNMS )

- ( )NMS t : cng sut pht ca nh my ti thi im t.(MVA)

- % : phn trm cng sut in t dng cc i. % 6%

Ph ti t dng cc thi im t c tng kt trong bng sau:

Bng 1.3 Ph ti t dng ca nh my in theo thi gian.

6

t (h) 0-8 8--12 12--14 14-20 20-24

SNM (MVA) 107.058 137.65 130 152.94 114.71

STD (MVA) 7.525 8.626 8.351 9.177 7.8

v

1.2.3. th ph ti a phng (10kV)

Ph ti a phng ca nh my c: 10 ,dmDPU kV 40 ,DP MaxP MW 0,85.DPCos

Ph ti a phng ti tng thi im xc nh theo cng thc sau:

%( )

( ) .100

DP MaxDPDP

DP

PP tS t

Cos (MVA)

Trong :

- ( )DPS t : cng sut biu kin ca ph ti a phng ti thi im t.(MVA)

- DP MaxP : cng sut tc dng cc i ca ph ti a phng. ( DP MaxP =40MW)

- %( )DPP t : cng sut tc dng tnh theo % ca cng sut tc dng cc i ca ph ti a

phng ti thi im t. (%)

- DPCos : h s cng sut trung bnh ca ph ti a phng. 0,85DPCos

t (h) 0--6 6--10 10--14 14--18 18--24

Pp (%) 60 90 80 100 75

Sp (MVA)

28,24 42,35 37,65 47,06 35,29

1.2.4. th ph ti trung p (110kV)

Ph ti trung p ca nh my c: 110 ,dmTU kV 130 ,T MaxP MW 0,85.TCos

Ph ti trung p ti cc thi im t c tnh ton theo cng thc sau:

%( )

( ) .100

T MaxTT

T

PP tS t

Cos (MVA)

Trong :

- ( )TS t : cng sut biu kin ca ph ti trung p ti thi im t.(MVA)

- T MaxP : cng sut tc dng ca ph ti trung p cc i. 110T MaxP MW

- %( )TP t : cng sut ca ph ti trung p ti thi im t. (%)

7

- TCos : h s cng sut trung bnh ca ph ti trung p. 0,85TCos

Bin thin ph ti trung p c tng kt trong bng sau:

Bng 1.5 Ph ti trung p theo thi gian trong ngy

t (h) 0--6 6--10 10--14 14--18 18--24

PTA

(%) 70 90 100 95 80

STA (MVA)

107,06 137,65 152,94 145,29 122,35

1.2.5. Cng sut pht v h thng (VHT)

Cng thc cn bng cng sut ton nh my nh sau:

( ) ( ) ( ) ( ) ( )NM TD DP TA VHTS t S t S t S t S t

Trong :

- ( )VHTS t : cng sut pht v h thng ti thi im t.(MVA)

- ( )NMS t : cng sut pht ca nh my ti thi im t.(MVA)

- ( )DPS t : cng sut ph ti a phng ti thi im t.(MVA)

- ( )TAS t : cng sut ph ti trung p ti thi im t.(MVA)

- ( )TDS t : cng sut t dng ca nh my ti thi im t.(MVA)

Do tn tht cng sut rt nh so vi cng sut cc ph ti nn thng b qua trong tnh

ton cn bng cng sut s b. ( ) 0S t

T ta tnh ton c cng sut pht v h thng nh sau:

( ) ( ) ( ) ( ) ( )VHT NM TD DP TAS t S t S t S t S t (MVA)

Tnh ton theo cng thc trn ta thu c bng kt qu nh sau:

8

Bng 1.7: Kt qu tnh ton cn bng cng sut.

t(h) 0--6 6--8 8--10 10--12 12--14 14--18 18--20 20-24

SNM

(MVA) 107,06 107,06 137,65 137,65 130 152,94 152,94 114,71

STD

(MVA) 7,525 7,525 8,626 8,626 8,351 9,177 9,177 7,8

Sp (MVA)

28,24 42,35 42,35 37,65 37,65 47,06 35,29 35,29

STA

(MVA) 107,06 137,65 137,65 152,94 152,94 145,29 122,35 122,35

SVHT (MVA)

-35,767 -80,467 -50,98 -61,57 -68,941 -48,587 -13,877 -50,735

9

CHNG 2: XUT CC PHNG N V CHN MY

BIN P

2.1. xut cc phng n ni dy.

Chn s ni in chnh ca nh my in l mt khu quan trng trong qu trnh thit k nh my in. N quyt nh nhng c tnh kinh t v k thut ca nh my thit k. C s vch ra cc phng n l bng ph ti tng hp, ng thi tun theo nhng yu cu k thut chung.

Theo nhim v thit k, nh my in c 3 t my vi cng sut nh mc ca mi t my l 55MW, c nhim v cung cp in cho ph ti cc cp in p(10 kV, 110kV, 220kV) v ti cng sut tha v h thng.

Cp in p cao (220 kV) v trung p (110 kV) l li trung tnh trc tip ni t nn dng my bin p lin lc l my bin p t ngu s c li hn(v khi ni ta s gim tn tht v truyn ti c cng sut tha t bn trung sang bn cao). H s c li khi dng my bin p t ngu (MBATN):

220 1100,5

110

C T

T

U U

U

Trong :

: h s c li ca my binp t ngu. (iu kin 0,5 )

TU : inp pha trung p ca my binp t ngu.

CU : inp pha cao p ca my binp t ngu.

T cc nhn xt trn ta c th xut cc phng p ni in cho nh my nh sau:

10

2.1.1. Phng n

Hnh 2.1 M t s ni dy phng n

2.2. Tnh ton chn my bin p.

My bin p l mt thit b rt quan trng trong h thng in. Tng cng sut cc my bin p gp t 4 - 5 ln tng cng sut cc my pht in. Chn my bin p trong nh my in l chn loi, s lng, cng sut nh mc v h s bin p. My bin p c chn phi m bo hot ng an ton trong iu kin bnh thng v khi xy ra s c nng n nht.

Nguyn tc chung chn my bin p l trc tin chn dmBAS ln hn hoc bng cng

sut cc i c th qua bin p trong iu kin lm vic bnh thng, sau kim tra li iu kin s c c k n h s qu ti ca my bin p. Xc nh cng sut thiu v h thng cng sut ny phi nh hn d tr quay ca h thng. Ta ln lt chn my bin p cho tng phng n. Gi thit cc my bin p c ch to ph hp vi iu kin nhit mi trng ni lp t nh my in. Do vy khng cn hiu chnh cng sut nh mc ca chng.

iu kin chn cng sut my bin p t ngu:

1 1

. 76,47 152,940,5

dmTN dmFS S

(MVA)

Trong :220 110

0,5110

C T

T

U U

U

: h s c lii ca my binp t ngu.

TU : inp pha trung p ca my binp t ngu.

CU : inp pha cao p ca my binp t ngu.

TN 1 TN 2

F 1 F 2

S T S C

S DP

220 kV 110 kV

HTD

S TD S TD

11

Ta chn MBA loi .

T ta c bng tham s my bin p cho phng n nh sau: (tra sch Thit k phn in nh my in v trm bin p PGS-TS Phm Hu Khi)

Bng 2.1 Thng s MBA phng n

2.2.1.1. Phn b cng sut cho cc my bin p (MBA)

Vic phn b cng sut cho cc my bin p cng nh cho cc pha ca chng c tin hnh theo nguyn tc c bn l phn cng sut cho my bin p trong s b my pht-my bin p hai cun dy bng phng trong sut 24h. Phn tha thiu cn li do my bin p lin lc m nhn trn c s m bo cn bng cng sut, khng xt n tn tht trong my bin p.

Nguyn tc trn a ra m bo vn hnh n gin, khng cn chn my bin p trong s b my pht - my bin p hai cun dy c iu p di ti, lm h vn u t.

Theo nhn xt trn ta phn b cng sut cho cc my bin p nh sau:

Cc b my pht - my bin p hai cun dy cho vn hnh vi ph ti bng phng sut c nm vi:

Cng sut ti qua pha trung ca MBA 2 cun dy pha 110kV.

1 1

76, 947 . 71, ,883

182

BT dmF TD MaxS S S (MVA)

Cng sut chuyn qua mt my bin p t ngu.

n gin ta xem h s cng sut cc pha ca my bin p t ngu l nh nhau. Khi trong ch lm vic bnh thng cng sut ti qua cc pha cao, trung v h p ca mi my bin p t ngu c tnh nh sau:

- Pha trung: 1

2. ( ) ( ) ( ) ( )2

TTN T TTN TS t S t S t S t

- Pha cao: 1

2. ( ) ( ) S ( )2

CTN VHT CTN VHTS t S t S t

- Pha h: ( ) S ( ) ( )HTN TTN CTNS t t S t

Thc hin tnh ton theo cng thc trn ta c bng kt qu nh sau:

Loi

MBA

dmS

(MVA)

in p cun dy

(kV)

Tn tht

(kW) %NU

0 %I

C T H

0P

NP

C-T C-H T-H

A C-T C-H T-H

160 230 121 11 85 380 - - 11 32 20 0,5

12

Bng 2.2 Phn b cng sut ca phng n 1 trong ch bnh thng.

t (h) 0-6 6--8 8--10 10--12 12--14 14--18 18--20 20-24

SB (MVA)

71,88 71,88 71,88 71,88 71,88 71,88 71,88 71,88

-17,88 -40,23 -25,49 -30,79 -34,47 -24,29 -6,94 -25,37

53,53 68,83 68,83 76,47 76,47 72,65 61,18 61,18

35,65 28,59 43,34 45,69 42,00 48,35 54,24 35,81

2.2.1.2. Kim tra qu ti.

Do cc my bin p hai dy cun u mang ti bng phng nh hn cng sut nh mc trong mi ch nn khng cn phi kim tra qu ti. Ta ch kim tra qu ti my bin p t ngu trong ch bnh thng v s c.

i vi my bin p t ngu th cng sut cun h l cng sut tnh ton thit k do m cun h ca my bin p t ngu khng b qu ti trong mi trng hp.

- Khi lm vic bnh thng.

