1 B GIO DC V O TOI HC NNG

DNG VN L

LA CHN CU TRC HP LH THNG CUNG CP IN KHU TH MIIN NAM - IN NGC ( QUNG NAM)

LUN VN THC S K THUT

Nng- Nm 2004

2B GIO DC V O TOI HC NNG

DNG VN L

LA CHN CU TRC HP LH THNG CUNG CP IN KHU TH MIIN NAM - IN NGC ( QUNG NAM)

Chuyn ngnh : Mng v H thng in M s : 60.52.50

LUN VN THC S K THUT

Ngi hng dn khoa hc: TS TRN VINH TNH

Nng- Nm 2004

3 LI CAM OAN

Ti xin cam oan y l cng trnh nghin cu ca ring ti, trn c s

vn dng l thuyt Mt s vn v qui hoch, thit k, vn hnh cc h

thng cung cp in th ca Tin s ng Quc Thng v s gip

trong qu trnh thc hin ca Tin s Trn Vinh Tnh

Cc s liu, kt qu nu trong lun vn l trung thc v cha tng c

cng b trong bt k cng trnh no khc .

Qua y, ti xin chn thnh cm n Tin s Trn Vinh Tnh c nhiu

ch dn qu bu, gip ti hon thnh lun vn ny.

Tc gi:

DNG VN L

4MC LC

TRANG

Trang ph ba Li cam oan 1Mc lc 2Danh mc cc k hiu, ch vit tt 4Danh mc cc bng 4Danh mc cc hnh v, th 4

Chng M u 6 1- L do chn ti 6 2- Mc ch nghin cu ca ti 8 3- i tng v phm vi nghin cu 8 4- ngha khoa hc v ngha thc tin ca ti 8

Chng 1- Tng quan 10 1.1 Tng quan li phn phi 10 1.2 Cng tc qui hoch,thit k li phn phi 12 1.2.1 Hm chi ph tnh ton 12 1.2.2 Cc phng php tnh ton li phn phi 15

1.2.2.1 Tnh li phn phi theo iu kin cc tiu phtn tnh ton vi thnh phn tn tht in p kinh t

15

1.2.2.2 Tnh li phn phi theo iu kin mt dng in kinh t

19

1.2.2.3 Tnh li phn phi theo iu kin ti u bn knh cung cp in

19

1.2.2.4 Tnh li phn phi theo iu kin khong chia ph ti kinh t

26

1.2.2.5 L do chn phng php khong chia ph tikinh t

27

Chng 2- Trnh t cc bc thit k theo phng php khongchia kinh t

29

2.1 S khi bi ton theo phng php khong chia ph ti kinh t

30

2.2 Cc gi nh 31 2.3 Cc bi ton nh 31

5 2.3.1 Bi ton chn tit din cp 33 2.3.2 Bi ton chn chiu di cp 36 2.3.3 Bi ton chn cng sut MBA 39 2.4 Ni dung chi tit cc bc tnh ton 41

Chng 3- Xc nh cu trc hp l cho h thng cung cp inKhu th mi in Nam - in Ngc

45

3.1 Gii thiu s lc Khu th mi in Nam - in Ngc 45 3.2 Mt s gi thit trc khi tnh ton 47 3.3 Xc nh cc s liu ph ti 51 3.4 Trnh t cc bc khi tin hnh la chn cu trc hp l cho

HTCCT53

3.5 Chng trnh tnh ton vit trn ngn ng PASCAL 54 3.6 Kt qu bi ton 54 3.7 Hiu chnh theo nhng iu kin ring 54 3.8 Kt lun 55

Chng 4- Kt lun v hng nghin cu tip theo 57 4.1 Kt lun 57 4.2 Hng nghin cu tip theo 58

TI LIU THAM KHO 60PH LC 1: Chng trnh vit trn Pascal PH LC 2: Kt qu bi tonPH LC 3: Chi ph tnh ton li h p Khu th mi in Nam-

in Ngc

6DANH MC CC K HIU, CC CH VIT TT

STT NI DUNG,TN VIT TT1 Chiu di hp l cp trc Lop2 H thng cung cp in HTCC3 H thng cung cp in th HTCCT4 H s ph tn vn hnh vhD5 H s tiu chun thu hi vn u t tcD6 Hm chi ph tnh ton Z7 My bin p MBA8 Mt ph ti V9 Ph tn do tn tht in nng hng nm ca

phng n th i Yi'A

10 Tit din cp F11 Tn tht in p U'12 Tn tht ngn mch MBA nP'13 Tn tht khng ti MBA 0P'14 Vn u t ca phng n th i Ki

DANH MC CC BIU BNG

STT TN BNG K HIU1 Sut ph ti Bng 1.1 2 Sut u t TBAPP Bng 3.1 3 Sut u t ng cp h th Bng 3.2 4 Mt s tiu ch Khu th mi in Nam-

in NgcBng 3.3

5 So snh kt qu Bng 4.1

DANH MC CC HNH V, TH

STT TN HNH V, TH K HIU1 Mt cu trc li phn phi c bn 1.12 S thut ton phng php khong chia ph ti

kinh t2.1

3 th khong chia kinh t ng cp 2.2

74 M t mt xut tuyn cp trc xc nh tit din 2.35 M t mt xut tuyn cp trc xc nh chiu di 2.46 S chi tit cc bc tnh ton 2.57 Cu trc c bn mt TBAPP v li 0,4KV 3.18 Cu trc c bn mt TBAPP v li 0,4KV 3.29 Cu trc c bn mt TBAPP v li 0,4KV 3.3

10 S ph thuc cng sut MBA c chn theo mt ph ti

4.1

11 Minh ha s ph thuc cng sut MBA c chntheo mt ph ti

4.2

8CHNG M U1 L DO CHN TI :

Yu cu c bn ca h thng in l phi lun lun m bo cung cp

in lin tc v m bo cht lng in nng trong phm vi cho php cho

cc h tiu th v tho mn tnh kinh t. Nhim v i hi cn b lm

cng tc thit k phi gii quyt nhng bi ton v kinh t - k thut la

chn phng n ti u nhm t mc tiu ra

Trong khuynh hng chung, vic la chn cu trc v cc thng s

ca HTCCT thng cn c vo nhu cu s dng in nng, ch lm

vic ca cc ph ti in... a ra cc phng n cung cp in, la chn

cc s cp in, trn c s phn tch cc ch tiu kinh t-k thut, la

chn phng n thit k hp l. Tuy nhin, phng php ny cng bc l

mt s nhc im [12]: Ch yu da vo kinh nghim chuyn gia, khi

lng tnh ton ln, c th t ti u cc b trong hin ti nhng c th tr

nn t hiu qu trong tng lai, nh s chng loi thit b, vt t trong ton

h thng c th rt ln, gy kh khn cho cng tc lp t, sa cha, vn

hnh sau ny

Vic la chn cc thng s cu trc ca HTCCT i hi phi

tun theo mt ch tiu thng nht vi tnh ti u tng th. Do vy cn c qui

hoch tng th trc khi c thit k c th v mi thit k c th phi tun

theo qui hoch tng th. Cng v vy, vic la chn thng s cu trc hp l

cho HTCCT l mt bi ton hp nht gia thit k v qui hoch, rt

phc tp vi nhiu tham s lin quan, bin thin lin tc nh in p, dng

in... v bin thin gin on nh chiu di, tit din ng dy, s lng

v cng sut cc trm bin p, gi in,... Qu trnh qui hoch tng th s

bt u t s phn tch nhng tnh cht c trng ca cu trc mt ph

ti, thit k la chn thng s cu trc hp l ca trm bin p phn phi v

9li h p, sao cho HTCCT tho mn nhu cu in nng trong mt thi

k tng i di vi s tng trng lin tc ca nhu cu ph ti. Hm mc

tiu cn t c l tng vn u t v chi ph vn hnh cc tiu ( xt trong

c chu k tnh ton ) Vic gii bi ton nh th s gp rt nhiu kh khn

[10], cc l do ch yu l :

+ a hnh t nhin khng phi bao gi cng cho php hnh thnh li

tng ng vi s nh trc ( theo li gii ti u )

+ Nhiu thng s cn la chn ch c th trong phm vi hoc nhng tr

s bt buc (tit din dy dn, thang cng sut MBA. . .)

+ Gi bn in, vn u t trang thit b, chi ph vn hnh . . . lun

bin ng

+ Tc tng trng ph ti kh xc nh,v tr phn b ph ti khng

ng u, phi qui lut. . .

Vi tnh cht phc tp v a ch tiu nh trn, vic gii bi ton la

chn mt cu trc ti u li phn phi trong trng hp tng qut, ni

chung l khng th gii c. Tuy nhin, c th c mt cu trc hp l,

chng ta c th tm cch ti u ho theo mt s tiu chun nh:

- Tiu chun gii hn la chn tit din ng cp trc

- Tiu chun gii hn la chn khong cch ng cp trc ( gii

hn cung cp in )

- Tiu chun gii hn la chn tit din ng cp nhnh

- Tiu chun gii hn khong cch ng cp nhnh

- Tiu chun v gam MBAPP

S dng cc gi thit theo tnh cht c trng ca i tng nghin

cu, cc gi thit kh thc ca cc tham s tham gia tnh ton nhm lm n

gin ho bi ton, p dng phng php khong chia kinh t s cho php

10

gim nh ng k khi lng tnh ton m vn cho kt qu c ngha thc

t cao

2 MC CH NGHIN CU CA TI : ti khng hy vng a ra mt cu trc chun ca HTCCT ni

chung, m ch nh s h tr ca my tnh v mt s phn mm ph bin

hin nay, ng dng phng php khong chia kinh t trong thit k

HTCCT nhm xc nh mt s thng s hp l ca HTCC Khu th

mi in Nam- in Ngc, c th xc nh :

+ S xut tuyn hp l ca TBAPP

+ Gam cng sut hp l ca MBA

+ S lng MBA hp l cho ton Khu th mi in Nam-in

Ngc

+ Tit din v chiu di hp l ca cp trc, cp nhnh

3 I TNG V PHM VI NGHIN CU : i tng nghin cu ca ti l li phn phi th, gm li h

p v h thng cc TBAPP.

Phm vi nghin cu ca ti gii hn trong HTCCT khu th

mi pha bc in Nam - in Ngc (Tnh Qung Nam)

4 NGHA KHOA HC V NGHA THC TIN

CA TI 4.1 ngha khoa hc:

1. ng dng c mt thut ton ti u ( phng php khong

chia kinh t ph ti ) vo trong thc t

11

2. Rt ngn thi gian tnh ton v nng cao chnh xc ca

cc php tnh trong cng tc qui hoch, thit k nhm xc nh cu trc hp

l cho HTCCT

4.2 ngha thc tin :

1. a ra mt m hnh cu trc hp l cho HTCCT Khu

th mi in Nam - in Ngc, lm c s cho vic tnh ton thit k sau

ny

2. Trn c s Khu th mi in Nam-in Ngc, phng

php Khong chia kinh t c th c m rng p dng cho cc Khu th

mi Qung Nam

12

CHNG 1 : TNG QUAN

1.1 TNG QUAN V LI PHN PHITrong h thng in, mng in c th c phn loi nh sau:

- Mng in cung cp : Mng in c nhim v truyn ti in nng,

khng trc tip tham gia phn phi in nng. Cp in p tng ng

110KV.

t

- Mng in phn phi: Mng in c nhim v trc tip cp in cho

cc ph ti. Cp in p U < 110KV (thng U d 35KV, bao gm li

trung p, TBA phn phi v li h p)

Do c im lch s li, li trung p hin ang tn ti nhiu cp

in p ( 35, 22, 15, 10, 6KV )

Hin nay trong qui hoch di hn, li trung p ca nc ta ang dn

xc lp cp in p 22KV. Ty theo tnh cht ca cc ph ti ngi ta chia

mng phn phi lm 3 loi :

a. Mng thnh ph: Mt ph ti (V ) tp trung cao v tng

i ng u, cng sut ca ph ti ln. Thi gian s dng cng sut cc

i ln, thng Tmax t 6000 y 7000h .

