18'
I Journal of transportation science and technology. Vol 15, May 2015
XAY DinVG MACH LOC TICH ClTC SU^ DUNG KY THUAT DIEU K H I £ N PI-MOr NHAM GIAM ANH IHTdNG CUA TAI PHI TUYEN
DEN LU*OfI DIEN
BUILD ACTIVE POWER FILTER USING PI-FUZZY CONTROL TECHNIQUE TO REDUCE THE INFLUENCE OF NON-LINEAR
LOAD TO THE GRID
Ch&u Vdn Bdo', Vo Cong Phmmg' 'NCS, khoa Dien-Dien tu viin thdng, Dgi Hgc Giao Thdng Van Tdi Tp. Hd Chi Minh, Vi4t Nam
^Khoa Dien-Dien tic viin thdng. Dgi Hoc Giao Thdng Van Tdi Tp. Hd Chi Minh, Viet Nam Tdm tdt: Bdi bdo ndy nhdm xdy dung mdt mo hinh mgeh Ige tich cue su dung ky thuclt dieu khien Pl-md de gidm dnh hudng cua tdi phi tuyen den ludi dien. Tdi phi tuyen dupc mo hinh hoa bdi mot bg chinh luu khong dieu khien bapha vdi tdi Id R, L vd C. Ddng hdi cua tdi phi tuyen vd ddng bii len ludi dupc xdc dinh theo phuong phdp ip-iq. Mdt bo dieu khiin PI-m& dupc thiet ki nhdm mue dich tao ra xung kich ddng md cdc khda IGBT ciia bg nghich luu de tgo ra tin hiiu bii nhu mong mudn. Cdc ket qud mo phong da chimg minh dupc rdng bd diiu khien Pl-md cd thdi gian ddp img dgng ngdn hem, sai sd d xdc lap nhd han vd hiiu qud loc hdi tdt han so vdi bd dieu khien PI truyen thdng trong ede trudng hpp tdi trude vd sau khi thay ddi.
Tk khoa: Bd dieu khien PI, bd dieu khien md, Mach loc tich cue, mach Ipc tich cifC dang lai ghep, Ige hdi.
Abstract: This paper aims to build a model of active filter circuit using Pl-fiizzy control technique to reduce the impact of a nonlinear load to the grid. The non-linear load is modeled by a three phase unrectifier with load R, L and C. Harmonic current of non-linear load and compensation current into the grid are determined by the method of ip-iq. A fuzzy-PI controller is designed to control on/off IGBTs switching of inverter, to generate compensation signals as desired. The simulation results have proven to be that Fuzzy-PI controller with a shorter response time, smaller error in steady-state and better harmonic filter efficient than traditional PI controller in the case load before and after the change.
K^fwords: PI controller, fuzzy controller. Active Power Filter. Hybrid Active Power Filter, harmonic filter.
1. Gidi thieu chdt tdi, higu qua cao...
Hien nay, vdn d l ehdt lupng dien nang Cac ky thudt dilu khiln da dugc dung da trd thanh mdt tieu chi quan trpng ttong eho APF cd thi dupc ligt ke nhu sau: ky san xudt, truyen tai va phan p h i i dien nang thudt dilu khiln hysteresis, so sdnh, trugt, cua tdt cd cac qudc gia tten t h i gidi. Nguyen PI, tich phdn tdng qudt, d i l u c h l vecto khdng nhdn chinh lam cho chdt lugng dien nang xdu gian,... va thudng dupc sii dung nhdt la ky di Id do cdc tdi phi tuyin. D I gidi quyet vdn thudt dilu khiln hysteresis va PI. Ky thuat d l nay, cd nhilu phuong phap nhu: su dung dilu khiln Hysteresis [4] cd im dilm la don cdc mach loc thy ddng LC truyin thdng [1] gian, dap ling nhanh nhung khuylt dilm la vd mach loc tich cue (APF)[2-3]. Do cdc phu thudc vao tdn sd chuyin m^ch, viec khde mach Ipc t h u d d n g cd khuylt dilm la khdng phyc nhupc dilm nay ciing dugc nhung linh boat, d l xay ra cpng hudng vdi trd mach dilu khiln hoi phiic tap. Vdi ky thuat khdng ciia ludi va hieu qud bu hai chua cao. dilu khiln PI truyin thdng thi don gidn, dg Vi vdy, hien nay mach Ipc tich cyc ddng vai thyc hien thuc nghiem [5]. Tuy nhien, khuylt ttd cyc ky hieu qua ttong vipc cdi thien chdt dilm cua dilu khiln PI la cdc thdng sd Kp, lugng dien ndng do cdc uu diem vupt trdi cua Ki la co diiih, nlu chpn mdt gia tri Kp qua nd nhu: bu linh hoat, khdng phu thudc tinh ldn thi dap ling se nhanh nhung rat dg mdt dn
