Barzam A.B. Automation in Electrical Power Systems (Системная автоматика)

=.....-F--

CEAPTEN

SEVEN

R.{PID

PARALLELING

OF

SYNCFR

ONOU.q

G

ENERATORS ool

rr or7 ^:_

2tl"ptpo6

U

6n:

/U

c

Sln

--T-

where

U":

value

of the

voitages

being synchronized

l,

p

:

permissible-specified

difference

of

the

frequencies

of

the voltages

being synchronized

t'iead:

tims 1.-ie_ad

the

optinum point

which

is equal

to ihe

own clos-ri.r-e

+;-^ ^f +L^ --,.:+^L

!I49

L,l

tllrt

Dh.lL,tJlt

The

frequency

at wbich

the

FCR relay

drops

out

its arnature

(control

of

the

ctrop-out

trequeuc-v)

is

controlied

by chauging

the

vaiues

of

resistors

J9

and 24

Lo

27.

tfe-

capacitance

of

eapacitor

L6

and

the val.ue

of

resistor

40

connected.

in

paraliel

with

the

coil

of reia1,

T arc seiected

so tbat the

decrease of

the

magDetic

Fig.

?-5.

Diagram expiaining

joint

o_peration

of

lead

and frequency

contro

relays

tlead-

optimum

lead

time;

m

-

moment

s'hen

trequenc1. control

rela-r'

piclis

up

flux

in the

magnetic

circuit

of

relay

7 to a

tahle

at

which the

relay armature

dropj^out under-

the

action

of its spring takes

place

at a beat

frequency

l,

(

<

(0.2

to

0.3)

Hz.

'elay

drops-out..first

(at

point

mr)

and

ue

swrl,ch

closes-

ie-s

being

s1-nchronized

j-s

performcd

bv

oltage

of phases

C.

and

Cr'is

applied

tb

re

potent.iometer

and

pirase

.B

common

to

voltage

transformers,

instaljed

from the

(7-1

1

)

un,

/l

3r/

rLK

a\

(,

un,

9

,)

$,-)--

---'

"ry

I

\t/

\i-/

(')

fI

,A,

Fig.

7-6.

Diagram

e-rpiaining

operation

(o)

u":

us,

6:

o;

",::jtiT.r:i"j

ur-

aA"c

oI rclar-used

s1'ncb

ron

ized

18C"; (c)

U^

>

1 8C.

to

control

coincidence

of

L,g,

d:0;

C-

U")

Ugt

via

resistors

29,30

and

Jl

Lo

9.

Capacitor

l7

is

connected

in

series

rn'ith

it.

Capacitan-

8

drops

out

its

armiture

at

the

armature

drop-out

cur-

Fig.- 7-5,

it

is the Iead

relay

that

drops

out

first

leadinf tne

optimum

poinf

by the time

lr..r.

The frequencv

control

relav havins a drJn-out sitting selbcted

ec

r-\

urJUar

ln

\:alue

and phase

to

tbe

voltage

of

the,,incoming

generaLot[ig,

then,

as

seen

from

Fig.

i-d,1he

""ri'"i,.rrl,ticn

s,iil

iia'e

th? iortage

- Th"

drop-out

voltage

U6-o

determined

by

(7-11)

is

dictated

by the condition

oj

th,e

joint

operation

of

the

frequency

contlol relay

and the

leid relay. If the

lljn

fle_queney

is

greater

thau

the

specified

frequenc5'

l,

p

then,

as

seen from

!y

(Z-ff)

is_the

second to

drop

out

(at

point

rnr).

The connection

circuit

of

the

lea.d relay.L.R

and

the

fuequbncy

contlol

relay

FCR is

so

designed that t.]re

shou'r

in

Fie'

i-6

are-di;;ili;#"iri"e

itre

ooeration

of

the

relay

con-

trolling

the

coincicjence

of

tEa.'ollages

heing Srnehrnnirpd Tf rho i!^l{^,^

Lrurrrrrg

rne

corncldence

of

the

vol.t,ages

h.eing

s1'nchronized.

If

tt.

i;"iirg,

,t;'".tt

jj:.:]-tl:t*:

"n-d,phTe

to.tt

E-oo.rffi

oi'

rrr"

incoming generator

u".

oh.rg,

Ji

:

proportionaiitl.

factor

u

ptt:

phase

voltage

-switch

cannot

be

closed

iu this

case.

If the

slip irequency

is less

tlan

the

speci-

CHAPTER

SEVE}i

RAPID

PARALI,ELING

OF

ST,I{CERONOUS

GENERA"ORS

0

degrees

apart,

the

voltage

to

the

VCR

of

the

armature,

i.

e.,

operation

of

the

es to

180

degrees.

tfe.r

({.

}

U

g),

then,

when

the

vectors

:i

de,

they

coriespond

to

Fig.

7_6c

al.d-i

rr , f V3

U

p

vcl:

fr

L

ff

(U

nn.

,-

(J

ph.

,)

+{5U

ro.

,1

OI

225

U

n

rrr:

k

VTt

(U

on.

,

*U

pn.

s)

ar

Whg.o

the

angle

d

reaches

lg0

degrees,

the

coil

of the

LIre

volEage

U

p

vcn:

n

l/r3

(U

pn.

,

-U

pn.

s)

L,U

:

{,i

7,h,.c-,,Li_pn.

e

.

T!"

voltage

applied

to

the

VCR

relav

when

anele

6

:

Ig0 deor

nained

i,l'

tfiE-aifurr*.r-n;];;r;

the

vorrag".

rrlo?t;;tt;f;iles

is

deter-

*;lf:':Tl",.ll?"":lT 14{

resulrs

in

breaking

the

circuir

of

the

relay

ZAR

* urlo^T",

I::,l"lI _th,"

rT;i

t.h

i;;lffi

;":iH#:

Ilj

;"T,,"11

:l:nt

":.

