u LUbl DANH QUAN Ht GltfA Hi Sd S6 PHU

(1)

E] KHOA HQC • CdNG NGHf:

DANH GIA QUAN Ht GltfA Hi Sd TUN THAT VA Hi S6 PHU TAI

TRONG LUbl PHAN P H 6 | D I E N V I £ T NAM

Lfl Minh Khinh, TrUmig Ng9C Minh, Pham Thinh Chung Trudng Dql hqc B6ch Khoa Hd Nfy

T6MTAT

V't^c tinh todn mUc tfd t6n th6t <Ji^n ndng trong ludi dl^n ddng m^f vai trd quan trqng trong cdng tdcqudn ly, quy hoqch vd vdn hdnh ludi di^n. Hl^n nay tql Vi$t Nam cdc cdng thdc kinh nghiem nhdm xdc djnh m(ic tSn tiidt dtfa theo phi^ tdi trong ludi di^n diu sOdqng cdc ddnh gid gdn dung cua nudc ngodi. Bdi bdo trinh bdy viic ddnh gid mdc dd chinh xdc khi dp dyng hf s6 tSn thdt nhdm tinh todn tdn thdt difn ndng trong ludi difn phdn phdi W^

Nam. Cdc sd llfu d4 so sdnh ddnh gid dupc xiy ly tUdCf li$u v l dlin ndng tifiu t/iy rrong glal doqn 2001-20W tai cdc dan VI difn li/c vd dd thf p/iy tdi di4n hinh dd dupc xdy di/ng cua ludi di^n phdn phdi Vift Nam.

I.OATVAND£

Tdn t h i t d i | n n i n g (TTDN) l i di&n n i n g dung d l truyin t i i v i p h i n phdi di^n. Trong dd, TTDN AA tr^n mdt ludi di&n trong mdt khoing thdi gian T la hi^u giufa tdng dien n i n g n h i n v i o A^,^^ trir tong di^n n i n g giao di A ^ cua ludi didn trong khoing thdi gian T dd.Tdng d i | n n i n g giao, n h i n cua ludi dien l i tong dai s6 luong di^n giao, n h i n dUdc xic djnh bdi hS thdng do d i m di&n nang tai c i c d i l m do d i m d ranh gidi cua ludi di^n dd v i tai khich h i n g sir dyng dien (cic hd tieu thy)'.

AA = A., .{kWh)

do p h i t ndng tr^n d i | n trd t i c dyng cua cic phin tif.

D i y cung l i t h i n h p h i n chinh c i n dUpc xic dinh cho cic d i n h g i i v l tdn t h i t d i | n n i n g trong quy hoach, thiet k l ludi dien,

Cd t h i coi tdn t h i t d i | n n i n g do p h i t ndng (ky hi^u Chung AA) l i h i m sd cua ddng d i | n phy t i i I trong lUdi di^n p h i n phdi hinh tia:

AA,kWH

TTDN trgn ludi dien bao gdm tdn t h i t ky t h u i t AA^

v i tdn that phi ky t h u i t AA^^ Trong dd ton t h i t ky t h u i t l i lupng dien n i n g tieu hao tren mang ludi dien do tinh c h i t vat ly ciia q u i trinh truyin t i i dien ning, bao gdm:

- Thinh p h i n phu thudc v i o ddng dien (I'), l i lupng dien n i n g tieu hao do phat ndng tren cic phan tCf khi cd ddng dien di qua. Tdn that di^n nang do p h i t ndng chu yeu tren dien trd t i e dyng cua dudng d i y v i cua cic cupn d i y trong MBA.

- TTON phu thudc v i o dien i p (U^), bao gdm tdn that v i n g quang dien, tdn that do rd dien, tdn t h i t khdng t i l eua MBA, tdn that trong mach tii cua cic t h i l t bj do ludng... Trong dd tdn that khdng t i i eua MBA l i t h i n h p h i n Idn nhat va cd the xac djnh thdng qua so lieu cOa eacTBA.

