MOT SO KET QUA KHAO SAT

KHOA HOC VA

C O N G

N6HE MO

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MOT SO KET QUA KHAO SAT

DANH GIA CHAT LI/OfNG CUNG CAP DIEN CHO CAC Xi NGHIEP MO KHU VUC QUANG NINH

KS. VU TUAN ANH, KS. LUU QUANG VU, TS. OAO OAC TAO - Vien Khoa hgc Cdng nghe Md

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hdt lupng cung cdp dien co anh hu'dng rdt Idn ddn s u lam viec ciia thidt bi dien

> ^ trong cac xi nghiep cong nghiep, gay nen nhO-ng thiet hai kinh td trong cac day chuydn cdng nghe nhu nang sudt, chdt lu'dng san phdm, tai nan lao dpng... ma doi khi chung ta khong nhan thdy dii-ac.

1. Vi sao phai quan tam ddn "chdt lirp-ng dien nang"?

O cac niroc cong nghiep phat triln "chdt lypng dien nang" dU'dc quan tam tir nhOng nam 50-^60 ciia thd ky truac bdi le;

••• Do lech dien dp co anh hu'dng rdt lan ddn su lam viec cua dpng co khong ddng bp, la phu tai chu ydu ciia cac xi nghiep cong nghiep. Khi dien ap tren cue dpng co giam qua mire, mdmen can cd t h i vupt qua gia tri cua momen quay, lam cho dong CO khong t h i quay dirpc. N l u khong cdt dien, dpng co ed t h i bj chay. Oien dp tren circ dong CO thap lam cho d i l u kien khdi dpng cua dpng CO giam di dang k l . Khi dien dp tren circ dong CO thdp thi cuong dp tir trirong cua stator cung giam di (din 2-3 % khi dien ap giam 1 %) va nhu vay cimg voi cong sudt tieu thu nhu tru-oc thi dong phai tang len, khiln cho cupn day bi nong qua mire, lam giam each dien ciia cupn day kem theo do la tudi thp cua dpng co.

• Oien dp Ipeh khdi gia tri danh djnh lam tang dang k l cong sudt phan khang tieu tan tren dirang day, trong cac may b i i n dp va cac dpng ca dien.

Nlu dipn dp tren eye dpng ca tang len 1 % thi cong sudt phan khang tdng them tir 3 % trd len (do tang dong khong tai cua dpng ca).

• Cdc thilt bj nhay cam vai sir dao dpng dien dp la eac 16 dipn, eac den c h i l u sang va cac thiet bj dien tir. S u nhdp nhay cua ngudn sang gdy su kho chiu, met mdi, anh hudng d i n nang sudt lao dpng, t i l m I n nguy ca gdy tai nan trong qud trinh san xudt.

•!• Dao dpng dien ap lam cho nhilu he thing dien tu', tu dpng hoa, thong tin lien lac, quan tr§c, giam sat... khong t h i hoat dpng duac binh thuang, gay t i n hai cho qua trinh giam sat, dilu hanh san xuat. Oien ap dao dpng lan han 15 % lam cho cac cupn hilt cua cac rale dilu khiln, cac aptomat va khdi dpng tir khdng giQ duac, can trd d i n su hoat dpng binh thLrang cua may mdc thilt bi trong cac day chuyin san xudt. Oien ap dao dong trong khoang tir 10-15 % co t h i lam hu hong cac tu dien bu cung nhu cac bp biin d i i ban d i n .

<• Sy mdt ddi xirng pha anh hudng true tilp d i n cac phu tai, dien hinh nhit la cac dong ca khong ddng bp. Nguai ta da chirng minh ring tuli thp cua dpng ca khong ddng bp mang ddy tai, khi lam viec trong luai co dien ap mdt ddi xirng 4 % se bi giam di 2 ldn va n l u nhu sy m i t ddi xirng la 5 % thi cdng suat cua dpng ca se bi giam di tu 5-10 %. Sy mdt ddi xirng pha cung gay nen ton hao cdng suit va phat nhiet trong stator va rotor, anh hudng tryc tilp den sy lam viec cua cac dpng ca ddng bp. Sy mat ddi xirng pha lam cho c h i dp lam viec cua cua cac bp biin ddi, bp chfnh luu nhilu pha xdu di rdt nhilu - lam tang dang k l sy nhip nho cua dien ap nan, lam cho he thdng dieu khiln xung-pha ciia cac bd biin ddi tiristor khong t h i lam viec binh thuang dupe.

