GIAI PHAP XAC DINH SU C 6 DUOTVG DAY TAI DIEN TREN KHONG
NGUYEN TUAN P H U O N G Khoa Dien - Dien tu
Trudng Dgi hgc Giao thdng Van tai Tdm tdt: Bdi bdo gidi ihiiu phuong phdp xdc djnh su cd dudng ddy tdi diin tren khdng hdng phuang phdp su dung cam bien de do su thay ddi dien tir trudng cua dudng day. Trong bdi bdo ciing gidi ihiiu cdch thuc lifa chgn tdi uu tga dd khdi cdm biin. Ngodi ra bdi bdo dua ra thiit ki so dd khdi chirc ndng vd thudt todn xdc dmh trgng thdi su cd cua dudng ddy tdt diin tren khdng.
Summary: The article presents the identification method of emergency modes of overhead transmission line using .sensors to measure changes of electromagnetic field, which are created by the overhead line. The article also presents a method for .selection of the optimal location coordinates of .sensors. In addilion. the article proposed the design of a functional block diagram and identification algorithm of emergenc\ modes of overhead
transmission line.
I. D A T V A N B E
D I giai q u y l t vdn d l xac djnh s u cd da cd nh&ng d e xudt trong [1]. He thdng nay cho phep bdng su thay ddi dien tir t r u d n g d u d i d u d n g day tai dien 6k xdc djnh logi s u cd Bdng vide so sdnh cdc h? t h d n g gidm sdt sir c 6 hien tai thay rang cdc p h u a n g phap ndy de ddng thudn tien trong v§n hanh vd sira chCra. Mdc dii trong t h i i t k l ndy sinh bai toan xac dinh vj tri dat cam bien d l tdi uu vi?c xdc djnh trgng thdi s g cd. D d n g thdi cdn t h i i t k l s a bg s a dd cdu triic va thudt toan xdc djnh trang thdi s g cd,
I I . N O I D U N G
Mo hinh todn hgc diSn trui/ng. Md hinh toan hgc dien t r u d n g dudi d u d n g ddy tai dien d u g c sir dyng trong [3]
Duang day don. D u d n g ddy truyen tdi d vi tri cd chieu c a o h so vdi mat dat, cdn khdi cam bien d c h i l u c a o A:,
Di^n the t m h di?n, d u g c tao bdi d u d n g ddy c a o dp tren khdng vd dnh g u a n g , tai vi tri ddt cam b i i n d^rgc xdc djnh trong [3],
ln(4h,'d)
T r o n g dd: r vd r' - khodng cdch tir cdm b i i n d i n d u d n g day va d i n dnh cua d u d n g day.
d - d u d n g kinh d u d n g ddy;
u - di?n dp tren day truyen tai so vdi mat ddt.
Tgp chi KHOA HQC GIAO THONG VAN TAI S6 50 - 02/2016 65
Cdng trinh Khoa hgc
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//in/i /. Wd hinh tinh todn cudng dd dien trudng cua dudng ddy don Phuang trinh (1) bien ddi sang tga do tuong ddi x va v trong mat phdng Oxy:
Sau dd xac dinh md ta cho cudng do dien trudng theo phuang Oy:
dy de
' d y '
2y_^(x" - 2 x x ^ +x ^" -i-y ^"
l n ( 4 y , / d ) [ ( x - x , , ) ^ + ( y + y j - ] [ ( x - x J - + ( y - y , J - ] ' (2)
(3)
(4)
Cudng do dien trudng Ev Id gid tri hieu qya vd bdi vay ludn duang va dirge tinh todn nhu gid tri tuyet ddi d (4). Trong phuang trinh md hinh hda (2) va (4) se duoc sir dung cho cdc pha rieng C vd B.
Budng ddy kep vd dudng day 3 day. Dien thi gay bdi dudng day ddi vd day ba dugc xdc dinh thdng qua dien thi dudng day don [3].
Mo hinh todn hgc tu- trirng. Tir trudng ciia cdc dudng day mang ddng dien cd thi tinh toan bdi phuang trinh Maxwell, Cac logi cot dien vd cdu triic treo day khac nhau dnh hudng din phdn bd tir trudng dudi dudng day. Bk thuan tien nghien ciru tinh toan, gia thiit dudng day ddi vd ban, khdng cd hien tugng vdng dudng ddy, nghien ciru tir trudng trong mdt phdng cdt ngang dudng ddy (hinh 2). Tren hinh 2 md td cdm img tir ciia cdc pha mang ddng dien tai vj tri cdm biin.
Sir phu thudc cam irng tir tdng vdo cdm ung tir cdc pha dugc md td bdi phuang trinh sau:
B - e, B,-I-e^ B^ +e^B^
= e^(B^cose^ + BbCose|, + B^cose,) + e, (B^sinO^ +B^sine^ -t-B^ sinO, ) + e,0.
Trong do: Ba, Bb. Be - cdc vec tacam irng tir thdnh phdn dugc tao bdi cac ddng dien pha:
ia, ib. ic- e\- Cj. e^ - vec ta don vi ciia cdc true tga do: \ . y. z;
9a, 9b, 9c,- cdc gdc giQ-a cdc vec to Bg, Bb- B^ va true tga dg Ox.
