chuyen de thiet ke tba 160kva

n tt nghip

Phn II: Thit k trm bin p 160 kVA 10/0,4 kV

Phan Vn Hi TC-K46 - H Thng in

1

n tt nghip

1.1. t vn Trm bin p l mt trong nhng phn t quan trng nht ca h thng cung cp in. Vic thit k tnh ton trm bin p c nh hng trc tip n tin cy cung cp in, cht lng in nng cho ph ti, ng thi nh hng n chi ph vn hnh, u t ca mng in. 1.1.1. Ni dung thit k TBA Chn my bin p v s ni dy ca trm. Chn cc thit b in cao p v h p. Tnh ngn mch, kim tra cc thit b chn. Tnh ton ni t cho TBA 1.1.2. Cc s liu trm bin p cn thit k Cng sut nh mc: Sm = 160 kVA. in p nh mc : 10/0,4 kV in tr sut ca t : = 0,4.104 .cm Cng sut ngn mch : SN = 30 MVA 1.1.3. Phng n d kin Vi cng sut ca trm cho, d kin lp t TBA kiu treo, l kiu trm ton b cc thit b in cao p v h p cng vi MBA c t trn ct. i vi t phn phi h th c th thit k trn gin trm hay thit k trong bung phn phi di t l ty theo iu kin c th. u im ca TBA kiu treo ny l tit kim c din tch, gim ng k v chi ph u t. D ang c dng ph bin, tuy nhin, loi trm ny cng vi ng dy trn khng thng lm mt m quan thnh ph nn v lu di loi trm ny thng khng c khuyn khch dng th. Trm bin p c thit k kiu trm treo t 1 MBA c cng sut 160 kVA 10/0,4 kV trn 2 ct.


2

n tt nghip Pha cao p lp 1 b cu ch ngoi tri t ri bo v MBA khi ngn mch v 1 b chng st van chng sng st truyn t ng dy vo ph hoi MBA. Pha h p t t phn phi h th 0,4 kV. Trong c: 1 ptmt tng (AT) 3 ptmt nhnh (AN), 3 ng h AMPE o cng dng in ca trm, 1 ng h Vn, km 1 chnh mch kim tra in p pha, 1 cng t v cng, 1 cng t hu cng o cng sut tiu th ca trm, 1 b bin dng (TI). 1.2. Chn my bin p v s nguyn l trm bin p 1.2.1. Chn my bin p Chn my bin p ba pha hai dy qun loi 160 kVA 10/0,4 kV do ABB ch to c c thng s k thut sau: Bng 1.1. Thng s k thut ca my bin p Sm (kVA) 160 in p nh mc, kV Cao p 10 H p 0,4 Tn tht, W P0 500 Pn 2950 Un, % 4,5


3

n tt nghip 1.2.2. S nguyn l trm bin p

Hnh II.1.1. S nguyn l trm bin p Phan Vn Hi TC-K46 - H Thng in 4

n tt nghip 1.3. Chn cc thit b in cao p v h p Vic chn ng cc thit b in c ngha quan trng l m bo cho h thng cung cp in vn hnh an ton, tin cy v kinh t. 1.3.1. Chn cc thit b in cao p 1. Chn cu ch t ri Cu ch t ri chn theo iu kin: UmCC UmL ImCC Icb Icm Scm I S

Dng in ln nht lm vic lu di i qua cu ch Icb chnh l dng lm vic ln nht ca MBA. Trong nhng gi cao im cho php MBA qu ti 30%. Vy dng cng bc bng:dmB Icb = IqtMBA = 1,3.ImBA = 1,3 3.U = 1,3 3.10 = 12 A dm

S

160

Tra bng 2.1 trang 104 sch: S tay la chn v tra cu thit b in t 0,4 n 500 kV ca tc gi Ng Hng Quang ta chn cu ch t ri do Chance (M) ch to c cc thng s sau: Bng 1.2. Thng s ca cu ch t ri Loi cu ch C710 - 114PB 2. Chn s cao th Tra PL III - 21 - trang 275- Gio trnh thit k cp in, ta chn s cao th t ngoi tri do Lin x ch to, c cc thng s sau: Ulvmax, kV 15 Im, A 100 IN, kA 16 Trng lng, kg 7,98