Bng 1.1 Sut ph ti cho mt h gia nh:

Mc sng ca khu dn c Sut ph ti tnh cho 1 h ( kW)

Thp 1- 1,5

Trung bnh 2-2,5

Kh 3-4

c bit t 5

13

b. Mng a phng (mng nng thn): Mt ph ti nh,

cung cp in cho nng nghip l ch yu, c Tmax nh, thng Tmaxkhong 500 y 3000h. Li phn phi khu vc nng nghip c c im

ng dy ko di, phn tn, cng sut truyn ti nh, ph ti lm vic c

tnh thi v, ph ti phn b trn din tch rng, h s thi gian s dng

thp, thi gian non ti ko di. Kt qu l gi thnh ca mng in nng

nghip tnh theo cng sut truyn ti kh cao

c. Mng x nghip cng nghip: Thuc phm vi x nghip,

phn b trn din tch hp, phn phi mt lng in nng ln ( chim 70%

in nng c sn xut ra) mt ph ti cao, Tmax ln, thng Tmax6.000 7.000h, thi gian lm vic nhiu, t c tnh cht thi v

t

y

y, trong phm vi lun vn ch cp n mng thnh ph ( H

thng cung cp in th HTCCT ), v gii hn cu trc cc TBAPP

v h thng li 0,4KV

Theo , mt cu trc hp l ca HTCCT bao gm :

+ S lng xut tuyn hp l ca cc TBAPP ( Cu trc TBAPP)

+ Dung lng, s lng, v tr hp l cc TBAPP

+ Bn knh cung cp in hp l ca cc TBAPP

+ Tit din hp l ca cp trc

+ Chiu di hp l v tit din hp l ca cp nhnh

xc nh s lng, dung lng ti u ca cc trm bin p chng ta

xut pht t bn knh cung cp in ti u ca cc TBAPP ( Lop ) T xc

nh c dung lng, s lng trm bin p cn thit phi b tr trn a

bn cp in

14

1.2 CNG TC QUI HOCH, THIT K LI

PHN PHI1.2.1 HM CHI PH TNH TON

Vic tnh ton kinh t li in l cng vic rt quan trng trong qui

hoch, thit k li in. Ch trn c s tnh ton kinh t ng mi c th

la chn c phng n pht trin li in mt cch ti u. Ph ti in

pht trin khng ngng theo thi gian v trong khng gian, cn cc thit b

in, li in c tui th kh di, cho nn khi la chn mt phn t no

ca li in phi xt hot ng ca n trong thi gian di v trong s hot

ng tng h vi cc phn t khc trong li in

Nh vy mi phn t ca li in phi c la chn s b trong qui

hoch di hn (20-30 nm), c khng nh trong qui hoch trung hn (10-

20 nm) v c nh r thi im thc hin trong qui hoch ngn hn (3-

10 nm) [1]

c th lm tt cng tc qui hoch pht trin li in th ngoi vic

thu thp s liu v tnh hnh v hin trng ca li in, v d bo pht trin

(pht trin ph ti, pht trin ca tin b KHKT, bin ng ca gi c...) cn

c vic so snh cc phng n pht trin li in v mt kinh t-k thut

la chn ra phng n pht trin ti u li in

so snh kinh t cc phng n pht trin li in, ta phi tnh hiu

qu kinh t ca tng phng n ri so snh vi nhau. C ngha l chng ta

phi tm cch cc tiu hm chi ph tnh ton (hm mc tiu)

tin hnh la chn phng n, ngi ta a ra nhiu phng

php ton hc, t n gin n phc tp, t nhng bi ton phi chp nhn

nhiu gi thit n cc bi ton c xt ti nhiu yu t gn st vi thc t

Tuy nhin cn ch rng khi tin hnh tnh ton so snh kinh t k

thut ca cc phng n, ta ch c th cp ti mt s yu t c bn m

15

thi, ch khng th xt ton b cc yu t nh hng ti vic chn phng

n

Gi tng vn u t l K v chi ph vn hnh hng nm l Y l hai s

liu c bn tin hnh so snh cc phng n. Trong giai on chn

phng n, chng ta khng th tnh tng K v chi ph vn hnh hng nm Y

mt cch chi tit c. Trong giai on ny ch cn tnh n nhng thnh

phn ch yu m thi. trnh vic tnh K v Y qu phc tp, ngi ta ch

tnh ton cho nhng thnh phn khc nhau gia cc phng n v cho php

b qua nhng thnh phn ging nhau gia chng.

Tng vn u t K c tnh theo biu thc sau:

K = Ktb + KxdTrong Ktb : Vn u t v thit b, k c u t lp rp chng

Kxd : Vn u t v cc cng trnh xy dng : xy dng

TBA, xy dng ng dy

Chi ph vn hnh hng nm Y c tnh nh sau:

Y = Ykh + Ybq + YA + Ym + YcnTrong : Ykh : Chi ph v khu hao

Ykh = Kkh .D khD : H s khu hao

Ybq : Chi ph v tu sa, bo qun

Ybq = Kbq .D .bqD : H s bo qun

YA : Chi ph v tn tht in nng

YA= cA.' A' : Tn tht in nng hng nm

c: Gi tin in [/KWh]

Ym : Tn tht kinh t do vic mt in gy ra. Nu trong

hm mc tiu khng tnh n yu t tin cy cung cp in th thnh phn

ny c th b qua

16

Ycn : Chi ph v lng ca cn b v cng nhn vn hnh

h thng cung cp in. Thng thnh phn ny khng khc nhau nhiu

gia cc phng n nn c th b qua

Thng thng gia vn u t K v chi ph vn hnh hng nm Y l

hai thnh phn i lp nhau. Mun gim tn tht in nng, gim tn tht

kinh t do ngng cung cp in, chng ta phi tng tit din dy dn, thm

s ng dy v s MBA d phng... kt qu l tng vn u t K. V vy

cn phi xy dng ch tiu phn nh c hai mt i lp ni trn nh gi

tnh kinh t ca phng n cp in, ch tiu thng gi l chi ph tnh

ton Z

Z = YKhq .D [ /nm]

hqD : H s hiu qu, ni ln mc s dng hiu qu vn u t

Nh vy Z chnh l tng chi ph v vn u t v vn hnh c tnh

phn b cho 1 nm

Do ch tiu ti u ca phng n cung cp in l:

Z = YKhq .D = min

Trong mt s ti liu khc, Z cn c gi l gi tr hin ti ca chi

ph PVC (Present Value of Cost ). Phng n c PVC min l phng n ti

u

So snh kinh t k thut c tin hnh theo cc bc sau:

+ Phn tch v loi cc phng n khng tho mn cc yu cu k

thut t ra. La chn cc phng n t yu cu k thut ngang nhau

em ra so snh

+ Tnh chi ph tnh ton Z cho tng phng n. Ch rng gim

nh khi lng tnh ton, cho php ch tnh ton nhng phn khc nhau gia

cc phng n

17

+ Chn phng n c Z min. l phng n ti u v mt kinh t-

k thut

Trong thc t, bi ton la chn cu trc hp l cho HTCCT l mt

bi ton phc tp. Trong kh khn ch yu l nhiu yu t kh th hin,

nh lng di dng gii tch. Khng nhng th, chng cn mang tnh

ngu nhin, hoc mt s trng hp, chng ta ch ghi chp c mt s

th hin m khng bit c lut phn phi xc sut ca chng

gii quyt bi ton ny, trong thc t hin nay thng da vo kinh

nghim cng tc v kin chuyn gia, phc tho ra mt s (n) phng n

cu trc, c xem l kh thi, trn c s s tnh ton, chn ra mt cu

trc cc tiu c hm chi ph tnh ton hng nm ( hm mc tiu):

Zi = (D vh + D tc ).Ki + Yi'A (i =1,2,...n)

R rng phng n cu trc vi Z min s ch l phng n tt nht

trong s n phng n a ra v hon ton ph th ch quan ca cn b

lm cng tc thit k, qui hoch v theo , tnh chnh xc, khoa hc ca kt

qu s khng cao

o

1.2.2 CC PHNG PHP TNH TON LI PHN

PHI

Trong thc t vn hnh, sn xut, cung ng in, tn tht in nng

trn li < 1.000V chim t l cao nht v sau l cc MBAPP. V vy

vn gim tn tht in nng trn cc phn t ca li ny c c bit

quan tm ch khi qui hoch, thit k li th ni chung. tnh ton

mng phn phi, hin nay c mt s phng php tnh ton sau y:

1.2.2.1 .TNH TON LI PHN PHI THEO IU KIN CC

TIU PH TN TNH TON VI THNH PHN TN THT IN P KINH

T [11]

18

Vic xc nh tit din dy dn mng phn phi thng xut pht t

iu kin tn tht in p cho php. Gi tr ny l lch in p t trm

bin p n ph ti. Vic chn tit din dy dn theo iu kin mt dng

in kinh t mng phn phi thng cho kt qu nh hn so vi kt qu

chn theo iu kin tn tht in p cho php.

Khi xem chi ph tnh ton l mt trong nhng tiu chun c bn tnh

ton mng vi iu kin hn ch v tn tht in p cho php, ta thnh lp

phng trnh ph tn tnh ton ph thuc vo tn tht in p.

T biu thc:

Z = (D vh + D tc ) K + c.'A (1-1).

Nu ta xem vn u t K v tn tht in nng A l cc i lng

ph thuc vo tit din dy dn F th ta c th vit li biu thc (1-1) nh

sau:

3103)( 2 cFLIbFLZ mvhtc WUDD (1-2 )

Trong :

- Im : Dng in cc i.

- b : H s tnh n s thay i gi thnh ng dy ph thuc vo

tit din (/mm2Km)

- F : Tit din dy dn (mm2).

- L : Chiu di ng dy (Km).

- U : in tr sut ca vt liu dy dn.( : mm2/Km)

- W : Thi gian tn tht cng sut cc i.

Nu t (1-2) ta thay cc gi tr :

UU10lPF

scoU3PI

2'U

M

19

Th ph tn tnh ton s l:

M

UDDW

22

2

cos10010iUiPii

UUPlbZ

cii

iiiivhtci

'

' (1-3)

T biu thc (1-3) nu bit cc gi tr Ui ; li ; M ; Ui ; ci ; tcD ; vhD th

ph tn tnh ton ca ng dy ch ph thuc vo tn tht in p. n

gin ta t:

Ai = ( D tc + D vh )bi Ui L2i Pi /10Ui2 (1-4)

Bi = W i ci Pi /100 cos2M (1-5)

Biu thc (1-3) ta s vit c:

ZAU

B Uii

ii '

' (1-6)

Ph tn tnh ton ca mt phn th i no ca mng s cc tiu nu

tha mn iu kin :

i2i

i

i

i BUA

UZ

'

'ww = 0 (1-7)

T (1-7) chng ta c th xc nh c tn tht in p kinh t tng

ng vi chi ph tnh ton cc tiu:

i

ikti B

AU ' (1-8)

Thay ga tr Bi v Ai vo (1-8) ta c :

ici

blU iivhtcikti WUDDM 10

Ucos

i

' (1-9)

Thay gi tr 'Ukti biu thc (1-8) vo (1-6) chng ta xc nh ph tn

tnh ton cc tiu :

iimini BA2Z (1-10)

Hoc khi thay Ai v Bi vo ta c:

20

3i

imin 10cosU

P2 icibl

Z iivhtci

ii WUDDM (1-11)

Chia (1-6) vi (1-10) ta c quan h :

''

''

kti

i

i

kti

mini

i

UU

UU

21

ZZ (1-12)

thy r nh hng ca tn tht in p n ph tn tnh ton ta vit

li biu thc (1-12) dng:

'

' i*

i*i* UU

15,0Z (1-13)

y:

min*

i

ii Z

ZZ Ph tn tnh ton tng i.

kti

ii U

UU

''

' * Tn tht in p tng i.

T (1-13) ta thy thnh phn th nht l vn u t tnh ton tng

i, cn thnh phn th hai l ph tn tnh ton ph thuc vo tn tht cng

sut. T ta c th vit :

Z*i = Z*Ki + Z* 'Ui (1-14)

Cc gi tr Z*i ; Z*ki ; Z* iU' u ph thuc vo iU*'

Khi < 1 ( iU *' ktii UU 't' ) : tit din dy dn cn c la chn theo

iu kin tn tht in p 'Ui , gi tr ny khng c vt qu gi tr cho

php.

