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Science & Technology Development, Vol 14, No.K2- 2011
Trang 80
NGHIN CU CC C TRNG SP IN P TRONG LI IN C KT
NI NH MY IN GI
Trnh Trng Chng
Trng i hc Cng nghip H Ni
TM TT: S lng cc nh my in gi ang ngy cng gia tng nc ta, tng cng sut
lp t tnh n cui nm nay d kin t 50 MW. Vi mc gia tng ngy cng ln vo h thng in,
trong cng tc quy hoch v vn hnh cn thit phi c cc nghin cu v nh hng ca chng n
cc h thng in, do c im ca ngun in ny kh khc bit so vi cc ngun in truyn thng
khc, trong cc cp in p phn phi khi kt ni vi in gi s c nhng nh hng ng k nht.
Ni dung chnh ca bi bo ny l kho st mc n nh ca li in kt ni cc ngun in gi ti
nt kt ni chung (PCC) khi thay i lng cng sut tc dng v phn khng ca my pht in gi
cho n khi din ra hin tng sp in p xc nh cc iu kin lm vic gii hn. Gii hn lm
vic n nh ca in gi c nghin cu da trn cc tiu chun n nh, t xc nh cc khu yu
cn quan tm: nhnh, nt... xut gii php nng cao n nh v lm vic tin cy ca h thng
cung cp in (HTCC).
T kho: sp in p, in gi, n nh tnh
1. GII THIU
Kh nng lm vic n nh ca nh my
in gi (WP) trong cc H thng cung cp
in (HTCC) ph thuc cc iu kin nh:
cng ngh my pht in gi, dung lng v
cng ngh thit b b cng sut phn khng ca
in gi, " mnh" ca li in m chng
kt ni...Vn ny c t ra lin quan n
s pht trin ngy cng mnh m, a dng ca
WP v cc li in. Vi cc nt nm gn WP,
in p c th s c nguy c gim thp v dao
ng mnh, dn n sp in p. c rt
nhiu nghin cu v nh hng ca WP n n
nh in p v cht lng in nng trong
HTCC [5, 7, 8], tuy nhin cc nghin cu
cha thc s cp n cc c trng n nh
v gii hn vn hnh ca cc phn t ng vai
tr quan trng trong HTCC. Trong bi bo
ny tc gi tp trung nghin cu cc ch tiu
nh gi mc n nh in p, t xc
nh cc khu "yu", v xut bin php nng
cao n nh in p trong h thng in c kt
ni WP.
2. MT S CH TIU NH GI N
NH IN P NT
i vi HTCC, vic nh gi c xy
dng trn gi thit thanh ci ngun cung cp c
cng sut v cng ln. Gi thit ny c ngha
khi xy dng m hnh ca in gi, theo cc
nh hng "nhiu" nh: chp chn in p (do
hiu ng ct thp), dao ng in p (do thay
i tc gi)...pht sinh t tuabin gi khng
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TAP CH PHAT TRIEN KH&CN, TAP 14, SO K2 - 2011
Trang 81
nh hng nhiu n s hot ng bnh thng
v cht lng in p ca h thng in v ph
ti. phn tch ch vn hnh mt n nh
ca chng c th s dng cc tiu chun v sp
in p nh: phn tch nhy, phng
php lin tc, phn tch gi tr ring, phn tch
tro lu cng sut....Trong bi bo ny, tc gi
s tp trung nghin cu ng dng cc tiu
chun thc dng, xy dng min n nh in
p trn mt phng cng sut nh gi gii
hn sp in p trong cc HTCC c kt
ni WP.
2.1. Ch s st p L (L - indicator)
Mt h thng in 2 nt nh hnh 1, trong
c mt nt ngun (G) v mt nt ti (L).
c phng trnh vit dng ng nht, cng
sut ti nt L vn c tnh theo chiu i vo
nt G nhng mang du m. Ch s L c nh
ngha nh sau [1]:
1121
112
101YV
S
YV
S
V
VLD
DD
==+=
(1)
Trong trng hp tng qut mt h thng
in c nhiu nt ngun v nhiu nt ti, cc
nt ny c th hin 1 trong 2 dng: nt PV
(i vi cc nt ngun) v nt PQ (i vi cc
nt ti). in p ti nt th j nh hng bi
cng sut v in p ca ngun in tng
ng v cch biu din l tng t vi trng
hp hnh 1.
