Introduction of control engineering.pptx

8/19/2019 Introduction of control engineering.pptx

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INTRODUCTION OFCONTROL ENGINEERINGBY

ASHVANI SHUKLAMANAGER(C&I)

BGR ENERGY


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BASIC INTRODUCTION• Control system engineering is the branch of engineering which dea

the !rinci!es of contro theor" to design a s"ste# which gi$es desiredin a controed #anner% &ence' this is interdisci!inar"% Control system

engineers ana"(e' design' and o!ti#i(e co#!e) s"ste#s which consi

high" integrated coordination of #echanica' eectrica' che#ica' #et

eectronic or !ne*#atic ee#ents% Th*s ontrol engineering deas w

di$erse range of d"na#ic s"ste#s which inc*de h*#an and technoog

interfacing%• Control system engineering foc*ses on ana"sis and design of s"ste

i#!ro$e the s!eed of res!onse' acc*rac" and stabiit" of s"ste#% The t

#ethods of contro s"ste# inc*de cassica #ethods and #odern #et

#athe#atica #ode of s"ste# is set *! as +rst ste! foowed b" ana"

designing and testing% Necessar" conditions for the stabiit" are chec,e

+na" o!ti#i(ation foows%


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CONTROL S-STE.

BLOC/ DIAGRA. OF CONTROLS-STE.

DISTURBENCES

IN0UT OUT0UT

.ANI0ULATED1ARIABLES


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• Mo!ern ontrol engineering deas with .*ti!e In!*t .*ti!e O*t!*t

s"ste#s' State s!ace a!!roach' Eigen $a*es and $ectors etc% Instead of

transfor#ing co#!e) ordinar" di4erentia e5*ations' #odern a!!roach

higher order e5*ations to +rst order di4erentia e5*ations and so$ed b"

#ethod% A*to#atic contro s"ste#s are #ost co##on" *sed as it does

in$o$e #an*a contro% The controed $ariabe is #eas*red and co#!ar

s!eci+ed $a*e to obtain the desired res*t% As a res*t of a*to#ated s"scontro !*r!oses' the cost of energ" or !ower as we as the cost of !roc

red*ced increasing its 5*ait" and !rod*cti$it"%

•Histori"l Re#ie$ o% Control Engineerin The a!!ication of A*to#atic contro s"ste# is beie$ed to be in *se e$e

ancient ci$ii(ations% Se$era t"!es of water coc, were designed and i#

to #eas*re the ti#e acc*rate" fro# the third cent*r" BC' b" Gree,s and

B*t the +rst A*to#atic s"ste# is considered as the 6atts F" ba Go$ern

7899' which started the ind*stria re$o*tion% The #athe#atica #odein

Go$ernor is ana"(ed b" .a)we in 79:9% In 7;th cent*r"' Leonhard E*e

Si#on La!ace and


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• T"!es of Contro Engineering

• Contro engineering has its own categori(ation de!ending on the di4erent

#ethodoogies *sed' which are as foows%

• Cl"ssi"l Control Engineering @ The s"ste#s are *s*a" re!resented b

ordinar" di4erentia e5*ations% In cassica contro engineering' these e5*

transfor#ed and ana"(ed in transfor#ed do#ain% La!ace transfor#' Fo*transfor# and ( transfor# are e)a#!es% This #ethod is co##on" *sed

In!*t Singe O*t!*t s"ste#s%

• Mo!ern Control Engineering @ In #odern contro engineering higher or

di4erentia e5*ations are con$erted to +rst order di4erentia e5*ations% T

e5*ations are so$ed $er" si#iar to $ector #ethod% B" doing so' #an"

co#!ications deat in so$ing higher order di4erentia e5*ations are so$eare a!!ied in .*ti!e In!*t .*ti!e O*t!*t s"ste#s where ana"sis in fre

do#ain is not !ossibe% Noninearities with #*ti!e $ariabes are so$ed b

#ethodoog"% State s!ace $ectors' Eigen $a*es and Eigen 1ectors ongs t

categor"% State 1ariabes describe the in!*t' o*t!*t and s"ste# $ariabes

http://www.electrical4u.com/laplace-transformation/http://www.electrical4u.com/laplace-transformation/