Llf:tji3g :ilt].ii :qliift .r3 a-

r

b{

th

e

c

on

ra

ct

z

A R

_

z

.

Thi;l;;;ffi

rJ'uvrues

Dvpassms

of

t_he

conract

144-3

by

the

conract

2AR_2.

arrer

operarion

"i?H:j":T;.Ti*r""::lg.i4x

U4

t;e,idn

in,

""J,

b,ct

FCR_I

ffffi

'ffi

iiilil":Jg

j,:*'*#"q+1"i:i.i;it'"'S:ifr'#ffi

ffi i'['i:;{

ritate

operation

or ;d

"",it"'i..'fh:Til#ir'ir

lfri

trt'#t?:#

l;""H:l"li"iT;

p-sp

rs

determined

by

cu*ve

e

in

fig.

7-8

whose

equation

re

voltage

(7

-13)

VCR rol^r; u'ill I"^-'^

,!

rrr

uq

YE

(i

-14)

(i-15)

contacts

LR-Z

and

FC.R_p.

The

relav

contacts

IAR-I

and

IAR_Z.

Simultane-

prepares

the-circuit

for

operation

of the

tion-s

after

the

rela_v

IzCfi

has

attracted

I/CR-Z,

the

conraits

LR_t

and

FCR-_I

Tbe

control

relay

zAR

must

oqgr.ate-

only

whel

th"

freq-uency-contror

rera5,

{:rf

drops

out

its

iontacr

before

it

is

a"opi"a

out

by the

i;;;-;."i;y

rft

(Fig.

-"1F.-^,:1

V_o-ltige

1.._"-r.

coiis

of

reiays

p.'.R

and

f.A.R

(see

iie.

t_2,)

wnen

Yectors

u

a."

""t"ru#,i:l':*";

,i|1;i".-:H""*iL!,

"*r"r

rirr

by

60

:;," -"{r

i.s

zero

(Fig-

f:zi.Tn,"firi"gr'i,

#i?:'Jfi;"#ffh:l

,'ff;:iL::

U

nt

and

Ut"

At@

180 rlcorooc on6h+ r-\^-- ,.

i

the

svritch

which

is

closed-when

the

sq,itch

isopened..

enr

device

include-q

two

,Iit;i;i*"p'.?

;;;ifllft

,s's[7-5].

tbe

relay

FAR

is

to

.the

voltage-

flre,n:

lene.rator

side;

U".-

ii-

the

'

-and

adjustment

resistor

phase

C

voltage

from

the

i

to

the.coils

of

relays

lAR

and

.F,S,R

from

the

in_

rers

of

the

circuit

and

*r;;;;toi-iir"

secondary

instrument

transformers

are

interconnected.

.

WL.l

the

vectors

IJ

oo

and.

i

relayj

rsn"i.

#o

(Fio

z-zr

.n"^tj:,ll!

F-

pf".:",

the.voltage

on

the

coil

of

|

5-207t1

Afl

qr7

6

ert-zFs.R

-

LU

t

ph

Srn

t

226

CHAPTER

SEVEN

No

voltag.e

wiII

be

appiied to

the

coi] of

relay

FAR if

the

vector

L;3,

ieads

tbe

vector

IJ

o,

by

60 degrees.

Depending

on

the

angle

6 the

r,oltage AfJro^

is determined b5

the

sine

cunie

whose eguatian is

LUFA.R:

2(r,rn l"

(3=q

)

f

7-r7)

The

voltages

appiied t.o the

relays

FAR

and FSfi

\'ersus

the angle

6 are

shown

in

Fie. 7-8.

The

angle 0

is

positive

u,hen

the speed

of

the

incoming

generator is

greater

than the

speed

of

the

generators

of

the

power s-vstem.

The

pickup

settings

of

the reiays

FSfi

and FAR

are

the same.

If

the

speed

of

tlie incoming

generator is

iess tltan

the

speed ol

the

po$'er

s-vstem

generators

the

relal

FAR operates

/irsl

in

each beat

cycie.

In

this

ca-.e

the contact

FAR-L

breaks

tiie

cir-

cuit of relal'

^FS.R and

a

controi

pulse

"more"

is sent

bi'

the

contact

FAR-4

oter

the

circuit

FAR-4

-

FSR4.

If

the

speed

of

the

incoming

gene-

rator

is

greater

than.

that

of

tire

po\^'er

system

generators. the

relal'

.F-SR

ll'ill

operate

f-irsi.,

thus

opening

*.he

coni,aci

,FS.R-l'

'and

closing

the

corrtacL

FSR-3.

In

thi-"

instance

tire

relay

FAR

is

rende-

red

ineffectii'e

and

its contact

FAR-3

remains closed.

A

control

pulse

''less"

is fed

to the

speed control

mechani-"m

via the

circuit

FAR-3

-

FSR-3.

The

time relay

in

the

circuit

shorvn

in Fig.

7-2

iimits

the duration

of

con-

trol

pulse to

a certain

critical

value.

This

time is

set

to

0.2-0.3

-",

u'hich

promotes

equal duration

of

action

practically independent

of

tire slip frequen-

c1,

of

the

incoming

eenerator

rn'ith respect

to

the

power s-r'stem

generators.

Limitation

of

the

control

puise

duration

is

obtained

because

the

starting cir-

cuit

of

the

motor

actuating

tlie

turbine

speed control

mechanism

is

triggered

lia contacLs TR-?.

The coit

of

auxiliarl-rela5'

f.R

becomes energized

when

the

FSr?-2

or

FAR-Z

eontacts

close.