Hnh 1. H thng in 2 nt
Ch s n nh in p ti nt ti th j
c cho bi:
' '0
22 '
1.
j j jj
j jjj j jj
U S SL
U YU U Y
= + = = (2)
iu kin n nh ca h thng l Lj
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Science & Technology Development, Vol 14, No.K2- 2011
Trang 82
'
1
kmm mN
kjjj k
YU UY
=
=
(4)
vi: Uk l in p pha ti nt k; Um l in
p pha ti nt m; Ykm l tng dn gia nt k v
nt m; Ykj l tng dn gia nt k v nt j; m l
nt c ni vi nt k. Gi tr ca VCPI nm
trong phm vi t 0 n 1, nu VCPIi ca mt
nt no bng 1 th nt xem nh mt n
nh in p. Gi tr VCPI kh thun li cho
vic xc nh cc nt "yu" trong HT.
2.2. Cc ch tiu nh gi n nh in
p nt khi tnh bng chng trnh
2.2.1. Cc ch tiu chung
a. d tr n nh theo kch bn in
hnh
Mt trong nhng kch bn thng hay xy
ra: l s gia tng t l cng sut ph ti cc nt,
phn b vo cc my pht theo c tnh iu
chnh tnh. Nu trong ch hin hnh tng
cng sut ti l P0, n gii hn ti c tr s l
Pgh th h s d tr c nh ngha bi [6]:
%1000
0
=P
PPK ghdt (5)
Ch tiu ny c th d dng xc nh c
bng cc chng trnh tnh ton gii hn n
nh.
b. d tr n nh theo cc kch bn
quan tm
+ Kch bn theo cc yu cu vn hnh
H thng c th vn hnh theo cc phng
thc khc nhau theo yu cu huy ng cng
sut. tm gii hn n nh cn lm thay i
t t cc thng s t ch hin hnh sang
phng thc mi. H s d tr n nh c dng
[6]:
%1000
0
i
ighidt P
PPK
= (6)
y cng sut Pi l thng s quan tm,
thay i trong phng thc vn hnh mi.
+ Kch bn nguy him nht
V l thuyt, t mt trng thi hin hnh
c mt kch bn nguy him nht l kch bn
i theo ng ngn nht n bin gii min n
nh. Nu bit ng i ngn nht ny c th
nh ngha h s d tr [6]:
%1000
0
i
ighidt L
LLK
= (7)
Li l thng s c trng cho hng i ngn
nht n gii hn n nh. Trong trng hp
chung, vic xc nh hng i nguy him nht
l bi ton kh phc tp, v th ch tiu ny
thng s dng cho cc trng hp ring.
c. Min n nh cc nt
Gi s xy dng c ng c tnh gii
hn n nh hp vi h trc ta xc nh
c min lm vic cho php trn mt phng
cng sut nh hnh 2.
Hnh 2. Min n nh trn mt phng cng sut
y O(Q0,P0) l mt im lm vic n
nh (cng sut nt ti). Cn c vo khong
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TAP CH PHAT TRIEN KH&CN, TAP 14, SO K2 - 2011
Trang 83
cch t O n ng gii hn cho php xc
nh c d tr n nh, oa l d tr
cng sut tc dng khi gi Q khng i, oc l
d tr cng sut phn khng khi gi P
khng i v ob l d tr n nh khi gi h
s cng sut khng i. xc nh c
ng c tnh gii hn ti mt nt ph ti, c
th s dng phn mm tnh ton gii tch mng
in v phng php lm nng ch . Gi c
nh gi tr P, tng dn Q cho n khi h thng
chuyn t trng thi n nh sang trng thi
mt n nh, ti xc nh c mt im
trn c tnh gii hn, thay i P v tnh ton
tng t s tm c tp hp im nm trn
c tnh gii hn, ni cc im ny li xc nh
c min lm vic cho php ca cng sut
ph ti theo iu kin gii hn n nh. Da
theo cc ch tiu nh gi gii hn n nh, s
tm c ch xc lp, min lm vic cho
php theo gii hn n nh tnh.