5

n tt nghip Bng 1.3. Thng s ca s cao th Kiu OH - 10 - 500 3. Chn chng st van Chn chng st van (CSV) theo iu kin v in p :UmCSV UmL Chn chng st van do Lin X ch to PB - 10 c cc thng s sau: Bng 1.3. Thng s ca chng st van in p nh thng khi f=50 Hz, kV PB 10 10 12,7 25 in p nh thng xung kch khi tp = 2 10s, kV 50 6 Khi lng, kg Um, kV 10 F, kg 500 UPh. kh, kV 50 UPh. t, kV 34 Khi lng, kg 4,1

Loi

UmCSV, kV

Ucpmax, kV

4. Chn thanh dn u vo trm bin p Dng in lm vic ln nht:Ilvmax

=

S 160 = = 9,23 A 3U 3.10dmB dm

Thanh dn c chn theo Ilvmax v bn c hc, ta chn thanh dn ng trn c ng knh 8mm c sn mu phn bit cc pha. Bng 1.4. Thng s ca thanh dn u vo trm bin p Loi Thanh ng trn 1.3.2. Chn thit b h p Cc thit b h p c chn theo iu kin: UmtbH Udm mngH ImtbH I lvmax 6 ng knh, mm 8 ICP, A 235


n tt nghip trong : Ilvmax l dng in ln nht chy qua thit b pha h p. I lvmax =S 3Udm B

=

dm H

160 =230,94 A 3.0,4

1. Chn cp tng h p t s h th ca MBA n t phn phi Chn cp ng h p 4 li cch in PVC, do hng LENS ch to c cc thng s sau: Bng 1.5. Thng s ca cp tng h p F(mm2) 3 x150+70mm2 2. Chn ptmt tng Chn theo dng in cng bc chy qua ptmt: iu kin: I mA Icb= 1,3.Ilvmax =1,3 . 230,94 = 300,2 A Chn ptmt tng loi hng Merlin Gerin ch to. Bng 1.6. Thng s ca aptomat tng Loi NS400N 3. Chn ptmt nhnh T thanh ci h p c 3 l ra cung cp cho h tiu th, coi cng sut cc l nh nhau th cng sut mi nhnh l: S cc 3 Um, V 690 Im, A 400 Ict N, kA 10 r0 200C, /km 0,206 ICP, A Trong nh 300 Ngoi tri 304

I lvmax =I lvnhanh =

I lvH 230,94 = =76,98A 3 3

Chn ptmt nhnh do hng Merlin Gerin ch to: Bng 1.7. Thng s ca Aptomat nhnh Loi NC 125H 4. Chn cp xut tuyn iu kin: I mA Ilvmax vi Ilvmax = 76,98 A Phan Vn Hi TC-K46 - H Thng in 7 S cc 3 Um, kV 0,415 Im, A 125 Ict N, kA 10

n tt nghip Chn cp ng 4 li cch in bng PVC do LENS ch to: Bng 1.8. Thng s ca cp xut tuyn F, mm 4 G 25 Li 6,0 d, mm V Min 20,5 Max 25,5 M, kg/km 1294 r0 200C, /km 0,727 Icp, Trong nh Ngoi tri 144 127

5. Chn thanh ci h p Chn thanh ci h p dng hnh ch nht bng ng, thanh gp t nm ngang, t 3 thanh gp trn 3 pha cch nhau 15 cm. Mi thanh c t trn hai s khung t cch nhau 70 cm. Thanh gp c chn theo iu kin pht nng lu di cho php: k1.k2.Icp Icb trong : k1 = 0,95 vi thanh gp t nm ngang; k2 - H s hiu chnh theo nhit mi trng , k2 = 1. Do :Icp Icb 230,94 = = 243,1 A 0,95 0,95