Ho$'ever,

at

the

first

instant

of

closure

the

coil

of rela-v

IR is

b1'passed b5 capaeil,or

19.

After

the

capacit.or

J9 is charged

the

reial'

?ft

fun-

ctions.

The

charging

time

of

the

capacitor

determines

the

pickup

time of relay

-600

00

60"

120"

tE?"

240"

3000

56Co

Fig.

?-8. Voltage across coils of

)

(

i,, \

:

FAR

(1\

and

F,SJ?

(2)

connected

as

jt,

Fig.

7-7 depentiing on

the angle

6

bet-

*'een

the

l'ector-c

of

voltages

being st,n-

,

chronized

RAPID

PARALLELING

OF

SYNCIIRONOUS

GEh,ERATORS

227

'

Resistor

37 is

used to

control

the voltag€

across

the

eoils

of rela1,

1"R and

cSpacitor

19

in

order

to

promo-te

the contr6l

of

the

tine

delaj

oireia5,

l -R

and

the

duration

of the

contrbl pulse

fed to

the

motor

rctu"ting

in"

.p"ea

cootrol

mechanism

of

the

turbine.

7-3.

Self-S1:nehronization

of Generators

Iaralieling

the

generators

by

the

self-synchronizing

method.

is

as

follows:

\4hile

yet

unexcited,

the

malhine

is

run

up

clo*"e

to"the

-*yo.h.ooous

speed.

.

Yh:f

the

slip

(Q_i.

within

:tB

per

cenr,

it,e

si"to"

":irai"J

Uecornes

ener_

gized.

Next,

the

AFD

device turns

on

the

excitation.

Under emergencl'

conditions

the

above-mentioned

amount

of

siip

may

be

somev'hat

exceeded'

In

_practice,

cases

have

been

noted,

when

self-s;nchiooi-

z-ation

s,'as

used

*n nrrollot rrr?l'^geiiei'ators

having

a siip

oi+20-per

eeni

anri

{'r-

il

fl I

IJJ

(')

ft.)

Fig.

z-9.

connection

of unexcited

svnchronous

aenerator

(a)

connectjon

diagram;

(b)

eguivalent

circuit

diagram

h-vdroelectric

generators

with

damling

coiis

ha'ing

a

slip

of

tl5

per

cent.

The

slip

is

positive,

if

the

speed

of thE

incomint

generator

is less

than

Lhe

speej-

of

the

po\^'er

system

generators.

The

slip values

at

u'hich the

stator

winding

is

connected

to

the

power

svs-

tem

voltage

are

usuali-v

dependent

on

the

r..ei&"tion

of the

incoming

machine.

Tbe

higher

tbe

acceleiation,

tlie

greater

tiru-positile

slip

at-wnrcii

the

conne-

ctio.n.

may

be

p-erformed-

When

ionnecting

tl. generatbrs

b_v the

self-synch-

ronizing

method,

tbe

time

taken

b]'the

iransi.;i

p;;."*""=-'Ao.r

not

exceed

2s.

n=f(s)

TR.

When

functioning,

the

relay fft

breaks

the

eircuit

of capacitor

/9

with

TR-z

to

discharge

the

capacitor

and

make

the

relay ready

for

the

pera-

FAR-2

tion.

The

relay

IR

remains closed until

the

reiav contacts

^F,S.R-Z

or

are

closed, i.

e.,

the

relay

I.R

functions

every beat

c-vcle.

.228

CEAPTER

SEVEIi

RAPID

PARALI/ELII{C

OT'

SYNCERONOUS

GENERATON,S

rents

decrease

with

resul.tios

reduction

in

their

demagnetizing

effect.

The

reactance

c.n

of the

equivalent

circuit

increases.

The

equivalent

inductive

rea-

ctance

of

the generator

risqs.

AJter the

free

current

in the

damping

coil

of

the

rotor

has decayed.,

the

equivaient

inductive

reactance

of

the

macLine

is

roughiy

assesssd

by t[e

du"a-

rature-axis

transient

reaotance

r' o

The

free

current

in the

statoi

winding,

an aperiodic

current

caused

by

it

ia

the

rotor loops,

and

the

free_

current

in the

dainping

coil

ciecay

within

0.04

uc=E

U

=Ut,

Fig.

7

-10.

Calculating

ci

rcui

t

gency

conditions.

It

is

terminals

of

an

excited

to

0.06

s, so

that

the

geateit

operating

vaiue

of

the

stator

current,

when

connecting

aD

unezcf,ted.

genera-

tor

to the

iine

voltage

U"

may

be determined

by

the

expression

7'

a"

I

con.

s:

:-?

&d-T

&E

u;ho.o - ic fha

qrrcfam

rnoafo^^^

v'4vtv

&5

tr

vuv

ueruvglg

lgqvuquuE.

Whether

a generator

is

permitted

to

be

connecled

by the

self-synchronizing

method

depends

on the

value

of

f'"on.,

calculated with

the

aid

of

(7-i8).

If this

value

does

not

exceed

the

3.S-fold

value

of the

generator

rated

current,

no limitations

are

laid down

on

the

use

of

the

self-synchronizing

method

for

conn-

ecting the

machine

f,o:the

po**r

iystem

uncier

emer-

taken

into

account,

that with

a

chort

circuit

at

the

generator

the

current

flowing

in

the

stator

winding

is

(7.18)

i:".,

1',..

is alwayi

greater

than 1i^,." aud the

-gene.aio"s

"."

*'loitt in"i

I

r-oey

must

withstaod

short

circuits

at the

iermiDals

aDd itr tbe

extertral

circuit. I

- ,coaneotiog

the

gsrerators

bv

tbe

self-svnchron.lziog

pethod

"t*"j', "riiiti

i --.-91-T?_-T.-Iic.

