Bao ve va dieu khien cac he thong dien - Cao hoc.pdf

6/6/2014 Ging vin: TS. Nguyn Xun Tng

B mn H thng in

i hc Bch khoa H Ni

Email: [email protected]

BO V V IU KHIN H THNG IN

CC THUT TON IU KHIN& BO V TRONG RLE K THUT S

Nguyn Xun Tng - B mn H thng in HBK HN

Nguyen Xuan Tung Department of Electric Power System Hanoi University of Science and Technology

Copyright of Nguyen Xuan Tung

Department of Electric Power System Hanoi University of Science and Technology

Do not copy or distribute without permission of the author




Chng 01: BU & BI dng cho mc ch bo v rle

Chng 02: Cu trc rle k thut s

Chng 03: Bo v qu dng in dng rle k thut s

Chng 04: Bo v so lch dng rle k thut s

Chng 05: Bo v khong cch dng rle k thut s

Chng 06: Cc chc nng ph bin khc ca rle k thut s

Chng 07: nh v s c trn ng dy truyn ti in

2

cng









3

Qui nh v nh s chc nng bo v









4

Qui nh v nh s chc nng bo v

Chng 01

5

My bin p o lng(dng cho h thng rle bo v )









Tn gi chung: BI, CT, TI

Nhim v:

Bin i t l dng in s cp th cp (5A hoc 1 A)

Cch ly mch s cp v th cp

To s phi hp dng in gia cc pha

6

My bin dng in

BI cao p

S nguyn l

Is cp*ws cp = Ith cp*wth cpNguyn l hot ng

CT: Current Transformer (ting Anh)









S thay th

Sai s ca BI xut hin do tn ti ca dng t ha

in p xut hin pha th cp

Vth cp=Ith cp*(Zcun th cp+Zdy dn ph + Zthit b ni vo)

Ti tng Vth cp tng tng dng t ho Ie tng sai s ca BI

7

My bin dng in

Vth cp

Zcun th cp

BI l tng S thay th n gin ca BI









c tnh t ha ca BI

Quan h gia dng in t ha cn thit (Ie) sinh ra mt in p h mch V

im gp VK:

L mt im trn ng cong t ha

T : tng in p ln thm 10% cn tng dng t ha 50%

8

My bin dng in

in p im gp VK(Knee-point)

Vng lm vic tuyn tnh

Vng bo ha









Khai bo cc tnh ca my bin dng (rle s)

9

My bin dng in

im u sao v pha ng dy im u sao v pha thanh gp









Hin tng h mch th cp BI

Gy qu in p nguy him

10

My bin dng in

BI l tng

H mch

o H mch th cp: ton b dng s cp lm nhim v t ha li to Li t b bo hao T thng tn ra ngoi li thp









Hin tng h mch BI

Dng sng in p u ra ca BI khi h mch

11

My bin dng in









S thay th khi BI b bo ha

Dng khi tnh ton bo v so lch tng tr cao

Khi BI b bo ha:

Dng u vo tng cao

Dng u ra c dng xung nhn gi tr hiu dng rt nh

Nh vy: c th coi l c dng u vo BI nhng khng c dng ura dng u vo khp mch qua nhnh t ha tng ngvi vic tng tr nhnh t ha gim rt thp, coi nh xp x bng 0

12

My bin dng in

BI l tng

X=0

Zs cp Zth cp










So snh BI dng cho o lng bo v rle

13

Thng s ca my bin dng in

Hng mc so snh BI dng cho o lng BI dng cho bo v rle

Phm vi hot ng chnh xc

(0,051,2)x Inh mc (o dng ti bnh thng hoc qu ti cho php)

ti (10-20-30)x Inh mc (m bo o c dng s c)

Li t Bo ha nhanh bo v cc dng c o khi s c, dng intng cao

in p bo ha cao hn (VK)(kh b bo ha)

chnh xc chnh xc cao 0.2 hoc 0.5 vi chun IEC 0.15 hoc 0.3 hoc 0.6 vi

chun IEEE

chnh cc thp hn 5P hoc 10P theo chun IEC

Thit b ni ti kW, KVar, A, kWh, kVArh

Rle, b ghi s c

La chn cp 5P hay 10P ty thuc loi bo v

Bo v so lch 5P

Bo v qu dng in 10P









BI cho bo v rle

Cng sut nh mc

Cp chnh xc

C thm thng s ALF: h s gii hn dng in theo chnh xc

14

V d thng s ca my bin dng in

5P20 30VA

Cp chnh xc 5P

P: dng cho mc ch bo v rle

(Protection) H s gii hn dng: 20Ti 20 ln dng nh mc, BI vn m bo sai s theo tiu chun