•!• Khi dien ap mdt ddi xirng cac tu bii se tieu thu cdng suat vd cdng d cac pha khdng d i u nhau Do vay ma tu dien khdng duac sir dung hit dung iLrpng ldp dat. Ngoai ra, do sy mdt ddi xirng ciia cac pha ma chinh cac bp tu dien trong truang hop nay cdn lam tang them sy mdt ddi xirng bdi vi cdng suit phan khang cua tu trong pha cd dien ap thdp se nhd han trong cac pha khac (ty le thuan vai binh phuang dien ap cua luai).

•:• Oien dp "khdng sin" cung mang lai nhO-ng tdn hai gidng nhu' la sy mdt ddi xirng. Sdng hai bac cao cung gay nen t i n thdt hiru cdng tren tdt ca cac phdn tir cua hp thdng cung cdp dipn nhu trong

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CNM

KHOA HOC VA C O N G NGHE MO

mang cung cdp, mdy b i i n dp, cdc may dien, cdc bp tu dien bdi vi dien trd cua cae phdn tii' nay phu thupc vao t i n sd.

<• Sy dao dpng cua t i n sd cd anh hudng tryc t i l p d i n thanh phdn dien tir, lien quan mat thilt d i n sy tieu hao cdng suit hiru cong va vd cong trong mang. Nguai ta da chirng minh ring - n l u nhu t i n sd giam di 1 % (0,5 herz) thi lu'png t i n hao cdng suit trong mang se la 2 %. Do dao dpng cua t i n sd ma sy thiet hai mang lai cho chdt lupng san phIm trong day chuyin cdng nghe cua xi nghiep nhilu khi cdn lan han nhilu, so vai nhirng t i n hao k l tren. Dao dpng tan sd cua dien ap cd anh hudng rd ret nhdt ddi vai cac thilt bi dien tu. Dao dpng t i n s i qua +0,1 herz da lam cho cac tin hieu cua cac man hinh monitor, camera theo ddi, man hinh vd tuyIn bi meo di rd ret. T i n sd d trong khoang tir 49,5-49,9 herz lam cho tin hieu tren man hinh biin dang d i n 4 l l n so vai tin hieu chuln. T i n sd <49,5 herz thi h l u h i t cac thilt bi thu phat tin hieu khdng t h i lam viec dirpc.

Cac ehl tieu c h i t lirpng dien khdng phii hpp vai tieu c h u l n , khac vai cac gia tri danh dinh khdng chi anh hirdng d i n nang s u i t cua may mdc thilt bi, d i n t u l i thp ciia chiing. C h i t lu-png dien nang khdng dam bao cdn cd kha nang gay nen cac sy cd lien hoan, gay nen sy tac ddng n h i m lan ciia cac bao ve, dac biet cd t h i cd nhirng tin hieu d i l u k h i l n eac qua trinh san x u l t bi sai lech do cd sy tac ddng nhdm lan cua cae thilt bi ddng cdt, va k i t qua la xac s u i t x u l t hien hu hdng cung tang len theo gay nen nhCi-ng hau qua khdng luang trirac du'pc.

2. Tieu c h u l n v l " C h i t lu'p'ng dien nang" d Viet Nam

O nuac ta, " c h i t lupng dien nang" da dupc nhirng nguai lam cdng tac nang lirpng quan tam tir nhirng nam 80 cua t h i ky truac. Trai qua nhirng nam c h i l n tranh keo dai, nganh dien mai ehl cd g i n g dap irng dii nhu c l u cung d p dien cho cac hp tieu thu, chiing ta chira t h i ddi hdi nganh dien phai dap irng ngay eho cac hp tieu thu dien nang cd c h i t lirpng nhir cac nuac cdng nghiep phat t r i l n .