7-!1

8re

claracreristic

oscillogrs.s

illustrarilg

the

seu-

a

d€ctease

itr the voltage

across

tbe terminals aad

in the

line couuecting

the

I

syl]chrouizstioD

process,

ramely

cbarc-es_iu_rhe

teiltiral-i:Ji"ga'ii

tir"

g"o*

:]"tTi%"T-"fj'ii'll,l\''""}ii.,xlil?Liagsyncbronized1,h"bu.b""uoI'"g"liiJ!1,.i'"1T',iJ;'JL"i1?.#.o.,11ror''curlentintine'Thecoi-e

1,.,:

*

(7.1g)

'e

\"Lvt

I

Fic'

rt

1,:-,of-tlL"-qt:T,-ot.,ptoce!s

ot cohecti'g

r turbogebe'rot

to

atro1ber

where-t,

is the d.esign

inductive

reactatrce oI

the

gelerator

lor tbe

givetr

tim€,

I

one

equal

i! rrtiog

!v t'b'e

t"tt-n,"hio-iiiil]6

;;ffi';;'#:1;p:j1"fi

U5

in Fig.

?-10)

can bi aea.iioea

",

touoi"

"

i un ll"t:.,:f'"rtfl:*:^;::t1,."^q:-r.!tt

rhe.

voltage

abiuptly

dropped

to

about

Ri*8

verDor,

the

excess

torsu

uu:L)"-

tex,

(7-zo')

I

,tgfiff'*,"t

lor:.""1i1,:*":"::l"h"f"'fj"i9iiiil.1;;5:'i."ff:ti:JidTJ:

os t'he

other

hand, like

in

(?-18)

for saoh

point

of time

i

,"#: ttt::il..:,1h^",.

si1"i{1;;'!ig

"l'"coromsm

arter

excitarion

tras

been

r,:.-o--e,-

u.z,)

i

:'":ilihi:.F:i:'i"liiidl.,"",**,1";i*rflJ:i"tliru*rl',1"

*_l?;

developed

bv

the

turbine

-"rth

-tt"

eio;-d;il'ffi"

d:'H:*r,tf;

ff;ff:

fl:

l,:,:'Tii,.orpi:i-o:,.q.i:I^3r;o3a- .ri-:.;;;il."rsue

acceterates

rbe

senera_

d"-ry

rr-i,

th€.desisu

i.nductive

!-eacrance or

th€

sensrator.

,

a*"''ililr,***li:iliii#'i".,!1"ftr'it"J.T'*,i'*

1""";

,ll'"d

.#

It follows lF n

(7-2OI

epd

(?-tl)

rhai

-

i

ting nnft-

Ulder

tb;

eft€et

of

tb;

l;rurle

speed

o it

CIIAPTER

SEVEN

ield.

its

value

is given

by

?r:

&s&

.1o

5

where

E

d

,t:generator

emf

at

, ,r""al,l

rotor

current

t1 ,2\

\

t

-LO)

--^

Id- io

I'7"os:

Uf'-;-:- sin

26

(7-24)

where.ra

and

eq

are the

generator

direcl-axis

and

quadrature-axis

s),-nchro-

nou-c

inductive

reactances.

'

RAPID

PARA],I/ELING

OF

SYIICERONOUS

GENERATORS

231

Tire

reactionary

torque

is proportional

to

the

square

of

the

stator

terminal

voliage

and

'aries

in

time

wi[u

i

coubiec

slip

frequency

A

generator

is puited

in

svnchronisr

at

a

speed

beiow

the

synchrbnous

one

the

stator

u'inding

has

been

connected

to

the generator

speed

and

thus

makes

me-c

comparativel;-

small,

the

excitatior

cnronous

torque

arises

which

pulls

the

srving-s.

In

this

case

the

influence

of

tionurl'

torque

is.

insignificant,

z.

^-

The_

synchronili"f

process

is

considerabil,

*.Ttqa

by

the

adiustment

of

rhe.p""d;;;;;;;;.

2

\Yit!

h1'droelectriC

generators

having

"3

a^-p.,

t*'indings,

the

best

conditions

for

ieif-svodro-

2

nization

occur

*'hen

the

gate

apparatus

is

con_

stantly

.gpe.n.

in

this

casjthe

slip

must

b,

pori

t,

rrrle

ar

lne

instant

t.be

connection

to

the

circuit

is

performed

and-

the

excess

torque

at

an

-h;;_

t.

s5'nchronous

speed

musr

be within

O.f;

O.Z ;f

;h-

.I

rot

ed.

u

s maxrmulll : -,

:

7-4.

+ulo{-ragc

ConnectioD

of

Generaton

Whea

bydroelectric

gensrators

are furoished

wiih dampef wiodi!.gs,

the

i

ly

Se[-Slachronization

characierrstrc

oI asvrchmaous

iorque is

sonewhat

differeot irom tl::;|"\It

i - -l.-g^"vics:

Ior

auromirtic

conneciion

oi.

the

generators

by

serr-synchroni-

0.

i.

?

.l 4

%

The

actioo

of

asvnch.r'ooous

torque always

ad'ds to

putiine

the

seneralor

t

..

r.

FmDo

th6

tbutdown.trt€

by.lro_electric.

g€Dersron

brving

dabper

wiDdilgr

roay

be

io synchroaisn.

!

-

pu'6d

to

e

bvpolrvbcbno'ous

sDesd

urd-€r_tb_s

qtJ;t

"r

"i-i"i"-iiffoiii'riigo"

*o"o

,o"

"rr"

i

-

aplalrtus

is

clo*d.