Qua bng 2.2 ta thy trong ch lm vic bnh thng, hai my bin p t ngu lun lm vic theo ch ti cng sut t h v cao sang trung, do cun ni tip mang ti nng nht. Vy my bin p t ngu khng b qu ti khi lm vic bnh thng.

- Khi c s c

Khi tt c cc my pht u cho pht vi cng sut nh mc,tng ng ph ti t dng ca chng cng c gi tr cc i.

13

a) S c mt my bin p t ngu.

S phn b cng sut cho cc my bin p trong trng hp ny nh sau:

Hnh 2.5 S khi s c mt b my bin p bn trung p

n gin ta xem h s cng sut cc pha ca my bin p t ngu l nh nhau. Khi cng sut cc pha ca mt my bin p t ngu c tnh ton nh sau.

Cng sut ti qua pha h ca my bin p t ngu:

1

( ) S ( )2

HTN dmF DP TD MaxS t S t S

Cng sut ti qua pha trung ca my bin p t ngu:

( ) ( )TTN TS t S t

Cng sut ti qua pha cao ca my bin p t ngu:

( ) ( ) ( )CTN HTN TTNS t S t S t

Lng cng sut h thng thiu:

( ) ( ) ( )Thieu VHT CTNS t S t S t

STD STD

F2

TN1 TN2

F1

ST

SDP

220 kV 110 kV

HTD

14

Bng 2.3 Phn b cng sut ca phng n 1 trong ch s c mt b my pht my bin p bn trung

t(h) 0--6 6--8 8--10 10--12 12--14 14--18 18--20 20--24

S H TN 46,01 31,90 31,90 36,60 36,60 27,19 38,96 38,96

S T TN 107,06 137,65 137,65 152,94 152,94 145,29 122,35 122,35

S C TN -61,05 -105,75 -105,75 -116,34 -116,34 -118,10 -83,39 -83,39

Sthiu (MVA)

25,28 25,28 54,77 54,77 47,40 69,51 69,51 32,66

Nhn thy :

SThieu Max = 69,51(MVA) < SDT-HT = 144 (MVA).

V lng cng sut thiu ny nh hn cng sut d tr quay ca h thng nn h thng b cng sut thiu ht.

15

2.2.1.3. Tnh ton dng cng bc (PA).

Cc kh c in c hai trng thi c bn:

Trng thi lm vic bnh thng : xc nh dng lm vic bnh thng chn cc kh c in theo iu kin kinh t. c xc nh theo lung cng sut cc i qua thit b (khng c phn t no b tch ra khi s ).

Trng thi lm vic cng bc : c xc nh chn cc thit b theo iu kin n nh nhit. c xc nh khi mt phn t ca nh my b s c v b tch ra, gy nn trn phn t ang xt trng thi lm vic nng n nht.

a) Pha cao p 220kV.

- Nh my ni vi h thng bng ng dy kp di 70 km.

Cng sut ln nht a v h thng trong ch bnh thng:

80,467VHT MaxS (MVA)

Pha cao ca my bin p lin lc:

Trong iu kin vn hnh bnh thng: 40,23CTN MaxS (MVA)

Khi s c, cng sut qua pha cao ca my bin p t ngu s ln nht khi hng mt my bin p t ngu. Theo tnh ton trong phn kim tra qu ti s c mt my bin p t ngu ta c:

( ) 118,1CTN Max SCTNS (MVA)

Vy dng in cng bc pha in p 220kV:

118,1CB MaxS (MVA)

220118,1

0,1873.220 3.220

CB MaxCB

SI (kA)

b) Pha trung p110kV

Trong ch vn hnh bnh thng: 76,47TTN MaxS (MVA)

Khi s c, cng sut qua pha trung ca my bin p t ngu s l ln nht khi s c mt my bin p t ngu. Theo tnh ton trong phn kim tra qu ti s c my bin p t ngu ta c:

( ) 152,94TTN Max SCTNS (MVA)

Cng sut cng bc xy ra khi my pht lm vic qu ti:

4 1,05. 1,05.76,47 80,29CB dmFS S (MVA)

Vy dng in cng bc pha in p 110kV:

152,94CB MaxS (MVA)

110152,94

0,8033.110 3.110

CB MaxCB

SI (kA)

c) Pha h p 10,5kV

Cng sut cng bc xy ra khi my pht lm vic qu ti

4 1,05. 1,05.76,47 80,29CB dmFS S (MVA)

16

Vy dng in cng bc pha in p 10,5kV:

10,580,29

4,4153.10,5 3.10,5

CB MaxCB

SI (kA)

Bng 2.6 Dng in cng bc phng n 1

dmU (kV) 220 110 10,5

CBI (kA) 0,31 0,803 4,415

17

CHNG 3: TNH TON NGN MCH 3.1. Tnh in khng cc phn t trong s .

Mc ch ca vic tnh ton ngn mch l chn cc kh c in v dy dn ca nh my m bo cc ch tiu n nh ng v n nh nhit khi ngn mch.

Khi chn s tnh ton dng in ngn mch i vi mi kh c in cn chn ch lm vic nng n nht nhng phi ph hp vi iu kin lm vic thc t. Dng in tnh ton ngn mch chn kh c in l dng ngn mch 3 pha.

Chn cc i lng c bn:

100CBS (MVA)

CB TBU U (kV)

in p c bn cc cp:

220 230CBU (kV)

110 115CBU (kV)

10,5 10,5CBU (kV)

Dng in c bn cc cp:

220220

1000,251

3. 3.230

CBCB

CB

SI

U

(kA)

110110

1000,502

3. 3.115

CBCB

CB

SI

U

(kA)

10,510,5

1005,499

3. 3.10,5

CBCB

CB

SI

U

(kA)

- in khng ca cc phn t tnh trong h n v tng i c bn:

+ in khng ca h thng in

in khng ngn mch tnh n thanh ci h thng: 0,82HTX

Do in khng ca h thng trong h n v tng i c bn:

100

. 0,82. 0,0461800

CBHT CB HT

HT

SX X

S

+ in khng ca ng dy ni vi h thng (220kV)

Nh my thit k ni vi h thng bng 3 ng dy kp c chiu di L = 70 km. i vi

cp in p 220kV ta c th ly gn ng in khng ca ng dy l: 0 0,4X / km

0 2 2

220

1 1 100. . .0,4.80. 0,03

2 2 230

CBD

CB

SX x L

U

18

+ in khng ca my pht in.

Cc my pht in chn l loi 65 2TB T c in khng siu qu dc trc l '' 0,1361dX trong h n v tng i nh mc ca my pht.

Do in khng ca my pht trong h n v tng i c bn:

" 100. 0,1361. 0,21

64,71

CBF d

dmF

SX X

S

+ in khng ca my bin p t ngu.

Tnh cc in p ngn mch cc cp:

1 1

% % % % 11 32 20 11,5%2 2

NC NC T NC H NT HU U U U

1 1

% % % % 11 20 32 0,5% 0%2 2

NT NC T NT H NC HU U U U

1 1

% % % % 32 20 11 20,5%2 2

NH NC H NT H NC TU U U U

% 11,5 100. . 0,072

100 100 160

% 0 100. . 0

100 100 160

% 20,5 100. . 0,128

100 100 160

NC CBC

dmTN

NT CBT

dmTN

NH CBH

dmTN

U SX

S

U SX

S

U SX

S

3.2. Xc nh im ngn mch tnh ton.

Chn cc im ngn mch sao cho dng ngn mch qua cc kh c in v dy dn l ln nht c th.

cp in p 220 kV.

Thng ch chn mt loi my ct in v dao cch ly, v vy ch tnh im ngn mch N-1 ngay trn thanh gp 220 kV. Ngun cung cp gm tt c cc my pht in ca nh my thit k v h thng.

cp in p 110 kV.

Tng t nh trn, ch tnh ngn mch N-2 trn thanh gp 110kV. Ngun cung cp cho im ngn mch l cc my pht in v h thng cp in p 10,5kV.

chn kh c in v mch h p 10,5kV. Trng hp ny cn tnh hai im ngn mch N-3 v N-4. Ngun cung cp cho im N-3 bao gm cc my pht in v h thng, tr my pht F2. Ngun cung cp cho im ngn mch N-4 ch ring my pht F2 cung cp. So snh hai dng in ngn mch trn, dng in ngn mch no c tr s ln hn c dng chn kh c in v dy dn.

19

Tnh ton ngn mch cho phng n

S cc im ngn mch:

Hnh 3.1 Cc im tnh ton ngn mch ca phng n 1

3.2.1. im ngn mch N-1

Lp v bin i s thay th:

Hnh 3.2 S thay th tnh ton ngn mch im N1

TN1 TN2

F1 F2SDP

220 kV 110 kV

HTD

STD STD

N1 N2

N3

N4

N5

N 1

E HT

X HT 0,046

X C 0,072

X D 0,03

E 1 E 2

X C 0,072

X H 0,128

X H 0,128

X F

0,21

X F 0,21

20

Ta c:

Bin i s v dng n gin:

212

12

0,3380,169

2 2

0,0720,036

2 2

CC

XX

XX

N 1

E HT

X 0

0,076

X 12

0,169

X C12

0,036

E 12

N 1

E HT

X 0 0,076

X C 0,072

E 1 E 2

X 1 0,338

X 2 0,338

X C

0,072

21

5 12 12 0,036 0,169 0,205CX X X

in khng tnh ton pha nh my in:

2 52.76,47

. 0,205. 0,314100

dmFTT

CB

SX X

S

Tra ng cong tnh ton ta c:

2 0 3,1TTI

Vy dng in ngn mch ti im N1:

" 2201 20 220

0,251 2.76,470 3,1. 4,493

0,0763. 3.230

CB dmFN TT

CB

I SI I

X U

(kA)

Dng in xung kch ti im ngn mch N1:

"

1 12. . 2.1,8.4,493 11,437XK N XK Ni k I (kA)

Trong XKk h s xung kch, ngn mch ti N1 ta ly 1,8.XKk



N 1

E HT

X 0

0,076

X 4

0,205

E 123

22



212

12

0,3380,169

2 2

0,0720,036

2 2

CC

XX

XX

N 2

X 12 0,169

E HT

E 12

X C12 0,036

X 0 0,076

N 2

E HT

X 0 0,076

X C 0,072

E 1 E 2

X 1 0,338

X 2 0,338

X C

0,072

23

4 0 12 0,076 0,036 0,112CX X X

in khng tnh ton pha nh my in.

