báo cáo điều khiển quá trình - dhbk

1 inh Hu Giang - 20111449

BO CO TH NGHIM IU KHIN QU TRNH

Sinh vin: inh Hu Giang

MSSV: 2011449

Nhm th nghim : 02

Bi 1: Xy dng h thng iu khin mt bnh mc.

1. Tn hiu vo l m (hoc lu lng) ca van vo In Flow, tn hiu ra l mc cht lng

trong bnh lever cn nhiu l m ca van ra Out Flow

2. Xy dng m hnh ton hc cho h thng

F1

F2 h

Phng trnh cn bng vt cht:

1 2dV dh

A F Fdt dt

(1)

Trong : A l tit din ct ngang ca bnh cha (coi nh u t trn xung). Phng trnh m hnh trng thi xc lp:

0 1 2d h

A F Fdt

(2)

Tr v ca (1) (2) ta c:

H thng


1 2d h

A F Fdt

t: ; 2; 1y h u F d F

Phng trnh tr thnh:

1

( )dy

d udt A

Ti trng thi ban u tt c cc bin chnh lch u y, u, d v dydt

u bng 0.

Laplace 2 v ta c

1 1

( ) ( ) ( )sy s u s d sA A

Do van l khu qun tnh bc nht nn hm truyn ca h thng s c dng:

3. M phng i tng bnh mc bng khi Single-Tank trn matlab

Phng php ng cong p ng

Vi b thng s

Course Number = 56 ( kho 56 )

Class Number = 02 ( nhm 02 )

Namelist Number = 49 ( SHSV 20111449)

Cho tn hiu tc ng bc thang u vo ta c p ng ca hm qu c dng qun tnh

bc nht.


T l thuyt v th ta xc nh c cc tham s ca m hnh nh sau:

T=3.7

K=14.8/(10-3.7) = 2.35

kim chng m hnh ta dng m hnh sau:

Nhn thy trn th m phng v th nhn dng c s sai khc nht nh. t c sai s ti thiu, ta iu chnh cc tham s K v T. Vi K = 3 v T = 4.7, ta c th


Cc sch lc iu khin Sch lc c th s dng: iu khin phn hi v iu khin tng. Sch lc khng s dng c: iu khin truyn thng, iu khin t l, iu khin la

chn v iu khin phn vng. V:

Qu trnh bnh nh mc l 1 khu tch phn khng c tnh t cn bng, trong khi iu khin truyn thng khng lm thay i tnh n nh ca h thng. Nn mt tc ng nh ca nhiu lm h thng i ti trng thi mt cn bng. iu khin t l c p dng cho h thng : duy tr quan h gia 2 bin nhm iu khin gin tip bin th 3, m iu khin bnh mc ch c 1 bin iu khin nn khng c p dng. iu khin la chn v iu khin phn vng cn t nht 2 bin iu khin m bnh 1 nh mc c 1 bin iu khin. Hm truyn t y PID:

)1

1()( ss

ksK di

c

4. Thit k sch lc iu khin cho h thng Tnh ton thng s b iu khin theo cng thc Ziegler Nichol 1 vi cc thng s sau: K=3; T=4.7


B iu khin Kc Ti Td

P 1/K=0.33

PI 0.9/K=0.3 10T/3 = 15.67

PID 1.2/K=0.4 2T=9.4 0.5T=2.35

Dng hm truyn t PID : K(s) = Kc(1 + +Td*s)

Ta c 3 sch lc iu khin l sch lc iu khin truyn thng, iu khin phn hi v iu khin tng

5. Sch lc iu khin truyn thng. Lu P&ID:

S simulink

So snh gi tr SP v Level (bng scope), chn stoptime = 49000 = MSSV


B iu khin P (P = 0.33)

B iu khin PI (P = 0.3, I = 0.019)


B iu khin PID (P = 0.4, I = 0.0425, D = 0.94)

Kt qu ta thy tn hiu u ra khng bm theo tn hiu ch o, qu trnh khng i n n nh. Khng th p dng sch lc iu khin truyn thng c. V sch lc truyn thng i hi phi bit r thng tin v qu trnh v nh hng ca nhiu. Tuy nhin, m hnh i tng v m hnh nhiu khng bao gi chnh xc, khng phi nhiu no cng o c, nn sai lch tnh bao gi cng tn ti. Thc t, b iu khin l tng khng bao gi c tnh kh thi.