Khi )(1* ktiii UUU 't'!' : tit din dy dn c chn theo tn tht

in p kinh t bi v trong trng hp ny khng c gii hn v tn tht

in p cho php.

21

1.2.2.2 .TNH TON MNG PHN PHI THEO IU KIN MT

DNG IN KINH T [11]

T biu thc (1-2) ta c :

3103)( 2 EUDD WFLIbFLZ mvhtc

Ph tn tnh ton cc tiu mng in s xut hin khi m bo iu

kin:

DD ww EW

2

2m

vhtc FI3bL

FZ 310 0 (1-15)

T (1-15) ta thy rng: Mt kinh t ca dng in tng ng vi

chi ph tnh ton cc tiu theo iu kin:

EUDD W3

bFIJ vhtcmkt (1-16)

Gi tr mt dng in kinh t tng ng vi tit din kinh t ca

dy dn xc nh theo iu kin ca ch lm vic nh mc ca ng

dy t biu thc :MscoJU

SFkt

kt ..310. 3 (1-17)

Trong :

-S l ph ti tnh ton ca ng dy (KVA).

-U: in p nh mc (V).

1.2.2.3 .TNH TON MNG PHN PHI THEO IU KIN TI

U BN KNH CUNG CP IN [11]

xc nh s lng, dung lng ti u ca cc trm bin p chng ta

xut pht t bn knh cung cp in ti u ca cc cp in p Ropt.T s

xc nh c dung lng, s lng trm bin p cn thit phi b tr trn

a bn cp in.

22

Trong mng in tn ti hai khi nim v bn knh cung cp in,

l bn knh cung cp in c xc nh cn c trn kh nng k thut ca

mng in, chnh l bn knh gii hn v tn tht in p cho php R'U v

bn knh ti u theo iu kin kinh t. Bn knh thng tng ng vi

cc khong cch sau:

R0,4 d 3Km ; R6 y 10 d 12Km ; R35 d 20 y 35Km ; R110 d 50Km.

xc nh bn knh ti u (v tr trm bin p) ta thnh lp quan h

gia hm chi ph tnh ton Z vi bn knh phc v (R) ca trm bin p.

Z = f ( R ) o min.

Ly o hm 0 ww

RZ , t ta xc nh c Ropt

Vic xc nh min cung cp in ca cc trm bin p da trn bn

knh phc v ca trm. n gin ngi ta c th phn min cung cp

in thnh tng vng theo hnh vung, hnh lc lng, hnh trn....Mi trm

bin p ph ti s cung cp in cho cho mt hnh nh vy. cung cp

in cho mt vng no chng ta cn phi xy dng mng cung cp, trm

bin p, mng phn phi chnh v cc nhnh r nh hnh 1-1.

Chi ph tnh ton Z ca ton b

mng in c vit nh sau:

Z = Z1 + Z2 + Z3Trong :

-Z1: Chi ph cho mng cung cp in.

-Z2: Chi ph trm bin p.

-Z3: Chi ph cho mng phn phi.

Din tch m 1 trm bin p c th

RR

Ghi ch:1.Mng cung cp2.Mch chnh3.Mch nhnh4.Trm bin p

cung cp l: Hnh 1-1

f = P1 R2

23

Trong :

Pl H s ph thuc hnh dng ca min cung cp in vi:

- Hnh vung : Pl = 4.

- Hnh trn : Pl = 3,14

Nu din tch min cn in kh ha l M th s trm bin p N cn b

tr trn din tch s l:

N = M/f (1-18)

Nu cho bit mt ph ti V th cng sut ca trm bin p s l:

S = V . f (1-19)

Chng ta tin hnh xc nh chi ph tnh ton Z

1) Chi ph tnh ton trm bin p Z2.

Ta c: Z2 = aT + bT.S (1-20)

Trong :

* aT = ( vh + tc )KT. (1-21)

aT : Thnh phn ph thuc bn knh cung cp in R, ph thuc vo

kt cu trm v khng ph thuc vo cng sut trm

* bT = ( vh + tc )Ks. (1-22)

bT : Thnh phn ph thuc vo cng sut trm bin p. Khng ph

thuc vo bn knh cung cp in R

Do khi kho st bn knh cung cp in ta ch cn ch n thnh

phn aT m thi.Cng thc trn ch ng khi cng sut ca trm bin thin

trong mt phm vi nht nh.

Tng qut ha ta ch xt chi ph tnh ton ca trm bin p cho mt

n v din tch cung cp in s l:

zaRT

i2 2 P

( /Km2.nm ). (1-23)

2) Chi ph tnh ton cho mng cung cp Z1

24

Chi ph tnh ton cho 1 Km ng dy mng cung cp l:

Z1 = ac + bcF ( F tit din dy ). (1-24)

Trong :

* ac = ( vh + tc ) Kcac :Thnh phn ph thuc bn knh cung cp in R, khng ph thuc

vo tit din dy dn.

* bc = ( vh + tc ) KFbc : Thnh phn ph thuc vo tit din dy dn. Khng ph thuc vo

bn knh cung cp in R

Tng t nh trn ta ch xt n thnh phn ac = f(R), b qua thnh

phn bc Chi ph tnh ton phn ng dy mng cung cp cho mt n v

din tch cn cung cp in s l :

za LNf

aR N

c c

i1 2

1

P (1-25)

Khi xt n min cung cp in ca 1 trm bin p l hnh vung hay

lc lng th ta c: LN

R 2 (1-26)

Trong thc t chiu di ng dy ca mng cung cp ph thuc vo

nhiu yu t nh: S phn b ca cc trm bin p, ph ti, a hnh

...Trong qu trnh tnh ton c th s dng cng thc kinh nghim ca

Zakharin xc nh chiu di ng dy cung cp:

L N M D . (Km). (1-27)

Trong - M: Din tch min cung cp in.

- N: S trm bin p .

- D : h s ph thuc mc phn b cc vng dn c nu:

- Phn b u D = 0,9 y 0,95

- Phn b khng u: D = 0,7 y 0,9

25

Gi tr D qua thng k vi cc khu vc khc nhau thng nm trong

khong D = 0,6 y 1,23

Khi D = 1 th : NRNRMNL ..2..4. 2 (1-28)

Trong thc t thy rng chiu di L tng theo s trm N nhanh hn

theo biu thc L N M D . . Do tc gi Dale a ra cng thc hiu

chnh sai s nh sau:

L = L0 + 'L.N (1-29)

Gi tr L0 l chiu di hnh hc v c xem nh l khng i cn 'L

l thnh phn ph thuc s trm bin p, a hnh ...do chng ph thuc

vo bn knh cung cp in. T ta c chi ph tnh ton ca mng cung

cp trn mt n v din tch cn in kh ha l:

za L

Rc

i1 2

'P

(1-30)

3) Chi ph tnh ton mng phn phi Z3.

Gi thnh xy dng 1 Km ng dy phn phi c xc nh theo

biu thc

Kd = K1 + K2 F (1-31)

102

3

2

UWDD F

l

U

SCKtcvhz d)( (1-32)

3

2

2

1021UWDDDD

F

l

U

SCFKtcvhKtcvhdz .)()(

t : b1 = ( Dvh + Dtc )K2

2

3

210

Uc

b... UW

T ta c:

26

lFSbFbkZ tcvh .

2

211

DD (1-34)

Ta nhn thy thnh phn u ca biu thc khng ph thuc R, khi

xem chi ph xy dng phn kt cu ng dy khng ph thuc s trm, t

ta c:

l)F

SbFb(z2

21d (1-35)

Khi xem tit din dy dn F khng i trn ton b ng dy, ta c

hm chi ph tnh ton mng phn phi trn mt n v din tch cn cung

cp in l :

zf

b F b SFK

lr

Lp

3 1 2

2

21

1 ( ) (1-36)

Trong

- l: di ca mng phn phi.

- f :Din tch min in kh ha trm bin p m nhn.

-Kr: H s ph ti trung bnh bnh phng.

-Lp: Tng di ca mng in phn phi.

Tn tht cng sut trong mng phn phi l:

'PSU

Rii

n

i 2

21

(1-37)

n gin ta c th vit:

'P SU

RK r

2

2 21 (1-38)

vi

RRS

SKR

RSSK

ii

r

ii

r

22

22

.

27

Bin i z3 v dng ph thuc vo bn knh cung cp in khi xem Lp

= const th constFbpL

i .

- ng dy phn phi s gm c mch chnh v mch nhnh trong

mch phn nhnh khng ph thuc R cn mch chnh ph thuc R vi gi

thit nh vy ch lm tng tn tht m thi. Nu ph ti ca mt mch chnh

l S th :

S = q.V

Trong - q: Din tch min phn phi in ca mt nhnh mch

chnh.

- V : Mt ph ti trn mt n v din tch.

Ph ti ca trm bin p s l:

ST = p.q.V = f.V

Trong p: S mch chnh ca 1 trm bin p.

T phn tch trn chng ta c hm chi ph tnh ton ca ng dy

phn phi trn mt mt n v din tch cn in kh ha s l:

zf

b S lFK

T

r3

22

21 (1-39)

Bin i tip chng ta c:

zf

b S lFK

pf

q lbFK

ff

lbFK

b RFK

T

r r r3

22

2

2 2 22

2

2 22

22

3 2

21 V V P V = = 2

r

(1-40)

Trong P2 : H s t l v f { R2 ; l { R

T ta c

z = z1 + z2 + z3 = a l

RaR

b RFK

c T

r

'P P

PV

12

22 2

23 2

2

Ly o hm z theo R v cho bng 0 ta tnh c Ropt :

28

RFK a a l

boptr T c

23

2

1 2 22

5( )'

P P V (1-41)

1.2.2.4 .TNH TON MNG PHN PHI THEO IU KIN

KHONG CHIA PH TI KINH T [11]

Trong trng hp s la chn khng ph thuc tit din dy dn. Tit

din kinh t ca dy dn c th c xc nh theo khong chia kinh t ph

ti, c xt n khi tnh n c trng phn tn ca s thay i tit din

dy dn, iu kin c th lm vic v xy dng ng dy ti in.

Tnh kinh t i vi tit din cho ca dy dn c gi l khong

chia kinh t. trong gii hn , cc ph tn tnh ton v truyn ti mt n

v in nng trn mt n v chiu di theo dy dn tng ng vi tit din

l nh nht so vi bt k dy dn c tit din no khc.

Ph tn tnh ton ph thuc vo dng in ti ca ng dy I.Vic

la chn dy dn theo tit din tiu chun Fi , in tr tc dng Ri ca dy

dn c xc nh theo biu thc.

Zi = ( D tc + D vh )Ki + 3I2W Ri Ci (1-42)

Gi tr ph ti gii hn to nn khong chia kinh t ng vi mi tit

din tiu chun, c th tm c nu cho tng cp gi tr ph tn tnh ton

ca dy dn c tit din Fi-1 v Fi ; Fi v Fi+1 bng nhau.

Kt qu nhn c gi tr bng dng in kinh t cc i v cc tiu.

1

1min 3

ii

iivhtckti RR

KKIEDDW (1-43)

ii

iivhtckti RR

KKI

1

1max 3 E

DDW (1-44)

Tit din kinh t ca dy dn c th la chn hoc theo bng khong

chia kinh t c thnh lp trn c s biu thc (1-43) v (1-44) hoc theo

th ph tn tnh ton Z ph thuc vo dng in ph ti I c xy dng

29

i vi cc tit din khc nhau ( Fi) theo biu thc (1-42). im giao nhau

ca cc ng cong xc nh khong kinh t ca dng in i vi mi tit

din ca dy dn.

Vic tnh ton mng in theo khong chia kinh t cho php xc nh

gi tr ng tin cy tit din kinh t ca dy dn v cp. Tuy nhin khi la

chn tit din dy dn v cp theo khong chia kinh t dn n nh hng

qua li gia cc thnh phn khc nhau ca mng in, n chi ph tnh ton

tng, s phn nhnh ca mng, cng nh cc hn ch khc n tr s tit

din dy dn c la chn.

