BAI 2:
(5 d)
Xap xi Taylor: e 181 =1-1.85
=> (5.55 + 1)775 + 1.1(775 + 1)(1 - 1.85) = 0
=> 3.52r,s2 + ( 2. It, - 1.98)5 + 1.1 = 0
1.98
Be he on dinh cac he so phai cung dau => 77 > - y y = 0.943
d. Thiet ke bo dieu khien PID theo IM C
Xap xi Gp thanh he bac 1 co tre nhu cau c, ta co
T (5) GCG
T(s) 1+ GCG
Trongdo: G = K mK vGp = 0.55e •i.*j0.5
5.55 + 1
Su dung cac phuang trinh (4.46) trong slide bai giang, ta co Gc la bo dieu
khi6n PID vai cac h? s6:
X, = 1 2t + 9 1 2x5.5 + 1.8
K 2r. + 6 0.55 2x1.8 + 1.8
9 1.8 , . , .
t, = —+ r =
-----
1-5.5 = 6.4
2 2
= 4.3 (chon rc = 9 = 1.8)
t95.5x1.8 = 0.773
2 t + 9 2x5.5 + 1.8
Vay bo dieu khien PID co dang sau:
r
G„ =4.3 1 + - 1
v6 .4 5 + 0.7735
a. Giai thich cac ky hicu:
LT: Level Transmitter (thiet bi do muc)
LC: Level Controller (bo dieu khien muc)
I/P: Transducer chuyen doi tu dong dien sang ap suat
P11: May bom ly tam
V4-V7: cac valve dieu khien (on/off)
Day la vong dieu khien muc chat long a day thap. Muc chat long dugc do thong
qua cam bien LT va tmyen tin hieu ve bo dieu khien LC. Tin hieu dieu khien dugc
chuyen d6i tu chuan dong dien sang ap suat thong qua transducer I/P, va sau do se
dieu khien do dong mo cua valve dieu khien a ngo ra cua may bom. De dam bao an
toan, may bom co duong hoi luu chat long tro ve day thap.
b.
Cac loai bien qua trinh cua vong dieu khien day thap:
MV: luu lugng ngo ra cua may bom (dieu khien thong qua valve dieu khien)
0.75
0.75
0.5