6. Sch lc iu khin phn hi : Lu P&ID:

S trn simulink:


So snh gi tr SP v Level (bng scope),

B iu khin P (P = 0.33), chn stoptime = 49000

Nhn xt: B iu khin vn t c gi tr t


B iu khin PI (P = 0.3, I = 0.019), stoptime = 49000

Nhn xt: B iu khin vn t c gi tr t nhng c qu iu chnh ln hn

nhiu so vi b iu khin P, do c khu tch phn.

B iu khin PID (P = 0.4, I = 0.0425, D = 0.94), stoptime = 49000

10 inh Hu Giang - 20111449

Nhn xt: B iu khin PID c tnh cht tng t nh PI, tuy nhin thi gian qu ln

hn

Vi sch lc iu khin phn hi vng n th ch cn P l p ng yu cu bm gi tr t. Khi thc hin m phng vi b iu khin PI v PID th xy ra hin tng mc nc vt qu, v khng th t c n nh. y l hin tng bo ha tch phn (Reset Winup), thng xy ra trong cc b iu khin c cha khu I (Integral), c cc c im: - qu iu chnh ln - Thi gian qu di - Tn ti sai lch tnh ln

khc phc ta xy dng s c thm khu chng bo ha tch phn.

S dng khu chng bo ha tch phn: + PI-RW:

S :Khu PI ni tip vi khu chng bo ha tch phn:

Trong : Thng s ca khu PI-RW c xc nh theo Zinger Nichol 1 nh sau: Gain: K=Kc=0.3

Gain1: K=1/Ti=0.064

Gain2: chn khong t 0 -> Ti, K = 1 S simulink:

Kt qu m phng: vi stoptime = 49000

11 inh Hu Giang - 20111449

Nhn xt: khi c b chng bo ha th gim bt qu iu chnh khi thay i lng

t khng qu ln,dao ng khng c nhng khi lng t ln cao th qu iu chnh rt ln.

+ PID-RW:

S :Khu PID ni tip vi khu chng bo ha tch phn:

Trong : Thng s ca khu PID-RW c xc nh theo Zinger Nichol 1 nh sau: Gain: K=Kc=0.4

Gain1: K=1/Ti=0.064

Gain2: khong t 1 -> Ti, chn K = 0.5 Gain3: K=Td=2.35

12 inh Hu Giang - 20111449

S simulink ging phn trc Kt qu m phng vi stoptime = 49000

S dng b iu khin PI-RW v PID-RW ta thy gim c hin tng bo ha tch phn, tn hiu ra nhanh chng bm ti tn hiu ch o m khng dao ng qu nhiu, qu trnh nhanh chng i n n nh : - qu iu chnh nh - Thi gian qu nhanh - gim c sai lch tnh xung mc thp. Ch ng vi lng t thp,khi lng t cao th rt kh bm lng t v khi lng t thay i ln th qu iu chnh cao. S dng b iu khin phn hi khng cn o lu lng u ra

C th kt hp iu khin phn hi v iu khin truyn thng t c cht lng iu khin tt hn. Khi u ra t b iu khin phn hi LC c cng vi tn hiu o lu lng ra trc khi a xung van iu chnh dng cp. Trong khi u ra t b iu khin phn hi c vai tr n nh h thng v trit tiu sai lch tnh, th thnh phn b nhiu gip h p ng nhanh hn vi lu lng ra khng i.

7. Sch lc iu khin tng : Lu P&ID:

13 inh Hu Giang - 20111449

Cn s dng sch lc iu khin tng v:

Mt trong nhng vn ca iu khin phn hi c phn tch l khi nh hng ca

nhiu qu trnh ti bin u ra cn iu khin chm c pht hin. qu iu chnh ca tn

hiu iu khin ln, thi gian p ng chm.

iu khin tng l mt cu trc m rng ca iu khin phn hi vng n, c s dng

nhm khc phc nhng vn nu trn. iu khin tng gip loi b nh hng ca mt s dng

nhiu v gip cho tnh ng hc ca h thng linh hot hn.

Xc nh nhim v tng vng nh mc:

- B iu khin vng trong (th cp) c chc nng loi tr hoc t ra l gim ng k nh

hng ca n ti bin cn iu khin thc.

- B iu khin vng ngoi (s cp) c chc nng p ng vi gi tr t thay i, loi tr

nh hng ca ngun nhiu cn li, nhm duy tr bin cn iu khin ti 1 gi tr t.