Nhng vn thuc v mng in khng ng nht nhng mng

vic xc nh cc tham s khi la chn tit din dy dn l tn tht in

p cho php. 1.2.2.5 . L DO CHN PHNG PHP KHONG CHIA PH TI

KINH T

Trong cc phng php tnh ton mng phn phi nu trn, mi

mt phng php c nhng thun li v kh khn ring

+ Phng php tnh ton mng phn phi theo iu kin cc tiu

ph tn tnh ton vi thnh phn tn tht in p kinh t :

Theo (1-3) ta c chi ph tnh ton ca phn t th i trong mng:

M

UDDW

22

2

cos10010iUiPii

UUPlbZ

cii

iiiivhtci

'

'

Theo , ng vi mi mt nhnh th i s tn ti mt gi tr tn tht

in p 'Ui cc tiu c hm chi ph tnh ton

Phng php ny ch c th p dng thun tin vi li phn phi c

ph ti tp trung cao

+ Phng php tnh ton mng phn phi theo iu kin mt

dng in kinh t :

30

Theo (1-17) ta c :

M

cosJU310SF

kt

3

kt

Theo tit din ca ng dy c xc nh qua cng sut ph ti

v qua gi tr mt kinh t ca dng in . Ta thy gi tr tit din dy dn

nhn c cha xc nh c gi tr nh nht ca hm chi ph tnh ton,

bi v mt kinh t ca dng in cng ch l gi tr gn ng [9]

+ Phng php tnh ton mng phn phi theo iu kin ti u

bn knh cung cp in :

Theo (1-41) ta c:

RFK a a l

boptr T c

23

2

1 2 22

5( )'

P P V

Bn knh cung cp in ti u l mt quan h tng i phc tp theo

tit din dy F v mt ph ti V

+ Phng php tnh ton mng phn phi theo khong chia ph

ti kinh t:

Khong chia kinh t ca dng in ( v tng ng l mt ph ti)

c xc nh d dng qua th ph tn tnh ton z c xy dng tng

ng vi cc tit din F khc nhau ca dy dn , phng php ny d dng

chp nhn c vi cc li phn phi c mt ph ti tng i u theo

din tch khu vc kho st, nht l li 0,4KV ti cc khu th mi

31

CHNG 2:

TRNH T CC BC THIT K

THEO PHNG PHP KHONG CHIA KINH T

Trn y, khi chn phng n cu trc theo iu kin cc tiu hm chi

ph tnh ton hng nm Z, thc cht bi ton c ti u ha theo 2 ch

tiu [3]:

a) Cc tiu vn u t K

b) Cc tiu chi ph vn hnh hm nm Y

Ngha l hm mc tiu Z ch cha hai yu t K v Y. Nh bit, y

l hai yu t i lp nhau, phng n ti u phi c gng dung ho ng

thi c hai yu t ny

Vic gii bi ton tng qut cc tiu hm chi ph tnh ton Z nh trn

l iu kh thc hin c trong thc t, n thuc lp bi ton ti u lin

tc [8] cc hm a ch tiu. Kh khn ch yu y l nhiu yu t kh th

hin, biu din nh lng di dng gii tch. Khng nhng th, chng cn

mang tnh ngu nhin, hoc mt s trng hp ch ghi chp c mt s

th hin m khng bit c lut phn phi ca chng . D , vic gii

cc bi ton a ch tiu v lin tc nh dng trn l rt kh khn v phng

php ny thng t ra km hiu lc, kh thc hin c trong thc t

Mt trong nhng phng hng gii quyt nhng kh khn trn

y l xy dng m hnh ton hc ca phng php khong chia ph ti

kinh t. Phng php ny da trn c s l mt s thng s tham gia vo

php tnh c chun ho v tp gi tr l hu hn (s chng loi dy, di

cng sut my bin p ...l hu hn). Hoc ng hn l tm cch cc tiu

hm chi ph tnh ton tng ng vi mt di thng s kh thc no . Ni

32

chung, phng php khong chia kinh t thuc lp cc bi ton ti u ri

rc [8] Ngy nay, nh s h tr ca my tnh s gim nh ng k khi

lng tnh ton, bng phng php khong chia kinh t s nhanh chng xc

nh c cu trc hp l ca HTCCT mt mc cho php

2.1 S KHI BI TON THEO PHNG PHP

KHONG CHIA PH TI KINH T [12]Vi mt mt ph ti V, gi bn in c, cc bc tnh ton v la

chn thng s cu trc TBAPP c tin hnh nh hnh 2.1

Trong :

+ F: Tit din cp.

+ SBm : Cng sut nh mc MBA

+ Tnh k thut : L tnh chn cc thng s cho php v mt k thut

ng vi cc trng hp sau:

x Pht nng do dng in lm vic bnh thng

x Pht nng ngn hn do dng in ngn mch

x Kh nng chu cc tc ng c hc ca dng in ngn

mch

x Tn tht in p ch lm vic bnh thng v s c

+ Thng s cho php l cc thng s c chn la, m bo cc

iu kin v mt k thut. Cc thng s ny u c s dng tnh ton

kinh t

+ Cc iu kin ring ca Khu th : l cc c im ring ca

khu vc cn kho st. Kt qu tnh ton c l kt qu tng qut, tu theo

iu kin a hnh ca tng khu vc, vic b tr cc MBAPP cng nh cc

33

hng tuyn cn phi c hiu chnh ( nht l ti cc v tr ng bin ca

khu vc cn kho st ) ph hp thc t.

+ Kt qu in ra l cc thng s cn phc v cho cng tc thit k,

y l gam cng sut my bin p v s lng trm bin p, qui cch v

chiu di cp trc, cp nhnh

2.2 CC GI NHNh nu trn, vic gii bi ton trong iu kin tng qut s rt kh

khn khng ch bi phc tp ca cc quan h rng buc m cn v khi

lng tnh ton kh ln. Trong thc t, bng vic a ra cc gi thit c cn

nhc k ti c im ring ca i tng nghin cu, xut pht t i hi

thc t, khi lng tnh ton c gim ng k m khng nh hng ti

chnh xc ca kt qu cng ngha p dng ca n. Lun vn da trn mt

s thng s thc t ca vt t thit b hin c trn th trng nh :

+ S chng loi cp

+ S chng loi my bin p

+ Mt ph ti phn b u : iu ny l kh thi v y l c im

ca li th, hn na Khu th mi in Nam - in Ngc l khu

th c xy dng mi hon ton, vic b tr cc cn h c tnh ton

hp l, khoa hc

+ Chiu di cp nhnh ban u tnh s b c ly trung bnh l

60m [12]

+ Cc thng s tnh ton ca cc loi thit b c a ra trn c s

cc tiu chun v yu cu hin hnh s dng cho HTCCT

2.3 CC BI TON NH: gii quyt vn mt cch trn vn v y , ta cn kho st

ring r tng bi ton c th :

34

Tnh gii hn kthut ( b phn )

Tnh ton kinh tk thut

Tnh kinh t (B phn)

La chn thng s k thut

Cc iu kin ring ca khu th

In ra kt qu

La chn thng s kinh t

Thng s tnh ton

La chn phngn cu trc hp l

Khong chia kinh t

Hnh 2.1: S thut ton phng php khong chia ph ti kinh t

Tp cc thng s khthc (V,F,c,SBdm)

35

2.3.1 BI TON CHN TIT DIN CP:2.3.1.1 TIT DIN CP NHNH:

Dng in trong ng cp nhnh:

dm

ll U

SI3

Trong Sl cng sut tnh ton ca ng cp nhnh. Nu xem ph

ti phn b u, ta c th vit :

dm

dddtkcl U

kkllI.3

.... V

ng vi V = 25 VA/ m2 (i vi th loi 3 th V khng th ln

hn gi tr ny)

Ta c I lmax < Ilcp ca cp c tit din 25mm2 ( 112 A)

Chnh v vy iu kin pht nng di hn ca cp nhnh u c tho

mn vi mi tit din tnh ton.

Khong chia kinh t ca dng in, v tng ng vi n l mt ph

ti, c xc nh nh sau: i vi mt tit din ca ng cp nhnh, hm

chi ph tnh ton c th vit di dng:

cRIKZ lllvhtc WDD .3.)(2max

clrUSKZ

dm

llvhtc ...)( .02

2max WDD

20

2

0....)....(.)(

dm

dddtkcvhtc U

clrkklllKZ WVDD (2.7)

Trong :

36

K: Vn u t xy dng ng dy

K0 : Sut u t xy dng ng dy, tnh cho 1 km

l: Chiu di cp nhnh

lkc : Chiu di khong ct

Trong c cu gi thnh ng dy, ta nhn thy :

+ Thnh phn u ca biu thc : (Dtc + Dvh ).K0.l Thnh phn ph

thuc chi ph xy dng ng dy ( Gi l Ai)

+ Thnh phn th hai : 2 02 ....)....(

dm

dddtkc

Uclrkkll WV

2.ViB

: Thnh phn ph thuc

vic vn hnh ng dy (gi l )

Ta c (2.8)2.Vii BAZ

Da vo (2.8) , ta tin hnh v cc ng cong biu din s ph thuc

ca cc hm chi ph tnh ton Z vo mt ph ti V, ng vi cc tit din

cp tiu chun khc nhau

Z F1 F2 F3

b a

1V 2V V (V.A/m2)

Hnh 2.2 Khong chia kinh t ng cp

37

th cc hm chi ph tnh ton i vi cc tit din F1,F2,F3 c v

hnh (2.2), trong F3 > F2 > F1. Cc ng cong ny ct nhau ti a v b.

C th nhn thy rng:

_ Trong khong mt ph ti (0yV1) : Tit din F1 l kinh t nht

_ Trong khong mt ph ti (V1y V2) : Tit din F2 l kinh t nht

_ Trong khong mt ph ti (V2y V3) Tit din F3 l kinh t nht

. . . . . . . .

Nh cng c my tnh v ngn ng Pascal, trn c s tit din dy cp

c tiu chun ho, ta c th kho st c ton b s bin thin ca Z

theo mt ph ti V. ng vi mi gi tr F v trong mi di V xc nh, ta

c mt gi tr F Z t ga tr Zmin2.3.1.2 TIT DIN CP TRC:

Hnh (2.3) m t cu trc ca mt ng cp trc li th

Ix TBAPP l

L

Hnh 2.3 M t mt xut tuyn cp trc xc nh tit din

Gi Ix l cng dng in trn ng cp trc ti im c to x

(xem v tr gc to ti TBAPP)

Ta cdm

xx U

SI.3

Nu xem mt ph ti phn b u, ta c :

38

dm

dtddx U

KKxLlI

3.)..(.

V

Hm chi ph tnh ton ca ng cp trc c th vit :

L

oxLvhtc dxcrIKZ0

2 ....3).( WDD

L

dtdddm

vhtc dxxLlKKUcrLK

0

222

00 )()...(.

...).( VWDD

Ldtdd

dmvhtc xllKKU

crLK

032

20

0 ))(31(.)...(.

...).( VWDD

cLrU

KKLlLKdm

dddtvhtc ....3

)....(.).( 02

2

0 WVDD

Bng phng php khong chia kinh t, tng t nh cp nhnh, ta

tm c tit din hp l cp trc

2.3.2 BI TON CHN CHIU DI CP

2.3.2.1 CHIU DI CP NHNH :

Chiu di hp l cp nhnh s c tnh ton da trn tit din cp

nhnh c chn hp l ( xem 2.2.1).

+ ng vi mt mt ph ti V v mt gi in c, bng phng php

khong chia kinh t, ta xc nh c mt tit din cp nhnh hp l F1+ Chiu di cp nhnh c chn sao cho m bo c tn tht in

p cho php i vi ng cp nhnh :

V cp nhnh ngn, in p nh, b qua in dung ca cp, tn tht

in p trn cp nhnh c th tnh theo cng thc:

"'.. UUU

XQRPUdm

'' ' (2.8)

Trong : 'U : Thnh phn tn tht in p do cng sut tc dng

39

'U : Thnh phn tn tht in p do cng sut phn khng

P,Q : Cng sut tc dng v cng sut phn khng ca ph ti

R,X : in tr v in khng cp nhnh

Ti gi tr gii hn : 'Ucp = 'U + 'U (2.9)

Hoc : 'U = 'Ucp - 'U

Trong dmU

lxQU

.." 0 ' (2.10)

Vi cp h p, r0 >> x0 .

Vi li h p , sin M thng rt nh, ta c th b qua thnh phn 'U

Vydm

cp Ulrp

UU..