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• Ro'st Control Engineering @ In rob*st contro #ethodoog"' the cha

!erfor#ance of s"ste# with change in !ara#eters are #eas*red for o!t

This aids in widening the stabiit" and !erfor#ance' aso in +nding atern

so*tions% &ence in rob*st contro the en$iron#ent' interna in acc*racie

and dist*rbances are considered to red*ce the fa*t in s"ste#%

• tim"l Control Engineering @ In o!ti#a contro engineering' the !ro

for#*ated as #athe#atica #ode of !rocess' !h"sica constraints and

!erfor#ance constraints' to #ini#i(e the cost f*nction% Th*s o!ti#a co

engineering is the #ost feasibe so*tion for designing a s"ste# with #i

cost%

• A!"ti#e Control Engineering @ In ada!ti$e contro engineering' the c

e#!o"ed are ada!ti$e controers in which !ara#eters are #ade ada!t

so#e #echanis#% The boc, diagra# gi$en beow shows an ada!ti$e co

s"ste#%

• Nonline"r Control Engineering @ Non inear contro engineering foc*s

non inearit"=s which cannot be re!resented b" *sing inear ordinar" di4

e5*ations% This s"ste# wi e)hibit #*ti!e isoated e5*iibri*# !oints'

c"ces' bif*rcations with +nite esca!e ti#e% The #ain i#itation is that it

aborio*s #athe#atica ana"sis% In this ana"sis the s"ste# is di$ided in


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•On O4 Contro Theor" Controer

• So#eti#es' the contro ee#ent has on" two !osition

f*" cosed or f*" o!en% This contro ee#ent does no

an" inter#ediate !osition' i%e% !art" o!en or !art" co

The contro s"ste# #ade for controing s*ch ee#ent

on o, ontrol t+eory% In this contro s"ste#' when !

$ariabe changes and crosses certain !reset e$e' the

of the s"ste# is s*dden" f*" o!ened and gi$es 7

•Genera" in on o4 contro s"ste#' the o*t!*t ca*ses c!rocess $ariabe% &ence d*e to e4ect of o*t!*t' the !r

again starts changing b*t in re$erse direction% D*ring

when !rocess $ariabe crosses certain !redeter#ined

o*t!*t $a$e of the s"ste# is i##ediate" cosed and

s*dden" red*ced to %


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• As there is no o*t!*t' the !rocess $ariabe again starts changing in its

direction% 6hen it crosses the !reset e$e' the o*t!*t $a$e of the s"s

again f*" o!en to gi$e 7 o*t!*t% This c"ce of cosing and o!enin

o*t!*t $a$e contin*es ti the said on>o4 contro s"ste# is in o!eratio

co##on e)a#!e of on-o, ontrol t+eory is fan controing sche#e

transfor#er cooing s"ste#% 6hen transfor#er r*ns with s*ch a oad'

te#!erat*re of the eectrica !ower transfor#er rises be"ond the !re

at which the cooing fans start rotating with their f* ca!acit"% As the

fans r*n' the forced air 2o*t!*t of the cooing s"ste#3 decreases the

te#!erat*re of the transfor#er% 6hen the te#!erat*re 2!rocess $aria

co#es down beow a !reset $a*e' the contro switch of fans tri! and

s*!!"ing forced air to the transfor#er% After that' as there is no cooi

of fans' the te#!erat*re of the transfor#er again starts rising d*e to

Again when d*ring rising' the te#!erat*re crosses the !reset $a*e' t

again start rotating to coo down the transfor#er% Theoretica"' we as

that there is no ag in the contro e5*i!#ent% That #eans' there is no

for on and o4 o!eration of contro e5*i!#ent% 6ith this ass*#!tion if

series of o!erations of an idea on o4 contro s"ste#' we wi get the g

gi$en beow%

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• B*t in !ractica on o4 contro' there is awa"s a non (e

dea" for cosing and o!ening action of ontroller ee

This ti#e dea" is ,nown as dead ti#e% Beca*se of this

dea" the act*a res!onse c*r$e di4ers fro# the abo$e

idea res!onse c*r$e% Let *s tr" to draw act*a res!onsc*r$e of an on o4 contro s"ste#%


