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Palestine Polytechnic University 

College Of Engineering

Electrical Engineering Department 

Control Lab

Exp#3 (PI controller)

Students Name :

Samee !addad "mad !oub

$allel "bu %altam

&or: Super'isor:

Eng"nas "bu abane

*+,3,-.*/

Objective:

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1.to study the Step Response of "PI" controllers.

2. to study the Typical characteristics of "PI" controller.

3. Capability of compensation for system deviations !ero input.

#. desi$n any PI % controller usin$ op amp .

Equipment :

1. P controller and I controller element .

2. Test function $enerator.

3. Po&er supply 1'v(3).

#. To& channel oscilloscope y1 * y2.

'. Probe sets and brid$in$ plu$s.

+. Summin$ point.

,.di$ital multimeter.

Theory :

PI  : is a controller used to improve the steady state error of a control systemby placin$ an open loop pole at the ori$in and therefore increasin$ the system

type by one .

PI controller combine the t&o controller proportional and the inte$ral controlle

properties.

Physical realization :

The p controller can be implemented usin$ operational )-P opamp.

Block diaram !or PI:

The PI controller feeds the error proportional plus inte$ral of the error for&ar

to the process .

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Input" output #ave !or PI :

$nalysis :

The circuit desin usin op amp:

3

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/10R1 /20  R2+  1

Cs .

  s0Z 2

Z 1∗Vi (s) .

  (   1 R1 )∗( R2+  1

Cs)

  R2

 R1 s+

  1

 R2C 

S¿

 o0 s s0 R2

 R1 4[s+

  1

 R2C ]

s5vis.

 os0 6PS+

 KI 

 KP

S¿ iS.

  6P0 R2

 R1 and 6I01

 R1C 

#

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%ultisim simulation &PI' square #ave input:

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+

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(onclusion :

,

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•  To vary 6p independently of 6I ad7ustin$ on R2.

•  To vary 6I independently of 6p ad7ustin$ on R1.

• 8e can use PI controller as a p or a I controller by ad7ustin$ one of them t

1 and vary the another .

• If &e need to improve the steady state error of the system &ithout

a9ectin$ the transient response the !ero of :cs must be very close to

the pole.

;