' 0 '|' (2.11)

i vi cp nhnh , ta c

MVM cos.....cos. dddtkc KKllSP (2.12)

Th (2.17) vo (2.16) , ta c :

dm

dddtkccp U

rKKllU MV cos...... 02

' (2.13)

T (2.18), c th tm c :

MV cos......

0rKKlUU

ldddtkc

dmcpcp

' (2.14)

i vi li h p, tn tht in p cho php trn cc ng cp nhnh

= 1%UcpU' dm

Vy chiu di hp l cp nhnh s l:

l = min{60, lcp} (2.15)

Trong 60 l chiu di trung bnh cp nhnh

2.3.2.2 CHIU DI CP TRC :

Chiu di hp l cp trc s c tnh ton da trn tit din cp trc

c chn hp l ( xem 2.2.1).

40

+ ng vi mt mt ph ti V v mt gi in c cho trc, bng

phng php khong chia kinh t, ta xc nh c tit din hp l ca cp

trc

+ Tng t i vi cp nhnh, chiu di cp trc c chn sao cho

m bo c tn tht in p cho php i vi ng cp trc :

Hnh (2.4) m t cu trc mt ng cp trc xut tuyn ca mt

TBAPP x TBAPP l

L

Hnh 2.4 M t mt xut tuyn cp trc xc nh chiu di

T (2.11), mt tn tht in p du ti im x c dng :

dmUdxrxPdu .).( 0

Trong P(x) : Dng cng sut tc dng trn cp trc ti im x, ta c

th vit :

dmUdxrxS

du..cos).( 0M

Nu xem mt ph ti phn b u, ta c:

dmUdxrxLl

du..cos)...(. 0MV

Tn tht in p trn ton b cp trc c dng:

'L

dm

dxxLrU

lU0

0 )(.cos... MV

L

dm

xLrU

lU0

20 )(.cos..

. ' MV

41

2.0.2

. LrU

lUdm

V ' ( 'U < 0 : in p gim )

MV cos.....

..2'

0 Ldddt

dmLcp

rKKlUU

L'

(2.16)

Trong :

H s 2 th hin ph ti phn b u

LcpU' : Tn tht in p cho php i vi cp trc ( 4%U| dm)

l : chiu di trung bnh cp nhnh

R rng ta c quan h L = f(V,FL)

+ Chiu di cp trc c chn theo phm vi phc v ca cng sut

MBAPP: Cu trc li h p nh ta chn l hnh tia, chiu di cp trc l

khong cch xa nht m mt TBAPP c th cung cp vi cc rng buc v

mt k thut

Cng sut truyn ti ln nht trn mt ng cp trc c xc nh

theo biu thc :n

KSS qtBdmL

. (2.17)

Mu s n biu th s xut tuyn ca TBAPP

Mt khc, cng sut truyn ti ln nht trn mt ng cp trc li ph

thuc mt ph ti theo quan h :

V.... dddtL KKlLS (2.18)

Thay (2.18) vo (2.17), ta c chiu di cp trc nh sau :

V.....

"dddt

qtBdm

KKlnKS

L (2.19)

R rng ta c quan h : L = f(V,SBdm)

V chiu di cp trc c chn l:

L= min{L, L} (2.20)

42

2.3.3 BI TON CHN CNG SUT MY BIN P :

Trong cc tnh ton trn y, ta thy cc thng s cp u l hm ca

cng sut TBAPP . iu ny cho ta thy rng trong khi i tm cu trc hp

l li h p, khng nn tch ri phn ng dy v phn trm bin p.

Cng sut TBAPP do s c chn trn c s cc tiu ho c hm chi

ph tnh ton ca ton b li h p, bao gm ng dy v TBA 2.3.3.1 LA CHN S LNG TBAPP:

Trn din tch kho st D, s TBAPP c th c xc nh nh sau:

Bdmqt

dtdd

Bdmqt

tt

SKDKK

SKSN

....

.1V (2.21)

Trong :

Stt : Cng sut tnh ton ca ph ti trong khu vc kho st

Kqt : H s qu ti ca MBAPP, nh gi thit , Kqt = 1,3

R rng ta c N1 = f(V,SBdm)

Mt khc, s TBAPP cn c th c tnh da trn phm vi phc v

ca n : lL

N.42

D (2.22)

Trong : L Chiu di cp trc, c xc nh t (2.20)

l : Chiu di cp nhnh, c xc nh t (2.15)

Khi chn s lng TBAPP, quan im l chn sao cho cc TBA khng

b qu ti lin tc. Do vy, vi mt gi in c, mt mt ph ti V, s

TBAPP s l: N = max {N1 , N2 } = f (V, SBdm, c ) (2.23)

2.3.3.2 LA CHN GAM CNG SUT MBAPP:

43

Hm chi ph tnh ton ca 1 TBAPP cng sut SBdm c xc nh

nh sau : cPSScTPKZ n

BmMBAvhtcMBA .....)( 2

max0 WDD ''

2

Trong : (Dtc + Dvh )KMBA :Thnh phn ph thuc chi ph xy dng

TBAPP

KMBA : Gi thnh xy dng mt trm bin p cng sut SBdm

cPSScTP n

Bm

..... 22max

0 W'' : Thnh phn ph thuc chi ph vn hnh

TBAPP

Cng sut TBAPP s c la chn trn c s cc tiu ho c hm

chi ph tnh ton ca ton b li h p:

ZHA = N.( ZMBAPP + ZL + Zl) (2.24)

Trong : N : S TBA trn khu vc kho st( din tch D)

ZMBA : Chi ph tnh ton lp cho 1 TBAPP

ZL : Chi ph tnh ton lp cho ton b cp trc ca 1 TBAPP

Zl : Chi ph tnh ton lp cho ton b cp nhnh ca 1TBAPP

2.4 NI DUNG CHI TIT CC BC TNH TON Ni dung chi tit cc bc tnh ton trong tng khi s c th

hin trong hnh 2.5

Trong :

+ Z1l : Hm chi ph tnh ton lp cho 1 ng cp nhnh

44

122

23

1

32

2max

1

10.......

10...

10...

clrU

KKlllKZ

cRUS

KZ

oldm

dddtkcolvhtc

dm

llvhtc

WV

DD

WDD

Trong :

K0l : Vn xy dng 1 km ng cp nhnh, [triu ng/km]

rol: in tr 1 km ng cp nhnh [ :/km]

Udm = 380V

l: Chiu di cp nhnh, [m ]

W : Thi gian tn tht cng sut cc i, [h]

c : gi in thng phm, [ng/KWh]

lkc : Khong ct, [m]

V : Mt ph ti, [VA/m2]

Slmax : Cng sut ph ti cc i trn 1 ng cp nhnh [KVA]

Ta thy Zl= f(V,Fl,c)

+ Fl : Tit din cp nhnh

+ FL : Tit din cp trc

Vi mi cp (V,c) ta s c mt dy gi tr hm Zl tng ng vi mt

dy gi tr tit din cp nhnh Fl . Trong s c mt gi tr Fopt lm cc

tiu hm Zl+ Chiu di cp nhnh theo tn tht in p cho php:

lcp= MV cos.....

0. rKKlUU

dddtkc

dmcp'

Ta thy lcp = f(V,Fl)

Vi mt cp (V,c) ta xc nh c Fopt( nh trn ), tnh c lcp v

chiu di hp l cp nhnh l : lop = min {60, lcp}= f (V,Fl,c)

+ Chiu di cp trc cho php L c tnh theo (2.20)

45

+ SB : Cng sut MBAPP

+ m : S cp nhnh r ra t cp trc , c xc nh sau khi c Lopt+ N : S lng MBAPP thuc khu vc kho st, c xc nh theo

(2.23)

+ Zl : Hm chi ph tnh ton ca cc ng cp nhnh trong mt

TBAPP

Zl = m.Z1l [ triu ng ]

+ Z1L : Hm chi ph tnh ton cho 1 ng cp trc, [ triu ng ]Fl,c,V

Tnh ton kinh tdy dn nhnh

f(Fl,c,V)La chn F1

Tnh bn knhphc v TBAPP

Tnh L theo 'Ucp

Tnh ton kinh tng cp trc

Tnh ZB

Tnh lcpTnh l theo 'Ucp

Chn S NCc iu kin

Tnh kinh t kthut chung

Chn FL

Tnh Lop Tnh ZL

Tnh Zl

Fop(c,V)

f(Fl,c,V)

m

L

L=f(SB,V)

L=f(FL,V)Fop=f(V,c)

ZL=f(FL,V,c)

ZHA=f(SB,V,c)

ZB=f(SB,V,c)

FL,V,c

D,FL,V

SB,V

lop=f(c,V)Fl,V

lcp=f(F,V)

46

Hnh 2.5 : Chi tit cc bc tnh ton

12022

31

32

2max

11

10...3

....10....

10..3

cLrU

KKLlLKZ

cRU

SKZ

Ldm

dddtoLvhtcL

dm

LLvhtcL

WVDD

WDD

Trong :

. KoL: Vn xy dng 1 km ng cp trc, [triu ng/km ]

. r0L : in tr 1 km ng cp trc, [:/km]

. L : Chiu di cp trc, [ m ]

+ ZL : Hm chi ph tnh ton cho cc ng cp trc, xut tuyn t 1

TBAPP

+ ZB : Hm chi ph tnh ton cho 1 TBAPP, [triu ng ]

622max6

0 10...10... '' cP

SScTPKZ n

BdmMBAPPvhtcB WDD

Trong :

. KMBAPP : Vn u t xy dng 1 TBAPP, triu ng

. 'P0 : Tn tht khng ti ca MBAPP, [KW]

. 'PN : Tn tht ngn mch ca MBAPP, [KW]

. T : Thi gian vn hnh MBA = 8.760h

47

R rng ZB = f (SB,c,V)

+ ZHA : Hm chi ph tnh ton li h p c xc nh theo (2.24) .

ZHA = f(SB,c,V)

+ Vi mt gi tr c v V xc nh, ta xc nh c mt gi tr ca

cng sut MBAPP ZHA min

CHNG 3:

XC NH CU TRC HP L CHO H THNG

CUNG CP IN KHU TH MI IN NAM-

IN NGC

3.1 GII THIU S LC KHU TH MI IN

NAM-IN NGC3.1.1 IU KIN T NHIN-KINH T-XHI:

Khu th mi in Nam-in Ngc nm trn phn ln a bn ca 2

x in Nam v in Ngc ( in Bn- Qung Nam)

+ Pha ty gip trc ng tnh l 603 v 607

+ Pha ng gip sng C c

+ Pha bc gip phng Ho Hi ( qun Ng Hnh Sn- thnh ph

Nng)

+ Pha nam gip x in Dng

Din tch 2.400 ha. Giai on mt d kin xy dng 520 ha

(Lun vn ny ch tp trung cp n giai on I )

48

Khu nghin cu nm trong vng ng bng Nng- Hi An, vi

nhng c im ca vng duyn hi Min Trung, ch yu l vng ct kh,

tng i bng phng, t ngp lt.

Kh hu khu vc nghin cu nm trong vng kh hu Trung b, nng,

m v ma nhiu.

Khu vc nghin cu (520 ha) thuc a gii hnh chnh x in Ngc

(in Bn) c 4.950 h dn vi 3 thn

Dn c ch yu sng bng ngh nng: Trng la, trng mu (khoai

lang, u, ng ...) nhng sn lng rt thp do t xu (ct pha). Mt s h

ang chuyn sang lm dch v, kinh doanh, thng mi. Khu vc bun bn

pht trin mnh nht gn trc cng Khu cng nghip in Nam- in

Ngc v ng t T Cu-in Ngc. Thu nhp bnh qun 352.000

ng/ngi/thng

Hin khu vc c cp in t Nng, t trm trung gian 35KV

Vnh in v trm 110KV Khu Cng nghip

Trong khu vc nghin cu hin c 7 TBA 15/0,4KV :

- Trm bin p 30KVA:1 trm

- Trm bin p 50KVA: 1 trm

- Trm bin p 100KVA: 5 trm

ng dy trung th ang c cp in p 15KV v s dng dy

3xAC-95

H thng in chiu sng cng cng hin ch tp trung dc ng tnh

l 603 v 607, dng loi n cao p 125W v 250W

3.1.2 NH HNG PHT TRIN:

Qui hoch chung ca Khu th mi in Nam- in Ngc c

Th tng chnh ph ph duyt ti quyt nh s : 124/1999/Q-TTg ngy

49

18/5/1999 vi mc tiu l xy dng mt khu th mi vi cc tiu ch :

xanh, sch, p, sng, mang sc thi ca mt th hin i nhng gi gn

c cnh quan sinh thi v bn sc vn ho dn tc

D n Khu th mi in Nam- in Ngc cng nm trong vng vi

hai d n ln :

+ D n xy dng Khu Cng nghip in Nam-in Ngc (420 ha)

c xem l d n trung tm, l mt tin hnh thnh khu th mi

+ D n i hc Nng: nhm xy dng mt Trung tm o to

i hc cho Min trung v Ty Nguyn (mt Trung tm nghin cu khoa

hc, chuyn giao cng ngh. . .) vi qui m 300 ha nm trn t phng

Ho Qu v x in Ngc

C 3 d n thuc v tr thun li v t ai, tn dng c cc iu

kin v c s h tng ca Thnh ph Nng v tnh Qung Nam pht

trin

Ngoi ra khu vc cn c cc d n du lch ven bin: Khu du lch ven

bin in Ngc, Khu du lch th k 21, Khu Du lch i dng xanh, Khu

du lch ven bin H My. . .