Theo bng 7.2 sch s tay la chn v tra cu thit b in t 0,4 n 500 kV ca tc gi Ng Hng Quang: thanh dn c chn c thng s k thut sau: Bng 1.9. Thng s ca thanh gp Kch thc, Tit din mt thanh, mm2 mm 30x3 6. Chn s h p S cch in c chn theo iu kin: UmS Um.L = 0,4 kV; ImS Ilv max = 76,98 A; Lc cho php tc ng ln u s Fcp = 0,6.Fph k.Ftt ; Phan Vn Hi TC-K46 - H Thng in 8 90 Khi lng, kg/m 0,8 Icp, A 405 ro, m /m 0,223 xo, m /m 0,189

n tt nghip Dng n nh nhit cho php : Im.nh I. Cc thng s k thut ca s h p c chn cho trong bng: Bng 1.10. Thng s ca s h p Loi s O -1-375 7. Chn bin dng in iu kin chn my bin dng: Um BI Um.L = 0,4 kV; Im BI Ilv max = 76,98; Ph ti cun th cp S2mBI Stt. Chn BI do Lin X ch to, s lng 3BI t trn 3 pha, u hnh sao. Theo bng 8.9 sch s tay la chn v tra cu thit b in t 0,4 n 500 kV ca tc gi Ng Hng Quang, BI c chn c thng s k thut sau: Bng 1.11. Thng s ca bin dng in Loi TKM 0,5 Um, kV 0,5 Im, A 200 Cp chnh xc 0,5 S, VA 10 Um, kV 1 UP kh, kV 11 Fph hoi, kg 375 Khi lng, kg 0,7

8. Chn cc thit b o m Bng 1.12. Thng s ca cc thit b o m Cp chnh xc 1,5 1,5 TB A TB 2 2 1,5 1,5 W 3W 9 Cng sut tiu th, VA Cun in p Cun dng in 0,1

Tn ng h Am Pe - mt Vn - mt Cng t tc dng

K hiu A V Wh

Loi (0 400)A (0 450)V Wh

Cng t phn VArh VArh 9. khng dy dn t BI n cc dng c o A Chn Phan Vn Hi TC-K46 - H Thng in

n tt nghip m bo bn c hc ta chn loi dy ng 1 si bc nha PVC c tit din 2,5mm2. 10. Chn chng st van h p Chn chng st van in p thp loi PBH do Lin X ch to bo v qu in p cho cch in ca thit b xoay chiu tn s 50 Hz. Tra bng 8.4 sch s tay la chn v tra cu thit b in t 0,4 n 500 kV ca tc gi Ng Hng Quang chng st van c chn c thng s k thut. Bng 1.13. Thng s ca chng st van h p Loi UmCSV, Ucpmax, kV PBH-0,5 Y1 0,5 kV 0,5 in p nh in p nh thng Khi lng, xung kch khi thng khi f=50, kg Hz tp = 2 10s, kV 2,5 3,5-4,5 2,0

11. Chn t phn phi h p Chn v t h p do nh my thit b in ng Anh ch to. Trn khung t lm sn cc l g dy c c th lp cc gi ty theo cc thit b chn lp t trn. Bng 1.14. Thng s ca t phn phi h p Kch thc Di 1200 Rng 800 Su 400 S cnh ca t 1

1.4. Tnh ton ngn mch v kim tra thit b in la chn Ngn mch l tnh trng s c nghim trng v thng xy ra trong h thng cung cp in. Cc dng ngn mch thng xy ra l: ngn mch ba pha, hai pha v ngn mch mt pha chm t. Trong , ngn mch 3 pha l nghim trng nht. V vy ngi ta thng cn c vo dng ngn mch ba pha la chn v kim tra cc thit b in. 1.4.1. Tnh ton ngn mch Phan Vn Hi TC-K46 - H Thng in 10

n tt nghip Gi thit ngn mch xy ra l ngn mch ba pha i xng v coi ngun c cng sut v cng ln, coi trm bin p xa ngun nn khi tnh ton ngn mch ly: IN = I trong : IN: dng in ngn mch, kA; I: dng in ngn mch siu qu , kA; I : gi tr dng in ngn mch ch xc lp kA; U: in p ng dy, kV;Z : tng tr ng dy n im ngn mch, .