The

rpeed_up

ume ol

a Dydrool€ctrjc

i€lsmtor

lj€3

qdthib

g

to

12 s,

CEAPTER

SEVEI{

RAPID

PARAUJqLING

OF

SYNCERONOUS

GENE.RATORS

?33

with

a

short

circuit

on

the

busbars

the generators

and the

lines

are

discon-

neoted.

The

ARc

device

connects

the

busiarr-i**

t[..y;;-ria..

If the

generators,

and

engine-powered

generE

starting

devices

from

the

cold

state

are

rating

unit

into

operation

needs

consj

However,

the

deviies

for

automatic

cr

chronization

may

be applied

at

therm

of

a

wa:sned

up

"machiirl

or toeether

v

after

a short-circuit

fault

on th-e

busba

ces are

operative.

A

freguencv-difference

ielav

or

a

speed

relay

i-q

used.

as

the

slip

indicator.

The

circuit

of tue

aetic;

i;;"l"matic

connection

of

penerarors

h' corr-o,,--

given,

the

relay ,S.R

closes

and

hold-s

ting

pulse

'nay

be sliort-time.

The

coijs

are

clo-"ed

by

the

contacts

Sfi-2

and

4

turns

on

the

turbine

starting

devic,e

it.

;ynchronou-"

speed

and the

slip

becomes

ference

reiav

(l

to

i.S

F,.z)

it ;,il]

make

ma-v

be accomplished

in

a pulse_like

a

pulse

pickup

rela1,

pJ?

which

irolds

cont,act

PR-?

breaks the

circuit

of

one

1eiay,

the

coil

being connected

to

the

The

contact

p:R-S

Eloses the

switch.

s

coil

is

deenergized.

iocLing

contaets

BC-Z

and

BC_4

close,

n.

The

contact

BC-I

opens

the

cireuii

reset.

device.

The

contact

BC-4

prepares

the

self-synchronization

device.

The

genera_

!rf,

tors

are

reconnected

one

after

inother

after

the

speed

has

decreased

to

, oulu"

suitable

f

or

self-str'nchronization.

it

shoujd

be

nored that

the tripped

generators

may

be

reconnected

also-by

the

precise

s-vncltronization

method

by

using i,he

ACT4

auiosynchronizer.

con_

L

sidered

in_

the

foregoing

section.

Given

belos'

is

a

typica]

circuit

of

a

-

The

starting

characteristic

of a

hydroelectric

generator

in this

case

is

un-

derstood

as

thJrelatijnship

beiween

speed

and time

from

the

instant

the

con-

trol

.signal

is

given.

This

iharacteristii

is

dererminld-;;

rt;

ffi;

of

turbine,

Figure

7-13

jLlustrates

t5rpical

-.tarii"g

-"Eu.u.tiirtim

of hydroelecrric

generators

for

different,

positions

of

the

tirbio"

rp..a-ili"rtid

mechanism

witll

the gate

apparatus

in

the

same.position.

Curv.

j

"or"eriooaiio

the

centre

reclosure

is

successful

and

the

busbar

r \.

voltage

is

recovered,

the

normal

circuit

t

/

tn

nf +ho hnst^, a*a*i^-

.l^

^--- r -r - -r .r

"n

_

of the

power

station

is

completed

after

connection

of

the

tripped

generators.

For

f

={

11

.

- ---rr--

vvru'

^

vl

tm-/n

?hrc llco frqv l-^ *^l^ ^f ^- ^--&--- -a!

s___1

__-v, gev

AqJ

uE

uarrl'

ur alll

duLu[IaLlc

generators

are

aost

often

started

against

the

centre

against

the

centre

characteristic

is

advisabie

if the

or lou,'er

accelera-

Hytiroelectric

curves.

Starting

position

of

the

turbipe

speed-adjusting

mechanis*,

loiii

PL'DrLrur'r

ur

LrIe

rurorne

spee0-adJustrng

mechanism,

initial

opening

of the

gate

apparatus

and

the

eharatteristic

of

t[e

speed

governor.

l^"?*::jj^lh: :l-r.:d-adjusting.r,,echanisp,

*1"" z,-tr"iir,

ffi;; ,od

,ur.,,

.?,

uu

VUIIC,

!1

,

::_:* :pqr_lt""itio.n. .Tire

r*Eit"tioo

is

blsi

"ppri"a

"t

io""r.i'=prra,

in

rhe

*vl'er

PUuururr'

ruu

c^cluaLlolr

rS

DeSl applled

at

IOWefgd

SpeedS

in

the

::fl:l:.:f_:,ql'::'l 19,1h'

-s-vnchronous

speed.

f"

tiri,

";*

;i;;ei'erating

unit

guicklv

pulis

in,synchronism

by increaiinf

itr

rp-"a

""i;;ili"";;frrilir

iir"

tr*i."Ea#i;:i,*;;.*ru8"ruff

#fft::.ff

;*-:,:-"i

The

reiay

p.R

becomes

! 1 - v

'*

iir"

Joriog

circuir

of

the

CH.A.ITER

SEVEN

RAPID

PARALLELING

OF

SYNCERONOUS

GENERATORS

switch

will

open,and

the

ci-osing

circuit

of

coil 1

of

rela;'

FDR

will

oe

prepared.

loading.requirements

and

set

b3, the

p

is

at f

ault,

the

stop

reiay

,St,R

functioui

rator

is tripped

manualiy

with

the

air

contact

2C

K-3)^o1

yher

lhe

output

prr

The]

reiay

Slft

holds

irself

with

thr

rg_c.ircuit.