dinh va ngugc lai. Hon niia, ttong Imh vyc khii hai thi qua tiinh dilu khiln la phi tuyin do tai thay ddi lien tuc va rdt nhanh. Do do, khi chi su dung dilu khiln PI truyin thdng nlu tai thay ddi thi rdt khd dl dat dugc ket qua tdt. Tuy nhien cac bai bao [1-6] chi nghien cihi ttgn md hinh tai cd dinh, khdng thay ddi ttong sudt qua trinh, dilu nay se khdn^ phii hgp ttong thyc tl. Dd gidi quylt khuyet diem ndy, bai bao dua ra mpt k j thudt dilu khiin sii dung bp dilu khiln PI truyin thdng kgt hgp vai bg dilu chinh md cd xet dgn dieu kien thay ddi tai. Kit qud md phdng chiing minh dugc rdng bp dilu khiln Pl-md cd thdi gian dap ung ddng ngdn hon, sai sd d xac lap nhd hon vd higu qud bii chinh xac hon so vdi bd dilu khiln PI truyin thong.
2. Mo hinh toan cua APF kit n6i he thong
Md hinh ciia APF kgt ndi vao he thdng dugc bieu dien d hinh 1, trong do: Us va Zg Id dien dp nguon va trd khang cua ludi. Ci vd Ll la dipn dung va dien cam edng hudng tai tdn sd CO ban. CF la di?n dung dupc thgm vao nhdm Igc hai va bu cdng suat phan khdng.
May biln dp cd ti sd n: 1 nham bao ve, cdch ly giiia ngudn vd bg nghich luu ngudn dp. Lo, Co la mach Ipc ddu ra ciia VSI nham ttigt tigu cac thanh phdn bac cao do qua trinh ddng ngdt tao ra. Tdi phi tuyin dugc xem nhu la ngudn phdt ra hai.
Hinh 1. Mo hinh kit ndi cua APF vol he thong.
Mach dign tuong duong mdt pha cua md hinh kit ndi APF vao he thdng dugc bilu dign nhu d hmh 2.
Hinh 2. Mach di^n tuong duong mgt pha cda md hinh APF kit ndi vdo he thong Trong dd:
Zs~Rs+ joiLs; -^1 = 1 ^ J'^^\ + i^h Z,=[jo>L,/ /{!/ jmC,)]/n^;Z^ =1/ JOJC^
Tir hinh 2, chung ta tinh dugc Is nhu sau:
^^_U,-K,U,+iK,+Z^)I, ^^^
" 2 "^ F "^ S
Vai: K, ij(,/j.
Theo [4] thi chi^n lirgc di8u khien theo dong tai la chiSn luoc di^u khien hieu qua
Vr -^i- Thay^'^ -KIL- (2) nhat. Do dd
(1) ta dugc:
^ _U,+{K^+Z,-K,K)I, AJ + Zp + Z^
Xet trong miln hdi ta cd U,,HK^+Z,-K,K)I^
' - - K^^Z.^Z, f'>
Do Ush=0. Ddng hdi cua tdi Iik dupc xac dinh theo phuong phdp ip-iq [4].
Tu (3) chiing ta thay rang: thdnh phdn hdi ciia ddng ngudn se dugc triet tieu neu K dli ldn. K la he sd dieu khien nd tuy thudc vdo chien luge va phuong phap dieu khiSn.
3. Thiit ke bp dieu ldii€n Pl-md cho APF
Bd digu khien Pl-md dugc thilt kl nhdm muc dich cue tieu sai sd giiia ddng hai cua tai va ddng hdi bii len ludi, ddng thdi tao ra tin hieu digu chg va ket hgp vdi ky thuat digu che dp rdng xung dg dieu khign ddng md cac khda IGBT cua bd nghich luu tao ra tin hieu bu nhu mong muon. Cdc thdng sd Kp, Ki ban dau ciia bp dieu khign PI dugc tinh toan offline. Bp dieu khien md se cho ra cac gia
20 I Journal of transportation science and technology. Vol 15, May 2015
tri hi?u chinh AKp va AKt theo do cac thong s6 Kp, KI cua bp diSu kliien PI se dupc diSu chinh hgfp h theo su thay doi cua tai nhu sau:
Cac dau vao cua bp di6u Ichien ma la : e(t)=iu(t) -iptft) vkAe(t)=e(t)-e(t-l)
Gia tri cua e(t) va Ae(t) duac bifa diln duoi dang cac ham thu6c nhu sau: duong lan (nb), duong trung bmh (mn), duong nho (ns), khong (zo), am nho (ps), am trung binh (pm) va am Ion (pb). Ham thuoc cua cac bien mof vao-ra dugc bieu dien nhu o hinh 3.