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• Sa" at ti#e T O the te#!erat*re of the transfor#er starts rising% The #

instr*#ent of the te#!erat*re does not res!onse instant"' as it re5*

ti#e dea" for heating *! and e)!ansion of #erc*r" in te#!erat*re s

b*b sa" fro# instant T7 the !ointer of the te#!erat*re indicator start

This rising is e)!onentia in nat*re% Let *s at !oint A' the ontroller s

starts act*ating for switching on cooing fans and +na" after !eriod o

fans starts dei$ering force air with its f* ca!acit"% Then the te#!era

the transfor#er starts decreasing in e)!onentia #anner%

• At !oint B' the controer s"ste# starts act*ating for switching o4 the

fans and +na" after a !eriod of T the fans sto! dei$ering force air% T

te#!erat*re of the transfor#er again starts rising in sa#e e)!onenti#anner% N.B./ Here !'ring t+is oer"tion $e +"#e "ss'me! t+"

lo"!ing on!ition o% t+e eletri"l o$er tr"ns%ormer0 "mien

temer"t're "n! "ll ot+er on!itions o% s'rro'n!ing "re 12e!

onst"nt.

http://www.electrical4u.com/electric-power-single-and-three-phase/http://www.electrical4u.com/electric-power-single-and-three-phase/


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•Contro S"ste# Cosed Loo! O!en Loo! Contro S"ste#

• 6hen a n*#ber of ee#ents are co#bined together to for# a s"ste# to !rod*ce

o*t!*t then the s"ste# is referred as contro s"ste#% As this s"ste# contros the

is so referred% Each ee#ent connected to the s"ste# has its own e4ect on the o

3e1nition o% Control System

•

A ontrol system is a s"ste# of de$ices or set of de$ices' that #anages' co##directs or reg*ates the beha$ior of other de$ice2s3 or s"ste#2s3 to achie$e desi

In other words the !e1nition o% ontrol system can be rewritten as A ontro

is " system0 $+i+ ontrols ot+er system%

• As the h*#an ci$ii(ation is being #oderni(ed da" b" da" the de#and of a*to#

increasing according"% A*to#ation high" re5*ires contro of de$ices% In recent "

ontrol systems !a"s #ain roe in the de$eo!#ent and ad$ance#ent of #od

technoog" and ci$ii(ation% 0ractica" e$er" as!ects of o*r da">to>da" ife is a4or #ore b" so#e contro s"ste#% A bathroo# toiet tan,' a refrigerator' an air co

a gee(er' an a*to#atic iron' an a*to#obie a are contro s"ste#% These s"ste#

*sed in ind*stria !rocess for #ore o*t!*t% 6e +nd contro s"ste# in 5*ait" con

!rod*cts' wea!ons s"ste#' trans!ortation s"ste#s' !ower s"ste#' s!ace techn

robotics and #an" #ore% The riniles o% ontrol t+eory is a!!icabe to en

and non engineering +ed both%

•4e"t're o% Control System


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• The #ain feat*re of contro s"ste# is' there sho*d be a cear #athe

reation between in!*t and o*t!*t of the s"ste#% 6hen the reation

in!*t and o*t!*t of the s"ste# can be re!resented b" a inear !ro!o

the s"ste# is caed inear contro s"ste#% Again when the reation b

in!*t and o*t!*t cannot be re!resented b" singe inear !ro!ortiona

rather the in!*t and o*t!*t are reated b" so#e non>inear reation'

s"ste# is referred as non>inear contro s"ste#% Re5'irement o% G

Control System

• A'r"y/ Acc*rac" is the #eas*re#ent toerance of the instr*#en

de+nes the i#its of the errors #ade when the instr*#ent is *sed in

o!erating conditions% Acc*rac" can be i#!ro$ed b" *sing feedbac, e

To increase acc*rac" of an" contro s"ste# error detector sho*d be contro s"ste#%

• Sensiti#ity/ The !ara#eters of contro s"ste# are awa"s changing

change in s*rro*nding conditions' interna dist*rbance or an" other

!ara#eters% This change can be e)!ressed in ter#s of sensiti$it"% An

s"ste# sho*d be insensiti$e to s*ch !ara#eters b*t sensiti$e to in!

