NGHIEN C I J U - T R A O B P I
NGHIEN CU-U CHON GIAI P H A P HOP LY D^ TU DONG HOA KHdl DONG CAC TUY^N BANG CHUYDN TRONG
NGANH CONG NGHlEP KHAI THAC M 6
RESEARCH REASONABLE SOLUTION FOR AUTOMATION STARTUP CONVEYORLINES IN THE MINING INDUSTRY
TS. D jng Van Chi, TS. Pham Thi Thanh Loan, ThS. Pham Minh Hai, ThS.Thai Hai Au Khoa Ca dien, Truong Dai hpc Mo - Dia chat
TOM TAT
Sdi bao nghien cm ung dung bp biin doi dong xoay chieu (AC Current Transducers), Encoder va vi dieu thien (VDK) PIC16fS77A dixdy dyng thanh cac module do dong va do toe di chuyen dung. Dua tren cong nghe van tai bang chuyen vd dac thii trong thuc te nganh Khai thac Mo, da thiit lap cac thugt toan do, xay dimg so do nguyen ly, Igp trinh mo phong tren Proteus de khang dinh ket qua ding nhu dinh humg nghien cm. Vai muc dich lua chon dufrc mot gidi phap phil hap di img dung cac module nay vao bai toan tu dong hoa quy trinh cong nghe khai dong cac tuyin bdng ehuyin trong cong nghiep noi chung, trong ngdnh Khai thac mo noi rieng. Ngodi ra, co the ung dung vdo linh vuc bdo ve ra le he thong dien, bdo ve nhiet dong ca, truat bdng, gidm sdt toe dQ vd cdc he thong truyen dong trong cong nghiep.
Tir kh6a: Tu dong hoa khai dong bdng tdi.
ABSTRACT
This paper proposes research applications ACJOurrentTransducers, Encoder, Microcontroller PJC16F877A to build modules current measurement and speed measurement. Based on the technological process of transport conveyor, the authors have established measurement algorithms, building structure diagrams, simulate in Proteus to confirm results of research. With the purpose of choosing a suitable solution can be applied to the automation process technology startup conveyor lines in general industry, in the mining industry in particular. Besides can be applied to this module in the field of protective relays for power system, motor thermal protection, protective skating, speed monitoring and transmission systems in other industry.
Keywords: Microcontroller PIC16F877a, Current measurement. Speed measurement, Control in the Process Industries.
ISSN 0866 - 7056
TAP CHl CO KHl VIET NAM, S6 3 nam 2016 www.cokliivietnam.vn
NGHIEN CUlU - TRAO D 6 |
1. BAT VAN BE
Trong cong ngh$ van tai bang ehuyin, van de tu d6ng h6a quy trinh khoi dong he thdng gom nhieu tuySn bang da duac dua vao giang day ly thuySt a cac Truong Dai hoc va timg buac duoc chuin hoa, xem mo ta quy trinh cong nghS tdng quat hinh 1, [1],[2], Tuy nhien, do dac thu cua nganh Khai thac mo nen quy trinh van hanh cong nghe tu dong hoa cac tuySn bang co su khae biet. Dac thii cong nghe van tai bang chuySn trong cong nghiep mo v6i cac tuySn bang thuong rit dai, hang chuc Km, diSu kien vi dia hinh, dia chat va moi trudng lam viec thudng rat khae nghiet.
(bp dieu khien logic kha trinh), viec khdi ddng he thdng theo cac nguyen tic: Thdi gian, ddng dien hoac toe do thudng duoc lua chon bdi s\r don gian, de cai dat va lap trinh. So dd nguyen ly khdi ddng theo nguyen tac thdi gian va tdc dd sii dung ro le duoc md ta nhu hinh 2, hinh 3, [2],[5].