- Vng 1( vng ngoi): o mc ca bnh ri phn hi li so snh vi SP.

- Vng 2( vng trong): o hiu lu lng In,Out flow cho ta tn hiu iu khin van ph hp.

B iu khin khng o lu lng ra

S trn simulink:

* Vng ngoi l b iu khin P (ly Kp = 10000) , vng trong l b iu khin P (Kp = 1000) b iu khin P-P Kt qu m phng nh sau:

14 inh Hu Giang - 20111449

Quan h gia gi tr t v mc nc trong bnh

Quan h gia gi tr u vo v u ra

Nhn xt: qu iu chnh nh, h thng t xp x gi tr t.

* Vng ngoi l b iu khin P(Kp = 10000), vng trong l b iu khin PI-RW c cc thng s nh trn bi iu khin phn hi. P-PIRW

15 inh Hu Giang - 20111449

Kt qu m phng

Quan h gia gi tr t v mc nc trong bnh

16 inh Hu Giang - 20111449

Quan h gia gi tr u vo v u ra Nhn xt: qu iu chnh nh, h vn t c gi tr t mong mun.

* Vng ngoi l b iu khin P(Kp = 1000), vng trong l b iu khin PID-RW c cc thng s nh b iu khin phn hi. P/PIDRW S simulink nh phn trn Kt qu m phng:

Nhn xt: h c qu iu chnh ln, khng t c gi tr t.

Nhn xt :

So snh gia sch lc iu khin phn hi v iu khin tng.

C hai sch lc iu khin phn hi v tng u em li kt qu iu khin kh tt, thi

gian xc lp nhanh, qu iu chnh v sai lch tnh nh.

17 inh Hu Giang - 20111449

Tuy nhin khi thay i gi tr t v lu lng ra, ta thy b iu khin tng c p ng

nhanh vi qu iu chnh nh hn b iu khin phn hi. V trong b iu khin tng c khu

t l P vng ngoi nn tc ng nhanh vi s thay i ca nhiu u vo v c tc dng trit

tiu c nhiu ny.

Bin php:

khi sai lch iu khin bng 0, tch b thnh phn tch phn trong b K, hoc xa trng

thi ca thnh phn tch phn.

gim h s khuch i nm trong gii hn cho php

t mt khu gii hn ti u ra ca b K b gii hn, phn hi v b K thc hin

thut ton b nhm gim thnh phn tch phn. H thng c b nhiu nhn tn hiu t mc nc

u ra iu khin d dng hn v n nh hn h thng khng c.

Bi 2 : Xy dng h thng iu khin hai bnh mc A: Xy dng m hnh l thuyt

1. Xc nh - Tn hiu vo: F2, F3 - Tn hiu ra: h1, h2 - Nhiu: F1

2. M hnh ton hc cho i tng

F1

F2 h1

F3 h2

Phng trnh cn bng vt cht:

H

thng ( )

1 3

( 1 2)1 3

d VF F

dt

d h hA F F

dt

18 inh Hu Giang - 20111449

1 2 1 11 3

dh dhF F

dt dt A A (1)

Phng trnh cn bng vt cht cho bnh mc1: 1

1 2dh

A F Fdt

1 1 11 2

dhF F

dt A A (2)

T (1) v (2) ta c: 1 1 1

1 2

2 1 12 3

dhF F

dt A A

dhF F

dt A A

Do van l khu qun tnh bc nht nn hm truyn G1(S), G2(S) s c dng:

3. M phng i tng bng khi TwoTank trong simulink

Vi b thng s

Course Number = 56 ( kho 56 )

Class Number = 02 ( nhm 02 )

Namelist Number = 49 ( MSSV 20111449)

Cho tn hiu tc ng dng bc thang u vo, ta c th p ng ca h thng nh hnh v.

19 inh Hu Giang - 20111449

Scope

Scope 1

Bnh 1 : i tng c m hnh khu qun tnh bc nht G(s) = K1/(S*(T1s+1))

Trong :T1 = 3.4; K1 = 20.65/(10-3.4) = 3.13 Bnh 2 : i tng c m hnh khu qun tnh bc nht G(s) = K2*/(S*(T2s+1))

Trong :T2 = 5.4 ; K2 = 1.83/(10-5.4) = 0.40

Kim chng m hnh ta dng m hnh sau:

20 inh Hu Giang - 20111449

Kt qu m phng nh sau:

21 inh Hu Giang - 20111449

Hiu chnh li thng s T1 = 4, K1 = 4 T2 = 5.8, K2 = 0.37

Thit k sch lc iu khin cho h thng Tnh ton thng s b iu khin theo cng thc ziegler Nichol 1 vi cc thng s K1=4,T1=4 v T2=5.8, K2=0.37 , c bng sau.