Vi cc thun li v tnh tt yu khch quan, vic xy dng khu th

mi in Nam- in Ngc l cn thit

xy dng Khu th mi in Nam-in Ngc, cn phi xy

dng hng lot cc c s h tng nh: giao thng, cp nc, thot nc, cy

xanh, cp in, chiu sng cng cng, thng tin lin lc. . .

Trong vn cp in cn phi c quan tm v xem xt nghim

tc, sao cho vic u t mang li hiu qu cao nht m vn m bo c

cht lng in nng

3.2 MT S GI THIT:

50

+ Gi thit v dy cng sut MBA : Th trng thc t hin nay ch

yu tn ti mt s gam cng sut MBAPP nh sau : 100,160, 250, 320, 400,

560, 630KVA

+ Gi thit v cu trc TBA phn phi : Chng ta bit rng, cu trc

TBA phn phi c qui nh bi phn b ph ti.

Khu th mi in Nam-in Ngc l khu th c hnh thnh

trn c s qui hoch mi hon ton. ng ph trong Khu th ny c

dng bn c. Cc ng trc l cc ph ln chy song song nhau. V ni

gia chng l cc ph nh m chiu di on ph ny l b su hai ng i

ra hai ph chnh v do thng khng ln. c im chung ca li phn

phi hin nay l vn hnh h, hnh tia hoc dng xng c . tng cng

tin cy cung cp in, c th s dng cu trc mch vng kn nhng vn

hnh h. Cc nghin cu v thng k t thc t vn hnh a n kt

lun nn vn hnh li phn phi theo dng h, bi cc l do sau:

+ Vn hnh, qun l n gin

+ Trnh t phc hi li kt cu li sau s c d dng hn

+ t gp kh khn trong vic lp k hoch ct in cc b

Theo cc quan im nh trn, cc cu trc li sau y u c xem

xtTBAPP

Hnh 3.1

51

TBAPP

Hnh 3.2 TBAPP

Hnh 3.3

Trong cc phng n cu trc li trn, phng n hnh 3.1 v hnh

3.3 d gy qu ti nng cp trc khi dng TBA c dung lng ln, v

phng n hp l nht vn l phng n hnh 3.2

Nh th c 4 tuyn trc chnh xut tuyn t mi TBAPP (Vic t

TBA ti cc gc ng t l iu bt tin trong giao thng, nhng ta c th

hiu chnh v tr trm i mt on nh v xem l c 4 xut tuyn h th ti

mi trm. Tt nhin s c sai s trong tnh ton, nhng on hiu chnh l

nh, nn c th b qua)

+ Gi thit v dy dn: Hin nay, theo qui phm trang b in, c th

c cc phng n i ng dy h th cho Khu th nh sau:

52

- i theo phng n 4 dy trn khng : Theo phng n ny, s

chim hnh lang tuyn ln, s lng dy nhiu gy mt m quan ng

ph, gi thnh tng i ln

- i theo phng n cp ngm : m bo m quan ng ph ,

nhng gi thnh ln, chi ph u t cho khu th ln, s kh thu hi vn

- i theo phng n cp vn xon: y l xu hng pht trin chung

ca cc li th, do hai yu cu chnh : Tnh an ton cho cc cng trnh

xung quanh cc tuyn ng dy v t chu tc ng ngu nhin ca mi

trng, cng vi vic tit kim hnh lang tuyn, bn c hc cao v tng

m quan th. Hin nay cp c dng rng ri l cp nhm vn xon

Trn th trng hin nay ch yu tn ti mt s chng loi cp nhm

vn xon, cch in Polyetylen lin kt ngang (XLPE) nh sau: 4x(35, 50,

70, 95, 120, 150)

- Cc ng cp nhnh s dng cp vn xon, cch in XLPE i

ni, c tit din 4x(35,50,70)

- Cc ng cp trc s x dng cp vn xon, cch in XLPE i

ni, c tit din 4x(70, 95, 120, 150)

+ Mt ph ti phn b u : iu ny hon ton c th chp

nhn c. V Khu th mi in Nam -in Ngc l khu dn c th

c quy hoch mi hon ton, vic phn l c tnh ton hp l, a hnh

tng i ng nht, bng phng, i tng dn c tng i ng u v

mt i sng v thu nhp

Qua s liu thng k mt s nm gn y trong cng tc xy dng c

bn, kt hp n gi vt t , thit b hin nay trn th trng, cng nh cc

ch hin hnh ca nh nc qui nh, ta xy dng c sut u tca

mt s TBAPP v ng cp h th nh sau:

53

Bng 3.1 Sut u t TBAPPCng sut TBAPP Gi thnh

100 KVA 118.000.000

160 KVA 132.000.000

180 KVA 138.000.000

250 KVA 152.000.000

320 KVA 173.000.000

400 KVA 198.000.000

Bng 3.2 Sut u t ng cp h th XLPE

Qui cch cp Gi thnh

4x35 205.000.000

4x50 232.000.000

4x70 263.000.000

4x95 310.000.000

4x120 339.000.000

4x150 403.000.000

3.3 XC NH S LIU PH TI:Do th mi in Nam -in Ngc l khu th c xy dng mi

t u, nn c s liu v mt ph ti, c th s dng cc s liu thng

k ti cc th Qung Nam v tc pht trin ph ti in thng

phm, kt hp vi Qui chun xy dng Vit Nam ta c th c s liu nh

sau:

Bng 3.3 Mt s tiu ch Khu th mi in Nam-in Ngc [6]

STT NI DUNG TIU CH GHI CH

54

1 Loi th 3

2 Dn s 32.417 ngi

3 Din tch qui hoch 520 ha 5,2km2

Trong : t 202,7 ha

t giao thng 114,5 ha

t cy xanh 138,7 ha

t d tr pht trin 17,3 ha

t cng trnh cng cng 46.8 ha

Trong :

t trung tm hnh chnh 6,02 ha

t trung tm vn ho 3,66 ha

Trung tm thng mi , dch v 8,55 ha

Trung tm th thao 13,92 ha

Trng hc 14,65 ha

Theo :

+ i vi th loi 3, tiu chun ri tnh trung bnh cho cc

ng giao thng : 0,5 lux (theo [2]), tng ng vi cng sut in : 0,95

W/m2

+ Ph ti chiu sng giao thng:

0,95 W/m2 x 114,5 ha x 104 = 108,8 x 104 W

+ Ph ti chiu sng cho cc dch v thng mi dch v:

1 Trung tm hnh chnh 6,02 ha x 18 W/m2 = 108,36 x104 W

2 Trung tm vn ho 3,66 ha x 15 = 54,9 x104 W

3 Trung tm thng mi dch v 8,55 ha x 25 = 213,75 x104 W

4 Trung tm th thao 13,92 ha x 12 = 167,04 x104 W

5 H thng cc trng hc 14,65 ha x 15 = 219,75 x104 W

55

Tng ph ti chiu sng cho khu vc dch v thng mi:763,8x 104 W

+ Ph ti ng lc cho khu vc dch v thng mi ( theo [4]) thng

chim khong 4,3 ln ph ti chiu sng = 3.284,34 x 104 W

+ S h dn c bnh qun: 32.417 : 4 = 8.104 h

+ Sut ph ti tnh ton cho mt h dn c, th loi 3 [2] :

2.500 W/h

+ Ph ti tnh ton cho sinh hot khu dn c :

8.104 x 2.500 = 2.026 x 104 W

+ Mt ph ti tnh ton :

2,1310.9,0000.200.5

026.23,284.38,7638,108 4 x

V VA/m2

+ Ltb : Theo [12 ] , vi li th, Ltb = 250m. Nhng trong thc t

qun l , vn hnh, kinh doanh in , Cng ty in lc 3 pht hnh Tiu

chun cng tc li phn phi ( trong phm vi qun l ca cng ty) vi

chiu di cp trc hp l l Ltb [400 y 600] . y chn Ltb = 600 m

3.4 TRNH T CC BC TNH TON KHI TIN

HNH LA CHN CU TRC HP L CHO HTCCT 1/ Thu thp, x l cc thng tin cn thit lin quan n khu vc nghin

cu v xc nh V

2/ T V v c, theo gin khong chia kinh t cu trc li h p, tm

cng sut hp l TBAPP cho khu vc

3/ Vi SBdm , V v c theo cc gin khong chia kinh t cp trc v

cp nhnh, xc nh thit din cp trc v cp nhnh hp l

56

4/ T SBdm , V , c , FL v Fl chn chiu di hp l cp trc v nhnh.

Nu tit din c qui chun, chn s lng cp chy song song cn thit

5/ Theo din tch thc t cn qui hoch, xc nh s lng TBA phn

phi

6/ Da vo cc c im ph ti v a hnh c th, sp xp thch hp

cc TBAPP

7/ Tnh ton cc ch tiu kinh t k thut ton li. Hiu chnh li v tr

trm, chiu di cc l cp c ch tiu kinh t- k thut tt nht

3.5 CHNG TRNH TNH TON VIT TRN NGN

NG PASCALTrn c s phn tch t 3.1 y 3.4, lun vn s dng ngn ng

PASCAL lp trnh cho bi ton la chn cu trc hp l H thng cung

cp in Khu th mi in Nam-in Ngc, ni dung chng trnh xem

trong ph lc 1

3.6 KT QU BI TON Bi ton la chn cu trc hp l h HTCCT Khu th mi

in Nam-in Ngc vi cc s liu u vo : D = 5, 2 km2 , V = 13.

VA/m2 ,

c = 630 /KWh, cho kt qu v cu trc hp l HTCC Khu th

mi in Nam in Ngc nh sau:

+ S lng cc xut tuyn hp l l 4 tuyn

+ Gam cng sut MBAPP hp l l 250 KVA

+ S lng MBA hp l l 102 my

+ Tit din cp trc hp l l 120 mm2

57

+ Tit din cp nhnh hp l l 35 mm2

+ Chiu di cp trc hp l l 426 m

+ Chiu di cp nhnh hp l l 60 m

3.7 HIU CHNH THEO NHNG IU KIN RING: Sau khi c kt qu tng th ca bi ton xc nh cu trc hp l

HTCC Khu th mi in Nam-in Ngc nh trn, bc sau cng l

b tr v hiu chnh theo cc iu kin ring ca Khu th, c th :

1/ Phn khu pha bc ca Khu th l Khu i hc dn lp Qung

Nam, d kin b tr 1500 SV v h thng cc phng ban chc nng ca

trng

Ti khu vc ny c mt ph ti ln , c b tr 2 my 400KVA

2/ Tng ng s lng MBA cn li l 98 my

3/ Phn b s b s lng MBA ( 98 my) trn din tch kho st

4/ iu chnh v tr mt s TBA ti cc vng bin cho ph hp vi

thc t

5/ Tin hnh tnh ton phn b dng cho cc xut tuyn ti cc MBA

vng bin ca khu vc kho st v tnh chn li cp trc, cp nhnh cho

cc MBA ny

3.8 KT LUN : 3.8.1 : Sau khi c kt qu bi ton c th, i chiu vi s liu

trong Bo co nghin cu kh thi ca Khu th mi in Nam - in

Ngc, chng ta nhn thy :

Gia s liu qui hoch v s liu tnh ton bng phng php

khong chia ph ti kinh t c s sai lch .