The

contact

SIR_S

prepares

This

circuit

is

controiied

li

iUe'con_

t

the

opening

pulse

is given

after

the

-apparatu-s

occup_v

the

no-load

pcsition-

riernor

sGtrr

.

rhe

conra

cL

stR-i

*"k.."tf;X?fi:r3trll;"fr:Tir":r*:,tf;S"f;;

starts

to

close

the

gate

.apparat,us

until

op.t"tion

of

the

limit

su,itch

of

tbe

spee4-adjusting

geai

SAG-2.

rFL^

o tn i

ii",:

T

f .ffi

id"i#

?f E'il"Tr,T

:T.

the

sg'itch

is

opened

manua}ll,

bj,

cio

or

g'hen

opened-

bl,

the

proteciion

cont

generator

srvitch

closes

immediatelv

u,i

to

move

to

the

no-]cad

position.

Ajter

the

sn'itch

is

opened,

the

blocking

contact

B!^i

opens

the

.,opening,,

:i::lil.

"t

the

gate

gonirpJ

iriotor

and

th"e

conract

ic-r;i;;;"

rhe

''cl.osing',

tripped

(rhe

AFD-I

contact

bas

been

The

contacts

of the

speed

r-ela1,

,SpR

are placed

into the

circuit

iJ

the

star-

the

frequency-diff

erence

1",'/f;i:;{

devzces

stR

Pout

-2

stn-2

Speed

gyoyernor

molor

JOfr

5P-1

stP-4

sPR

t

!

rrr-,

sAE'z

8C_6

GCfr-/

r-.-.<

Bc

-)

GCn-Z

From

slarting

rclays

tro-tl

rcx-t

I'

s!

|

t

5P- |

sA7'I

l''ore

cc

-B

pT

BC-l

tDN-t

2cx-l

l^

_t

|

8c-3

Slorltnc

pulse

PtCttUP

atd.Totu

"r-f

t

r?gyencv-

dt'tfer"icp

Closinq

brea*fr

rl

ir

15K-2

2t

ll

toil II

of

ntazi

FDR

Coil

f

of rfui,

oPtn

rt

Rt

\\

c'\

q'F

\\

a\f

nzsm

o,[

t.tmi ter

BC

-6

ArD.2

-s:!,-!:!!:',=,

-..v

1.

vavq

s.9

o./

stop

relal'

'##+

--

::':-

Aii_J_..-)

ryrnzry

on

etcita.tion

L -

--

---

--

---r>

l''f{f

,'!;1

aDd

regutqt

t

on

from

busbar

yollace

trtnstlorme,7

Fig.

7-14.

Automatic

self_synchronizatjon

of

hydroelectric

generators

$Iter

the

switch

is

closed,

the

blocki

ting

rv

s

eug

ouql-

ting.

operation

is

accom-plished

against

the

iower

characleristic.

In

this

case

thg

iUmner./ i.c rornnwod Tha c^o^.t -^1^-.:^ ^r:---r,r r

l:ip:i l:.::::ved.

fhe

.,pgid

Tgr^I

i*

uai"rt.J'

to

* seffiing

of

85

ro

e5

lu'l_"?_ot^*]l:_'1r"9 :tg*d

and

the

iimit

,il;;;;i;h;

s;a;

i'r""aff"d

;;

8;

;;;';'"i"JfJ"ll',7

cha^rl

speed.

gate

controi

gear

compliance

iith

moves

until

the

limit

the

load

dictared

bv

switch

GCM-

the

automatic

operates,

this

is

set

in

CHAPTER

SE\|EN

7-5.

Speed

Control

Methods

With

the

circuits

for

automatic

,

rtian fhp rliffoo.-^o !,a+_.^^- _r-^ao:l:"tion

of

g-enerators

by seU_synchro_

li:i:,"T

"

*l:

^ TIr:l:: l. . I :ll _,.."

ii

.-

r,

;;;

qry

p

l'

fi

*ri'J'ffi

"

#;

#fi:l

:ff"T

fl"Xtit'%'ligt*i

jjo:-i'^:."1"i3":::ilidd;v*;;:.;;"1'ii5niJ""il-Tr"t"-

RAPID

PARALLELING

OF

SYNCERONOUS

GENERATORS

T*lrror""**"ry, *m_l^r":":^rl:li:d

byr.eans

of

eeutrif_ugal

relays

or

retrays

:lglll*""t',o*,"-*..^:.^T"lo;q139,"t*."1nuJ;"ir*Ti;;:.Lilf

!""#Jn"H

:l*::H:1H.f ul'.i'l^il::*sT.td,.t;;-iiipi,h*"ril1itu=["r"T',1i,lJ

respo_nd.ing-

to

the

a.c.

oonponeniof

the

rotor

,*i&rt.

y"tr"1,:l:"llj-'"^1.11^:f.

tlr^:oeea

to

ine;y;d;;;;

vatue,

the

rippie

cycie

::j,t- {j:::::::* _'H.:T1

in

tne

r.ot;;

;i,;;ir-i,"";;;;.

r#;rliJ,'#:f

,l"rli.l

;iljT_::T-:llrmer"is:*:j_'1$:fi.ra-,"ir-e.**illttit1T;"ilal"r'Xl,'i_

iil'J.'ili'f

ji,,Tf

jioe"'i::*,"":'.-1"j:::*:l*i:i{i$l':i'lf

iiff

'#ffj-

:,',:,**r.::#]';"':*i:

j::p+;;F;;;;;;i"

jil#;#..tlltl'f'*#i:

sured

via

voltage

regulato.J,

-rV

be

used.

;-;;

ffi

fJ

;"itri

iT'T"Jjil-

taincd hrr ahqnci-o +t ^ ^i+:*- ^- r

"1"r.ffi?:.:1."ri:,t,_rrti:"*-i1$'_:qur;rq"i

rera1,

ma,v_

be

connected

ro

the

vol_

tained

by

changing-the

seiting

""a

"l.ri'tidr.

tage

rrom

the

side

or

the

"":T:lr-l

E.?1;."C;^i.