2.2.2. Cc ch tiu ring
Ngoi cc ch tiu phn tch mc n
nh chung cho h thng, phn tch cc yu
t nh hng n tnh n nh ngi ta cn a
ra cc ch tiu ring [6].
a.H s st p cc nt ( nhy dao ng
in p)
%100U
UU%k
0
gh0U
= (8)
trong U0 v Ugh tng ng l tr s in
p nt ch ang xt v ch gii hn.
Vi cng mt kch bn nt c kU% ln l cc
nt yu.
b.H s bin thin cng sut nhnh
%100P
PP%k
0
0ghP
= (9)
vi P0 v Pgh tng ng l tr s cng sut
truyn ti trn nhnh ch ang xt v
ch gii hn. Vi cng kch bn nhnh c
kP% ln l nhnh nguy him.
2.2.3. Nhn xt chung
Ch tiu tng hp nh h s d tr (kdt)
theo kch bn in hnh c th dng nh
gi mnh ca ton li v phng din n
nh, c ngha kim tra ring cho tnh hung
tng ti t ngt hay c t bin cng sut pht
ca in gi (ng/ct tuabin ra khi li). Tuy
nhin cc ngun in gi c cng sut thng
khng ln, kh c th gy ra t bin cho h
thng, do vy vic s dng ch tiu ny nh
gi cho h thng c kt ni ngun in gi s
cho ngha c trng cho tin cy n nh
khng tht r rng.
Cc ch tiu ring kU, kP t ra ph hp hn,
n cho php xc nh nhanh cc nt yu, nhnh
yu xut bin php ci to. Mi phng
thc vn hnh v mc pht cng sut khc
nhau ca in gi s a ra mt gi tr ch tiu
xc nh. Ch tiu n nh in p nt Lj c
s dng nhiu i vi cc h thng in nhiu
dng ngun pht khc nhau, rt ph hp i
vi li in phn phi; cho php xc nh gi
tr gii hn ti a ca ti hay kh nng pht
cng sut cc i ca WP vo h thng. Min
n nh l ch tiu ring c th cho bit mt nt
c th pht hay nhn ti a bao nhiu cng
sut. Do vy kho st min n nh theo khng
gian cng sut nt cng c th a ra nhiu
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Science & Technology Development, Vol 14, No.K2- 2011
Trang 84
thng tin c li nh gi mc n nh h
thng. Ch tiu ny c th c p dng trong
cc h thng in c kt ni my pht khng
ng b nh WP, theo s cho bit kh nng
pht trin ph ti ca HTCC.
3. M HNH CNG SUT CA WP
Trong trng hp chung, cc nt kt ni
WP c th c m t nh mt nt PQ hay nt
PV, cng sut pht ph thuc in p. Trong
[3] m t cng sut pht ca WP di dng:
2
W 2. .P n sp ip zpn n
U UP P C C CU U
= + + (10)
y cc h s Csp, Cip, Czp biu din t
trng thnh phn P(U) ca WP khi coi chng
tng ng vi cng sut hng, dng in hng
hay tng tr hng; Udm, Pdm l cc gi tr nh
mc ca in p, cng sut tc dng. RU l h
s hiu chnh ph thuc cc iu kin khc
nhau.
Thng thng khi c dao ng tc gi
v in p li in thay i th cng sut pht
cng dao ng. T khi bt u khi ng
tuabin (khi cha t n gi tr nh mc) cng
sut pht bt u tng dn, in p my pht
cng thay i t gi tr khi im Ub2 ln n
gi tr Ub1, trong in p Ub1 l gi tr m
tc gi v cng sut pht xp x gi tr nh
mc. Trong khong gi tr [Ub1; Ua1] tuabin gi
lm vic n nh, cc gi tr in p v cng
sut t gi tr nh mc. Khi tc gi vt
qua gi tr "cut out", ng vi gi tr in p
U>Ua1 th tuabin s c ct ra khi li in.
in p U trn hnh 3 cng c xem xt khi U
l in p pha li in. Nu gi tr ny st
gim s lm gim cng sut pht tc dng P(U)
ca in gi v tng lng cng sut phn
khng m my pht s nhn t li in.