4. Cac ket qua mo phong va thao luan De so sanh hieu qua lam vi^c ctia bp diju khiSn Pl-mo so voi bg diSu khiSn PI truyen thong. Cac kh qua m6 phong dugc thuc hien tren mpt he th6ng APF 380V- 50Hz. Thong s6 mo phong cua he th6ng APF dugc cho nhu sau: CF=88pF, Ci=349.2nF, Li=30mH, Lo=0.5mH, Co=21 pF, Ls=0.2mH, R,=0.Oia VDC=800V, n=2.
Tai phi tuySn dugfc m6 hinh hoa bdi rngt bg chinh lira khong diSu khiSn ba pha voi tai R=50 va L=0.3mH. Ban dJu tai co THD=27.98% (1^0 dSn 0.1s) sau do tang len 39.62% (t=0.1 din 0.2s). Hmh 4 va hinh 5 the hien ph6 tin s6 cua dong tai trudc \k sau khi thay doi
1 M O
-1 -0 6 - 0 2 0 0.2 0.6 1 M , Hinh 3. Cdc ham tfm^c cua cdc bien mcr vdo - ra
Cac luat mo co the thu dupc nhu o bang 1 va bang 2.
Bdng AK,
efl)
nb nm DS ZO ps pm pb
'. Cdc lugt dieu chinh n AKf Ae(t) nb
nb nb nm nm ns zo zo
nm nb nb nm ns ns zo ps Bang 2. Cdc lugt d AK,
e(t) n b nm ns zo ps pm pb
ns nm nm ns zo zo ps pm
zo nm ns ns zo ps pm pm eu chinh mc
ps i ^
ns zo ps ps pm pm
pm ns zo ps ps pm pm pb r ciia AKj
p b zo zo pm pm pm pb pb
Ae(t) nb zo zo zo zo zo zo zo
nm zo zo zo zo zo zo zo
ns pm pro ps ps zo ns ns
zo pm pm ps zo ns ns nm
ps pm
pm zo pm I zo zo i zo ns ns nm nm
zo zo zo zo
p b zo zo zo zo zo zo zo
Chpn luat hpp thanh theo nguyen tac mm-max. Giai md theo phuong phap trgng tdm.
Rndamenal (SOIb) = 13ZT.
Frequenqr [Hz)
Hinh 4. THD cda //. trudc khi thay doi
Furaamenal (SOHz)=t33.7. T H D : 39 62%
Hlnh 5. THD cua ii khi tdi thay doi
Hinh 6 the hien dap ling dgng ciia hp thdng khi su dung bd ^ l u khiln PI truyin tiidng vdi Kp=5, Ki==0.1. Trong khodng thdi gian tii 0 dgn 0.1s, sai so giiia tin hieu tham chieu va tin hieu bii gidm cdn ±12A trong khodng 0.02s, THD ciia is giam tii 27.98%
xudng cdn 5.71% vd sai sd nay khdng gidm cho din t^O.ls, coscp tang tir 0.82 Ign 0.94.
Trong khoang thdi gian tii 0.1 din 0.2s, ddng tdi thay ddi theo hudng tang THD tii 27.98%
len 39.62%, sai sd giiia tin hieu tham chilu vd tin higu bii tang tu ±12A Ign ±20A trong khodng 0.02s, THD cua is ciong tang tii 5.71% Ign 7.72% va sai sd nay khdng gidm
cho den t=0.2s, coscp giam tit 0.94 xudng con 0.92
Hinh 7 va hinh 8 the hi$n pho tan s6 cua is truac va sau khi tai thay doi voi bp didu khiln PI.