Nhu v i y cd t h i thay viec d i n h gia TTON trong he thdng di&n chju i n h hudng ciia nhieu y l u to. Bii b i o nay de cap d i n viec xic dmh p h i n tdn that dien nang 1. Dua Iheo Quyet dinii so 288/QD-EVN-KTLD-KD&DNT ng^y 18/02/2008 cua Tap doan Di^n lire Vi?t Nam.

r,n u

AA = jy;r.(il = Y,^I;r.At,

(1)

Trong cdng thdc t r i n :

T- khoing thdi gian c i n x i c dinh tdn that dien nang (thdng thudng l i l n i m )

r - di^n trd t i e dung cua ludi

I, - ddng d i i n t i i trung blnh trong q u i n g thdi gian t At, - khoing thdi gian t ciia dd thi phy t i i , n - tdng sd c i c khoing thdi gian.

Viec tinh t o i n TTON ddi hdi nhdng thdng tin day dii v l dd thi phy t i i . Tuy nhien, thuc t l trong nhieu trudng hpp khi khdng cd dCi thdng tin e i n thiet, nhit l i trong e6ng t i c quy hoach va t h i l t k l lUdi dien, ngt/di tinh t o i n thudng sir cac cdng thCfe kinh nghiem khic nhau de xac dinh tdn that di^n n i n g vdi gia trj phu tii cue dai.

10 I Dien & D&i song

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KHOA HQC - CONG NGHE Q

II. cAc NGHI£N cCru HI£N C 6

Cdng thCfe kinh nghidm sau thudng dupc sd dung d l xic djnh g i i trj ciia T khi d i biltT^^, (theo [5]):

Atl

Ati Atn

T = (0,124+ Tmaxx 10-4)2x8760

(4)

0 t(h)

Hinh 1. Dd thi phu tdi kio ddi.

Cic eich tiep c i n sau thudng dupe sit dung d l tfnh ton t h i t dien nang trong trudng hpp nay:

a. Xac djnh ton t h i t dien nang b i n g thdi gian tdn that cdng suit Idn nhat (T):

AA = APmaxx x (2)

Trong do: AP_,_^_ - tdn that cdng suat Idn nhat, kW.

Trong eich tiep c i n niy, thdi gian tdn t h i t cdng suat Idn nhat T la ham sd ciia thdi gian sd dung cdng suit Idn nhat T_^: T= f ( T ^ , [5]. Vdi T ^ , la mdt trong nhSng d i e trung tieu thy dien nang quan trpng ciia phy t i i dUdc thdng ke tai cic hd phu t i i .

b. Xic djnh tdn that dien n i n g bSng he sd ton that (LsF - Loss Factor):

AA = APmaxxLsFxT (3)

Trong dd: T - khoing thdi gian can xac dinh tdn that dien n i n g (trong 1 nam T = 8760h).

He sd ton that cung dupe x i c djnh theo quan he vdi he sd t i i {LF - Load Factor):

LsF = f(LF).

Tr^n thue te he sd t i i LF dupc thdng ke nhu l i l;^ le giCfa cdng suit trung binh eua phu t i i vdi cdng suit phu tai dinh trong do thi ngay dem [4].

Nhu v i y LsF ^ T/T and LF = T^^/T. Cd the thay r i n g 2 each t i l p can ndi tren k h i tUdng dong vdi nhau.

N h i m x i y dUng cic quan h^ giCfa he sd t i i va he sd tdn that {LsF v i LF), cung nhUgiCfa thdi gian ton that cdng suat Idn n h i t va thdi gian sddyng cdng suat Idn n h i t (T va J^J. ngudi ta tien hanh d i n h g i i cic d i e trUng tieu thu dien nang cua phu t i i trong mdt he thdng dien cy the, trong mdt khoing thdi gian nhat djnh.

Quan h$ (4) dupe t h i n h l i p dua trfen viec d i n h g i i die trung phy t i l ciia h i thdng di^n U^n Xd (cu), cd trong nhilu quy trinh tinh t o i n t i i u chuin, hi^n v i n dang dUpc sir dijng rdng r i i t^i Vi&t Nam, nhit l i trong cie hudng d i n tinh nhanh TTDN tai eie dOn vj O i i n lUc {[5,6]).