2 62.76,47

. 0,169. 0,258100

dmFTT

CB

SX X

S

Tra ng cong tnh ton ta c: 2 0 4TTI


" 1102 26 110

0,502 2.76,470 . 4. 7,553

0,1123. 3.115

CB dmFN TT

CB

I SI I

X U

(kA)


"

2 22. . 2.1,8.7,553 19,227XK N XK Ni k I (kA)




N 2

X 12 0,169

E 12

X 4 0,112

E HT

24


0

1

0,076

0,338

HT D

H F

X X X

X X X


12

0,0720,036

2 2

CC

XX

X 1 0,338

E HT E 1

X C12 0,036

X 0 0,065

N 3

X H 0,128

E HT

X 0

0,076

X C 0,072

E 1

X 1

0,338

X C 0,072

N 3

X H

0,128

25

4 0 12 0,112CX X X

46 4

1

17 1

4

. 0,112.0,1280,112 0,128 0,282

0,338

. 0,338.0,1280,338 0,128 0,852

0,112

HH

HH

X XX X X

X

X XX X X

X

in khng tnh ton pha nh my in:

2 8

76,47. 0,852. 0,652

100

dmFTT

CB

SX X

S

Tra ng cong tnh ton ta c: 2 0 1,5TTI


N 3

E HT

X 6

0,282

E 1

X 7

0,852

X 1

0,338

E 1

X 4

0,112

E HT

N 3

X H

0,128

26

10,5" 3 27 10,5

5,499 76,470 . 1,5. 25,81

0,2823. 3.10,5

CB dmFN TT

CB

I SI I

X U

(kA)


"

3 32. . 2.1,8.25,81 65,702XK N XK Ni k I (kA)




Ngun cung cp cho im ngn N4 ch c my pht in F3 nn ta c s thay th tnh ton ngn mch sau:

64,71. 0,21. 0,136

100

dmFTT F

CB

SX X

S

Tra ng cong tnh ton ta c: 0 6,4TTI


" 410,5

64,710 . 6,4. 22,77

3. 3.10,5

dmFN TT

CB

SI I

U (kA)


"

4 42. . 2.1,91.22,77 61,51XK N XK Ni k I (kA)

Trong XKk h s xung kch, ngn mch ti N4 ngay u cc my pht ta ly

1,91.XKk

N 4

X F

0,21 E 2

27



Dng ngn mch ti N5 bng tng dng ngn mch ti N3 v N4:

" " "

5 3 4 48,58N N NI I I (kA)

Dng xung kch ti im ngn mch N5:

5 3 4 127,21XK N XK N XK NI I I (kA)

Bng 3.1 Kt qu tnh ton ngn mch ca phng n.

Phng n

im NM N1 N2 N3 N4 N5

1

"

NI 4,493 7,553 25,81 22,77 48,58

XKi 11,437 19,227 65,702 61,51 127,21

N 5

E HT

X HT

0,046

X C 0,072

X D 0,03

E 1 E 2

X C 0,072

X H 0,128

X H 0,128

X F 0,21

X F 0,21

28

CHNG 4: TNH TON KINH T - K THUT CHN PHNG N TI U

Khi tnh ton thit k bt k mt nh my in no cng phi tin hnh so snh chn phng n hp l nht. Khi chn phng n phi da trn phn tch ton din cc ch tiu kinh t- k thut. Cc ch tiu k thut c bn bao gm tin cy cung cp in, s thun tin trong vn hnh, bn vng ca cng trnh, khi lng sa cha nh k v i tu, mc t ng ha, cht lng in nng. Cc ch tiu kinh t c bn l vn u t v ph tn vn hnh hng nm.

tin cy ca s ph thuc vo vai tr quan trng ca h tiu th in. V d: h tiu th in loi 1 phi c cung cp bng 2 ng dy ly 2 ngun c lp, mi ngun phi cung cp cng sut khi ngun kia ngh lm vic.

Tnh linh hot ca s th hin bi kh nng thch ng vi nhng trng thi vn hnh khc nhau.

Tnh kinh t ca s c gii quyt bng hnh thc ca cc h thng thanh gp, s lng kh c in dng cho s . Ngoi ra cch b tr thit b trong s phi m bo an ton cho ngi vn hnh.

Trn thc t vn u t vo thit b ch yu ph thuc vo vn u t my bin p v cc mch thit b phn phi. Trong vn u t vo cc mch thit b phn phi ch yu ph thuc vo vn u t my ct. Do mt cch gn ng khi tnh ton kinh t s b chn phng n ti u ta xt vn u t cho tng phng n bao gm vn u t my bin p v vn u t my ct cc mch phn phi.

4.1. La chn s thit b phn phi (TBPP) 4.1.1. Phng n :

- Pha cao p (220kV) bao gm (4 mch):

+ 2 ng dy kp ni vi h thng.

+2 ng dy ni t cc my bin p t ngu .

Pha trung p(110kV) bao gm(8 mch):

+ 2 ng dy kp v 1 ng dy n cp cho ph ti trung p.

+2 ng dy ni t cc my bin p t ngu

29

Hnh 4.1 S ni in chi tit phng n 1

4.2. Chn my ct in cho cc mch.

My ct in l mt phn t rt quan trng trong h thng in, my ct in dng ng ct mch in vi dng ph ti khi lm vic bnh thng v dng ngn mch khi c s c bo v cc phn t trong h thng in.

thun tin cho lp t, vn hnh v sa cha ta chn mt loi my ct cho cc mch cng cp in p.

Cc my ct in c chn v kim tra theo iu kin sau:

- in p nh mc ca my ct: dm dm mangU U

- Dng in nh mc ca my ct: dm CBI I

- Dng in ct nh mc ca my ct: "

Cat dm NI I

Trong :

+ CBI l dng cng bc ca mch t my ct.

+ "

NI l dng ngn mch siu qu thnh phn chu k.

Ngoi ra my ct c chn cn phi kim tra iu kin n nh ng v n nh nhit khi ngn mch:

- Kim tra iu kin n nh ng: d dm xki i ( xki l dng xung kch khi ngn mch)

- Kim tra iu kin n nh nhit:2 .nh dm nh NI t B . Trong :

F1

AT 1

F2

AT 2

220 kV

MCLL

MCLL

110 kV

30

+ nh dmI - dnginn nh nhit ca my ctng vi thi gian n nh nhit .nht

+ NB - xung lng nhit ca dng ngn mch.

i vi cc my ct c 1000dmI A th khng cn kim tra n nh nhit. Cn c vo kt qu tnh dng cng bc v dng ngn mch ta tin hnh chn my ct cho phng n 1 nh bng sau: (Tratrang 235 sch thit k phn in nh my in v trm binp PGS Nguyn Hu Khi)

Bng 4.1 Thng s my ct.

PA

Cp in p

(kV)

Cc i lng tnh ton

K hiu my ct

Cc i lng nh mc

CBI

(kA)

"

NI

(kA)

xki

(kA)

dmU

(kV)

dmI

(kA)

CatI

(kA)

d dmi

(kA)

1

220 0,31 4,493 11,437 3AQ1 245 4 40 100

110 0,803 7,553 19,227 3AQ1-FE 123 3,15 31,5 80

10,5 4,415 25,81 65,702 8FG10 12 12,5 80 225

31

CHNG 5: CHN KH C IN V DY DN

Trong qu trnh lm vic kh c in v dy dn thng b pht nng. Nguyn nhn ch yu l do:

- Tc dng nhit ca dng ph ti lu di

- Tc dng nhit v lc ng in ca dng ngn mch

Nu nhit tng qu cao c th lm cho chng b h hng, nht l nhng ch tip xc hoc lm gim tui th cch in ca chng. Sau y chng ta s i la chn kh c in v dy dn m bo chng chu c cc tc ng nhit trn.

5.1. Chn thanh dn cng u cc my pht 5.1.1. Chn loi v tit din thanh dn

Thanh dn cng c dng cp in p my pht 10,5kV dng ni t my pht in n cun h ca my bin p t ngu v my bin p hai cun dy. Do chiu di cc thanh dn thng khng ln cho nn thanh dn c chn theo iu kin pht nng lu di cho php:

'

CP CBI I

Trong :

- '

CPI -dng cho php lm vic lu di hiu chnh theo nhit ni t thanh dn.

- CBI - dng in cng bc qua thanh dn. 10,5 4,415CB ThanhDan CBI I (kA)

' 0

0

. .CPCP hc CP CPCP qd

I k I I

Vi:

- 070CP C - nhit cho php lm vic lu di ca thanh dn.

- 0

0 35 C - nhit mi trng ni t thanh dn.

- 0

0 70qd C - nhit quy nh khi tnh .CPI

' 70 35 . 0,882.70 25

CP CP CPI I I

Ta c: 0,882. 4,415CPI (kA) 5,006CPI (kA)

Vy ta chn thanh dn cng mng ng gim hiu ng mt ngoi v hiu ng gn ng thi tng kh nng lm mt. Ta chn thanh dn c thng s k thut nh sau: (Tra trang

285 sch "Thit k phn in v trm bin p PGS-Nguyn Hu Khi" )

32

Bng 5.1 Thng s thanh dn cng.

Icp

(A)

Kch thc

(mm)

Tit din mt

cc

(mm2)

M men tr khng

(cm3)

M men qun tnh

(cm4)

Mt thanh Hai thanh

Wyo-yo

Mt thanh Hai thanh

Jyo-yo h b c r Wx-x Wy-y Jx-x Jy-y

5500 125 55 6,5 10 1370 50 9,5 100 290,3 36,7 625

V thanh dn chn c 5500 1000CPI A A nn khng cn kim tra n nh nhit.