on"%


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• Noise/ An *ndesired in!*t signa is ,nown as noise% A good con

s"ste# sho*d be abe to red*ce the noise e4ect for better !erfo

St"ility/ It is an i#!ortant characteristic of contro s"ste#% Fo

bo*nded in!*t signa' the o*t!*t #*st be bo*nded and if in!*t

then o*t!*t #*st be (ero then s*ch a contro s"ste# is said to b

s"ste#% B"n!$i!t+/ An o!erating fre5*enc" range decides thebandwidth of contro s"ste#% Bandwidth sho*d be arge as !oss

fre5*enc" res!onse of good contro s"ste#% See!/ It is the ti#

b" contro s"ste# to achie$e its stabe o*t!*t% A good contro s"

!ossesses high s!eed% The transient !eriod for s*ch s"ste# is $

s#a% sill"tion/ A s#a n*#bers of osciation or constant o

of o*t!*t tend to s"ste# to be stabe%

• T"!es of Contro S"ste#s%

•en loo ontrol system

•Close! loo ontrol system

• A contro s"ste# in which the contro action is tota"


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• A contro s"ste# in which the contro action is tota"

inde!endent of o*t!*t of the s"ste# then it is caed oe

loo ontrol system% .an*a contro s"ste# is aso an o

oo! contro s"ste#% Fig > 7 shows the boc, diagra# of o

oo! contro s"ste# in which !rocess o*t!*t is tota"

inde!endent of controer action% 6r"ti"l E2"mles o%

en Loo Control System

• Eletri H"n! 3rier H &ot air 2o*t!*t3 co#es o*t as ong

"o* ,ee! "o*r hand *nder the #achine' irres!ecti$e of ho

#*ch "o*r hand is dried%

• A'tom"ti 7"s+ing M"+ine H This #achine r*ns

according to the !re>set ti#e irres!ecti$e of washing is

co#!eted or not%


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• Before I introd*ce "o* the theor" of contro s"ste# it is $er" essentia

the $ario*s tyes o% ontrol systems% Now there are $ario*s t"!es

s"ste#s' we are going to disc*ss on" those t"!es of s"ste#s that w

to *nderstand the theor" of contro s"ste# and detai descri!tion of

t"!es of s"ste# are gi$en beow@ Line"r Control Systems

• In order to *nderstand the line"r ontrol system' we sho*d ,now !rinci!e of s*!er!osition% The !rinci!e of s*!er!osition theore# inc

the i#!ortant !ro!erties and the" are e)!ained beow@

• E2"mles o% Line"r Control System

• Consider a !*re" resisti$e networ, with a constant dc so*rce% This c

foows the !rinci!e of ho#ogeneit" and additi$it"% A the *ndesired

are negected and ass*#ing idea beha$ior of each ee#ent in the n

we sa" that we wi get inear $otage and c*rrent characteristic% This

e)a#!e of line"r ontrol system% Non-line"r Systems

• 6e can si#!" de+ne non line"r ontrol system as a those s"ste

do not foow the !rinci!e of ho#ogeneit"% In !ractica ife a the s"s

non>inear s"ste#%

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• E2"mles o% Non-line"r System

• A we ,nown e)a#!e of non>inear s"ste# is #agnet

c*r$e or no oad c*r$e of a dc #achine% 6e wi disc*s

brie" no oad c*r$e of dc #achines here@ No oad c*r

gi$es *s the reationshi! between the air ga! *) and +ed winding ##f% It is $er" cear fro# the c*r$e gi$en

that in the beginning there is a inear reationshi! betw

winding ##f and the air ga! *) b*t after this' sat*ra

has co#e which shows the non inear beha$ior of the

or characteristics of the non line"r ontrol system%

A l C ti S t

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• An"log or Contin'o's System

• In these tyes o% ontrol system we ha$e contin*o*s signa as the in!*t to the s"

These signas are the contin*o*s f*nction of ti#e% 6e #a" ha$e $ario*s so*rces of

in!*t signa i,e sin*soida t"!e signa in!*t so*rce' s5*are t"!e of signa in!*t so*r

