Điện Tử Tự Động - Tự Động Hóa Bằng Kỹ Thuật Số Phần 4 doc

iu khin t ng (1)  Bùi H
Trang - 25 -

Hình 1-13: Rơ-le nhiệt với bầu cảm biến từ xa dùng khí của Danfoss

Lời giải


 
 

không khí trong phòng là 
u 


 



 

bha


1-2 ta có

bha @22C

kgf
cm
2


= 2

kgf
cm
2

+ {22  20}



× 0.1

kgf
cm
2
. C

= 2.2

kgf
cm
2

;
 T (C ) còn là
1-3

bg


kgf
cm
2

= p
bha

kgf
cm
2

 p
a

kgf
cm
2



iu khin t ng (1)  Bùi H
Trang - 26 -

bg@22C
= 2.2

kgf
cm
2


 1.0

kgf
cm
2

= 1.2

kgf
cm
2

;


g 
2
) = 1 (cm
2


1-4
F
p
(kgf) = A(cm
2
) × P
bg
(
kgf

cm
2
)
F
p@22C
(kgf) = 1

cm
2

× 1.2



2

= 1.2




i F
P

kgf

.
òng (Tc).

LX

 

F
p

kgf

@ 22C = F
LX

kgf

;


 là

0



=




=
1.2




1




= 1.2





dLo = 
phòng (Tc). 
sau


( 
0
) 

() = 

(


) × 
0







g 

bha @21C

kgf
cm
2

= 2

kgf
cm
2

+ (21  22)



× 0.1

kgf
cm
2
. C

= 2.1


kgf
cm
2

;
iu khin t ng (1)  Bùi H
Trang - 27 -

bg@21C
= 2.1

kgf
cm
2

 1.0

kgf
cm
2

= 1.1

kgf
cm
2

;


F
p@21C

kgf

= A(cm
2
) × P
b
(
kgf
cm
2
) = 1

cm
2

× 1.1



2

= 1.1






bg
thì
c
1-5

@
() =





 











;

@21




=

1.2



 1.1



1.0 



= 0.1



;
lên trên 
 . Máy nén 





bha@23C

kgf
cm

2

= 2

kgf
cm
2

+

3



× 0.1

kgf
cm
2
. C

= 2.3

kgf
cm
2

;

bg@23C


kgf
cm
2

= p
bha@23C

kgf
cm
2

 p
a

kgf
cm
2

= 2.3

kgf
cm
2

 1.0

kgf
cm
2


= 1.3

kgf
cm
2

;


@23



=

1.2



 1.3



1.0




= 0.1




;
  

 
 


Còn Q
L

N

phòng, là nóng .

iu khin t ng (1)  Bùi H
Trang - 28 -


Hình 1-14: Sơ đồ khối thể hiện chức năng của các phần tử trong hệ điều khiển nhiệt độ
phòng học.
HÌNH 1-15 là s
HÌNH 1-15 




Hình 1-15: Sơ đồ khối thể hiện nguyên lý hoạt động của hệ thống điều khiển phòng học.

1.7.2 Bài tập:
Bài 1:

HÌNH 1-15 1-2
iu khin t ng (1)  Bùi H
Trang - 29 -
khW = Tc/F
LX
trên hình này 


Bài 2:
HÌNH 1-15 1-2 
1-6 
1-6





2

= 



× 





2
. 

,



2

;  

= 0.1



2
. 


Hãy xây trên HÌNH 1-15 
T p
bha

LX
 Tc 1-6.

Bài 3:




Bài 4:



===================================================

Tóm tắt



Ta c






===============================================


Câu hỏi ôn tập
iu khin t ng (1)  Bùi H
Trang - 30 -
1- 

2- 
3- 


4- 

5- Hãy 



6- 
Các xung n.
7- 
8- 



===========================================







iu khin t ng (1)  Bùi H
Trang - 31 -

Chương 2:
2 Biến đổi Laplace – Hàm truyền –
Sơ đồ khối – Mô hình toán.
2.1 Phép biến đổi Laplace
2.1.1 Phép biến đổi Laplace

a.





= + j


b.







= F
x
+ jF
y

:
 F
x
và F
y

 


F
x
2
+ F
y
2
.
 Ga F(s) là = tan
1





.
Góc này 

c.





 tích
phân Laplace

e
st
dt


0
;
iu khin t ng (1)  Bùi H
Trang - 32 -
F(s) f(t)
.

f(t) 
2-1






= 



= 







= 








0

0

 
f(t)

F(s)
i
là

K 
-1



2-2

1
[



] = ()
2.1.2 Một số hàm cơ bản và ảnh Laplace của chúng

Hàm số mũ (exponential function)
Hàm s m 
f(t) =
0
v t<0

Ae
-

v 



nh Laplace c hàm này có th tính nh sau
2-3





=  



=  


+




0

0
=

+ 
;