Hnh 3. c tnh cng sut ca WP ph thuc in
p
Do vy trong thc t mt h s hiu chnh
RU s c thm vo m hnh pht cng sut
ca in gi P(U) theo tc gi v in p
my pht. ng vi ng c tnh cng sut
tuabin gi, nu U>Ua1 hay U < Ub1 th RU s c
gi tr nm trong khong t 1 n 0 tu theo gi
tr ca vn tc gi ("cut in" hay "cut out") v
tng ng s c cc gi tr cng sut Pdm ca
WP. Vi mt tp hp nhiu tuabin gi trong
WP cung cp cng sut nh mc Pm th RU c
gi tr xp x bng 1. Trong a s cc trng
hp, thc nghim cho kt qu: Ua1 = 1,2pu;
Ua2 = 1,3pu; Ub1 = 0,7pu; Ub2 = 0.1 pu. Theo
hnh 3, trong [3] xc nh quan h gia RU
v in p U nh sau:
2
11
1 2
1 1
2
11
1 2
max 1 ;0
1
max 1 ;0
bb U
b b
b b a U
aa U
a a
U UU U RU U
U U U R
U UU U RU U
< = =
> = (11)
Pm
P
U Ub2 Ub1 Ua1 Um Ua2
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TAP CH PHAT TRIEN KH&CN, TAP 14, SO K2 - 2011
Trang 85
Cc thng s Ua1, Ua2, Ub1, Ub2 c ngha
quyt nh n h s hiu chnh RU, cng vi
cc h s Csp, Cip,, Csq, Ciq biu din s thay i
cng sut pht ca my pht (WP), trong :
Cip + Csp + Czp = 1. Theo phng trnh cng
sut c biu din bi:
( )22. . . . , , , , ,n U sp U ip zp n U sp ip zp nn n
U UP P R C R C C P R C C C UUU U
= + + =
(12)
Tng t cng c th xy dng c mi
quan h gia Q ca in gi vi in p ca
li in nh sau:
( )22. . . . , , , , ,n U sq U iq zq n U sq iq zq nn n
U UQ Q R C R C C Q R C C C UUU U
= + + =
(13)
y Ciq + Csq + Czq = 1. Nh vy ng vi
mt tc gi xc nh s tm mt gi tr in
p v cng sut pht tng ng ca in gi.
Biu thc (12) v (13) c tnh tng qut, th
hin c nhiu tnh hung lm vic ca in
gi khi tc gi v in p thay i. Gi UPCC
l in p ti nt kt ni my pht WP vi li
in (hnh 4) v Zkn = Rkn +jXkn l tng tr
ng dy kt ni, m l t s bin p. Nu b
qua tn tht nng lng v tn tht in p ca
MBA ta s tm c quan h gia cng sut
WP vi in p li in nh sau:
( / )PC C luoiPC C kn kn
U U mP jQU R jX
+ = + (14)
Hnh 4. M hnh kt ni WP vi h thng cung cp
in
Theo (14) thy rng khi in p ti im
kt ni suy gim mnh th lc ny WP s hot
ng nh mt ng c khng ng b v nhn
cng sut t pha h thng v, iu ny d gy
mt n nh in p v nh hng ln n kh
nng pht cng sut ca chng. Gii php
thng p dng trng hp ny l s dng cc
thit b c iu chnh nh SVC, STATCOM
[8].
4. NG DNG TNH TON
Li in khu vc Ninh Thun nm 2015
c mt WP cng sut 20 MW ni li in 22
kV, sau kt ni vi li in 110 kV nh
hnh 5 [4]. My pht s dng l loi my in
khng ng b ngun kp DFIG (ca hng
VESTAS-an Mch). Cng sut nh mc mi
tuabin my pht l 2 MW kt ni vi li in
phn phi 22 kV qua my bin p 0,69/22 kV -
2MVA. S hiu cc nt cho trong hnh 5. c
tnh cng sut my pht theo tc gi cho
trong hnh 6.