n - r ^ K i
Kl RThl K2 RTh2
H
Hinh 2. Sa do nguyen ly khdi ddng theo nguyen tdc thai gian
Hinh 1. Sa do cong nghe van tdi he 3 bdng tong qudt Trong cong nghiep bp dieu khi§n logic kha trinh PLC ducfc chon nhu mot giai phap toi mi trong diSu khien va dong vai tro nhir mpt bp dieu khien tap trung. Viec chon nguyen tac khai dpng cac tuyen bang se anh huong den sir lam viec on dinh va tin cay cua toan he thong. Thuc te CO the chon, van dung cac nguyen tac:
1) Khoi dpng theo nguyen tSc thai gian {T^^: Thai gian qua trinh qua do 1 bang);
2) Khai dong theo nguyen tAc dong dien (Ij^: Dong lam viec dpng ca d i n dpng);
3) Khai dpng theo nguyen t i c toe dp (n : Toe dp dinh miic dpng ca dan dpng);
4) Khai dpng theo phuang phap to hop cac nguySn t i c tren: T,, - 1 , ^ ; T^, - n,^; 1,^ - n^^; T^^
Vai bp dieu khien tap trung su dung T LC
1
I Kl ||RI1~J [ *C2 11 RI2 I I K3 |
T^ T^ r
Hinh 3. Sa do nguyen ly khdi dgng theo nguyen tdc ddng dien
Tuy nhien, cac nguyen tac dieu khien nay co nhuac diem la khong thS hpi tu va dam b^o cac dieu kien Ij^=^I^^ hoac n^^^n^. Phuong phap nay cung chi nen ap dung khi he th6ng c6 ngu6'i van hanh va giam sat t^i cho. Khic phuc nhuoc diSm nay, cac nguyen tac dieu khiln theo cac t6 hap:
Tfca - Idn,; \<! ~ n , ; I ^ - n^^ thuang duac ehpn.
Hinh 4 la mpt vi du minh hoa nguyen tac dieu khien toe dp ket hpp thai gian [2],[5]. ^
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NGHIEN CUfU-TRAOOCl
Hinh 4. Sa do nguyen ly khdi dgng theo nguyen tac thai gian vd tdc do
Cac to hpp tren ciing khong chac chan va dam bao dp tin cay can thiet voi mpt bp dieu khiln tap tmng dung PLC. Truong hpp ehpn nguyen tic T,^^ - 1 ^ thi trong thuc t8 ciing khong thi chic chin la toe dp dpng ca khi do n^^ > n ^ , hay nguyen tic T^ - n^ thi trong thuc te cung khong thi chic chan la I^^ > I^_^. Hon nua cac dai lupng Ijj. va n^^ dupe do va giam sat lien tue bai cac cong vao analog hoac bp dem toe dp cao ciia P L C . V i vay, voi mpt bp dieu khien tap tnmg su dung PLC, thuc hien cac chiic nang do luong tap trung, dilu khien thi he thong se rat kho de lam viec on dinh va tin cay nhu mong muon.
Xu the hien nay, cac he dieu khien duac xay dung dua tren he thong dieu khien phan tan (DCS). May tinh va PLC dupe eoi nhu bp giam sat va dieu khien tai trung tam, cac chuc nang do, giam sat qua trinh, dieu khien ca cau chap hanh dupe giao nhiem vu cho cac module do chuyen dung va cac PLC tram. Tu thuc te tren, nhom tac gia de xuat giai phap ling dung vi dilu khiln Picl6f877a, AC Current Tranducer, Encoder de xay dung module chuyen dung do dong va toe dp dpng CO bang tai. Vai muc dich do va giam sat dpe lap cac thong so dong dien, tic dp ciia dpng ca dan dpng, ung dung vao cong nghe khai dpng tu dpng nhieu tuyln bang. Kit qua nghien cuu dupe khang dinh bai cac uu dilm:
- Giai phap xay dung he dieu khien phan tan tren n l n PLC giup t6i uu hoa cac thuat toan trong lap trinh PLC, chuang trinh se gpn nhe, tilt kiem duac bp n h a cho PLC.
- Chiic nang do, thu thap va xu ly s6 lifu se dupe giao nhiem vu cho cac module chuyen dung truac khi giri thong tin bao cao v l PLC.
- Thuan tien trong viec cai dat, hieu chinh thong s6 lam viec, cung nhu giam sat quy trinh van hanh. Dac biet co loi khi xii ly cac sir co bat thuang ma khong anh hucmg den viec dimg toan bp cong nghe.
- D I dang trong viec phat trien, ma rang va cai tao he thdng ma khong nhat thiet phai can thiep qua sau vao cac thuat toan dieu khien chinh cua PLC.