(5)
66 Tgp chi KHOA HOC GIAO THONG VAN TAI S6 50 - 02/2016
Do tdn sd ddng dien truyen tai Id 50 Hz. dien trudng va tir trudng cd the dugc nghien ciru khdng phu thudc ldn nhau va cd the coi Id dien trudng va tir trudng ttnh. Tir trudng cd the dugc tinh toan dua vao dinh ludt Biot-Savart-Laplace [5], khi do cam ung tir cac pha cd the tinh todn nhu sau:
27cr, B . - ^ ,K--
2TZT (6)
Khi xdy ra ngdn mgch, ddng di?n tren cac pha su cd thudng rdt idn, ddng dien tren cac pha cdn Igi gid thiet khong ddi vd nhd. Bdi vay cd thi bd qua ddng dien tren cac pha khdng su cd.
Hinh 2. Cdc vec ta cam irng tir lai cam biin
Xem xet moi quan he giu-a cdc thanh phdn B, vd B, trong trgng thai su cd.
B, ^ B^sin9^+B|,sine,-HB^sine^
B, B^ cos9^ + B^ cosB^ + B^ cosB^ (7)
2 pha, 3 pha ngan mgch. Khi do cd:
- cdc gdc tir trudng su cd, tuang irng vdi mdt pha.
e„ = arctan—^
B,
Tir cac phuong trinh (5) den (8) vdi phdn tich ddng dien ngdn mgch dan den trong trang thai su cd ngdn mach 1 pha va 2 pha cac gdc vec ta tir trudng khdng phu thudc vao thdi gian. NghTa la gdc ciia vec ta tir trudng khdng ddi vd d cdc trang thdi su cd khdc nhau la khdc nhau. Do dd bdng viec xdc dinh cdc gdc tir trudng ndy khi xdy ra su cd cd the xac djnh dugc loai su cd ngdn mgch.
Cdc ket qud mo phong cirdng dp diin truifng vd cdm irng tir tren cdm biin de lira chgn vi tri khdi cdm biin.
Vi dit bdi todn. Cdc day ddn bd tri tren 3 dinh ciia mdt tam giac deu vdi cdc tga do:
A(0, 11.73)m;B(l, 10)m;C(-l, 10)m;s = 2 m . u = 10 kV; l„p = 5000A; I = 200A.
Lua chgn vi tri cua cdc cdm bien tu dien. Tir md hinh todn hgc cua dien trudng dan den ket qud tinh todn cudng dd dien trudng cdc trgng thai su cd dugc md td tren hinh 3. Tir phdn tich mdi quan he dd thi [2] (hinh 3) cd thi xac dinh rdng de xac djnh trang thai Idm viec ciia dudng ddy cam biin tren cdt dgt phii hgp d tga dg x =1M. k = 7M. Trong trudng hgp nay khdng thi phan bi?t dugc trgng thai ddt pha C va trgng thai lam viec binh thudng. Bdi vdy cdn phai ddt them cam biin thu hai d tga do x = - IM, k = 7M. Hai cam biin dugc dat d cdc tga dp dd cho ph6p xdc djnh tdt ca cac trgng thai dirt ddy ciia dudng ddy tren khdng.
Tap chi KHOA HOC GIAO THONG VAN TAI So 50 - 02/2016 67
Cdng trinh Khoa hgc
Khoang each theo true toa 36 x (m)
Hinh 3. Cudng do diin trudng theo phuong y (k V/m) tai chieu cao k= 7 m tTir ddy cd the xdy dung thuat todn de vi xir ly thuc hien xdc djnh cac trang thai sg cd dirt ddy pha.
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Hinh 4. Cdc gdc tir trudng Gxi trin dd cao y ^ 8.M
Lua chgn vl trj cdm hiin tir trucmg. Ttr md hinh todn hgc tir trudng d tren ddn den vi6c tinh todn cdc gdc tir trudng ciia cac trgng thdi ngdn mgch dugc the hien tren hinh 4. Tir phan tich quan he dd thj trong [4] cd the xdc djnh rang dl lua chgn vi tri cam bien phii hgp Id ddt d vj tri tga do X = Om, y = 8m. Khi dd cdc do lech gdc tir trudng dgt gia tri Idn nhdt va diu nhau,
-56.6": 6 ^ = 9 0 " ; e , „ = 5 6 . 6 "
9„ * 0"; ( = - 2 6 , 6 ^ 9,^-26.6"; ( (9)
Tir phdn tich cdc kit qud ciia md hinh cd the thiit ke sa dd nguyen ly he thdng dl thu thdp tin hieu, xir ly thdng tin cho viec nhdn dang cdc trang thdi su cd dudng ddy tai dien (hinh 5).
68 Tgp chi KHOA HOC GIAO THONG VAN TAI So 50 - 02/2016
Sff do khdi chirc ndng he thdng. Tren hinh 5 md td so dd khdi chiic nang he thdng thdng tin do ludng.