Hnh 5.1 Hnh dng thanh dn cng mng ng

5.1.2. Kim tra n nh ng

Theo tiu chun bn c, ng sut ca vt liu thanh dn khng c ln hn ng sut

cho php ca n, ngha l tt CP .

ng sut cho php i vi ng l 1400CP (Kg/cm2) tra bng 4.5 trang 130 sch

phn in trong nh my in v trm bin p- o Quang Thch

i vi thanh ghp, ng sut trong vt liu thanh dn gm hai thnh phn:

- ng sut do dng in gia cc pha tc ng vi nhau sinh ra: 1

- ng sut do dng in trong cc thanh dn ca cng mt pha tc ng vi nhau sinh ra:

2

Do ng sut tnh ton c xc nh nh sau: 1 2tt

Ly khong cch gia cc pha l a=60 cm, khong cch gia hai s 1 200l cm . Cc thanh dn c t ng trn mt phng nm ngang v trong cng mt pha cc thanh dn c hn cht vi nhau.

b

y y

y yyo

yo

h

hx x

c

r

33

Theo chng 3 ta c bng dng ngn mch ti cc im 3 4,N N nh sau:

Bng 5.1 Dng in ngn mch ti im N3, N4

im ngn mch "

NI (kA) XKi (kA)

3N 25,81 65,702

4N 22,77 61,51

Tnh ng sut gia cc pha.

Dng in ngn mch xung kch ln nht u cc my pht:

10,5 3 65,702XK XK Ni i (kA)

Lc tnh ton tc dng ln thanh dn pha gia trn chiu di nhp:

2 2 2 211

2001,76.10 . . 1,76.10 .1. . 253,265,702 5

60hd XK

lF k i

a

(KG)

M mem un tc dng ln chiu di nhp (gi s s nhp 3n )

1 11

. 253,25.2005065

10 10

F lM (KG.cm)

Do cc thanh dn c t ng trn mt phng nm ngang v trong cng mt pha cc thanh dn c hn cht li vi nhau ti cc ming m nn ta tnh c ng sut do lc ng in gia cc pha tc ng vi nhau sinh ra:

11 20 0

506550,65

W 100y y

M KG

cm

Xc nh khong cch gia 2 ming m :

Lc tc dng ln 1cm chiu di thanh dn do dng ngn mch trong cng mt pha gy ra

mt cch gn ng c th ly gn ng: 1,2

hk b

2 2 2 2

2

1 10,52.10 . . 0,52.10 . 65,702. 1,796

12,5xk

kGf i

h cm

ng sut do dng in trong cc thanh dn ca cng mt pha tc ng vi nhau sinh ra:

2 2 22 2.

W 12.Wy y y y

M f l kG

cm

iu kin n nh ca thanh dn khi khng xt n dao ng:

1 2

2 1

1

2

2

12.W .

tt CP

CP

y y CPl

f

34

Vy khong cch ln nht gia cc ming m m thanh dn vn m bo n nh ng:

2

12.9,5. 1400 50,65292,66( )

1,796Maxl cm

m bo n nh ng ca thanh dn, chiu di thc gia hai ming m lin tip

phi tha mn iu kin: 2 2 292,66Maxl l cm

Xt s giao ng ring ca thanh dn :

Tn s dao ng ring ca thanh dn cn phi nm ngoi khu vc cng hng vi gii

hn 10% tn s chnh ca h thng. i vi tn s h thng l 50 Hz th tn s ring ny phi

nm ngoi gii hn 45 55 Hz v 2 90 100 Hz . Tn s ring ca thanh dn c xc nh theo cng thc:

6

0 0

2

. .10.

.

y y

r

E Jf

L S

Trong :

- E - m un n hi ca vt liu thanh dn. 6 21,1.10 /CuE kG cm

- - khi lng ring ca vt liu thanh dn.3

8,93Cug

cm

- L - di thanh dn gia 2 s. 1 200L l cm

- - h s ph thuc cch c nh thanh dn.

- S - tit din ngang ca thanh dn. 2

12. 2.13,7 27,4cucS S cm

- 0 0y yJ - m men qun tnh i vi trc y0-y0. 2

0 0 625y yJ cm

Do gi thit s nhp n>3, thanh dn c t trn cng mt phng nm ngang, tra bng 4.6 trang 138 sch phn in nh my in v trm bin p- TS.o Quang Thch ta c

3,56. Thay cc thng s vo cng thc ta c:

6 6

2

3,56 1,1.10 .625.10. 194,185

200 27,4.8,93rf Hz

Vy thanh dn chn tha mn iu kin n nh ng khi xt n dao ng ring ca thanh dn.

5.2. Chn s cho thanh dn cng

S thanh dn cng c chn theo iu kin sau:

- Loi s: chn loi s t trong nh. (do thanh dn c t trong nh )

- in p: 10dm Su dm MangU U kV

- Kim tra n nh ng.

Ta chn loi s: 20 2000 3O KB Y c thng s k thut nh sau:

20 ; 2000 ; 206 .dm Su phU kV F kG H mm (Tra trang 253 sch Thit k phn in nh my in

v trm binp PGS-Nguyn Hu Khi)

35

Hnh 5.2 Hnh dng s thanh dn cng

Kim tra n nh ng:

S c chn cn tha mn iu kin: ' 0,6. 0,6.2000 1200 .tt phF F kG

Trong :

- phF - lc ph hoi nh mc ca s.(kG)

- '

ttF - lc tnh ton ln nht tc ng ln u s khi c ngn mch.(kG)

' .tt ttS

HF F

H

- ttF - lc ng in ln nht tc ng ln thanh dn khi c ngn mch.(kG)

1 253,25ttF F (kG)

- SH - chiu cao ca s. 206 .SH mm

- H - chiu cao t y s n trng tm tit din thanh dn.(mm)

Thanh dn chn c chiu cao h= 125mm. (t thanh dn ng).

Do : 125

206 268,52 2

S

hH H

Lc ph hoi tnh ton ca s c tnh ton nh sau:

'268,5

. 253,25. 330,086206

tt tt

S

HF F kG

H

' 330,086 0,6. 1200tt phF kG F kG

Vy s chn tha mn iu kin n nh ng.

h/2

HSH

Ftt

F'tt

36

5.3. Chn thanh gp v thanh dn mm

Trong nh my in i vi cp in p 35kV tr ln, thanh dn mm c dng lm thanh gp v thanh dn ni cc my bin p chnh vi h thng thanh gp. Cc thanh dn v thanh gp trong nh my in v trm bin p c chiu di khng ln nn chn tit din theo iu kin pht nng lu di.

Khi thanh dn chn phi tha mn iu kin: lvcb

CP

hc

II

k

- hck h s hiu chnh.Dy nhm trn c: 0 0

070 ; 25 .CP dmC C Vi gi thit nhit

mi trng thc t0

0 35 .C

0

0

70 350,882

70 25

CPhc

CP dm

k

- CPI dng in lm vic cho php ca dy dn

- lvcbI dng in lm vic cng bc ca dy dn.

5.3.1. Chn thanh dn mm lm thanh gp cp in p 220kV

Dng lm vic cng bc ca mch 220kV: 0,31lvcbI kA

Dy dn chn phi tha mn iu kin: 0,31

0,3520,882

lvcbCP

hc

II kA

k

T ta chn thanh gp v thanh dn mm loi dy nhm li thp c cc thng s ghi trong bng sau: (Tra bng trang 292 sch Thit k phn in nh my in v trm binp PGS-Nguyeenc Hu Khi )

Bng 5.2 Thng s tit din dy dn mm mch in 220kV

Tit din

chun

nhm/thp

Tit din

2mm ng knh

(mm) CPI

(A)

Nhm Thp Dy dn Li thp

240/32 244 31,7 21,6 7,2 610

Cc thanh dn c b ch trn mt phng nm ngang

5.3.2. Chn thanh dn mm lm thanh gp cp in p 110kV

Dng lm vic cng bc ca mch 110kV: 110 0,803lvcb CBI I kA

Dy dn chn phi tha mn iu kin: 0,803

0,910,882

lvcbCP

hc

II

k

37

T ta chn thanh gp v thanh dn mm loi dy nhm li thp c cc thng s ghi trong bng sau: (Tra PL10.12 trang 194 sch Thit k phn in nh my in v trm binp PGS-TS Phm Vn Ho).

Bng 5.3 Thng s tit din dy dn mm mch in 110kV

Tit din

chun

Tit din

2mm

ng knh

mm

CPI

A

Nhm Thp Dy dn Li thp

240/32 244 31,7 21,6 7,2 610

5.4. Chn dao cch ly trong mch in chnh

Dao cch ly l thit b in cao p dng ng m c kh cc mng in cao p khi khng c dng in hoc c dng in nh theo quy nh. thun tin cho vic lp t, vn hnh v sa cha, ta chn mt loi dao cch ly cho cc mch in cng cp in p.

Cc dao cch ly c chn v kim tra theo cc iu kin sau:

- in p: dm DCL dm MangU U

- Dng innh mc: dm DCL lvcbI I

- Kim tra theo iu kin n nh ng: d dm XKI i

- Kim tra theo iu kin n nh nhit: 2 .nh dm nh NI t B

i vi cc dao cch ly c 1000dmI A th khng cn kim tra n nh nhit.

Ta chn dao cch ly vi cc thng s sau: (Tra PL4.1 trang 159, PL4.6 trang 163, PL4.7 trang 164 sch Thit k phn in v trm binp PGS-TS Phm Vn Ho):

Bng 5.4 Thng s dao cch ly

Cp in p

(kV)

Cc i lng tnh ton

K hiu dao cch ly

Cc i lng nh mc

CBI

kA

XkI

kA

dmU

kV

dmI

kA

d dmI

kA

220 0,41 16,185 SGC-245/1250 245 1,25 80

110 0,434 29,012 SGCP-123/1250 123 1,25 80

10,5 4,547 81,428 PBK-20/7000 20 7 250

38

5.5. Chn my bin dng in (BI) v my bin in p(BU)

Hnh 5.3 S u ni BI, BU

5.5.1. Chn my bin in p(BU)

BU c chn theo cc iu kin sau:

- Loi bin in p c chn da vo v tr t, s ni dy v nhim v ca n. cp in cho cng t ch cn dng 2 BU mt pha u V/V.