Tuy nhien, trong qua trinh xay dyng va phat triln chiing ta cung da t h i y du'pc muc tieu phin d i u cua nganh dien nhdm hirang tai nhirng muc tieu nay, dd la;

•:• Ngay 21 thang 11 nam 1984 theo d l nghi cua Bp Oien Lye, Uy ban Khoa hpc vd Ky thuat Nhd nuac da ban hanh Tieu chuln Viet Nam TCVN 3971-84 quy djnh v l "Mire c h i t lypng dien nang d cac thilt bi tieu thu dien nang noi vao lu'ai dien cong dung chung".

• Ngdy 02/08/2001 Chinh phu dd ban hdnh Nghj djnh sd 45/2001/ND-CP vd "Cdc hoat dpng dien lye vd sir dung dien".

• "Quy pham trang bj dien" dupe ban hanh theo Quylt dinh sd 19/2006/ QO-BCN, ngay 11/07/2006 cua Bp trudng Bp Cdng nghiep la mpt bu'ac t i l n mai trong viec dira dan cae "chi tieu chit lupng dien" cua Viet Nam phii hap vai Tieu chuln ciia cdc nuac cong nghiep phat triln. Quy pham nay cd bdn phdn dirpc bien soan thdnh dang Tieu chuln cua nganh. Tuy nhien, trong TCN-19-2006 cung mai chi cd quy djnh v l "chit lupng dien dp va t i n sd ciia lu-ai dien".,

Tieu c h u l n v l c h i t lupng dien nang ciia cac nu'ac hien d i u tuan theo cdc Tieu chuln ciia Uy ban Ky thuat dien Qudc t l (lEC), bao gdm nhilu chi tieu, cd eac yeu cdu va quy dinh r i t chi tilt v l cac chi tieu nay. Trong qua trinh hda nhap d l phat t r i l n , Viet Nam cung cdn thilt phai ban hanh cac Tieu c h u l n (TCVN) phii hpp vdi'cac Tieu c h u l n k l tren.

3. Mpt s6 kdt qua khao sat danh gia v l c h i t lu'p'ng dien ndng cung cdp cho cac xi nghiep md

Thai gian vira qua nhdm nghien ciru cua Vien Khoa hpc Cdng nghe Md k i t hpp vai cac can bp ky thuat cua mdt sd md t i l n hanh khao sat, danh gia mdt sd chi tieu c h i t lirpng cung cdp dien cho cae md h i m Id khu vyc Quang Ninh bdng t l hop t h i l t bj do luang da ndng WM 14-96 dupc c h i tao d dang "an toan nd" diing trong mo him Id cd t h i do dirpc cae thdng sd tire thai cua chit lupng dien ddt vdo phu tai nhu U, I, f, Coscp, P, S, Q, cac dang sdng hai... Cdc thdng s i hoat dpng nay dupe cap nhdt lien tuc va luu vao the nha, sau dd dung p h i n m I m chuyen dung (ACE- Reader-VI) d l l i y vd dpc (ACE-PowerSoft-V1) cac dir lieu do. T h i l t bj dupe t h i l t k l e h l tao va k i l m dinh theo tieu c h u l n TCVN 7079-0; 2002, v a T C V N 7079-1:2002.

Cac sd lieu do dufgc thye hien tai cdc tram b i i n dp 35/6 kV d l xdc djnh sy dao dpng dipn dp vd t i n sd cua mang d d p dien dp 35 va 6 kV.

Ddi vai cdc khu vyc khai thdc vd ddo Id, nhdm nghien ciru da t i l n hdnh ldp ddt t h i l t bj d l xdc dinh cae thong sd ddc trung cua mang ha dp nhdm danh gid c h i t lupng dien ndng tren mpt sd ehl tieu chu y l u nhu; chdt lupng dien dp, chit lupng t i n sd, he sd mang tai, he sd cdng suit, t i n hao dien ndng, mpt sd dang song hdi....