,,r#].rli'r"i"l'i""'illTrlfj:

llf: H:1.t:iT."*:,:1h.,,"r ::lt,e.

i.-sJ,to;;;;inT""""f;',':;?Jiri:i

;:i:

Another

oossiu.i]1tv-

o,f

usiie

.{

$p.;tlJiJ*ployr}g

-a

variabre

componenr

of

the

curteit

in

the

rotor

cirEuit

is

shown

in

Fig.

7-16.

RectiJied

current

is

!il:

of

^tbe

tg]ll:

and

-rhe

fr.qu.i"l,1airi.ir""",

Excitatton

vindino

circuct

!

,

l?IlJ: ,:Ilr,

ge_u.

o{-

irr"ti"#"ii"il;1;i;il:

Excitation

circuit

of

the lino ic nnrninol

-p

sv&_rluqlr

I \ \ | E'nt fho ni-^,,.t+ -t rL - r'n?Y ^.

I

#

rig.

7-rb.'"ciii"i"tr"'."ill.r"TT;lld;'T;::

. ^lrJ) :|1 I 1a-l;_5;6'

to

_the;iotiage

tran-do.ry*-}

tn.

sene_

.rffiu

.31o,t

jl-

operaring

Jurrent

o1 tfr.

*it,

i.

SS=t

| -eJ -A

I I

-+15

mA

and

the

resista_nce

oi

tri,

"i1,

is

0.f

5

zsl

-iu

a-*1",

thT.

The.urt*f-io

the

circuit

of

coiisr

is

-

controiied

bv

a

rlieostat hnvin- +1,^ _^*^^ ^. .,

i

e,C

Ohr

Fig.

7-i5.

Connectjons

of

relav

a

current

ilpg_of

-

dual

vol

Fig.

7-16.

Connection

ol

slio

relay

I

-

c,urrent

translormer;

2

_

re*ti-

fr€ri o'

-

r€Ia]

coiis;

I

_

capiCitor

Fig.

T-fZ.

Circuits

of slip

coatrol

relay

(a)

delaTed^rtse-t_re].a.r

-c^?l-lryEl

tg

part

ol-

.iiischarging

(damp.

lng)

reslstoi;

(b)

r€Iay

connectei

to

additional_ch*ot<e

The

relav

in

the

circuit

shown

il-Fig.

7_t|b

is

connected.

in parallel

rr_ith

the

choke

wired

in

series-il;h'iil-e

discfi..g,

,rrirtor

of

tue

zutd wind.iug.

.Tle

hish.er

the

frequtoty

of

l[r;il;;;iii"gLrrenr

in

the

fierd coil cir-

s.ed

19

prevent

demagnetization

of

should

be

eorrected

ii

au,

ii-,

o"

txcitotion

circuit

ti,e

perm

";;"r

;;;r[

"ri;",:#r'!-ffr

iT

the

magnets

must

-1,

,"-"l"rtir"a.

y,_::lli,^,0_.1*i,,

the

vortag;

"il;,"ffif:##l:"":i{"!il:iiTllToi"",l}-,i.f;

a

value

corresponding

ro

thJ

reset

yql;.g;,;ffid;

"f

-tnr'".irfl

iu"

armarure

drops

out

and

the

contacts

carry

out

the

required

operations.

CEAPTER

SEVEN

RAPID

PARAILELING

OF

SlAICERONOUS

GENERA"ORS

239

7-6.

Asyn_chronous

Connection

of

Generators

and

Parts

of

power

System

If

an

excited

gelerator,

whose

emf

is

E,

(see

Fig.

?4),

is

connected

to

the

power

svstem

busbars

under

a-"vnchrorou3

conditi;";

;;

;d;iil'ioe

current

arises

at

the

instant

of

connectio"n

rLE

cs:

--;--

xdgi

z"

an

unes.cite

t

generatorJ.

LE -

ZE'i

sin'.|

-

2U

"sin

$

The

calculation

of

t.he

maximum

value

of

the

tor

cument

in

as!'nchronous

connpction

(/;".;

;;"

tion

that

Et

=

Er:

(i.0b

_

t.tf

i;r.:as.m,

Le

lcomp-are

with

(Z-iS)

for

When

Ee:

Ea:

U"

permissible

torgue

multinlicitv

are

carried

out through

thl

mui

gf^^thg

asynchronous

connection

rdu

degrees

relative

to

the

Do_

periodic

cornponent

of

sta_

performed

frpm

the

assump-

(7-25)

(7-26)

(i-27)

three-phase

short

circujt

at

the

(7-28)

In

;?Y:::l':-(';?jl

"'d

(T-26)

eu

-

vsvuL'r

uure'rerlce

Detween

tbe

emf

of

an

asynchronou-"1\,

connpoterl

generator,

afier

the

direcr-axis

(inrushl

,"p.rtril;;i

;;ffi;;i;:

reactanc.e^.':J.t-"g:

.Ef;,

and the

circuit

voltage

tJ;

'ir

:

direct-axis

supertra".ieni

(i;r;.h)

l;dirctive

reactance

rs

:

inductive

reaetance

oi

ihe'p;";'ri;;;

The

as-vnchronous

connection

current

is at

its

msaipum

when

the

gene_

rator

is

connect:9,.1+

opposition

to

the

emf

of

an

equivalent

generator

of the

power

s-v-stem.

\\l;11

asynchronous

coanection

to

an

infinite_pon,er

sS,stem

(s, :

0) iraving

angie

6

5i&"jrnr.*

r

,,r.

o

-

2(L'05-

t'1)

{!