Ddi vdi h& sd tdn t h i t v i he sd t i i , cung tdn tai cdng thCfc kinh nghiem mifiu t i quan hfi gida chiing, gpi l i phuong trinh Buller and Woodrow ([4]) nhu sau:

LsF-kxLF + (l-k)xLF^ (5)

Cdng thCfc n i y cho p h i p hieu chinh hf sd quan he k tCiy theo die trUng ciia phu t i i . Cu t h i trong phuong trinh (5)dtrentaed:

LF- < LsF < LF

Tr^n cd sd sd lieu phy t i i eua lUdi di^n 8ic My va Canada, cic t i c g i i Buller, Woodrow/ and Hoebel (trong [1]) d i danh g i i quan he g i n dung giUa he sd tdn that v i he sd t i i vdi g i i trj k = 0,3. Khi dd:

LsF-0,3xLF + 0,7xLF=

(5) Cdng thde tren cung dupc sirdung trong nhieu t i i lieu v i nghien cufu cua nUdc ngoii ve tinh toan quy hoach t h i l t klludi dien nhim dinh g i i nhanh TTDN tren iUdi.Tuy nhien ed the thay k i t q u i tinh toan phu thudc vao dac trutig tieu thu dien nang cua phu t i i trong lUdi dien hi$n hinh.

Trong [1], cac t i c g i i d a t i l n h i n h p h i n tich d i n h gia lai tdng sd 31 phu tai v i p h i n tich 65 dd thj t d cac n i m 1976-1985 ddi vdi sd lieu ciia Bic My DUa tren ket q u i d i n h g i i , g i i trj khic ciia h f sd k dupe de xuat la 0,08, khi dd quan he giCfa LsF v i LF la:

LsF - 0,08xLF + 0,92xLF^

(6) Hinh 2 b i l u dien quan he giCfa he sd ton that v i he s d t i i .

1,Or

LsF

^ • ' " ^ ^

= 0,3

^.^

i ^ LF+

,•''

^

0,7 L

^y

^^y

LsF

1

LsF = LF

y

^y

\

= o,c

y /' //'

8LF

y'/.

Y''

•'

LsF

*-o,9;

€' ,-/

= LF=

LF^

0 0,5 1,0 Hinh 2. Cac dudng cong quan he giCfa hi s6 ton thdt vd he

so tdi.

Dien & D&i songl W

(3)

E] KHOA HQC - CdNG NGHf:

Do 2 phuong trinh (4) v i {5) tuong ddi phd b i l n t?l Vi$t Nam ([5]), nghiln cdu n i y t^p trung v i o vl|c so sinh k i t q u i vdi sd li|u g i n d i y eua phy t i i ciia ludi d l | n Vl|t Nam.

III.QUYTRINHTINHTOAN

1. Thu t h i p dd ll|u d l | n n i n g t i l u thy ciia phy t i l v i dd thj phy t i i ngiy d i l n hinh ciia cic t h i n h p h i n phy t i l . Sd li^u tinh t o i n dya t r i n ngudn l i Ban K^ t h u i t s i n xuit, EVN v i Cyc D i l u t i l t d i | n lt;c, Bd Cdng Thuong trong giai dO9n2001-2010,([6]).

1 2 3 4 S 6 7 8 9 10 11 12 13 14 15 IE 17 II 9 20 2112 23 24

Trong dd:

A,^, v i \ , l i d l | n n i n g t l i u thy n g i y tUong Cfng vdi n g i y l i m vl$c v i n g i y cudi t u i n d i l n hinh.

n, =261 n g i y l i m vl|c;

n,= 104 n g i y cudi t u i n ;

Td d d l l | u d l | n n i n g t l l u thy h i n g n i m , cd t h i tinh ddpc cdng suit phy t i i trong mdi gid t ciia dd thj phy t i i n g i y d i m . Cdng suit tdng P, dupc cOng t d g i i trj cdng suit c i c t h i n h p h i n phy t i l .

Hinh 4 l i vl dy cua dd thj phy t i i n g i y x i y dung cho ludi p h i n phdi Nam Djnh t r I n co sd d d li^u n i m 2009,

Hinh 3. Do thi ngay tam viec dien hinh cua cdc thdnh phdn phu tdi

Trong hinh tren: NN - Ndng nghifep; CN - Cdng nghiep;

CC - Cdng cong; TM - ThUong mai; DD - D i n dung.

Trong [6], dd thj phij t i i d i l n hinh dupe x i y di/ng v i ehuan hda ddi vdi 5 t h i n h phan phy t i l chinh. Mdi t h i n h phan ed d d l i i u ve dien nang tieu thy dupc thdng k^ trong giai doan tCf 2001-2010. Od thj phy t i i ngiy d i l n hinh dupc t h i n h l i p cho ngay l i m viie v i ngiy eudi t u i n . TrIn hinh 3 l i do thj chuan hda ciia 5 t h i n h phan phy t i i trdng ludt dien phan phdi Viet Nam, dupe xay dUng cho n g i y lam viec d i l n hinh.