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Science & Technology Development, Vol 14, No.K2- 2011
Trang 86
Hnh 5. Li in Ninh Thun nm 2015
0
500
1000
1500
2000
2500
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
m/s
Cng
sut
, kW
Hnh 6. c tnh cng sut ca my pht DFIG
(VESTAS) - 2 MW
Gi thit tt c cc tuabin gi ti thi im
tnh ton u nhn c mt nng lng gi
nh nhau. Mt khng kh bng 1,125 kg/m3,
cao ct thp 60m. Vi bin thin tc gi
trung bnh Ninh Thun t 10 m/s n 16 m/s
th di gi tr ny cng sut pht khong 1,5
MW. Khi tc gi nm trong khong 16 m/s
n 25 m/s th UMF = Ua1 = 1,2 pu v cng sut
pht n nh mc 2,03 MW. Khi tc gi
vt qu 25m/s, tuabin gi s c ct ra khi
li in.
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TAP CH PHAT TRIEN KH&CN, TAP 14, SO K2 - 2011
Trang 87
nh gi n nh in p nt qua cc
ch tiu
T m hnh cng sut ca my pht in
gi, ti gi tr tc gi v = 16 m/s ng vi
ng c tnh cng sut, xc nh c cng
sut pht ca mi my pht trong ch xc
lp (RU = 1). Ch c bn l WP ch pht
cng sut tc dng P theo m hnh (12), tin
hnh xc nh gi tr in p gii hn ti mi
nt, theo tm c ch s VCPI tnh theo
cng thc (3) thng qua gi tr in p v tng
dn nt. Theo kt qu tnh ton trong hnh 7
(nt 1 l nt cn bng); c th nhn thy cc
nt 18, 99, 100 v t 101 n 110 l cc nt c
ch s VCPI ln, y l cc nt yu trn
phng din n nh in p. Mt s nt cng
c ch s VCPI kh cao: nt 17, nt 20 - y l
nhng nt nm ln cn nt kt ni WP.
Kt qu tnh ton ch s n nh in p
nt L cho nt 100 hnh 8 cho thy: nt ny s
mt n nh ti gi tr cng sut 22,5 MW (lc
ny L = 1), in p gii hn Ugh = 0,61pu. Khi
nt kt ni cc my pht in gi mt n nh
cng lm nh hng ng k n ch lm
vic ca cc nt khc, thng s ch th L mt
s nt ln cn c xu hng gia tng. Trong
hnh 8 cng m t nh hng ca ch s L nt
100 n nt 19 (thay i thng s nt 100 cho
n khi mt n nh, trong khi gi nguyn cng
sut nt 19). Ti gi tr sp in p ca nt
100, thng s ch th L ca nt 19 tng t gi tr
ban u L = 0,05 ln gi tr L = 0,2, kt qu
biu din trn hnh 8.
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 30 32 34 99 100Nt s
VC
PI
Hnh 7. Ch s VCPI cc nt ca li in Ninh
Thun
0
0,2
0,4
0,6
0,8
1
1,2
10 11 12 13 14 15 16 17 18 19 20
P, MW
pu
L-100
U-100
L-19
Hnh 8. nh hng ca qu trnh mt n nh in
p nt 100 n nt 19
Vi thng s ch vn hnh nm 2015,
tng ph ti ca P0 ca Ninh Thun l 251MW.
Gi thit tng ng thi ph ti cc nt (cng
t l), cng sut my pht tng theo h s iu
chnh tnh s tm c ch gii hn tng
ng vi Pgh. S dng chng trnh CONUS
(B mn H thng in - i hc BK HN), m
t cng sut pht ca WP theo cng thc (12)
v (13) kt hp vi m hnh li in Ninh
Thun nm 2015 tm c h s d tr n nh
bng 57,7%. Bng 1 l kt qu tnh ton ch s
st p ca cc nt ti ca li in Ninh Thun.
T bng ny thy rng cc nt c ch s st p
khc nhau, ngoi ra cn th hin tr s in p
nt trc khi h thng mt n nh. Kt qu
ny cng ph hp vi kt qu xc nh cc nt
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Science & Technology Development, Vol 14, No.K2- 2011
Trang 88
yu bng ch s L. Nt kt ni vi WP (nt 99)
c ch s st p ln nht, cc nt khc (t nt
100 n nt 110) l nt kt ni my pht in
tuabin gi vi li in a phng (thanh ci
22 kV trm Phc Ninh) u c ch s st p >
20%. C th hiu cc nt yu v phng
din n nh in p (nt nh du "*").