"

= I =

U dm 3.Z

Cc im ngn mch cn tnh ton trong s :

im N1: Kim tra cu ch t ri pha cao p im N2, N3: Kim tra cc thit b h p 1. Tnh ngn mch pha cao p (N1) +/ S thay th: Phan Vn Hi TC-K46 - H Thng in 11

n tt nghip

HT

XHT

XD N1

+/ Chn cc i lng c bn: Utb1= 0,4 kV Utb2=10,5 kV in khng ca h thng in bng :2 U dm 102 = XHT = = 3,3 SN 30

in khng ca ng dy t trm bin p khu vc n trm bin p phn phi bng ng dy di 2,5km,dy AC-70 XD = x0.l = 0,44.2,5 = 1,1 Dng in ngn mch ba pha bng: IN1 =U tb = 3.(X HT + XD )10, 5 = 1,37kA 3.(3,3 + 1,1)

Tr s dng in xung kch l (V ngn mch xa ngun nn kxk=1,8): ixk1 = 1,8. 2 .IN1 = 1,8. 2 .1,37 = 3,5 kA 2. Tnh ngn mch pha h p Khi tnh ton ngn mch pha h p c th coi my bin p h p l ngun. V

vy, in p pha h p khng thay i khi ngn mch. Do ta c IN = I

"

= I

Mt khc, phi xt n in tr, in khng ca tt c cc phn t trong mng nh: my bin p, dy dn, cun dng in ca ptmt, thanh ci a. Tnh ngn mch ti im N2 + S thay th:HT ZB ZC ZAT N2


12

n tt nghip

Tng tr ca my bin p l: ZB2 2 PN .U dm U %. U dm .106 + j N .106 = 2 Sdm 100.Sdm

2,95.0, 42 4,5.0, 42 6 .10 + j .104 = 18,43 + j 45m = 2 160 160

Cp t my bin p n t phn phi l cp 3 x150+70mm2. Gi thit cp ni t my bin p n t phn phi di 10m. r0 = 0,206 m/m x0 = 0,07 m/k (ly gn ng) Do , tng tr ca cp l: ZC = (0,206 + j 0,07 ) . 10 = 2,06 + j 0,7 m Tng tr ca cun dy bo v qu dng in ca ptmt tng c Im=400A tra bng 3.54 sch s tay la chn v tra cu thit b t 0,4 n 500kV ca tc gi Ng Hng Quang: ZAT = 0,12 + j 0,094 m Vy tng tr ca im ngn mch N2 l: Z = ZB + ZC + ZAT = 18,43 + j 45+ 2,06 + j0,7 + 0,12 + j0,094 = 20,61 + j45,794 m Vy:Z = 20, 612 + 45, 794 2 = 49,9 m

Dng in ngn mch ba pha bng:IN2 = U dm = 3.Z 400 = 4, 63 kA 3.49,9

Tr s dng in xung kch l ( V ngn mch xa ngun nn kxk=1,8): ixk2 = 1,8.2

. IN2 = 1,8.

2

. 4,63 = 11,78 kA 13


n tt nghip b. Tnh ngn mch ti im N3 S thay th:

HT

ZB

ZC

ZAT

ZTC

ZAN

N3

Tng tr thanh ci h p tra trong s tay c: ZTC = l.( r0TC + x0TC ) =1,2.(0,223+ j0,189) = 0,268 + j0,227 m Tng tr ca cun dy bo v qu dng in ca ptmt nhnh c Im=125A tra bng 3.54 sch s tay la chn v tra cu thit b t 0,4 n 500kV ca tc gi Ng Hng Quang: ZAN = 0,74 + j0,55 m Vy tng tr ca im ngn mch N3 l: Z3 = Z2 + ZTC + ZAN = (19,79 + j45,794) + (0,268 + j0,227) + (0,74 + j0,55) = 20,68 + j46,548 m Do : Z3 = 20, 682 + 46,5482 = 50, 93 m Dng in ngn mch ba pha bng:I N3 = U dm = 3.Z 3 400 = 4,53 kA 3.50,93

Dng in xung kch bng (V ngn mch xa ngun nn kxk=1,8): ixk3 = 1,8.2

. IN3 = 1,8.