- Dam bao he thong lam viec on dinh, tang dp linh hoat va tin cay cho h6 thong di6u khien nho chiic nang phan tan cua cac module.
2. SO DO NGUYfiN LY, CAU TRUC CUA HE THONG
Sa d6 cdu tnic va thanh phan co ban dupe mo ta nhu hinh 5, [6], [7].
Tbik bl dieu khien PLC
1 ^ ^ T t
QUY TRPiH CONG h'GH$ V ^ TAI Cap lieu ~~i \ BanE 3
•y^ = P Bane 2 .
Chieu kboi dong ~~~~...___ " t ^ -
r
BANGCHtrytN . dneu dragHinh 5. Sa do cdu true vd thdnh phdn ca bdn he thong.
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NGHIEN CIJU-TRAO 061
Trong sa do:
Nl: Network - Interface (giao dien man^);
I/O: Input - Output (c6ng vao ra tren thiet hi).
Yeu cdu qity trinh khai dpng tuyen bdng:
[2]. [5].
- Tu dpng khoi dpng lien tilp cac hang theo chieu ngupc dong van chuyln va co duy tri thai gian khai dpng giua cac bang.
- Khai dpng bang tiep theo chi c6 thi tien hanh khi bang hay ca eiu keo bang truac do dong dien dat dong dinh miic va t6c dp bang dat toe dp dinh miic.
- Kiem tra va theo doi thai gian khai dpng tai tram dieu khien, thai gian qua trinh qua dp phai dam bao tu dpng kiem tra t6c dp ttmg bang hay ca cau keo bang.
3. THIET KE XAY DyTVG MODULE DO DONG VA TOC DO
3.1. Thiet ke xay d ^ g sff do nguy8n iy;
[1],[61,[71.
Sir phat trien ciia khoa hpc ky thuat da tao ra nhung thiet bi do chuyen dung, cac Card do luang da nang co dp chinh xac cao, kha nang ghep noi may tinh, noi mang...Ket hop voi cac phan mem SCADA co kha nang dieu khien giam sat thu thap du lieu dap ling dupe hau het cac yeu cau thuc te dat ra.
Tuy nhien, nhiing he thong nay co gia thanh rat dat, phu thuoc hoan toan cong nghe vao nha che tao. Vai muc tieu nam bat kip thai xu thi phat trien chung trong ky thuat do, chu dpng trong cong nghe, phuc vu cong tac dao tao thuc hanh, nghien cuu khoa hpc chuyen nganh.
Nh6m tac gia da de xuat xay dung module do chuyen dung c6 sa do nguyen ly duac mo ta nhu hmh 6, trong do su dung: Bien dong TI, VDK Picl6f877a, ACCurrent Tranducer, cam bien t6c dp Encoder.
T I - H c A * MCfK.-L£deMe«
i W K A C X
S DOtXi CO D A N D E R )
ACCumnl * * * » * . _ _ VBK-PIc O 0
Hinh 6. Sa do nguyen ly module do chuyen dung
3.2. Lira chon cac thilt bi trong module,|4],[5]
• Bien dong dien TI: Bien dong c6 tri so lan thanh dong dien co tri so tieu chuan 1A hoac 5A, dong thii cap cua bien dong se cung cap cho dau vao ciia ACCurrent Transducers.
AC_Current Transducers: AC_Current Transducers duac dung de do dong AC va chuyen doi thanh tin hieu ra theo chuan cong nghiep ti le vai dau vao (1A hoac 5A). Tin hieu dau ra duac chuan hoa 0-20mA hoac 0-1OV DC voi kha nang khu tap nhieu cao va tuong thich vcfi dau vao cho VDK, PLC va cac he thong hien thi may tinh.
Vi dilu khiln Pic_16F877A: Dong VDK Pic (Programable interlligent controller) dupe sii dung rpng rai do cac tinh nang ky thuat vupft trpi so vai nhieu dong VDK khae. Dac biet, dong 16F877A da, dang dupe rat nhieu cae nha khoa hpc va sinh vien trong cac truong khoi ky thuat nghien ciiu, hpc tSp. Nhom nghien ciiu da ehpn VDK nay de xay dyng thanh Module, hp VDK 14 bit vai 40 chan, du manh cho cac ling dung a muc dp thong thuong.