Bng 1. Ch s st p cc nt
Bng 2. nhy bin thin cng sut nhnh
Trong bng 2 trnh by kt qu xc nh
nhy bin thin cng sut nhnh pht hin
cc nhnh yu trong iu kin c WP. Kt qu
cho thy cc nhnh kt ni vi WP u rt d
mt n nh nu xy ra bin ng t ngt ca
ph ti hay khi tng cng sut truyn ti ca
nhnh kt ni. Qua bng 2 cho thy nhnh 12 -
18 v nhnh 3-12 c cc h s kP% ln nht v
cch bit so vi cc nhnh khc, y l nhng
nhnh "yu" v mt n nh tnh, cn c bin
php ci to nng cao mc n nh.
Mt b b tnh cng sut 10 MVAR gi
thit lp t ti nt 99, gii php ny c so
snh vi trng hp cu trc li li in gn
khu vc WP. Gii php cu trc li li in
c thc hin l: do v tr a l ca trm bin
p Vnh Ho v trm bin p Ninh Phc i
qua khu vc WP, do thay th ng dy lin
lc gia 2 nt ny bng cch: xy dng ng
dy 110 kV kt ni 2 trm bin p ny vi trm
bin p 110 kV Phc Ninh (nt PCC) to
thnh cc mch kp. Ti nt PCC s c 4 xut
tuyn lin lc vi h thng, trong hnh 9 trnh
by hiu qu cc gii php nng cao n nh
ca li in Ninh Thun.
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TAP CH PHAT TRIEN KH&CN, TAP 14, SO K2 - 2011
Trang 89
Khng c WF
-20
0
20
40
60
80
100
-10 0 10 20 30 40 50
Q
P
C WF
0
20
40
60
80
100
120
-20 -10 0 10 20 30 40
Q
P
C WF, c b
-20
0
20
40
60
80
100
120
-20 -10 0 10 20 30 40 50
Q
p
C WF, cu trc li li in v c b
-20
0
20
40
60
80
100
120
140
-20 -10 0 10 20 30 40 50
Q
P
Hnh 9. Min n nh nt 99 trn mt phng cng sut trong cc phng n
Kt qu tnh ton cho thy h s d tr n
nh ca h thng tng t 57,7% (trng hp
c bn) ln 75,7% khi c t b b tnh. ng
cong bin thin in p cc nt trong h thng
cng c ci thin r rt, min n nh in
p nt 18 c tng thm ng k. Trong
trng hp c bn khi khng b cng sut
phn khng nu tin hnh ci to nhnh 12 -18
bng cch thay dy dn AC 185 bng dy dn
ACSR 330, mc d tr n nh h thng tng
thm 6,8%, t gi tr 64,5% nh hnh 10, ng
thi in p cc nt c ci thin, h s st p
nt 99 gim t 22,19% xung cn 19,69%.
Mc mang ti cc nt tng t gi tr k = 1,57
ln k = 1,63.
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Science & Technology Development, Vol 14, No.K2- 2011
Trang 90
a)
b)
Hnh 10. Min n nh in p cc nt trc (a) v sau ci to (b)
Trong bng 3 trnh by kt qu xc nh
cc thng s ch ti nt s 18 trong cc iu
kin: khng c kt ni WP (iu kin A); c
kt ni WP nhng khng t thit b b (iu
kin B) v c kt ni WP, ng thi c t b
b tnh 10 MVAR (iu kin C).
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TAP CH PHAT TRIEN KH&CN, TAP 14, SO K2 - 2011
Trang 91
Bng 3. Thng s nt 18 trong cc iu
kin vn hnh khc nhau
iu
kin
in p
khi im
U0, kV
in p
gii hn
Ugh, kV
Ch s st
p nt, %
D tr n
nh h
thng,%
A 111,37 90.03 19,1 104,2
B 109.69 95,36 13,06 57,7
C 113,23 98,92 12,64 75,7
C th thy khi c s tham gia ca ngun
in gi, in p ti nt kt ni cng nh cc
nt khc c ci thin, tuy nhin mc d tr
n nh in p thp hn do kh nng pht
cng sut phn khng hn ch ca WP. Khi c
s tham gia ca WP v khi t t b, in p
vn hnh v in p gii hn c nng ln
nhng c gi tr kh gn vi in p khi im
v in p gii hn. iu ny cng c th c
gii thch bng m t ton hc l: Tr s dung
dn ca t in s c tnh cng thm vo tr
s phn t tng dn Y. Nh vy khi xt v
quan h ton hc s lm gim tnh tri ca ma
trn tng dn nt, tc l lm gim kh nng xc
nh nghim in p m phng trng thi xc
lp ca h thng.