Tren cdc hinh H . I , H.2 vd H.3 md ta mpt s6 k i t qua khao sat duoc trong qua trinh do cung nhu XU" ly eac sd lieu do d l ddnh gid.

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H. 1. Duung phan phoi tan suat cua dien ap (a) va tan sd (b) tai tram 35/6 kV, Cdng ty than Vang Danh.

Bi4u d& cdng suit

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H. 2. Tinh trang mang tai cua mang cao C14 PX khai thac 7, Cdng ty than Mdng Dwang

1 - ^ r g C C O O ^ O ^ ^ L / ^ - > ^ • ^ » « * l - ^ ^ J ^ • - < ^ ^ - ^ ' * ^ - " • - ' r ^ ^ _ ' - l ^ - ^ l J ^ C ' n r r m f Y i f N r s i y r - i r - t r - « . ~ t . - i m c o o O O C * J - v J f « ' 0 rM

H.3. Dien ap ghi nhan tai quat cue bo Phan xudng khai thac 7, Cdng ty than Mdng Dwong

4. Cac ket qua nghien ciiru Cac k i t qua nghien ciru cho thIy;

'> Ddi chilu vdi Tieu chuln ta thIy - dien ap trung va cao dp cua cac TBA la tuang ddi I n dinh, cac gia tri cua dien ap khdng cd sy dao dpng nhilu, nhung dien ap tren cyc phu tai g i n vai tram thuang dupc giir d mire kha cao so vai gia tri danh dinh, do h l u h i t cac may biin ap d i u khdng cd he thong ty dpng dilu chinh dudi tai;

<• T i n sd cua ngudn nhin chung la I n dinh, dao ddng trong khoang nhd, chu y l u n i m trong khoang gidi han cho phep cua Tieu chuln, dam bao d l cac thilt bi lam viec binh thuang;

••• Mang ha ap cua hlu hit cac khu vyc khao sat diu cd tin thit dien nang kha lan. Tin thit dien nang chu ylu xay ra tren duang cap true chinh va cap mIm. Cac mang ha ap md deu cd he sd yeu clu, he sd cdng suit va he s i mang tai thip. Nlu dupc chii y diu tu, cai tao chic chin se nang cao duac cac chi tieu kinh t l ky thuat va hieu qua sir dung dien nang trong quan ly van hanh mang cung d p dien.n

TAI LIEU THAM KHAO . .,, 1. Dao Dac Tao va nnk. Nghien ciru d l xult cac giai phap cung cap dien dn dinh va an toan va hieu qua cho cac md than him Id Quang Ninh dap irng yeu d u ca giai hda, hien dai hda nganh than giai doan 2008-2025.

Bao cao ting kit d l tai. Ha Npi. 2009.

2. rOCT 13109-97. HopMbi KaMecTBa aneiapuHecKoPi aHepruM s cucreMax 3neKTpocHa6>KeHnq odinero HaaHaMBHMfl. MocKea. 1997.

3. B. B. flerrqpoB; B. 1/1. Cepos; f. KD.

LlenennHCKMM, CnpaBOHHUK no sneicrpoycTaHOBKaM yronbHbix npeflnpunTHflivi. MocKsa Heflpa. 1988.

Ngw&i bien tap: Hd Sy Giao

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/ / t h e article shows sorne results assessing the quality of electrical supply network at the

'J t!i!«i'-H| I ffi 11MI i-f^ll! 11..^ J • f - l l i f B i k . M l i l !,•',.•?> 18 • / .

1. Mpt ngay la quy ddi vdi nhCfng ai biet sdng. E. Spitne.

2. Khdng c6 gi cao quy va dang kinh hdn ong chung thuy. Ciceron.

3. Cudc sdng vdn cong bang. Vi vay ban lay biet thi'ch nghi vdi nd. Bill Gates.

VTH. suu tam

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