2

. 4,53 = 11,54 kA

1.4.2. Kim tra cc thit b la chn 1. Kim tra cu ch t ri iu kin kim tra: Sm ct SN1; Im ct IN1. Phan Vn Hi TC-K46 - H Thng in 14

n tt nghip Cu ch t ri chn c: Im ct = 16 kA > IN1 = 3,5 kA Sm ct = 3.U m.Im ct = 3 .10.16 = 277, 128 MVA SN1 = 3 .Um.IN1 = 3 .10 . 1,37 = 23,73 MVA Vy Sm ct > SN1 . Do cu ch t ri chn t yu cu. 2. Kim tra cp h p Kim tra theo iu kin n nh nhit: F..n . IN. t qd trong : : l h s nhit. Vi cp li ng: = 6; tq: l thi gian qui i, ly bng thi gian tn ti ngn mch. V coi ngn mch trong h thng cung cp in l ngn mch xa ngun nn tq = 0,5s; IN = IN2 = 4,63 kA Ta c: .IN . t qd = 6.4,63. 0,5 = 19,64 < F = 150 mm2. Vy cp chn tha mn yu cu. 3. Kim tra ptmt ptmt tng IcmA = 10 kA I N2 = 4,63 kA Vy ptmt tng t yu cu. ptmt nhnh IcmAN = 10 kA I N3 = 4,53 kA Vy ptmt nhnh t yu cu. 4. Kim tra thanh ci h p Kim tra n nh lc in ng:


15

n tt nghip Khi c ngn mch sy ra, dng in ngn mch chy qua thanh ci lm cho thanh ci chu mt lc rt ln, s rung ng c th lm cho thanh ci b un cong dn n ph hoi thanh ci v cc s . Do phi kim tra thanh ci theo iu kin sau : tt cp

Lc tc dng ln thanh dn do ixk gy ra:L 2 Ftt = 1, 76.10 -2. .i xk a

trong : L=70 cm l khong cch gia cc s thanh ci; a=15 cm l khong cch gia cc pha; Ixk=3,5 kA l dng in xung kch khi ngn mch. Do :Ftt = 1, 76.10 2. 70 .3,5 2 = 1, 006 kg 15

M men un:M= Ftt .L 1,006.70 = = 7,04 kg.c m 10 10

ng sut tnh ton: tt =M W

trong : W l m men chng un ca thanh dn i vi tr thng gc phng ca lc tc dng. y cc thanh ci t nm ngang nn:W= b.h 2 6

Vi b = 3 mm, h = 30mm, ta c:W= 0,3.32 = 0, 45cm 3 6

Vy: Phan Vn Hi TC-K46 - H Thng in 16

n tt nghip tt = 7,04 =15,6 kg/cm 2 0, 45tt

ng sut cho php vi ng l 1400 kg/ cm2 > Kim tra n nh nhit khi ngn mch iu kin kim tra: F..n Fmin = . I. t qd trong : : l h s nhit. Vi thanh ng: = 6;

= 15,6 kg/ cm2

Do thanh dn chn m bo iu kin n nh ng.

tq: l thi gian qui i, chn theo iu kin ct ca Aptomat. Ly tq = 0,5s; Fmin: l tit din tnh ton nh nht m bo iu kin n nh nhit I = IN2 = 4,63 kA Ta c: Fmin = .IN2 . t qd = 6.4,63. 0,5 = 19,64 mm2 < F = 90 mm2. Vy thanh ci chn m bo iu kin n nh nhit. 5. Kim tra s h p iu kin kim tra: FCP > Ftt trong : FCP = 0,6. FPh = 0,6. 375 = 225 kg Ftt = F1.H + h/ 2 l 2 H +h / 2 = 1,76. 10-2. .ixk 2 . H a H

V l = 70 cm ; a = 15 cm ; h = 4 cm ; H = 6,5 cm Do : Ftt =1,76. 10-2.6, 5 + 4 / 2 70 .11, 782 . =14,98 kg 6, 5 15

Ta thy: FCP =225 kg > Ftt=14,98 kg nn s c chn tha mn yu cu.