Mt c im cng d nhn thy l: khi
m t in gi nh mt ngun pht cng sut
tc dng th khi cng sut pht cng gia tng s
ng ngha vi vic cng sut phn khng m
WP nhn v t h thng cng tng, iu ny s
gy gim in p cc nt ln cn v lm tng
nguy c mt n nh in p. Nh vy ch s L
thc cht l ch tiu ring nh gi mc n
nh in p nt nhng vn c th xem xt Nt
kt ni vi WP c ch s st p ln nht, k n
l cc nt kt ni my pht in tuabin gi vi
li in a phng. iu ny hon ton ph
hp thc t l: khi gia tng cng sut ti nt
PCC, lng cng sut phn khng m my pht
nhn t pha h thng tng ln [7, 8], cc nt
ln cn c nguy c b gim thp in p. c
bit nguy him khi c s c ngn mch ti nt
thanh ci 22 kV, in p ti y s b suy gim
mnh, lm mt cn bng cng sut phn khng
trong WP, nu khng c gii php ngn chn s
dn n sp in p.
5. KT LUN
Bi bo phn tch cc ch tiu nh gi
n nh in p trong h thng cung cp in,
t la chn ch tiu trong trng hp h
thng cung cp in c cc ngun in gi
tham gia. Vi cc ch tiu la chn ny cho
php xc nh c cc nt yu, nhnh yu
trong h thng in c kt ni nh my in
gi s dng loi my pht khng ng b v
xut cc bin php nng cao n nh in p.
Cc WP cng sut ln khi kt ni h thng
in, trong qu trnh vn hnh c gy nh
hng nht nh n n nh in p ca li
in. Vic mt n nh in p ca chng c
th gy nh hng n mt s nt ln cn. Vic
ng dng cc tiu chun n nh in p nt
nh gi mc n nh ca h thng in c
kt ni ngun in gi ng vai tr quan trng
trong qu trnh thit k, ci to hay quy hoch
mng in, trong c cc khu yu cn quan
tm: cc nt kt ni (PCC), cc nhnh c ni
vi nh my....Gii php b cng sut phn
khng lun c ch trng b vo phn
cng sut m WP nhn v t pha h thng,
gp phn nng cao cht lng in p.
-
Science & Technology Development, Vol 14, No.K2- 2011
Trang 92
STUDY OF VOLTAGE COLLAPSE CHARACTIRISTICS IN GRID CONNECTED
WIND POWER PLANT
Trinh Trong Chuong
HaNoi University of Industry
ABSTRACT: The scale of wind power plants is increasing continuously in Vietnam. The
installed capacity of the largest wind farm is about 50MW by the end of this year. Therefore, power
system planners will need to study their impact onthe power system in more detail. Wind energy
conversion systems are very different in nature from conventional generators. Therefore dynamic
studies must be addressed in order to integrate wind power into the power system. The impact of this
wind power on voltage distribution levels has been addressed in the literatures. The majority of this
work deals with the determination of the maximum active and reactive power that is possible to be
connected on a system load bus, until the voltage at that bus reaches the voltage collapse point. This
article introduces the methods of research standards, evaluation criteria of stable electricity supply; it
identifies the centers of loads and focuses on the branch is "weak" in small signal stability to improve
operational efficiency, reliability in electricity power supply.
Key words: voltage collapse, wind power, small signal stability
TI LIU THAM KHO
[1]. P. Kessel; Estimating the Voltage
Stability of a Power System; IEEE
Transactions on Power Delivery, Vol.1,
No. 3, July (1986).
[2]. Stefan Johansson; Voltage collapse in
power systems-The influence of generator
current limiter, on-load tap-changers and
load dynamics; Licentiate thesis Chalmers
University of Technology (1995).