?M^vwwtvWWwwwCwvwW
k-~__
;¥ i Hinh 6. Cdc kit qud mo phong ddp img dgng voi bd
dieu khien PI
FunUmenlBU&DHi) = 1 3 Z 6 , THD: 5 7 1 %
Hlnh 7. Pho tdn so ciia (j tru&c khi tdi thay doi
FunOamentfll lEOm) = 134 2 . m O : 7 7 3 %
? ^°
1 20
0
• •
200 400 BOO SOO 100
is tdng nhe tu 1.56% Ign 1.71% va coscp hdu nhu giii nguyen la 0.98
Td cac kgt qud md phdng chiing ta cd the nhan thay rang: phuong phap dieu khien su dung bp dilu khiln Pl-md cd thdi gian dap ung ddng tdt hon, sai so d xac lap nhd hon, THD cua is gidm nhd hon vd he sd cdng sudt dugc nang cao hon so vdi bp digu khien PI truyen tiidng.
Frequency (HI)
Hinh 8. Pho Idn so cua (j sow khi idi thay doi Hinh 9 the hien dap ling ddng ciia he thdng khi sd dung bp dieu khien Pl-md.
Trong khoang thdi gian tu 0 den 0.1s, sai sd giiia tin hieu tham chieu vd tin hieu bu la
±4A trong khoang 0.02s, THD ciia is gidm tii 27.98% xudng edn 1.56% vd costp tdng tii 0.82 ldn 0.98. Trong khoang thdi gian tir 0.1 d i n 0.2s, ddng tai tiiay ddi theo hudng tang THD tu 27.98% len 39.62%, sai sd giiia tin hieu tham chieu va tin hipu bu tang len tu
±4A Ign ±5A trong khodng 0.02s, THD cua
^ ,. :
•.11Hinh 9. Cdc ket qud mo phong ddp ung dong voi bg diiu khiin Pl-mo
Hinh 10 va hinh 11 the. hjen-phd tdn sd ciia is trudc va sau khi tdi thay ddi vdi bd dieu khien Pl-md.
^ ao
^ 20
0
FuixtonailallSOHi)^
200 400 13S.Z.™
600 0^15614
aoo 100
Hinh 10. Pho tdn so cua i^ trudc khi ldi thay doi voi bo diiu khiin Pl-md
Hlnh 11. Pho tdn so cua i^ trudc khi idi thay doi vdi bg dieu khiin Pl-md
5. Ket luan
Bai bao ndy da xdy dung dugc md hinh mach Ipc tich cue su dung ky thudt dilu
22
Journal of transportation science and technology. Vol 15, May 2015
khiln Pl-md nhdm giam anh hudng cua tai phi tuyin d i n ludi di?n. So sdnh vdi ky thudt dilu khiln PI truyin thdng thi 1 ^ thuat dilu khiln Pl-md cho cac k i t qua tdt hon trong viec giam cac hai, giam thdi gian dap ung ddng, cue tigu sai so va ndng cao he sd coscp.G
Tai lieu t h a m khao
[1] S. Bhattachaya, P.-T. Cheng (1997, May), "Hybrid solutions for improving passive filter performance in high power applications", IEEE Trans Ind. AppL Vol. 33, No. 3, pp. 732-747.
[2] MmhThuyen Chau, VanBao Chau (2013, July), "Comprehensive Analysis of the Control Strategy for Hybrid Active Power.
[3] Filter with Injection Circuit", Intemational Journal of Scientific Engineering and Technology ,Vol. 2, No. 7, pp. 694-699.
[4] Hu Ming, Chen Heng (2000), "Active power filter technology and its
application", [J]. Automation of Electric Power Systems, pp. 66-70.
[5] P. Ratiiika, Dr D Devaraj (2010, June), "
Fuzzy logic - Based Approach for Adaptive Hysteresis Band and DC Voltage Control in Shunt Active Filtei^', Intemational journal of Computer and Electrical Engineenring. Vol. 2, No. 3, pp. 1793-8163.
[6] An Luo, Zhikang Shuai, Weiji Zhu...
(2009, Jan), " Development of Hybrid Active Power Filter Based on the Adaptive Fuzzy Dividing Frequency- Contiol Method", IEEE Transactions on Power Delivery. Vol 24, No. 1, pp. 424- 432.
[7] MinhThuyen Chau (2014), "An adaptive contiol method for hybrid active power filter", Mitteilungen Klostemeuburg.
Vol. 64, No. 4, pp. 201-212.
P ^ ^ d y n M n t i ^ 20/37201?^
I Ngdy chdp n h | n ddng: 20/1/2015 [ Phdn bi$n:TS. Lg Quang Dire