2. Xay dung do thi phy t i i tdng ngiy dem cho cho c i c ludi dien p h i n phdi cu the theo nguyen ly c i n b i n g di&n n i n g tieu thy, dUa tren do thi ciia cic t h i n h p h i n phu t i i .

Trong budc niy, xuat phat t d dien nang tieu thy h i n g n i m :

A _ = n xA,. + n X A ^ nam I L\ 2 CT

12 I Dien Jk D&i song

1 1 1 4 3 S 7 • • 1 0 1 1 1 1 1 3 1 4 l S 1 6 I 7 l t » l f l l l l ] » M -^-^4o•v ltHr«na -s-CuAluln

Hinh 4.06 thi phu tdi cua lUdi phdn phdi Nam Dinh xdy di/ng cho ngdy Idm vi^ vd ngdy cu& tuSn.

3. Tinh t o i n tdn t h i t d i i n n i n g v i c i c he sO quy dfii.

3.3 Tinh chinh xac c h i dO ludi n h i m x i c djnh tfin t h i t di§n n i n g vdi 24 gid trong dd thi phy t i i theo cdng t h d c ( l ) .

3.b Tinh t o i n c i c h$ s6 quy ddi t d cic cdng Oidc goc {2)vi(3).Cythe.

".^«.Z^'...+«:-P.Z^n

Trong dd P^, l i phy t i i dinh n g i y d6m; P^^-K^^ vi '^m..'S:i. '^ 9'^ ^n ^ * " 9 suSt nio' 9 ' ^ tUdng iJfng vdi ngay l i m vi^e v i n g i y eudi t u i n .

Thdi gian sddyng cdng suit Idn nhitT^^^^ se bing:

Gi^ tri thdi gian ton that cong suat idn nh^t T tinh chinh xdc theo do thj phu t3i nhu sau:

M AF

**",''1X^.'» +"2-^lZ^™**

(4)

TUdng t u nhU v i y l i he so t i l LF:

P^..-T Vh he so ton that LsF tinh chinh xdc bSng:

AP^ 1 ; , , ^t^<'>]' LsF = ^ = ^—\[Pil)] dl = ^ ^ (10) 3.C Tinh g i n dilng cic he sd quy ddi theo eie cdng thdc kinh nghiem (4) v i (5).

4. Phin tich v i d i n h g i i k i t q u i : sddung mdt phUdng p h i p hi&u chinh sd lieu phu hpp n h i m tinh lai dUdng cong quan he tr^n cd sd k i t q u i thu dUdc.

IV.K^TQUATfNHTOAN

Sai sd gida gia tri tinh t o i n chfnh xAc b i n g dd thj phu t i i (CX) vdi g i i tn nhan dupe t d c i e cdng thdc kinh nghiem (KN) dupe x i c djnh nhu sau:

6 = ^ - ^ ^ . 1 0 0 0 / 0

CX

^{{ I D}

Trong b i n g 1 l i vi du tinh t o i n ddi vdi viec tinh cho do thi phu t i i eua mdi t h i n h phan phy t i i va k i t q u i tinh toan khi tong hpp cho phu t i i toan quoe nam 2010.

Bang 1. Vi du ve sai sogiffa ket qua tinh chinh xdc cdc hi sd tdn thdt vd tinh theo cong t/iu'c kinh nghiem TT

1 2 3 4 5 1 2 3 4 5

Thdnh phan fiCUBT 6 cua LsF 2009

Conq nghiep Thudng mai

Cong conq Nong ngiep

Dan dung

4,60 7,68 3,40 6,13 5,15

5,75 9,70 4,85 8,09 7,56 2010

Cong nghiep Thuonq mai

Conq cong Ndng ngiep Dan dung Toan he thonq

4,57 7,61 3,45 5,99 5,08 2,83

5,72 9,62 4,91 7,92 7,48 3,84 Quy trinh tr^n da dupc ap dyng de tinh lai he sd tdn that va thdi gian tdn that cdng suat Idn nhat tuong Cfng vdi phu t i i cung n h u t o i n bd cic ludi dien phin phdi Viet Nam theo sd lieu thdng ke tCr 2001-2010. Dinh g i i eie k i t q u i nhin duoc, co the rut ra mdt so nhan xet sd bp nhU sau:

- Sai sd tuyet doi Idn nhat khi so sinh t o i n bd ket q u i tinh toan gida tinh chinh x i c v i tinh gan dung la 11,68%.