Ph'

n

o-"-EF--

(7-29)

u'here

t

:

::ilicient

which

account-s

for

the

emf

vectors

being

igO

deerees

,ra

I

or,

,:

+!

*dg

The short-circuit

cunent

in

tbe

case

of a

generator

terminals

Dn

f

"ti

rs.c:--

,dE

Short-Circuit

poner

yersus

Sl,stem

Voltaqe

System

.

voltage

Un,

kV

b.bort-ctrcuit

power,Ssc.

I\.IYA

b1'stem.

voJtage

Ur,

kV

Upto6

J000

220

,Ct35

Js00

110

5000

nol,

exc

il:.'-iJ:i.:'*T,:?,i;;*:'J',,_'-i"H.i:;iJ,'?;:

l1ffi,,lm'j,.

,Xl

*i,,*..*";

fntTlAftna+ia f^--',i.:^ rL- J-

.

The

circular

rl-ej

draws

attention

to

the

fact

that

connection

of

the

lines,

derermined

ty

;r;Gi*g

"iiv

15,000

re

thaB

330

96 nrtn

sometim

es

asynchronous

the

above-teuched

upon

ro

m

a

g

n

e t

i

c

tor q

u

0

-i

s th

e

d

ec

i s

i

v

J

i

r.

tli"

o r

"i

;#"f##r"

"Hff

uXT'

t*".t'r:J:

CE.APTER

SEVEN

US

GENERATORS

synchronous

operation

rx,hich

should

be

rs

specilied

in

soecial

instructions.The

tronous

connection

current

multipiicity

s.ions prove_

to

be

gredter

than

the pei-

;ion-q

nust

be

made

to

take

into

account

rynchronous

connections

are

calculated

.

From

(i'2J)

it

is cleariy

seen

that

asyqchro-nous

connection

of

a

single

gene-

rator

to

infinite-power

busbars

cannoi

be aliowed.

when iz:

ti-F;;

;;;;,

for example,

the

ratio

of-

asynchronous

connection

current

relative

to

the

no-

minal value

is

greater

thau

17.

Asynchrooor.-"oonection

of

generators

per-

forming^

a

joint

operatiou

through

a

transformer

and

a

tran-smission

line,

into_^a'fiaite-power

system,

someii-es

may

be

permitted.

If

there

is

a

group-

ol-paralleied

geoer"torc,

ihro-

oGo

simultaneous

svn-

chronous

eonugr.tinn

of a]-I-tUe

ppnhil^.

nf +L^'-----,^-

--!-:+

:- ---;--;;i--'--

\r./p" strqtortr rirotr lrn n^-al+{^J h"iT":-:t-r"-l

tst*ur

Pra''u

or

part

or

rne

po-

*er

rJrvujj.

ildi

iru

ljoi.iiiiLrea.

'ine

as:\Aehronous

Conneot,ion

current

deter_

mined

by

(7-29)

should

be

apportioned

"*oog

the

parallei.a

g.r.t*tors.

When

making

caiculations

the

minimum

possible"

num|er

of muJniaei

should

be

considered-

(i.t-,

the

most

severe

caie

from

the

point

of vien,

of

the

current

value

used

in

asynchronous

connection).

I

---

s-vstem.

For

the

resynchronization

ca

ous

connection

is

permissible

measures

wanted

operation

of

various

protec,tion

(see

Sections

4-7 and

8-3).

ynchronous

connection

mav

sometimes

ds

located

near

the

electric

centre and

power

piants

out

of

synchronism.

The-

s'hich

asynchronous

connection

may

be

with

a

preliminary

analysi-s

to

see whe-

nizarion

or

the

parts

or

the power

,rfr$"t*:ffi::|iXf,

Ti$t:TJ.?r,:Tu:i1T;

protective

relaying.

241

synchronous

itself,

after

.

The

operation

f^oto.,.:

is

restored.

The

tl:

:."iid;

;;##;"itt

asvnchronous

laod

should

resrarr

by

i::ttlf^,giscusses.

the-

problems

of

a

n

d

th,

i"

-;;;;;#;,:;?,iiTr.,,?t

rf;

ff

,ls

l{j ilj" :

"

us

m

o tors

7-7.

Connection

of

SSrnchron!)us

Motors,

Prevenrinn

T"r.,

D;"pfffi

oi..st"p

and

Respchronizatio;

-

-"

"^

theS'

ari

p"tirJ

our

of

step.

:*i-"iT'Er"-"fri:tjr*t'i;f,x1..-:ilis.i?:,,,"r,uii*":_l,l:"r-_,1:":,,,

srar-

starting

a

shutdown

.roh^F^+:_-

s

t

a

r r

i

ng

a

s

hu

t

d

o

wo

e.o

*uJil*

.lj',

r-,lfr'i#'1",?j;

ru

H:

i

:t*l;

jj

r:ifi

(")

Yc

(a)*,r0"",t'.*.;'"-.',1;.r:il:i:f

".",,,1T"r,.;,"1,T,,:i

jJ,

jrlronous

.onrll8l.o"'tttdins

circuit;

(b)

rnotors

when

resistance

is

asynchron"",;;l:h,l,"J*':,Jff

l:;:t;dtr"l;Tt"#,:lX',:T,,'"-i*lf

T"tlll

guickly

the

normal

operation

of

tfe

loads,

including

inr-*l'*hronous

and

"

iiJf

"*

TiT::i#.

T

;fi

J'.[ff;i

*i

i

J I^

p

"l

i"

ilil|i'j

Jr:lT*","".,

:r"T

jJii:

t6-2076

Barzam A.B. Automation in Electrical Power Systems (Системная автоматика)

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