BK Kc Ti Td

Bnh 1 Bnh 2 Bnh 1 Bnh 2 Bnh 1 Bnh 2

P 0.250 2.703

PI 0.225 2.432 13.200 19.140

PID 0.300 3.243 8.000 11.600 2.000 2.900

4. Cc sch lc c th s dng l sch lc iu khin phn hi v sch lc iu khin tng. Khng th s dng sch lc iu khin truyn thng.

Ta la chn sch lc iu khin tng trit tiu ti a sai lch tnh v cho cht lng iu khin h thng tt hn sch lc iu khin phn hi.

5. Sch lc iu khin phn hi kt hp b nhiu a. Lu P&ID

22 inh Hu Giang - 20111449

b.S trn Simulink:

+) B iu khin P

23 inh Hu Giang - 20111449

Bnh 1

Bnh 2

24 inh Hu Giang - 20111449

+) B iu khin PI-RW S : Khu PI ni tip vi khu chng bo ha tch phn:

S simulink:

Trong : - B iu khin PI-RW 1 c cc thng s xc nh theo ziegler Nichol 1 l: Gain: K=Kc=0.225

Gain1:K=1/Ti=0.076

Gain2: ly K = 1 - B iu khin PI-RW 2 c cc thng s xc nh theo ziegler Nichol 1 l: Gain: K=Kc= 2.432

Gain1:K=1/Ti=0.051

Gain2: ly K = 1

25 inh Hu Giang - 20111449

Kt qu m phng:

+) B iu khin PID-RW: S : Khu PID ni tip vi khu chng bo ha tch phn.

26 inh Hu Giang - 20111449

Trong : - B iu khin PID-RW 1 c cc thng s xc nh theo ziegler Nichol 1 l: Gain: K=Kc=0.3

Gain1:K=1/Ti=0.125

Gain2: ly K = 0.5 Gain3:K=Td= 2

- B iu khin PID-RW 2 c cc thng s xc nh theo ziegler Nichol 1 l: Gain: K=Kc= 3.243

Gain1:K=1/Ti=0.0862

Gain2: ly K = 0.5 Gain3:K=Td=2.9

Kt qu m phng:

27 inh Hu Giang - 20111449

Khi s dng b chng bo ha tch phn gim c ng k hin tng dao ng, qu iu chnh nh, tuy nhin vn tn ti sai lch tnh, b hn ch l khi lng t ln cao th khng theo kp c.

6. Sch lc iu khin tng. Lu P&ID.

Xc nh cc vng iu khin cn xy dng:

Vng th nht: iu khin m van InValve 1

Vng th hai: iu khin m van InValve 2 c im, nhim v ca tng vng:

Vng th nht: iu khin m ca van 1, v c c tnh ng hc bin i nhanh hn vng th hai

Vng th hai: iu khin m ca van 2, v c c tnh ng hc bin i chm hn vng th nht

28 inh Hu Giang - 20111449

M phng vi cc b iu khin: +) Vng ngoi l b iu khin P (ly Kp = 1000) vng trong l b iu khin P (Kp = 10000) tng p ng ca h thng. S :

B P/P Kt qu m phng:

29 inh Hu Giang - 20111449

Nhn xt: b iu khin P khng t yu cu,tn hiu khng bm lng t,gy trn bnh

B P/PI-RW +)Vng ngoi l b iu khin P (Kp =1000) tng p ng ca h thng, vng trong l b iu khin PI-RW trit tiu sai lch tnh Trong cc thng s b iu khin PI-RW ly phn trn S simulink:

Kt qu m phng:

30 inh Hu Giang - 20111449

Nhn xt: D c b chng bo ha tch phn nhng gi tr cn iu khin vn cha t c

gi tr t SP ca n v b vt gi tr t gy trn bnh

31 inh Hu Giang - 20111449

B P/PID-RW

+)Vng ngoi l b iu khin P (Kp =1000), vng trong l b iu khin PID-RW Trong cc thng s ca b iu khin PID-RW ly phn trn - S simulink:

Kt qu m phng:

32 inh Hu Giang - 20111449

báo cáo điều khiển quá trình - dhbk

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