He thdng bao gdm khdi xu l\' thdng tin ban dau. bao gdm trong dd cdc cdm bien xac djnh cudng do dien trudng E va cam img tir trudng B. Cdc cam bien dien trudng Id hai tu dien cd dien dung C. cdn cam bien tir trudng la cam bien tir dien trd [6], cho phep xac dinh cam ting tir trudng theo hai hudng vudng gdc. Cam bien 1 va 2 xac djnh cudng dd dien trudng tdng theo phuong thang diing, cdn cdm bien tir trudng ghi lai cdm img tir trudng B theo 2 true tga do [6].
Hinh 5. So dd khdi chirc ndng hi thdng
Thugt todn nhdn dgng. Tir phdn tich cdc ket qud md hinh va so dd chirc ndng he thdng ddn tdi de thuc hien nhan dang cac trgng thdi su cd tren khdi xu ly thdng tin 9. cdn phdi thuc hien chuang trinh theo thudt toan nhan dang (hinh 5). Vi xir ly lien tuc thu thdp tin hieu cdc cdm biin vd chan dodn logi su cd. O dd U,i, Uy: - dien dp tren cam bien I va 2. Tren hinh 4 cd kiem tra dieu kien ciia 2 dgng su cd Id su cd ngdn mgch va su cd dirt day. Neu cd hai dien ap cam bien tu dien bang dien dp cua che dd binh thudng (L'.), thi ba pha hoat dgng binh thudng. Neu cam ung tir trudng toan phdn (fi) Idn ban gid trj cdm ling tir ngudng (S„). thi xay ra ngan mach. Tren ca sd ket qud md hinh cd the xdy dung cdc thudt todn nhdn dgng rieng cho tirng logi su cd dirt ddy va ngdn mgch.
Xac dmh Inm su co ngSn msch
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Hinh 6. Thugt todn Idng quan nhdn dgng trgng that su cd
T?p chi KHOA HOC GIAO THONG VAN TAI So 50 - 02/2016 69
Cdng trinh Khoa hgc
I I I . K E T L U A N
T h e o nguyen ly phdn bd dien tir t r u d n g x u n g quanh d u d n g ddy tdi dien tren k h d n g cd th6 lua chgn vi tri c a m b i i n tdi uu d l nhdn d a n g trgng thdi s u cd d u d n g day. T r e n c a s d p h a n tich gid tri dien tir t r u o n g t h i i t k l d u g c s a dd khdi nguyen ly. Vd xdy d u n g d u g c thuat todn nhan d a n g cdc trgng thdi s u cd d u d n g ddy tai dien tren khdng.
N g a y n h d n b a i Idn d a u : 2 5 / 9 / 2 0 1 5 N g a y n h a n b a i siJa: 2 7 / 1 1 / 2 0 1 5 N g a y c h a p n h a n d a n g b d i : 3 0 / 1 0 / 2 0 1 5
Tai liSu tham khao
[I]. mH,nHH A.H., LUHJIHH A . A , , (2011), "MHt|)0pMauH0HH0-H3MepHTejii>Hafl CHCTerna onpeAeJieHHB nOBpexcacHHfi Bosaymuoi^ JIHHHH 3JieKTponepeflaHH", ripHdopbi, K°5, C, 23-29.
[2]. UIHJIHH A.H., LLIHJIHH A.A., Hryen O.T., Jle <I>.C., ""Hcnojib30BaHne KOwnbioTepHOro MoaejiHpoBaHHJi ann onpeaejieHna nojioweHHS AariMKOs MOHHXopMHra aBapHtiHwx CHTyauHti Ha BOSayujHbix jTHHHHX 3jieKTponepeflaiH", (2014), BCCTHMK KoiwnbioTepHbix M HH())opMauMOHHbix TeXHOJlOFHH, K2 7, C. 35-41.
[3]. PEOflHuSepr, P.. (1955), 'TlepexojiHbie npoueccbi B 3.neKTpo3HepreTHHecKHX CMCieMax", M^JI-BO HHOcrp. ,nHT., 717 c.
[4]. LLIHJIHH A.H., UIHJIHH A.A,, HryCH O.T., Jle ^ . C , (2014), "KoMObioTepHoe MOiiejinpoBaHne MarHHTHoro-nojiJi BoanyiuHbix jiHHMi^ 3jieKTponepenaiH npH aeapnax", BBCTHMK KOMnbiorepHbix H HHiJiopMauHOHHbix TexHOJioFHii, Xe 11, C, 43-50.
[5]. ^MHTpweBa B.O,, (2003), "OnaHKa", Haa-ao: AKaAeMH«, 464 c.
[6]. ynaRKHH C.B., Canrepa X., (2013), "MaMepeuHe cjiadoro MarHHiHoro nojia c noMouibio AMP flaTiHKOB", BecTHHK HayKH CHSHPH, Ne2, C. 33-38.
Phan bien: TS. T r a n H o a i T r u o g ; TS. Nguyen Van Nghla.
70 Tgp chi KHOA HOC GIAO THONG V^N TAI So 50 - 02/2016