- iu kin v in p: dm BU dm MangU U

- Cp chnh xc ca BU: Ph hp vi yu cu ca cc dng c o.

- Cng sut nh mc: 2dm BUS S

Trong ph ti th cp 2S c xc nh nh sau:

2 2

2 DC DCS P Q

DCP v DCQ l tng cng sut tc dng v phn khng ca cc dng c o, xc nh da trn s ni dy ca cc dng c o vo th cp ca my bin in p.

5.5.1.1. Chn BU cho cp in p 10kV

Ph ti cc pha ca cp 10 kV ghi vo bng sau:

A CB

AA AB AC kW kVAr

kW kWh kVArh

2 x HOM - 10

V f

c

b

a

MC

~

39

Bng 5.5 Ph ti cc pha ca BU

Tn ng h K hiu Ph ti pha AB Ph ti pha BC

P (W) Q(VAr) P(W) Q(VAr)

Vn k B 2 7,2 - - -

Ot k 341 1,8 - 1,8 -

Ot k phn khng 342/1 1,8 - 1,8 -

Ot k t ghi 33 8,3 - 8,3 -

Tn s k 340 - - 6,5 -

Cng t tc dng 670 0,66 1,62 0,66 1,62

Cng t phn khng 672 0,66 1,62 0,66 1,62

Tng cng 20,42 3,24 19,72 3,24

Ph ti ca my bin in p pha AB c:

2 22 20,42 3,24 20,675ABS VA

20,42

0,98820,675

ABCos

Ph ti ca my bin in p pha BC c:

2 22 19,72 3,24 19,984BCS VA

19,72

0,98719,984

BCCos

Tng ph ti th cp ca BU(xem nh cng h s cng sut):

2 2 2 20,675 19,984 40,659AB BCS S S VA

Ta chn BU cho cp in p 10,5kV c thng s: (Tra PL6.1 trang 169 sch Thit k phn in v trm binp PGS-TS Phm Vn Ho)

Bng 5.6 Thng s BU cp 10kV

Kiu BU

Cp in p

(kV)

in p nh mc

(V)

Cng sut nh mc ng vi cp chnh xc (VA)

Cng sut max

(VA) Cun s cp Cun th cp Cp 0,5 Cp1

40

HOM - 10 10 10500 100 75 150 640

Chn dy dn t BU n cc dng c o:

a) Tit din dy dn c chn sao cho tn tht in p trn n khng vt qu 0,5% (0,5V) in p nh mc th cp khi c cng t v 3% (3V) khi khng c cng t.

b) m bo bn c, tit din nh nht i vi dy ng l 21,5mm ; v i vi dy

nhm l 22,5mm .

Tnh dng in trong cc dy dn:

20,675

0,207100

ABa

AB

SI A

U

19,984

0,200100

BCc

BC

SI A

U

n gin ta coi: 0,207a cI I A v 1AB BCCos Cos

Nh vy dng in 3. 3.0,207 0,359b aI I A

in p ging trn dy A v B bng:

Vi dy ng c 20,0175 . /mm m

Gi s khong cch t dng c o n BU l 60l m

Trong cc ph ti ca BU c thit b o m in nng nn iu kin chn tit din dy dn l tn tht in p trn dy dn khng c ln hn 0,5% in p p nh mc th cp(0,5V).

.

. 0,5a bl

U l l VS

20,207 0,359

. . .0,0175.60 1,1890,5

a bI IS l mmU

Theo tiu chun bn c hc ta ly dy dn l dy ng c tit din 21,5S mm .

5.5.1.2. Chn BU cho cp in p 110kV v 220kV

Ph ti cp cho BU pha 110kV v 220kV thng l cc cun dy in p ca cc ng h o c tng tr tng i ln, cng sut thng nh nn khng cn tnh ph ti th cp.

Nhim v chnh ca cc BU cc cp in p ny l cung cp tn hiu cho rle bo v o lng cng sut, in nng v o lng in p do vy ta chn bin in p u Y0/Y0/

Ta chn cc BU c thng s sau: (Tra PL6.1 trang 170 sch Thit k phn in v trm bin p PGS-TS Phm Vn Ho) :

41

Bng 5.7 Thng s BU cp 110kV, 220kV.

Loi BU

Cp in p

(kV)

in p nh mc cc cun dy

(V)

Cng sut theo cp chnh xc

(VA)

Cng

sut max

(VA) S cp

Th cp chnh

Th cp ph

Cp 0,5 Cp 1

HK-110-58 110 110000 /100 3 100 / 3 100/3 400 600 2000

HK-220-58 220 220000 /100 3 100 / 3 100/3 400 600 2000

5.5.2. Chn my bin dng in (BI)

Bin dng c t trn c ba pha v ni hnh sao.

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

- S ni dy v kiu my: s ni dy ph thuc vo nhim v ca my bin dng in. Kiu bin dng in ph thuc vo v tr t trong nh hay ngoi tri,kiu xuyn, thanh dn, cun dy...

- in p nh mc: dm BI dm MangU U

- Dng in nh mc s cpvi kh nng qu ti cho php lu di 20% khng c nh

hn dng cng bc cho php: 1,2

CBdm SC

II

- Cp chnh xc ca BI chn ph hp vi yu cu ca dng c o. Ph ti th cp ca BI

chn tng ng vi cp chnh xc. BI c mt ph ti nh mc l dm BIZ . m bo

chnh xc yu cu tng ph ti th cp 2Z ca n k c tng tr dy dn khng c

vt qu .dm BIZ

2 dc dd dm BIZ Z Z Z

Trong :

dcZ tng ph ti ca dng c o.

ddZ tng tr dy dn ni t BI n dng c o.

- iu kin n nh ng: 2. .odd dm BI xkK I i

- iu kin n nh nhit: 2

. .odn dm BI odn NK I t B

42

Ch : Nu 1000dm BII A th khng cn kim tra n nh nhit.

5.5.2.1. Chn BI cho cp in p 10 kV

T s ni dy cc dng c o lng ni vo BI ta xc nh c ph ti th cp ca BI cc pha nh sau:

Bng 5.8 Ph ti ca BI cp 10kV

Tn dng c o lng K hiu Ph ti th cp (VA)

a b c

Ampe mt

Ot k tc dng

Ot k t ghi

Ot k phn khng

Cng t tc dng

Cng t phn khng

302

341

33

324/1

670

672

1

5

10

5

2,5

2,5

1

-

-

-

5

6

1

5

10

5

2,5

2,5

Tng cng 26 12 26

Thng s ca mng in.

- in p nh mc ca BI: 10,5dm BI dm MangU U kV

- Dng in nh mc s cp: 10,54,547

3,7891,2 1,2

CB

dm SC

II kA

- Cp chnh xc: 0,5 (v trong mch th cp c cng t)

T cc iu kin trn ta chn BI c cc thng s trong bng sau:(Tra PL5.1 trang 167 sch Thit k phn in v trm binp PGS-TS Phm Vn Ho)

Bng 5.9 Thng s BI cp 10kV

43

Loi BI

dmU

kV

dm SCI

A

dm TCI

A

Cp chnh xc

2 dmZ

/

1/

nh nhk t

s

20 6000 5 0,5 1,2 20/4

- My bin dng chn khng cn phi kim tra n nh ng v n c quyt nh bi iu kin n nh ng ca thanh dn mch my pht.

- Ta c 6000 1000dm BII A A do vy BI chn khng cn kim tra n nh nhit.

Chn dy dn t BU n cc dng c o:

m bo chnh xc yu cu, tng ph ti th cp khng vt qu ph ti nh mc:

2 1,2dc dd dm BIZ Z Z Z

Trong :

dcZ tng ph ti cc dng c o.

ddZ tng tr ca dy dn ni BI vi dng c o.

Ly gn ng:

.

dd dd

lZ R

S

dd dm BI dcZ Z Z

2.

dm BI dc

lS mm

Z Z

Tng ph ti ca cc pha: 26 ; 12a c BS S VA S VA

Ph ti ln nht: 26Max a cS S S VA

Tng tr cc dng c o mc vo pha A (hay pha C):

2 226

1,045

adc

dm TC

SZ

I

Gi thit khong cch t BI n dng c o l l = 60m v dng dy dn ng c

20,0175 . /mm m . V bin dng mc trn c 3 pha u hnh sao nn chiu di tnh ton l

60ttI l m

Tit din dy dn ni BI vi dng c o th cp c tnh theo cng thc:

2. 0,0175.60

6,5631,2 1,04dm BI dc

lS mm

Z Z

Vy ta chn dy dn bng ng c tit din l 210S mm

5.5.2.2. Chn BI cho cp in p 110 kV v 220kV

44

Cc my bin dng in i km vi cc mch my ct, c nhim v cung cp tn hiu cho h thng bo v rle v o lng.

BI chn theo iu kin.

- in p nh mc ca BI: dm BI dm MangU U

- Dng in nh mc s cp: 1,2

CBdm SC

II

- Vi cp in p 110kV ta c 110434

361,671,2 1,2

CBdm SC

II A

- Vi cp in p 220kV ta c 220410

341,671,2 1,2

CBdm SC

II A

Ta chn BI c thng s nh bng sau:(Tra PL5.1 trang 168 sch Thit k phn in v trm binp PGS-TS Phm Vn Ho)

Bng 5.10 Thng s BI cp 110kV

Thng s tnh ton

Loi BI dmU

kV

Bi s n nh

nhit

/kA s

Im

A

Cp chnh

xc

Ph ti

()

Bi s n nh ng

dmU

kV

1, 2

CBI

A

S cp

Th cp

110 361,67 THP-110M 110 34,6/3 600 5 P 1,2 110

Bn5.11 Thng s BI cp 220kV

Thng s tnh ton

Loi BI

dmU

kV

Bi s n nh

nhit

/kA s

Im

A

Cp chnh

xc

Ph ti

()

oddi

kA

dmU

kV

1, 2

CBI

A

S cp

Th cp

220 341,67 TH-220-3T 220 25,5/1 750 5 3P 2 45

a) Kim tra BI 220kV

- Kim tra iu kin n nh ng:

1

45 16,185odd xk Ni kA i kA

- Kim tra iu kin n nh nhit:

2 22 6 2. . 25,5.750 .1 365,766.10 .nh nh odn dm BI odnI t k I t A S

45

Ta tnh c xung lng nhit ca dng ngn mch ti im N1:

1

2 6 2. 365,766.10 .N nh nhB I t A S

Nh vy BI chn t yu cu.

b) Kim tra BI 110kV

- Kim tra iu kin n nh ng:

2

2. . 2.110.0,6 93,338 29,012odd odd dm SC xk Ni k I kA i kA

- Kim tra iu kin n nh nhit:

2 22 6 2. . 34,6.600 3 1292,933.10 .nh nh odn dm BI odnI t k I t A S

Ta tnh c xung lng nhit ca dng ngn mch ti im N2:

2

2 6 2. 1292,933.10 .N nh nhB I t A S

Nh vy BI chn t yu cu.