Cd nghTa la gia trj tinh he sd ton t h i t theo cdng thitc kinh nghiem (5) cao hdn 11,68% so vdi k i t q u i tinh chinh xic theo dd thj phy t i i x i y dung dupc (10).

KHOA HQC • CdNG NGHE Q

- N l u so sinh gida cie cdng thdc kinh nghiem (4) v i (5), g i i trj tinh thdl gian tdn t h i t cdng suit Idn n h i t theo (4) cho k i t q u i chfnh xic hdn k h i nhilu. Hau h i t cic sai sd t u y i t ddi n h i n dUpc (vdi khoing 94% d d lieu phy tii) n i m trong gidi han 10%. Nhu viy, vi§e sd dung cdng thdc kinh nghiSm n i y ed t h i chip nhin dupe trong mdt sd b i i t o i n khi khdng ed dii d d li#u v l dd thj phy t i i , hoic khi khdng ddi hdi k i t q u i cd dd chfnh xic cao.

- Xu hudng cua k i t q u i n h i n dUpc (vdi hon 99% d d li^u phu t i i ) cho t h i y cic g i i tri tinh theo c i 2 cdng thdc kinh nghiem (4) v i (5) d i u Idn hdn gia trj tJnh chinh x i c theo dd thj phu t i i . Do dd cic h^ sd tdn that ed t h i hi&u chinh theo sd li^u thyc cCia h§ thdng di$n Vi^t Nam.

V. K£T LUAN

Vi^c sd dijng cic cdng thdc kinh nghiem d l xic djnh nhanh tdn that dien nang trong ludi dien p h i n phdi ed y nghia quan trpng khi p h i n tich h& thdng dien. Tuy nhi&n cd nhufng sai sd nhat djnh khi i p dung cic cdng thdc kinh nghiem nay v i o tinh t o i n cho ludi di^n Vi^t Nam.

Bii b i o gidi thieu mdt eich tiep can nham d i n h g i i lai quan he gida he sd tdn that v i he sd t i i trong d i l u kien ludi dien Vi^t Nam. Ket q u i tfnh toan cho thay mot danh gia ban dau ve sai sd cd t h i nhin dUpc ddi vdi cac k i t q u i tinh theo cac cdng thCi'e kinh nghiem dang dupc ap dung phd bien tai Viet Nam.

Can thiet cd cac nghien edu tiep theo tren cd sd dd lieu dii Idn n h i m 34 x u i t cdng thdc kinh nghiem phu hpp cho quan he gida he sd t i i va he sd ton that n h i m i p dung cho viec tinh toan ddi vdi he thong dien Viet Nam.

TAI Lieu THAM K H A O

1. Gustafson M.W., 8aylor J.S., Mulnix S.S., TTje equivalent hours loss factor revisited, IEEE Transactions on Power Systems, Vol. 3, Nov 1988.

2. De Oliveira, M.E. Padilha-Feltrin, A. Candian, FJ., Investigation of the Relationship between Load and Loss Factors for a Brazilian Electric Utility, Transmission &

Distribution Conference and Exposition: Latin America, IEEE/PES, 2006.

3. Yung-Chung Chang, Wei-Tsen Yang, Chun-Chang Liu, A new method for calculating loss coefficients, IEEE Transactions on Power Systems, Vol. 9, Aug 1994.

4. Goenen Turan, Electric Power Distribution System Engineering. McGraw-Hill Series in Electrical Engineering, 1986.

5. Tran Bach. Ludi dien vd Hi thong dien. Tap h NX8 Khoa hoc va Ky thuit. H i Npi, 2006.

6. Hdi Dien lUc Viet Nam. Ddnh gid tiem ndng vd cdc gidi phdp giam ton thdt dien ndng trong he thong dien Viet Nam den nam 2015. Du i n nghien cdu khoa hoc cap nha nUde, Bp Cdng thuong. Ha Npi, 2011.

7. Gustafson M,W., Baylor J.S, Approximating the system losses equation power systems, IEEE Transactions on Power Systems, Vol. 4, Aug 1989.

8. Leonard L Grigsby, Electric Power Engineering Handbook - Electric Power Generation, Transmission and Distribution, CRC Press, 2007.