CONTROL CIRCUITS AND DEVICE NUMBERS.ppt

8/20/2019 CONTROL CIRCUITS AND DEVICE NUMBERS.ppt

1/30

1. One-line diagram of the system or area involved

2. Impedances and connections of power equipment, systemfrequency, voltage level and phase sequence

3. Eisting schemes

!. Operating procedures and practices a"ecting protection#. Importance of protection required and maimum allowed

clearance times

$. %ystem fault studies

&. 'aimum load and system swing limits

(. )*s and +*s locations, connections and ratios

. uture epansion epectance

1. /ny special considerations for application.

Information Required to ApplyProtection


2/30

One 0ine iagram

• on-dimensioned diagram showinghow pieces of electrical equipmentare connected

• %implication of actual system

• Equipment is shown as 4oes, circlesand other simple graphic sym4ols

• %ym4ols should follow /%I or IE)conventions


3/30

1-0ine %ym4ols 516


4/30


5/30


6/30


7/30


8/30


9/30


10/30


11/30


12/30


13/30


14/30


15/30

/%I )3&-2 eviceum4ers

21 Distance Relay25 Synchronizing Device

27 Undervoltage Relay

32 Directional Power Relay

49 her!al Relay

5" #nstantaneo$s %verc$rrent Relay

51 &' i!e %verc$rrent Relay

52 &' 'irc$it (rea)er


16/30

/%I )3&-2 eviceum4ers

59 %vervoltage Relay*7 &' Directional %verc$rrent

72 D' 'irc$it (rea)er

7* D' %verc$rrent Relay

79 &' Reclosing Relay

+1 ,re-$ency Relay

+* .oc)o$t Relay

+7 Di//erential Relay


17/30


18/30


19/30

a 4 c 7hase sequence a-4-c

/) 8us

#1-

#1-/#1-) #1-8

#2

#19 *ime overcurrent relay#29 /) circuit 4rea:er

7 r o t e c t e d

0 i n e

a

c

4

)*

/) Elementary iagram


20/30


/) 8us

#1-

#1-/#1-) #1-8

#2

#19 *ime overcurrent relay

#29 /) circuit 4rea:er

7 r o t e c t e d

0 i n e

a

c

4

)*


*O) phase relays#1-/, #1-8, and #1-)should send trip signal

to 4rea:er #2


21/30


/) 8us

#1-

#1-/#1-) #1-8

#2

#19 *ime overcurrent relay

#29 /) circuit 4rea:er

7 r o t e c t e d

0 i n e

a

c

4

)*


*O) ground relay#1- ;set sensitively<should send trip signal

to 4rea:er #2


22/30

=elay operating coil=elay contacts

#1-/

#1-/#1-/

s

s

#2

#2a

#1-8

#1-8#1-8

s to #1-)and #1-

s

*)

) Elementary iagram


23/30

=emar:s

• *he elementary diagrams aredrawn for electromechanical relays 0 *he auiliary relay mar:ed with s is

the seal-in or contact switch 0 *his is not usually needed with solid-

state relays, 4ut the relay must latchin the trip position


24/30

)onventional contactpositions

• )onvention9 contacts are shown inthe de-energi>ed or non-operatedposition

0 #2a is auiliary contact that is insame position as the 4rea:er

0 #24 is auiliary contact that is in theopposite position as the 4rea:er


25/30


#1-/

#1-/#1-/

s

s

#2

#2a

#1-8

#1-8#1-8

s to #1-)and #1-

s

*)

) Elementary iagram

%hows the operated condition for a faultproducing a trip signal to the 4rea:ertrip coil #2 *)


26/30


#1-/

#1-/#1-/

s

s

#2

#2a

#1-8

#1-8#1-8

s to #1-)and #1-

s

*)

) Elementary iagram

%hows the operated condition for a faultproducing a trip signal to the 4rea:ertrip coil #2 *), with relay latched


27/30


#1-/

#1-/#1-/

s

s

#2

#2a

#1-8

#1-8#1-8

s to #1-)and #1-

s

*)

) Elementary iagram

/fter 4rea:er trips, #2a opens, whichunlatches the circuit, when relay no longersees the fault, #1-/ and #1-8 will open


28/30


29/30


30/30

Date post:	07-Aug-2018
Category:	Documents
Upload:	muazaminu1422
View:	215 times
Download:	0 times

CONTROL CIRCUITS AND DEVICE NUMBERS.ppt

Documents