5.6. Chn cp v khng ng dy cho ph ti a phng

5.6.1. Chn cp cho ph ti a phng

- Ph ti a phng c cc thng s c bn nh sau:

+ 40 W ; 0,85.DP MaxP M Cos

+Gm c: 2 ng dy cp kp: 3 2 .MW km

2 ng dy cp n: 2 2 .MW km

Ta chn tit din dy theo phng php mt dng in kinh t.

in p nh mc: 10,5dm Cap dm MangU U kV

Ta s dng loi cp li ng i trong t.

5.6.1.1.Xt ng cp kp.

a) Chn tit din cp.

Dng in lm vic bnh thng ln nht qua cp:

33.10

97,032. . 3. 2.0,85. 3.10,5

bt

PI kA

Cos U

Dng in lm vic cng bc ca cp:

2. 2.97,03 194,06CB btI I kA

Tit din ca cp c chn theo mt dng in kinh t:

2btktkt

IS mm

J

Trong :

btI dng in lm vic bnh thng ln nht qua cp.(A)

46

ktJ mt dng in kinh t. 2/A mm

ktJ c xc nh da trn thi gian s dng cng sut ln nht ca ph ti a phng.

. 60%.6 90%.4 80%.4 100%.4 75%.6

.365 .365 6898,5100%

DPi i

Max

DP Max

P tT h

P

Tra bng 5.3 trang 56 sch thit k nh my in v trm bin p PGS-Nguyn Hu

Khi vi cp li ng cch in bng giy c 6898,5MaxT h ta c 22,0 /ktJ A mm

Tit din kinh t ca cp:

297,03

48,522

btkt

kt

IS mm

J

Vy ta chn cp li ng cch in bng giy tm du nha thng v cht do khng chy, v bng ch hay nhm, t trong t. (Tra trang 288 sch Thit k phn in nh my in v trm binp PGS-Nguyn Hu Khi)

Bng 5.12 Thng s ca cp a phng

dmU

kV

Tit din

2mm CPI

A

0CP

C

0

0

dm

C

10 50 180 60 15

b) Kim tra iu kin pht nng ca cp

Ta cn kim tra iu kin pht nng ca cp nh sau:

Kim tra iu kin pht nng khi bnh thng:

' 1 2. . 97,03CP CP btI k k I I A

Kim tra khi s c:

' 1 2. . . 194,06CPSC qt CP CBI k k k I I A

Trong :

CPI dng in lm vic lu di cho php ca cp.

1k h s hiu chnh theo nhit mi trng t cp

2k h s hiu chnh theo s cp t song song. Cp kp gm 2 cp n i song song, chn khon cch gia cc cp a=100 (mm), tra bng 11 trang 337 sch li in v h

thng in Trn Bch ta c 2 0,9.k

qtk h s qu ti s c.

47

t cp trong t c nhit 25 , nhit pht nng ca rut cp 10 kV cho php l 60 , nhit tiu chun l 15 . Do :

01

0

60 250,882

60 15

CP

CP dm

k

' 1 2. . 0,882.0,9.180 142,884 97,03CP CP btI k k I A I A

Vy cp chn tha mn iu kin pht nng khi bnh thng.

Khi xy ra s c mt l trong ng dy cp kp:

H s non ti khi lm vic bnh thng:

'

97,030,679 0,8

142,884

btnt

Cp

IK

I

Theo trang 68 sch thit k nh my in v trm bin pPGS-TS Phm Vn Ho Vy

h s qu ti s c ca cp: 21,3; 1qtK k

Dng in lm vic cho php qua cp trong ch s c( hiu chnh):

' 1 2. . . 1,3.0,882.180 206,338 194,06CPSC qt CP CBI k k k I A I A

Do vy cp chn tha mn khi lm vic trong ch qu ti.

5.6.1.2.Xt ng cp n

a) Chn tit din cp.

Dng in lm vic bnh thng ln nht qua cp:

32.10

129,378. 3. 0,85. 3.10,5

bt

PI kA

Cos U

Tit din kinh t ca cp:

2127,378

64,6892

btkt

kt

IS mm

J

Vy ta chn cp li ng cch in bng giy tm du nha thng v cht do khng chy, v bng ch hay nhm, t trong t. (Tra trang 288 sch Thit k phn in nh my in v trm binp PGS-Nguyn Hu Khi)

Bng 5.15 Thng s ca cp a phng

dmU

kV

Tit din

2mm CPI

A

0CP

C

0

0

dm

C

10 150 355 60 15

b) Kim tra iu kin pht nng ca cp

Ta cn kim tra iu kin pht nng ca cp nh sau:

Kim tra iu kin pht nng khi bnh thng:

48

' 1 2. . 129,378CP CP btI k k I I A

Trong :

CPI dng in lm vic lu di cho php ca cp.

1k h s hiu chnh theo nhit mi trng t cp.

2k h s hiu chnh theo s cp t song song. Do l cp n nn 2 1k .

t cp trong t c nhit 25 , nhit pht nng ca rut cp 10 kV cho php l 60 , nhit tiu chun l 15 . Do :

01

0

60 250,882

60 15

CP

CP dm

k

' 1 2. . 129,378CP CP btI k k I I A

Vy cp chn tha mn iu kin pht nng khi bnh thng.

V l ng dy cp n nn khng cn kim tra iu kin pht nng khi s c.

5.6.2. Chn khng ng dy cho ph ti a phng

Khng in l cun dy khng c li thp, in khng ln hn in tr rt nhiu. Khng in dng hn ch dng in ngn mch hay dng in m my ca ng c in khi khi ng. Do c th chn c cc thit b in dung lng nh hn. Ring vi khng in ng y cn c tc dng chn cp tit din b m vn m bo n nh nhit.

N 5

N 6

N 7

49

Hnh 5.4 S u khng in ca ph ti a phng ( 1kp v 1 n tnh ton)

Khng in c chn theo cc iu kin sau:

- in p: dm K dm MangU U

- Dng in: dm K lvcbI I

Trong : lvcbI dng in cng bc qua khng, c tnh khi ph ti a phng l ln nht v s c mt khng.

- Tr s in khng %KX chn xut pht t iu kin hn ch dng ngn mch c th

dng c cc kh c ng ct hng nh v cp c tit din nh hn m bo n nh nhit.

- Kim tra n nh ng: odd xki i

- Kim tra n nh nhit: 2 .nh nh NI t B

- Kim tra tn tht in p trn khng khi lm vic bnh thng v cng bc.

Dng in cng bc qua khng in c tnh ton nh sau:

340.10

2587,563. . 3.0,85.10,5

dp Max

lvcb

PI A

Cos U

Ta c 3000dm KI A

Ti trm cui ph ti a phng thit k chn my ct in c 20CatI kA . Thi

gian ct ngn mch ca my ct MC3 l 3 0,5Catt s , cp li ng tit din 250MinS mm

Thi gian ct ngn mch ca my ct MC2:

2 3 0,5 0,2 0,7Cat Catt t t

Xc nh in khng: %KX ca khng in:

in khng ca khng in ng dy dng cho ph ti a phng c chn sao cho m bo hn ch dng ngn mch nh hn hay bng dng ct nh mc ca my ct v m bo n nh nhit cho cp c tit din chn.

N5: im ngn mch ti ni u khng in. ( tnh chng 3)

N6: im ngn mch ngay sau MC2 u ng dy cp 1 phc v cho chn MC2 v kim tra n nh nhit cho cp 1 khi ngn mch.

N7: im ngn mch ngay sau MC3 u ng dy cp 2 phc v cho vic m bo n nh nhit cho my ct v cp chn.

S thay th:

X HT X K X C1 E HT X C2

N5 N7 N6 MC 2 MC 3 MC 1

50

Hnh 5.5 S thay th cc im khi ngn mch dng chn khng in

Khi lp s thay th cho tnh ton ngn mch chn:

10,5 10,5100 ; 10,5 ; 5,499CB CB CBS MVA U kV I kA

Dng ngn mch ti N5 c " 5 48,58NI kA

- Vy in khng ca h thng tnh n im ngn mch N5:

10,5

"

5

5,4990,113

48,58

CB

HT

N

IX

I

- in khng ca cp dy kp:

10,5

1 0

10,5

3. 3.5,499. . 0,08.2. 0,07

2. 2.10,5

CB

C

CB

IX x l

U

- in tr ca cp dy kp:

10,5

1 0

10,5

3. 3.5,499. . 0,077.2. 0,07

2. 2.10,5

CB

C

CB

IR r l

U

- in khng ca cp dy n:

10,5

1 0

10,5

3. 3.5,499. . 0,08.2. 0,143

10,5

CB

C

CB

IX x l

U

- in tr ca cp dy n:

10,5

1 0

10,5

3. 3.5,499. . 0,077.2. 0,143

10,5

CB

C

CB

IR r l

U

Dng n nh nhit ca cp 1S (cp n hoc cp kp) tnh cho cp c tit din nh hn

(cp li ng):

1

31

2

. 150.141.10 25,28

0,7nh S

S CI kA

t

Hng s C ph thuc vo vt lu lm dy dn (cp li ng) tra s tay k thut 1

2

2

.S141Cu

AC

mm

Dng n nh nhit ca cp 2S (cp li ng):

2

32

3

. 50.141.10 9,970

0,5nh S

S CI kA

t

Theo iu kin ca nhnh mt:

51

6 1

"