Bng 4.1 So snh kt qu

58

Kt qu ca vic gii

bi ton bng phng php

khong chia kinh t

S liu qui

hoch

Gam cng sut MBA 250 KVA 400 KVA

S lng MBA 102 46

iu cho ta thy trong cng tc qui hoch, kho st thit k cung

cp in cho khu dn c, khu th cn phi quan tm ng mc vic tnh

ton hp l, tnh chn ti u thit b

3.8.2 : Kt qu trn ch l kt qu lm c s cho vic lp Bo co

nghin cu kh thi. Trong qu trnh thit k c th cho tng hng mc ca

d n, vic cung cp in s c tnh ton cho tng trng hp, nhng vn

phi tun th theo ni dung c bn ca Bo co nghin cu kh thi

59

CHNG 4 : KT LUN V HNG NGHIN

CU TIP THEO 4.1 KT LUN

1/ Trong qu trnh nghin cu bi ton chung cho cc trng hp,

chng ta nhn thy

+ ng vi mt gam MBAPP c chn l mt di gi tr mt ph

ti V xc nh ( xem hnh 4.2)

+ Ti min V chuyn tip 2 gam MBAPP xy ra s dao ng trong

vic tnh chn MBAPP ( Xem hnh 4.1) :

Qua chng ta thy rng, vic tm kim mt phng php khoa hc

trong vic xc nh cu trc hp l cho HTCCT l cn thit

S

S4

S3S2

S1V

60

V' V' V' (VA/m2)Hnh 4.1 S ph thuc ca cng sut MBAPP c chn theo mt phti 2/ Phng php khong chia kinh t vi thut ton v ni dung chi

tit cc bc tnh ton nh trnh by , mt mc cho php l c th

chp nhn c trong vic tnh chn cu trc hp l cho HTCCT ni

chung v Khu th mi in Nam in Ngc ni ring. Phng php ny

cn c th vn dng cho mt s khu th mi, c qui m, c im tng

t nh Khu th mi in Nam - in Ngc

050100150200250300350400450

0.5 5.5 10.515.520.525.530.535.540.545.5

Hnh 4.2 Minh ho s ph thuc ca cng sut MBAPP c chn

theo mt ph ti

61

4.2 HNG NGHIN CU TIP THEOKhi tnh ton kinh t-k thut li phn phi th, chng ta cn phi

xem xt c li 22KV, TBAPP v c li 0,4KV trong mt th thng nht

v chng l nhng phn t c bn cu to nn li phn phi th v lin

h cht ch vi nhau v ch vn hnh cng nh cu trc (tnh phi hp

gia cc li trung v h th trong cng mt tuyn, s b tr cc TBAPP

cng quan l n li trung th ...)

Hin nay, bi ton xc nh cu trc hp l li trung th cung cp

in khu th trong mt s trng hp xc nh cng c th gii quyt

c

Tuy nhin, vn phi hp c li trung th, h th v cc TBAPP

trong mt bi ton chung xc nh cu trc hp l li phn phi th

vn cn l mt vn cn phi quan tm, v y cng l hng nghin cu

tip theo ca bn thn ti.

62

CC TI LIU THAM KHO : [1] Trn Bch (2002), Li in v h thng in, NXB Khoa hc v

K thut

[2] B Xy dng (1999), Qui chun xy dng Vit Nam

[3] ng Ngc Dinh, Nguyn Hu Khi,Trn Bch (1981), H thng

in I v II, NXB i hc v Trung hc chuyn nghip

[4] ng Ngc Dinh, Nguyn Cng Hin, Nguyn nh Ho (1987),

Cung cp in trong cc lnh vc kinh t quc dn, NXB

i hc v Trung hc chuyn nghip

[5] Nguyn Vn m (2001), Mng li in, NXB Khoa hc-K

thut

[6] Nguyn Sn Hi (2003) Thuyt minh qui hoch chi tit Khu

th pha bc- th mi in Nam in Ngc Vin Qui

hoch th-nng thn

[7] Nguyn Cng Hin, Nguyn Mnh Hoch (2001), H thng cung

cp in ca x nghip cng nghip, th v nh cao tng,

NXB Khoa hc v K thut

[8] Nguyn c Ngha (1998), Ti u ho, NXB Gio dc

[9] Ng Hng Quang, V Vn Tm .(1980) Thit k cp in, NXB

63

Khoa hc K thut

[10] Trn Vinh Tnh (2001), p dng cc phng php ti u ho

nhm nng cao hiu qu kinh t vn hnh h thng cung

cp in, (Lun vn tin s khoa hc)

[11] Trn Vinh Tnh (2001), Bi ging Qui hoch in, ( Lu hnh

ni b)

[12] ng Quc Thng (2003), Mt s vn v qui hoch, Thit k

v vn hnh cc h thng cung cp in cho th, (Lu

hnh ni b)

[13] Mandal, S. (2002), Distrib. feeder conductor selection

optimization, IEEE Transactions on power systems Vol. 17

PH LC 1 CHNG TRNH TNH TON VIT TRN PASCAL

program DIENNAM_DIENNGOC;

uses crt;

const

Kdd=0.7;Kdt=0.7;Kqt=1.3;anfa1=0.125;anfa2=0.04;Lkc=40;t0=1600;T=8760;Ltb1=60;Ltb2=450;var F1:array[1..3] of integer ; (*Tietdien*) K1:array[1..3] of real; (* gia thanh cap nhanh*) F2:array[1..5] of integer ;

64

K2:array[1..5] of integer; I1:array[1..3] of real; I2:array[1..5] of real; r1:array[1..3] of real; r2:array[1..5] of real; Sbdm:array[1..6]of integer; Smax:array[1..6]of integer; dPo:array[1..6] of real; dPn:array[1..6] of real; Zmba:array[1..6] of real; Z2:array[1..5] of real; Z1:array[1..3] of real; ZL2:array[1..6]of real; ZL1:array[1..6]of real; Zha:array[1..6]of real; K: array[1..6] of integer; (* gia thanh 1 TBA*) Nb:array[1..6] of integer;(*So TBA*) D,T1,T2,T3,xima,Fb,Fa,K02,K01,r01,r02,L1ph,L2ph,L2,L1,Lcp,min,Z:Real;N1,N2,N,S,a,m,c:integer; begin ClrScr; (************************************************) BEGIN (* CHI PHI TINH TOAN 1 TBA*) (************************************************)Sbdm[1]:=100;Sbdm[2]:=160;Sbdm[3]:=180;Sbdm[4]:=250;Sbdm[5]:=320;Sbdm[6]:=400;K[1]:=118; K[2]:=132; K[3]:=138; K[4]:=152; K[5]:=173; K[6]:=198;(*gia thanh TBA*) dPo[1]:=0.32;dPo[2]:=0.5;dPo[3]:=0.53;dPo[4]:=0.64;dPo[5]:=0.7; dPo[6]:=0.84;

65

dPn[1]:=2.05;dPn[2]:=2.95;dPn[3]:=3.15;dPn[4]:=4.1;dPn[5]:=4.82;dPn[6]:=5.75;Writeln(' KET QUA BAI TOAN LUA CHON CAU TRUC HOP LY HT CUNG CAP DIEN '); writeln(' KHU DO THI MOI DIEN NAM- DIEN NGOC'); writeln('*************************************************');write('Nhap dien tich khu vuc khao sat D(km2) = ');readln(D); write('Nhap gia dien c = ');readln(c); write('Nhap mat do phu tai xima = ');readln(xima); writeln(' HAM CHI PHI TINH TOAN CHO 1 TBA'); writeln(' Theo cong suat MBA'); writeln('Sbdm(KVA) Smax(KVA) Gia thanh(trieu dong) Zmba(trieu dong)'); writeln(' '); for a:=1 to 6 do begin Smax[a]:=round(Kqt*Sbdm[a]); T1:=(anfa1+anfa2)*K[a]; T2:= dPo[a]*T*c*1.0E-06 ; T3:= (Smax[a]/Sbdm[a])*(Smax[a]/Sbdm[a])*dPn[a]*t0*c*1.0E-06; Zmba[a]:=T1+T2+T3; Writeln(Sbdm[a]:5,Smax[a]:10,K[a]:20,'',Zmba[a]:11); end; readln; END; (**************************************************) BEGIN (*CHI PHI TINH TOAN CHO CAP TRUC *) (**************************************************)

66

begin F2[1]:=70; F2[2]:=95; F2[3]:=120; F2[4]:=150; I2[1]:=213; I2[2]:=263; I2[3]:=298; I2[4]:=336; r2[1]:=0.533;r2[2]:=0.385;r2[3]:=0.305;r2[4]:=0.248;K2[1]:=263 ; K2[2]:=310; K2[3]:=339; K2[4]:=403;min:=1000;(*chon gia tri ban dau de tim gia tri cuc tieu*) writeln(' HAM CHI PHI TINH TOAN CAP TRUC'); writeln(' Theo tiet dien cap truc'); writeln('F(mm2) Z2(trieu dong)'); writeln(' '); for a:=1 to 4 do begin T1:=(anfa1+anfa2)*K2[a]*Ltb2*1.0E-03; T2:=Ltb1*Ltb1*Ltb2*Ltb2*xima*xima*Kdd*Kdd*Kdt*Kdt*r2[a]*Ltb2*t0*c*1.0E-12; Z2[a]:=T1+(T2/(3*380*380)); writeln(F2[a]:3,' ',Z2[a]:11); if Z2[a]

67

Writeln('CHI PHI TINH TOAN CAP TRUC DA CHON UNG VOI Smba ');writeln('Sbdm(KVA)Ham chi phi tinh toan cap truc(trieu dong)'); writeln(' '); L1ph:=sqrt((2*0.04*380*380*1000)/(Ltb1*xima*Kdd*Kdt*r02*0.9)); for a:=1 to 6 do (* 6 chung loai may*) begin min:=4*Ltb1*Kdt*Kdd*xima; L2ph:=(Smax[a]/min)*1000; if L1ph

68

writeln(' '); begin for a:=1 to 3 do (*3 loai cap nhanh*) begin T1:=(anfa1+anfa2)*K1[a]*Ltb1*0.001;T2:=Ltb1*Ltb1*Lkc*Lkc*xima*xima*Kdd*Kdd*Kdt*Kdt*r1[a]*Ltb1*t0*c*1.0E-12; Z1[a]:=T1+(T2/(380*380)); writeln(F1[a]:3,' ',Z1[a]:9); if Z1[a]

69

else L1:=Ltb1; for a:=1 to 6 do (* 6 chung loai may*) begin L2ph:=(Sbdm[a]*Kqt*1000)/(4*L1*Kdt*Kdd*xima); if L1phN2 then Nb[a]:=N1 else Nb[a]:=N2; end; readln; end; END; (**************************************************) BEGIN (*CHI PHI TINH TOAN LUOI HA AP*) (**************************************************) writeln(' CHI PHI TINH TOAN LUOI HA AP'); writeln(' Theo cong suat TBA'); writeln('Sbdm(KVA) Nb Zha(trieu dong)'); writeln(' '); Z:=9.0E+20; for a:=1 to 6 do (* 6 chung loai may*) begin Zha[a]:=Nb[a]*(Zmba[a]+ZL1[a]+ZL2[a]);

70

if Zha[a]

71

PH LC 2

KT QU BI TON XC NH CU TRC HP L HTCC KHU TH MI IN NAM-IN NGC

******************************************************

Nhap dien tich khu vuc khao sat D = 5.2 [km2]

Nhap gia dien c = 630 [d/kWh]

Nhap mat do phu tai xima = 13 [VA/m2]

******************************************************

Dien tich khu vuc dang khao sat la : 5.2E+00 km2

Gam cong suat MBA la : 250 KVA

So luong MBA la : 102 may

Chung loai cap truc la : 1.20E+02 mm2

Chieu dai cap truc hop ly la : 4.26E+02 m

Chung loai cap nhanh la : 3.5E+01 mm2

Chieu dai cap nhanh hop ly la : 6.00E+01 m

72

******************************************************

PH LC 3

CHI PH TNH TON LI H P

KHU TH MI IN NAM - IN NGC

( Theo mt ph ti V (bc nhy 0.1 VA/m2 ) v SBdm )