#a" be in the for# of contin*o*s triange etc% 3igit"l or 3isrete System

• In these t"!es of contro s"ste# we ha$e discrete signa 2or signa #a" be in the fo

as the in!*t to the s"ste#% These signas ha$e the discrete inter$a of ti#e% 6e can$ario*s so*rces of contin*o*s in!*t signa i,e sin*soida t"!e signa in!*t so*rce' s

of signa in!*t so*rce etc into discrete for# *sing the switch%

• Now there are $ario*s ad$antages of discrete or digita s"ste# o$er the anaog s"st

these ad$antages are written beow@

• Digita s"ste#s can hande non inear contro s"ste#s #ore e4ecti$e" than the ana

s"ste#s%

• 0ower re5*ire#ent in case of discrete or digita s"ste# is ess as co#!ared to anao

Digita s"ste# has higher rate of acc*rac" and can !erfor# $ario*s co#!e) co#!*

easi" as co#!ared to anaog s"ste#s%

• Reiabiit" of digita s"ste# is #ore as co#!ared to anaog s"ste#% The" aso ha$e s

co#!act si(e%

• Digita s"ste# wor,s on the ogica o!erations which increases their acc*rac" #an"

•

Losses in case of discrete s"ste#s are ess as co#!ared to anaog s"ste#s in gene


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• Single In't Single 't't Systems

• These are aso ,nown as SISO t"!e of s"ste#% In this the s"ste# has sin

for singe o*t!*t% 1ario*s e)a#!e of this ,ind of s"ste# #a" inc*de te#

contro' !osition contro s"ste# etc% M'ltile In't M'ltile 't't S

• These are aso ,nown as .I.O t"!e of s"ste#% In this the s"ste# has #

o*t!*ts for #*ti!e in!*ts% 1ario*s e)a#!e of this ,ind of s"ste# #a" 0LC t"!e s"ste# etc% L'me! 6"r"meter System

• In these t"!es of contro s"ste#s the $ario*s acti$e 2resistor3 and !assi$

!ara#eters 2i,e ind*ctor and ca!acitor3 are ass*#ed to be concentrate

!oint and that=s wh" these are caed *#!ed !ara#eter t"!e of s"ste#%

of s*ch t"!e of s"ste# is $er" eas" which inc*des di4erentia e5*ations

3istri'te! 6"r"meter System

• In these tyes o% ontrol systems the $ario*s acti$e 2resistor3 and !a

!ara#eters 2i,e ind*ctor and ca!acitor3 are ass*#ed to be distrib*ted *

aong the ength and that=s wh" these are caed distrib*ted !ara#eter t

s"ste#% Ana"sis of s*ch t"!e of s"ste# is sight" dic*t which inc*de

di4erentia e5*ations%

, i f

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•Boc, Diagra#s of Contro S"ste#

• The boc, diagra# is to re!resent a contro s"ste# in

for#% In other words !ractica re!resentation of a cont

its boc, diagra#% It is not awa"s con$enient to deri$e

transfer f*nction of a co#!e) contro s"ste# in a sing

It is easier and better to deri$e transfer f*nction of con

connected to the s"ste#' se!arate"% The transfer f*nc

ee#ent is then re!resented b" a boc, and the" are t

connected together with the !ath of signa ow% For si#co#!e) contro s"ste#' boc, diagra#s are *sed% Eac

the contro s"ste# is re!resented with a boc, and the

s"#boic re!resentation of transfer f*nction of that ee

co#!ete contro s"ste# can be re!resented with a re

n*#ber of interconnected s*ch boc,s% In the +g*re be

• In addition to that the diagra# aso shows there is a

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• In addition to that' the diagra# aso shows there is a

feedbac, !ath thro*gh which o*t!*t signa C2s3 is fed b

and co#!ared with the in!*t R2s3 and the di4erence be

in!*t and o*t!*t E2s3 J R2s3 H C2s3 is acting as act*atin

signa or error signa%

• In each boc, of diagra#' the o*t!*t and in!*t are rea

together b" transfer f*nction% 6here' transfer f*nction%• G2S3 JC2S3R2s3

• where' C2s3 is the o*t!*t and R2s3 is the in!*t of that

!artic*ar boc,% G2S3C2s3 R2s3

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Introduction of control engineering.pptx