10,5

1. .5,499 25,28

0,113

HTN CB nh S

HT K K

EI I I kA

X X X

0,105KX

10,5

3% . .100% 0,105. .100% 5,73%

5,499

dm KK K

CB

IX X

I

Theo iu kin ca nhnh hai:

7 2

1 1

"

10,52 2

.HTN CB nh S

HT K C C

EI I I

X X X R

1 1 1

min ;C C Don C KepZ Z Z Chn dy cp kp 1 1C C KepZ Z

7

"

2 2

10,5

1.5,499 9,970

0,113 0,07 0,07

1,5% . .100% 0,364. .100% 19,86%

5,499

N

K

dm KK K

CB

IX

IX X

I

5.7. Chn my ct, dao cch ly cho ph ti a phng.

5.7.1. Chn dao cch ly

chn dao cch ly pha 10,5kV ta da vo kt qu tnh ton ngn mch im ngn

mch N5: 5

127,21XK NI kA

Dng lm vic bnh thng ca mch ph ti a phng:

340.10

1294,782. . 3. 2.0,85. 3.10,5

dp Max

lvbt

PI A

Cos U

Dng lm vic cng bc ca mch a phng:

2. 2.1294,78 2589,56 2,589cb lvbtI I A kA


- in p: dm DCL dm MangU U

- Dng in nh mc: 2,589dm DCL lvcbI I kA

- Kim tra theo iu kin n nh ng: 5

127,21odd xk Ni i kA

- Kim tra theo iu kin n nh nhit: 2 .nh nh NI t B


Ta chn loi dao cch ly c cc thng s bng sau: (Tra trang 240 sch Thit k phn in nh my in v trm bin p PGS Phm Hu Khi)

52

Bng 5.16 Thng s dao cch ly ca ph ti a phng

Cp in p

kV

Thng s tnh ton

Loi dao cch ly

Thng s dao cch ly

CBI

(kA)

xki

(kA)

dmU

(kV)

dmI

kA

xki

(kA)

10 2,589 127,21 PBP-20/6300Y3 20 6,3 220

Do dao cch ly c dng nh mc 6300 1000dm DCLI A A nn khng cn kim tra iu kin n nh nhit.

Chn my ct in cho cc mch.

My ct in l mt phn t rt quan trng trong h thng in, my ct in dng ng ct mch in vi dng ph ti khi lm vic bnh thng v dng ngn mch khi c s c bo v cc phn t trong h thng in.

thun tin cho lp t, vn hnh v sa cha ta chn mt loi my ct cho cc mch cng cp in p.

Cc my ct in c chn v kim tra theo iu kin sau:

- in p nh mc ca my ct: dm dm mangU U

- Dng in nh mc ca my ct: dm CBI I

- Dng in ct nh mc ca my ct: "

Cat dm NI I

Trong :

+ CBI l dng cng bc ca mch t my ct.

+ "

NI l dng ngn mch siu qu thnh phn chu k.

Ngoi ra my ct c chn cn phi kim tra iu kin n nh ng v n nh nhit khi ngn mch:

- Kim tra iu kin n nh ng: d dm xki i ( xki l dng xung kch khi ngn mch)

- Kim tra iu kin n nh nhit:2 .nh dm nh NI t B . Trong :

+ nh dmI - dnginn nh nhit ca my ctng vi thi gian n nh nhit .nht

+ NB - xung lng nhit ca dng ngn mch.

53

i vi cc my ct c 1000dmI A th khng cn kim tra n nh nhit. Cn c vo kt

qu tnh dng cng bc v dng ngn mch ta tin hnh chn my ct cho phng n 1 nh bng sau: (Tratrang 235 sch thit k phn in nh my in v trm binp PGS Nguyn Hu Khi)

Bng 4.1 Thng s my ct.

PA

Cp in p

(kV)

Cc i lng tnh ton

K hiu my ct

Cc i lng nh mc

CBI

(kA)

"

NI

(kA)

xki

(kA)

dmU

(kV)

dmI

(kA)

CatI

(kA)

d dmi

(kA)

1

220 0,31 4,493 11,437 3AQ1 245 4 40 100

110 0,803 7,553 19,227 3AQ1-FE 123 3,15 31,5 80

10,5 4,415 25,81 65,702 8FG10 12 12,5 80 225

5.8. Chn chng st van cho cc cp in p Chng st van l thit b c ghp song song vi thit b in bo v chng qu in p kh quyn. Khi xut hin qu in p, n s phng in trc lm gim tr s qu in p t trn cch in ca thit b v khi ht qu in p s t ng dp h quang xoay chiu, phc hi trng thi lm vic bnh thng.

Cc chng st van chn theo iu kin sau:

- in p nh mc ca chng st: dm CSV dm MangU U

Sau y ta tin hnh chn chng st cho tng cp in p.

5.8.1. Chn chng st van cho thanh gp

Trn cc thanh gp 220kV v 110kV t cc chng st van vi nhim v quan trng l chng qu in p truyn t ng dy vo trm. Cc chng st van ny c chn theo in p nh mc ca trm.

Ta chn loi chng st van sau:(Tra PL8.1 Trang 180 sch Thit k phn in nh my in v trm binp PGS-TS Phm Vn Ho)

Bng 5.18 Thng s chng st van thanh gp cp 110kV v 220kV

Loi chng st van

Cp in p

(kV)

in p ln nht ca li

(kV)

in p lm vic ln nht

(kV)

Dng in phng nh mc

(kA)

Vt liu v

SiC 220 245 216 50/63 S

54

3EP1 110 170 186 40 S

5.8.2. Chn chng st van cho my bin p

5.8.2.1.Chn chng st van cho my bin p t ngu

Cc my bin p t ngu do c s lin h v in gia cao p v trung p nn sng qu in p c th truyn t cao p sang trung p hoc ngc li. V vy, cc u ra cao p v trung p cc my bin p t ngu ta phi t cc chng st van.

- Pha cao p ca my bin p t ngu ta chn chng st van SiC 220 c 220dmU kV v thng s nh bng trn, t c 3 pha.

- Pha trung p ca my bin p t ngu ta chn chng st van 3EP1 110 c

110dmU kV v cc thng s nh trn bng, t c 3 pha.

- Pha h ca my bin p t ngu. Do my bin p t ngu ngoi nhim v ti cng sut t h ln cao v trung p cn c nhim v lin lc gia cao v trung v vy khi my ct pha h b ct ra th my bin p vn cn in. ng lc c sng qu in p truyn vo trm, chy v pha h ca my bin p t ngu. lc ny theo quy tc petersen sng b phn x qua li nhiu ln c tnh cht nng cao, xp chng dn n ph hng cch in pha h ca my bin p t ngu. phng trng hp ny ta t chng st van PBT-10 do lin bang nga ch to cc thng s nh trong bng, t c 3 pha.

Ta chn chng st van vi cc thng s sau: (Tra PL8.3 trang 181 sch Thit k phn in nh my in v trm binp PGS-TS Phm Vn Ho)

Bng 5.19Thng s chng st van ca MBA t ngu pha 10kV

Loi

dmU

(kV)

in p cho php ln nht

MaxU

(kV)

in p nh thng khi tn

s 50Hz

(kV)

in p nh thng xung kch khi thi gian phng

in 2 n 10s

(kV)

Khi lng

(kg)

PBT-10 10 12,7 26 50 6

Bng 5.20 Thng s chng st van u vo ca MBA t ngu pha 110kV, 220kV

Loi chng st van

Cp in p

(kV)

in p ln nht ca li

(kV)

in p lm vic ln nht

(kV)

Dng in phng nh mc

(kA)

Vt liu v

SiC 220 245 216 50/63 S

3EP1 110 170 186 40 S

55

5.8.2.2.Chn chng st van cho trung tnh my bin p hai cun dy

Mc d trn thanh gp 220kV v 110kV c t cc chng st van nhng i khi c nhng sng c bin ln truyn vo trm, cc chng st van y s phng in.in p d cn li truyn ti cun dy ca my bin p vn cn rt ln c th ph hng cch in ca cun dy c bit l phn cch in gn trung tnh nu trung tnh cch in theo iu kin vn hnh ca h thng (dao cch ly trung tnh m). V vy ti trung tnh ca my bin phai cun dy cn b tr mt chng st van mc song song vi dao cch ly.Tuy nhin do in cm ca cun dy my bin p nn bin sng st khi ti im trung tnh s gim mt phn, do chng st van t trung tnh c chn c in p nh mc gim i mt cp.

Ta chn chng st van vi cc thng s sau: (Tra PL8.1 trang 179 sch Thit k phn in nh my in v trm binp PGS-TS Phm Vn Ho)

Bng 5.21 Thng s chng st van t trung tnh my bin p

Loi chng st van

Cp in p

(kV)

in p ln nht ca li

(kV)

in p lm vic ln nht

(kV)

Dng in phng nh mc

(kA)

Vt liu v

B3,4 3EE 35 45 10 S

56

CHNG 6: CHN S NI IN V THIT B T DNG

6.1. Chn s t dng.

sn xut in nng cc nh my in phi tiu th mt phn in nng cc c cu t dng m bo cho my pht in c th lm vic c. Trong nh my nhit in in t dng chim t l kh ln ch yu cho cc khu chun b nhin liu, vn chuyn nhin liu vo l t, a nc vo ni hi, bm nc tun hon, bm ngng t, qut gi, qut khi, thp sang, iu khinphn in t dng quyt nh trc tip n s lm vic bnh thng ca nh my.

V vy s t dng ca nh my phi c tin cy tng i cao m vn m bo c nhng ch tiu v mt kinh t. Do nh my thit k khng c thanh gp in p my pht nn in t dng cho mi t my c ly ngay t u cc my pht qua cc my bin p h p.

Trong nh my nhit in, in t dng dng hai cp in p 6,3kV v 0,4kV.

- Cp t dng 6,3kV chim t l ln, cung cp cho ng c cng sut ln, m bo s lm vic ca l hi v cc t my.