17

n tt nghip 6. Kim tra my bin dng Cng sut nh mc th cp BI l: SmBI =10 VA > Stt = 7,1 VA, nh vy BI chn tho mn iu kin. 1.5. Tnh ton ni t cho trm bin p Tc dng ni t l tn dng in, gi mc in th thp trn cc vt c ni t, m bo s lm vic bnh thng ca thit b. Ngoi ra vic ni t cc phn khng mang in (t in, v my) m bo an ton cho ngi vn hnh. D kin h thng ni t bao gm cc thanh thp gc L60 60 6 di 2,5m c ni vi nhau bng cc thanh thp trn 12, to thnh mch vng ni t bao quanh trm bin p. Cc thanh thp gc ng su di t 0,7m, thp trn c hn cht vi cc cc su 0,8m. in tr ni t yu cu ca trm bin p l : Rnyc 4 in tr sut ca t l : = 0,4.104 .cm H s hiu chnh theo ma ca in tr cc v thanh l:t c K m = 1,6; K m = 1,4

Hnh II.1.2. S mt bng v mt ct h thng ni t trm bin p

1.5.1. Tnh in tr ni t ca thanh in tr ni t ca thanh c tnh theo cng thc sau: Rt = trong : kL2 ln 2L h.d

=

d0

t .K m = 0,4.104.10-2.1,6 = 64 m;


18

n tt nghip L: l tng chiu di ly bng chu vi L= (10+5).2 =30m; h: l su (h = 80 cm); d: ng knh thanh ca thp trn d = 0,012 m; k : h s ph thuc vo hnh dng ca h thng ni t, K = f(l1/l2).Theo thit k mch vng ta c l1/l2 =10/5=2. Tra bng 2.6 sch hng dn thit k tt nghip KTCA ca tc gi Nguyn Minh Chc c k=6,42. Do in tr ni t ca thanh c tnh:64 6, 42.302 ln Rt = = 4,52 2 .30 0, 012.0,8

1.5.2. Tnh in tr ni t ca cc Gi thit: + S cc cn phi ng l n; + Khong cch gia cc cc l a = L/n; + Chiu di cc l=2,5m. Nu ly t s a/l=2 th a = 2.2,5 = 5 m Vy s cc phi ng l: n=L 30 = = 6 cc a 5

Tra ti liu KTCA ta c h s s dng ca thanh v cc l t =0,48, coc = 0,75. in tr ni t ca n cc c tnh theo cng thc: Rc = trong : : in tr sut c hiu chnh theo ma

2.l 1 4t + l .(ln + ln ) 2 .l d 2 4t l

= d 0 . k c = 0,4.104.102.1,4 = 56 .m ; m

l: l chiu di cc (l=250 cm); t = h + L/2 = 80 + 250/2 = 205 cm; d: l ng knh cc. d = 0,95b = 0,95.6 = 5,7 cm. Phan Vn Hi TC-K46 - H Thng in 19

n tt nghip Thay s vo ta c: RC = 2 .2,5 (ln 0, 057 + 2 ln 4.1,95 2,5 ) = 17,07 1.5.3. in tr ni t ca ton trm RHT = R . + n.R . = 17, 07.0, 48 + 6.4,52.0, 75 = 2,70 C t t C Vy ta c RHT = 2,70 < Ryc = 4 Do phng n ni t vch ra trn t yu cu v k thut. Kt lun: H thng ni t dng 6 cc thp L60 60 6 di 2,5m c ni vi nhau bng cc thanh thp trn 12, to thnh mch vng ni t bao quanh trm bin p. Cc thanh thp gc c ng su di mt t 0,7m, thp trn c hn cht vi cc cc su 0,8m tha mn yu cu v mt k thut.RC .Rt

56

2.2,5

1

4.1,95 + 2,5

17, 07.4,52


20

n tt nghip


21

chuyen de thiet ke tba 160kva

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