Din tch khu vc kho st D = 5,2 km2

Gi in c = 630 [ /kWh ]V 100 160 180 250 320 400 (KVA)

5.00E-01 9.104E+03 9.898E+03 1.023E+04 1.166E+04 1.352E+04 1.622E+04

73

1.00E+00 9.302E+03 1.013E+04 1.047E+04 1.192E+04 1.380E+04 1.652E+04

1.50E+00 9.292E+03 1.014E+04 1.049E+04 1.194E+04 1.380E+04 1.651E+04

2.00E+00 9.596E+03 1.044E+04 1.080E+04 1.228E+04 1.419E+04 1.695E+04

2.50E+00 9.910E+03 1.055E+04 1.091E+04 1.241E+04 1.432E+04 1.710E+04

3.00E+00 1.025E+04 1.050E+04 1.087E+04 1.235E+04 1.425E+04 1.700E+04

3.50E+00 1.058E+04 1.077E+04 1.115E+04 1.266E+04 1.460E+04 1.741E+04

4.00E+00 1.073E+04 1.087E+04 1.124E+04 1.276E+04 1.470E+04 1.752E+04

4.50E+00 1.105E+04 1.103E+04 1.142E+04 1.296E+04 1.491E+04 1.774E+04

5.00E+00 1.125E+04 1.120E+04 1.139E+04 1.303E+04 1.500E+04 1.786E+04

5.50E+00 1.154E+04 1.140E+04 1.165E+04 1.309E+04 1.504E+04 1.787E+04

6.00E+00 1.175E+04 1.170E+04 1.176E+04 1.326E+04 1.523E+04 1.810E+04

6.50E+00 1.204E+04 1.191E+04 1.212E+04 1.320E+04 1.517E+04 1.802E+04

7.00E+00 1.239E+04 1.208E+04 1.212E+04 1.326E+04 1.523E+04 1.808E+04

7.50E+00 1.270E+04 1.240E+04 1.254E+04 1.354E+04 1.553E+04 1.843E+04

8.00E+00 1.297E+04 1.248E+04 1.261E+04 1.360E+04 1.559E+04 1.849E+04

8.50E+00 1.407E+04 1.327E+04 1.316E+04 1.339E+04 1.383E+04 1.547E+04

9.00E+00 1.418E+04 1.350E+04 1.335E+04 1.353E+04 1.387E+04 1.543E+04

9.50E+00 1.472E+04 1.370E+04 1.352E+04 1.346E+04 1.400E+04 1.539E+04

1.00E+01 1.485E+04 1.400E+04 1.380E+04 1.371E+04 1.410E+04 1.553E+04

1.05E+01 1.537E+04 1.415E+04 1.392E+04 1.377E+04 1.431E+04 1.561E+04

1.10E+01 1.543E+04 1.428E+04 1.415E+04 1.397E+04 1.437E+04 1.586E+04

1.15E+01 1.586E+04 1.439E+04 1.424E+04 1.416E+04 1.455E+04 1.583E+04

1.20E+01 1.587E+04 1.478E+04 1.469E+04 1.433E+04 1.476E+04 1.580E+04

1.25E+01 1.635E+04 1.485E+04 1.475E+04 1.448E+04 1.491E+04 1.577E+04

74

1.30E+01 1.683E+04 1.523E+04 1.489E+04 1.462E+04 1.505E+04 1.609E+04

1.35E+01 1.675E+04 1.527E+04 1.522E+04 1.474E+04 1.517E+04 1.614E+04

1.40E+01 1.715E+04 1.573E+04 1.522E+04 1.508E+04 1.528E+04 1.642E+04

1.45E+01 1.762E+04 1.572E+04 1.564E+04 1.518E+04 1.538E+04 1.630E+04

1.50E+01 1.745E+04 1.608E+04 1.561E+04 1.526E+04 1.567E+04 1.655E+04

1.55E+01 1.789E+04 1.604E+04 1.602E+04 1.559E+04 1.575E+04 1.673E+04

1.60E+01 1.921E+04 1.717E+04 1.671E+04 1.611E+04 1.621E+04 1.684E+04

1.65E+01 1.960E+04 1.753E+04 1.711E+04 1.643E+04 1.627E+04 1.706E+04

1.70E+01 2.005E+04 1.743E+04 1.741E+04 1.646E+04 1.654E+04 1.706E+04

1.75E+01 1.975E+04 1.777E+04 1.739E+04 1.678E+04 1.658E+04 1.725E+04

1.80E+01 2.018E+04 1.820E+04 1.769E+04 1.678E+04 1.685E+04 1.743E+04

1.85E+01 2.061E+04 1.855E+04 1.799E+04 1.709E+04 1.687E+04 1.760E+04

1.90E+01 2.099E+04 1.837E+04 1.792E+04 1.740E+04 1.714E+04 1.757E+04

1.95E+01 2.143E+04 1.871E+04 1.821E+04 1.737E+04 1.714E+04 1.793E+04

2.00E+01 2.187E+04 1.905E+04 1.859E+04 1.767E+04 1.755E+04 1.788E+04

2.05E+01 2.140E+04 1.939E+04 1.889E+04 1.761E+04 1.753E+04 1.806E+04

2.10E+01 2.182E+04 1.914E+04 1.875E+04 1.791E+04 1.778E+04 1.818E+04

2.15E+01 2.219E+04 1.947E+04 1.904E+04 1.821E+04 1.774E+04 1.835E+04

2.20E+01 2.258E+04 1.986E+04 1.939E+04 1.838E+04 1.797E+04 1.843E+04

2.25E+01 2.292E+04 2.011E+04 1.960E+04 1.820E+04 1.815E+04 1.853E+04

2.30E+01 2.326E+04 2.036E+04 1.981E+04 1.841E+04 1.833E+04 1.880E+04

2.35E+01 2.360E+04 2.061E+04 2.010E+04 1.863E+04 1.851E+04 1.889E+04

2.40E+01 2.388E+04 2.086E+04 2.031E+04 1.884E+04 1.836E+04 1.889E+04

75

2.45E+01 2.422E+04 2.111E+04 2.060E+04 1.906E+04 1.854E+04 1.899E+04

2.50E+01 2.455E+04 2.136E+04 2.081E+04 1.927E+04 1.871E+04 1.909E+04

2.55E+01 2.489E+04 2.093E+04 2.049E+04 1.949E+04 1.888E+04 1.935E+04

2.60E+01 2.522E+04 2.123E+04 2.070E+04 1.970E+04 1.906E+04 1.944E+04

2.65E+01 2.551E+04 2.148E+04 2.098E+04 1.946E+04 1.923E+04 1.942E+04

2.70E+01 2.584E+04 2.172E+04 2.118E+04 1.967E+04 1.941E+04 1.951E+04

2.75E+01 2.618E+04 2.196E+04 2.139E+04 1.988E+04 1.922E+04 1.976E+04

2.80E+01 2.535E+04 2.220E+04 2.166E+04 2.009E+04 1.951E+04 1.986E+04

2.85E+01 2.567E+04 2.244E+04 2.187E+04 2.020E+04 1.968E+04 2.010E+04

2.90E+01 2.594E+04 2.268E+04 2.214E+04 2.041E+04 1.984E+04 2.020E+04

2.95E+01 2.626E+04 2.292E+04 2.235E+04 2.061E+04 2.001E+04 2.014E+04

3.00E+01 2.658E+04 2.322E+04 2.263E+04 2.082E+04 2.018E+04 2.024E+04

3.05E+01 2.689E+04 2.347E+04 2.283E+04 2.103E+04 2.035E+04 2.034E+04

3.10E+01 2.721E+04 2.371E+04 2.311E+04 2.123E+04 2.052E+04 2.058E+04

3.15E+01 2.749E+04 2.395E+04 2.331E+04 2.144E+04 2.029E+04 2.068E+04

3.20E+01 2.780E+04 2.419E+04 2.352E+04 2.113E+04 2.046E+04 2.091E+04

3.25E+01 2.812E+04 2.443E+04 2.308E+04 2.133E+04 2.062E+04 2.101E+04

3.30E+01 2.844E+04 2.467E+04 2.328E+04 2.153E+04 2.079E+04 2.092E+04

3.35E+01 2.876E+04 2.491E+04 2.354E+04 2.173E+04 2.095E+04 2.102E+04

3.40E+01 2.903E+04 2.438E+04 2.374E+04 2.193E+04 2.112E+04 2.124E+04

3.45E+01 2.935E+04 2.461E+04 2.400E+04 2.205E+04 2.128E+04 2.134E+04

3.50E+01 2.967E+04 2.484E+04 2.420E+04 2.225E+04 2.145E+04 2.144E+04

3.55E+01 2.998E+04 2.507E+04 2.447E+04 2.245E+04 2.161E+04 2.167E+04

3.60E+01 3.030E+04 2.530E+04 2.466E+04 2.265E+04 2.187E+04 2.177E+04

76

3.65E+01 3.057E+04 2.554E+04 2.486E+04 2.285E+04 2.204E+04 2.199E+04

3.70E+01 3.089E+04 2.577E+04 2.513E+04 2.304E+04 2.176E+04 2.209E+04

3.75E+01 3.121E+04 2.600E+04 2.533E+04 2.324E+04 2.192E+04 2.196E+04

3.80E+01 3.152E+04 2.623E+04 2.559E+04 2.344E+04 2.208E+04 2.206E+04

3.85E+01 3.184E+04 2.652E+04 2.579E+04 2.364E+04 2.224E+04 2.228E+04

3.90E+01 3.211E+04 2.675E+04 2.605E+04 2.326E+04 2.240E+04 2.238E+04

3.95E+01 3.243E+04 2.698E+04 2.625E+04 2.345E+04 2.256E+04 2.259E+04

4.00E+01 3.275E+04 2.721E+04 2.651E+04 2.364E+04 2.272E+04 2.269E+04

4.05E+01 3.306E+04 2.744E+04 2.671E+04 2.383E+04 2.288E+04 2.279E+04

4.10E+01 3.338E+04 2.767E+04 2.691E+04 2.395E+04 2.304E+04 2.301E+04

4.15E+01 3.385E+04 2.857E+04 2.800E+04 2.508E+04 2.373E+04 2.385E+04

4.20E+01 3.417E+04 2.886E+04 2.821E+04 2.528E+04 2.389E+04 2.407E+04

4.25E+01 3.448E+04 2.909E+04 2.847E+04 2.548E+04 2.406E+04 2.368E+04

4.30E+01 3.480E+04 2.933E+04 2.868E+04 2.568E+04 2.422E+04 2.390E+04

4.35E+01 3.511E+04 2.956E+04 2.894E+04 2.588E+04 2.438E+04 2.400E+04

4.40E+01 3.539E+04 2.980E+04 2.915E+04 2.608E+04 2.464E+04 2.421E+04

4.45E+01 3.570E+04 3.003E+04 2.827E+04 2.628E+04 2.480E+04 2.432E+04

4.50E+01 3.602E+04 3.027E+04 2.847E+04 2.647E+04 2.496E+04 2.453E+04

4.55E+01 3.633E+04 3.050E+04 2.867E+04 2.667E+04 2.513E+04 2.463E+04

4.60E+01 3.665E+04 3.079E+04 2.892E+04 2.603E+04 2.529E+04 2.474E+04

4.65E+01 3.692E+04 3.103E+04 2.912E+04 2.622E+04 2.545E+04 2.495E+04

4.70E+01 3.724E+04 3.126E+04 2.938E+04 2.634E+04 2.535E+04 2.505E+04

4.75E+01 3.752E+04 3.236E+04 3.034E+04 2.765E+04 2.642E+04 2.613E+04

77

4.80E+01 3.783E+04 3.260E+04 3.060E+04 2.785E+04 2.658E+04 2.624E+04

4.85E+01 3.815E+04 3.283E+04 3.080E+04 2.804E+04 2.675E+04 2.645E+04

4.90E+01 3.842E+04 3.307E+04 3.106E+04 2.824E+04 2.691E+04 2.656E+04

4.95E+01 3.873E+04 3.331E+04 3.126E+04 2.844E+04 2.708E+04 2.678E+04

5.00E+01 3.904E+04 3.355E+04 3.146E+04 2.864E+04 2.724E+04 2.689E+04