- Cp t dng 0,4 kV cung cp cho ng c cng sut nh v chiu sng.

m bo cung cp in cho h thng t dng thng phn on h thng t dng cho ph hp vi s nhit v in ca nh my. S phn on ca thit b phn phi 6,3 kV khng c t hn s ni hi ca nh my khi ct mt phn on khng ko theo s ph hoi lm vic ln hn mt ni hi v tubin t my.

Nh my thit k c 5 t my 100MW v khng c thanh gp in p my pht, ta s dng s t dng gm 5 phn on thanh gp 6,3kV v 5 phn on thanh gp 0,4kV.

d tr cho cp 6,3 kV dng mt my bin p d tr ni vo pha h my bin p t ngu (pha trn my ct u cc). D tr cho cp 0,4kV cng dng mt my bin p ni vo thanh gp d phng 6,3kV.

Phn in t dng ca nh my thit k c b tr nh sau:

6.2. Chn cc thit b in v kh c in t dng

6.2.1. Chn my bin p t dng 10,5/6,3kV

Cc my ny c nhim v nhn in t u cc my pht 10,5kV cung cp cho ph ti t dng cp in p 6,3kV phn cn li cung cp tip cho ph ti cp in p 0,4kV. Ph ti ca h thng t dng phn phi theo s ng u gia cc phn on. Ph ti mi phn on ph hp vi t my tng ng v phn ph ti chung.

Cng sut t dng ln nht ca nh my:

130

. . 6%. 9,180,85

DatTD Max Dat

PS S MVA

Cos

Cng sut nh mc ca my bin p t dng cp 1 c chn nh sau:

1

9,184,59

2

TD Maxdm B

SS MVA

n

Ta chn my bin p c cc thng s nh sau:(Tra trang 140 sch Thit k phn in nh my in v trm binp PGS-Nguyn Hu Khi)

57

Bng 6.1 Thng s my bin p t dng cp 1 (10,5/6,3kV)

Loi my bin p dm CU

(kV)

dm HU

(kV)

dm BS

(kVA)

0P

(kW)

0P

(kW)

%NU 0 %I

THC 10,5 6,3 10000 12,3 85 14 0,8

Chn my bin p t dng d phng cp 1 (10,5/6,3kV).

Cng sut ca my bin p d tr c chn ph hp vi mc ch ca chng. My bin p d phng nu ch phc v thay th my bin p cng tc khi sa cha chng th cng sut nh mc ca n chn bng cng sut ca my bin p cng tc. Trong nh my in cn c my pht in c ni theo s b, nhim v ca my bin p d phng cn cung cp cho h thng t dng trong qu trnh dng v khi ng. Cng sut cn thit dng mt t my v khi ng t my khc chim khong 50% cng sut cn thit cho s lm vic bnh thng ca khi lc y ti. Bi vy cng sut ca my bin p d phng ln hn mt cp so vi cng sut ca my bin p t dng cp 1.

Cng sut my bin p d phng c chn nh sau:

19,18

1,5. 1,5. 6,8852

TD MaxdmB dp

SS MVA

n


Bng 6.2 Thng s my bin p t dng d phng cp 1 (10,5/6,3kV)

Loi my bin p dm CU

(kV)

dm HU

(kV)

dm BS

(kV)

0P

(kW)

0P

(kW)

%NU 0 %I

THC 10,5 6,3 10000 12,3 85 14 0,8

6.2.2. Chn my bin p t dng 6,3/0,4kV

Cp t dng 0,4kV cung cp cho cc ng c cng sut nh v chiu sng. My bin p d phng cp hai (6,3/0,4kV) lm nhim v thay th my bin p cng tc khi s c hoc sa cha, do vy ta chn cng loi vi my bin p cng tc.

Ngun cung cp t dng 0,4kV c ly t phn on 6,3kV xung. Thng thng cng sut t dng cp 0,4kV chim khong (15-20%) cng sut t dng mt t my. Khi my bin p t dng 6,3/0,4kV c chn theo iu kin sau:

2 2

9,180,2. 0,2. 0,918

2

TD Maxdm B dp

SS S MVA

n


Bng 6.3 Thng s my bin p t dng cp 2 (6,3/0,4kV)

58

Loi my bin p

dm CU

(kV)

dm HU

(kV)

dm BS

(kV)

0P

(kW)

0P

(kW)

%NU

TM 6,3 0,4 1600 2,8 18 5,5

6.2.3. Chn my ct 10,5 kV

Dng in cng bc:

9,18

1,5. 1,5. 0,3793. . 3.10,5.2

td MaxCB

SI kA

U n

Dng in ngn mch: 5 5

" " 48,58 ; 127,21N N xk NI I kA i kA

iu kin chn v kim tra my ct:

- in p: 10,5dm MC dm MangU U kV

- Dng in nh mc: 0,379dm MC lvcbI I kA

- Dng in ct nh mc: 5

" 48,58Cat dm NI I kA




i vi cc my ct c 1000dmI A th khng cn kim tra n nh nhit.

Ta chn my ct c cc thng s nh sau:(Tra trang 232 sch Thit k phn in nh my in v trm binp PGS-Nguyn Hu Khi)

Bng 6.4 Thng s my ct in cp 10kV

Cp in p

kV

i lng tnh ton

Loi my ct

i lng nh mc

CBI

(kA)

"

NI

(kA)

xki

(kA)

dmU

(kA)

dmI

(kA)

Cat dmI

(kA)

d dmI

(kA)

10,5 0,379 48,58 127,21 M-20-6000/3000 20 6 87 300

My ct c dng nh mc 6000 1000dm CatI A A nn khng cn kim tra iu kin n nh nhit.

6.2.4. Chn dao cch ly 10,5KV


- in p: 10,5dm DCL dm MangU U kV

- Dng in nh mc: 0,379dm DCL lvcbI I kA



59



Ta chn loi dao cch ly c cc thng s bng sau: (Tra trang 240 sch Thit k phn in nh my in v trm bin p PGS-Nguyn Hu Khi)

Bng 6.5 Thng s dao cch ly cp 10kV

Cp in p

kV

Thng s tnh ton

Loi dao cch ly

Thng s dao cch ly

CBI

(kA)

xki

(kA)

dmU

(kA)

dmI

(kA)

xki

(kA)

10 0,379 127,21 PBP-20/6300Y3 20 6,3 220

Dao c dng nh mc 6300 1000dm DCLI A A nn khng cn kim tra iu kin n nh nhit.

6.2.5. Chn my ct pha h ca my bin p t dng cp 1 (6,3kV)

n gin trong vn hnh, bo dng v sa cha cc thit b ta chn cc my ct ging nhau cho cng cp in p.

Dng in cng bc qua my ct c tnh nh sau:

9,18

1,5. 1,5. 0,633. . 3.6,3.2

TD MaxCB

SI kA

U n

chn my ct cho mch 6,3kV cn xc nh dng ngn mch sau cc my bin p t dng 10,5/6,3kV.

Trong chng tnh ton ngn mch ta tnh c dng ngn mch chn kh c in

mch t dng l: 5

" 48,58NI kA

in khng ca h thng tnh n im ngn mch N5:

5

10,5

"

5,4990,113

48,58

CB

HT

N

IX

I

in khng ca my bin p t dng cp 1:

1

1

% 14 100. . 1,4

100 100 10

N CBB

dm B

U SX

S

1

0,113 1,4 1,513HT BX X X

N 8

X B1 1,4 E HT

X HT 0,113

60

Hnh 6.2 S ngn mch dng chn my ct 6kV

Vy dng ngn mch ti im N8:

8

" 100 6,0573. . 3.6,3.1,513

CBN

TB

SI kA

U X

Dng xung kch ti im ngn mch N8:

8

2.1,8.6,057 15,42xk Ni kA

Ta chn my ct khng kh c cc thng s k thut sau: (Tra trang 237 sch Thit k phn in nh my in v trm bin p PGS Nguyn Hu Khi)

Bng 6.6 Thng s my ct 6kV

Cp in p

kV

i lng tnh ton

Loi my ct

i lng nh mc

CBI

(kA)

"

NI

(kA)

xki

(kA)

CBI

(kA)

"

NI

(kA)

xki

(kA)

d dmI

(kA)

6,3 0,63 6,057 15,42 8BM20 7,2 1,25 25 63

My ct chn c: 1250 1000dm MCI A A do vy khng cn kim tra n nh ng v n nh nhit.

6.2.6. Chn aptomat

p t mt c chn theo iu kin sau:

- in p nh mc: 0,4dmU kV

- Dng in nh mc: dm MaxI I

- Dng in ct nh mc:9

"

Cat dm NI I

Trong :

MaxI dng in ln nht pha 0,4kV

9,18

0,2. 0,2. 1325,01. 3. 2. 3.0,4

td MaxMax

dm

SI A

n U

chn aptomat ta tnh dng ngn mch ti thanh gp phn on 0,4kV (im N9).

9

"

NI dng ngn mch ti thanh gp phn on 0,4kV.

in khng ca my bin p t dng cp 2:

2

2

% 5,5 100. . 3,438

100 100 1,6

N CBB

dm B

U SX

S

61

1 2

0,113 1,4 3,438 4,951HT B BX X X X

Ta c s thay th tnh ton ngn mch nh sau:

Hnh 6.3 S ngn mch dng chn aptomat

Vy dng ngn mch ti im N9:

" 9100

29,153. . 3.0,4.4,951

CBN

TB

SI kA

U X

Tra bng 3.6 trang 150 sch S tay la chn v tra cu thit b in t 0,4 500 kV Ng Hng Quang ta chn aptomat c thng s k thut nh sau:

Bng 6.7 Thng s aptomat

dm MangU

(kV)

MaxI

(A)

"

NI

kA

Loi

aptomat

dmU

(kV)

dmI

(A)

Cat dmI

kA

0,4 1325 29,15 CM2000N 690 2000 50

N 9

X B1

1,4 E HT X HT

0,113

X B2

3,438

62

TI LIU THAM KHO

1. PGS.Nguyn Hu Khi. Thit k phn in nh my in v trm bin p. ( Nh xut bn khoa hc v k thut 2006)

2. TS. o Quang Thch, TS. Phm Vn Ha. Phn in trong nh my in v trm bin p. (Nh xut bn khoa hc v k thut 2009)

đồ án nhà máy điện

Documents