• Thiet bi do toe Encoder: La thiet bi do vi tri goc ciia dpng co, chiing co co 2 loai: Loai tuang doi (incremental) va loai tuyet doi (absolute).
Encoder gom: Nguon sang, dia quay, cam bien
anh sang va mach tao xung vuong. ^
ISSN 0866 - 7056
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NGHIEN Cli(U - TRAO OOl
3.3. Thiit k l mo phdng he thing do voi Proteus, (11,(3],[61
• Module do ddng tai: Hinh 7, md ta ket qua md phdng vdi diim do gia tri djnh mijc ddng tai tren ddng co thii nghiem cdng suat P=2.2kW.
Hinh 7. Kit qud mo phong vai dong tdi tai diem do I,=4,7A
Viec su dung bien ddng Tl va ACCurrent Transducers da duoc nhdm tac gia thuc hien tren md hinh thi nghiem thuc, ket qua phu hgp vdi dac tinh nha san xuat. Trong bai bao, nhdm tac gia chi thuc hien md phdng tin hieu do lay tu cdng ra cua A C C u r r e n t transducer sau dd, qua chuyen ddi ADC lObit ciia VDK va hien thi LCD, md rdng k6t ndi RS232 qua cdng COM ciia may tinh...
• Module do toe do dong ca:
Chon Encoder quang cd do phan giai lOOxung/vdng, gia thiet trong thdi gian Is VDK dSm duge sd ximg la N xung.
Khi do, gia tri tinh toan tdc do quay cua dong co la: n^^=(N*60)/100 vdng/phiit.
Thu^t toan do tdc dp va hiSn thi tren LCD duge md ta nhu hinh 8.
Hinh 8, K.k qua md phdng tren Proteus ddng co thii nghiem d tdc dp 166 vdng/philt.
Hinh 8. Ket qud mo phong ket qua do tdc do tai nj=l66 vong/phiil
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NGHIEN CUfU - TRAO OOl
4. KET LUAN
Y tudng xay dung module do chuyen dung ddng dien va tdc dp ddng co da giai quyet duoc cac yeu can va muc tieu dat ra. Vice su dung bito ddng Tl, AC_Current_Transducers, VDK_Pic- 16f877a va Encoder da duoc md phdng thanh cdng tren phin mgm Proteus.
Giai phap de ra dupe danh gia la hpp ly ddi vdi bai toan tu ddng hda khdi ddng he thdng bang chuyen trong edng nghiep khai thac md, cd thi phat triln triln xay dung mach ciing d l ling dung vao thuc t l .
De xuat tiep tue cai tiln, phat triln module theo xu thi tu dpng hda he thing dp da kenh, kit ndi giao dien hiln thi va luu trO tren may tinh.
Ket qua nghien cuu cd t h i triln khai trong thuc t l c h l tao thanh san phim thuang mai, ling dung cho cae he SCADA, quan ly nang lupng, cho cac he thdng Ipc bui tinh dien, cac hinh thiic bap ve ddng ddng c a cdng suit Idn, bao ve trupt bang va bao ve role frong he thdng dien... •
Ngay nhan bai: 08/02/2016 Ngay phan bien: 18/3/2016
Tai ligu tham khao:
[1]. Dao Van Tan; Ky thuat so vd do ludng dien trong cong nghiep mo vd dau khi. NXB. Giao thong Van tai, 1999.
[2]. Dang Van Chi; Bdi gidng mon hoc tif dong hoa vd thiet bi do ddu khi. Bo mon Tu dong hoa, Tnidng Dai hoc Mo-Diachit, 2013.
[3]. NguySn Manh Giang; Cdc vi dieu khiin PIC, NXB. Khoa hgc Ky thuat, 2009.
[4]. Cdc bo cdm bien trong ky thuat do lircmg vd dieu khien, ^XB. Khoa hgc Ky thuat, 2001.
[5]. Dao Van Tan, Nguyen Chi Tinh; Tu dong hod qud trinh sdn xudt trong cong nghiep mo vd ddu khi, NXB.
Giao thong Van tai, 2001.
[6]. Emest O.Doebelin, Measurement System Application and design, Mc Graw Hill, 2003.
[7]. Brian.R.Patrick.Chin, Computer Control in the Process IndusUies, Lewis Publishers, INS 1999.
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