[3]. I.A. Hiskens; Voltage stability
enhancement via model predictive control
of load; Intelligent Automation and Soft
Computing, Vol. 12, No. X, pp. 1-8,
(2006).
[4]. Feasibility Assessment and Capacity
Building for Wind Energy Development in
Cambodia, Philippines and Vietnam;
RIS - November (2006).
[5]. J.G. Slootweg; Wind Power:
Modelling and Impact on Power System
Dynamics; PhD thesis ; Technische
Universiteit Delft; (2003).
[6]. Bekob B.A; epexoe ekmpom exahueckue npoecc
ekmpueckux cuctemax; Bea
koa, Mockba, (1981).
[7]. Trinh Trong Chuong; Power quality
Investigation of Grid connected Wind
turbines; GMSARN International Journal;
No 3 (2009), pp 1 - 6.
-
TAP CH PHAT TRIEN KH&CN, TAP 14, SO K2 - 2011
Trang 93
[8]. Trinh Trong Chuong; Voltage quality
Improving of Phuoc Ninh (Vietnam) Wind
farm by using Static Synchronous
Compensator; The International
Conference on Electrical Engineering
2008, No. O-055.
-
Science & Technology Development, Vol 14, No.K2- 2011
Trang 94
MC LC CC CNG TRNH NGHIN CU
Trang Phm Vn Trung
V Vn Cng
L Khnh in
Nguyn Vn Nang
Phan nh Tun
Nguyn Thanh Nam
Nghin cu kh nng bin dng ca tm composite nn nha
nhit do khi gia cng bng SPIF
5
Phan nh Tun
Nguyn Thin Bnh
L Khnh in
Phm Hong Phng
ng dng cng ngh ISF gia cng mu chi tit v t
13
Nguyn Thnh Huy
o c Cng
V Thanh Thu
Bi T An
Hp cht siu dn st t UCoGe
21
Nguyn Hu Niu
Phan Thanh Bnh
Hunh Su
Tnh cht c hc ca compozit nn nha polypropylen c
gia cng bng si da (Sisal) Vit Nam
29
inh c Anh V
Paid - mt khung sn cho vic thit k v m phng vi
mch bt ng b
37
Phm Trn V
Biu din v so snh ng h s c nhn trong cc mng
khoa hc
46
Trn Ngc Thnh So trng mu da trn Cuckoo Hashing ng dng cho Nids 53
Hunh Hu Lc
Lu Quc Hi
inh c Anh V
Nhn dng ch vit tay dng rt trch thng tin theo chiu v
mng nron
62
Dng Tun Anh Tng quan v tm kim tng t trn d liu chui thi gian 71
Trnh Trng Chng
Nghin cu cc c trng sp in p trong li in c
kt ni nh my in gi 80
-
TAP CH PHAT TRIEN KH&CN, TAP 14, SO K2 - 2011
Trang 95
CONTENTS Page
Pham Van Trung
Vo Van Cuong
Le Khanh Dien
Nguyen Van Nang
Phan Dinh Tuan
Nguyen Thanh Nam
Deformation ability of single point incremental forming for
themo-plastic composite materials
5
Phan Dinh Tuan
Nguyen Thien Binh
Le Khanh Dien
Pham Hoang Phuong
Applying the ISF technology to produce the car part models
13
Nguyen Thanh Huy
Dao Duc Cuong
Vu Thanh Thu
Bui Tu An
On discovery of the ferromagnetic superconductor UCoGe
21
Nguyen Huu Nieu
Phan Thanh Binh
Huynh Sau
Mechanical properties of the Viet Nam sisal fibre reinforced
polypropylene composite
29
Dinh Duc Anh Vu
PAID A novel framework for design and simulation of
asynchronous circuits
37
Pham Tran Vu Dynamic profile representation and matching in distributed
scientific networks
46
Tran Ngoc Thinh CPM: Cuckoo-based pattern matching applied for NIDs 53
Huynh Huu Loc
Luu Quoc Hai
Dinh Duc Anh Vu
Modified direction feature and neural network based
technique for handwriting character recognition
62
Duong Tuan Anh An overview of similarity search in time series data 71
Trinh Trong Chuong
Study of voltage collapse charactiristics in grid connected
wind power plant
80
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