Cng sut nh mc 30VA

BI cho o lng

Cng sut nh mc

Cp chnh xc

30VA Cp chnh xc 0,5

Cp chnh xc 0,5

Cng sut nh mc 30VA









Dng cho mc ch c bit

Bo v so lch thanh gp C rt nhiu BI

Cc BI phi c cng c tnh lm vic gim dng khng cn bng

Bin dng cp X: thng s c cho chi tit hn

Dng nh mc

T s bin

in p im gp VKDng in kch t ng vi in p im gp

in tr ln nht cho php pha mch nh th

15

My bin dng in cp X (hay PX theo IEC)









Thc t, mi BI c th c:

1 hoc 2 cun th cp - Mc ch o lng

2 ti 4 cun th cp - ng dng bo v rle.

16

Cc thit k ca my bin dng in

Cun s cp

Cc cun th cp









BI loi thng cha bn di (Dead tank)

Trng tm thp, n nh v mt c kh

C th ch to vi li t loi to m khnggy qu ti v mt c kh i vi s cchin

Dy s cp c chiu di ln nn gy phtnng nhiu hn hn ch v dng nnh nhit (ln nht 63kA/1 giy)

17










BI loi thng cha bn trn (Live tank)

Dy dn s cp ngn, gim pht nhit

C dng nh mc v dng n nh nhitcao hn

Trng tm cao hn, km n nh v mt ckh so vi loi thng cha di (dead tank)

Khi ch to vi li t ln c th gy titrng ln v mt c kh i vi s cchin.

Kh lm mt cc cun th cp

18










Nguyn l:

Dng 3 BI ring bit

Do s dng 3 BI ring bit nn s c sai s gia cc BI

ch bnh thng, pha s cp l i xng: lun c dng in chy quarle do sai s ca BI

Ch s dng o dng chm t ln dng mng in c dng chm t ln:mng in trung tnh ni t trc tip

19

o dng inth t khng (I0)

Ia

Ib

Ic

RoleIa Ib Ic 3I0+ + =

Role

3I0

V rt gn

Ia+Ib+Ic=3I0









Dng BI th t khng (Flux Summation CT hoc Core Balance CT) Bin dng c mt li t hnh xuyn

Cun dy c phn b u trn li

Dy dn s cp chy xuyn qua li t (ng knh trong 1025 cm)

20

u sai u ng

o dng inth t khng (I0)









BI th t khng

u ng: dy ni t v cp chy xuyn qua li t

21

My bin dng in

Rle

V kim loi ca cp

BI0









BI th t khng

Ngc li - u sai: dy ni t v cp khng chy xuyn qua li t

Dng in chy qua v cp c th trit tiu dng in s c (honton hoc mt phn): rle c th khng nhn c thng tin s c.

22

My bin dng in

Rle

V kim loi ca cp

BI0









u ni BI lc thnh phn TTK

ng dng ca BI th t khng Do ch s dng mt li t sai s o lng rt nh

S dng cho cc mng in c dng chm t nh (mng in c trung tnh cch in hoc ni t qua cun dp h quang)

Do c 3 pha chy qua li t ng knh li t ln kch thc BI ln thch hp trang b vi ng cp hoc u cc my pht in

23

My bin dng in









Nhim v

Bin i t l in p s cp sang in p th cp theo tiu chun(100V hoc 110V)

Cch ly mch s cp v cc thit b, ngi vn hnh bn th cp

Qui c cc tnh

Cc tnh cng tn c nh du : hnh sao, chm trn, chmvung...

Trn bn v: cc tnh cng tn v cnh nhau.

24

My bin in p









in p danh nh s cp v th cp

BU ngoi tri thng s dng in p pha: in p danh nh ca cun s cp l in p danh nh ca li in.

ng dng o lng: phm vi in p lm vic: 80120%

ng dng bo v rle: t 0.05 1.5 hoc 1.9 ln in p danh nh.

25

My bin in p (BU)









BU kiu t phn p

BU loi cm ng in t thng thng

La chn kinh t nht i vi cp in p ti 145kV

BU kiu t phn p (CVT Coupled Voltage Transformer)

La chn khi dng cp cao p

Thng c s dng kt hp vi h thng thng tin ti ba PLC

26

My bin in p (BU)

u cao p

in khng b

T phn

p Mch dp dao ng cng hng

BU cm ng thng thng

u ra

K{ hiu trn s









Cu trc BU kiu t phn p

1. Bnh gin du

2. Cc t phn p

5. in khng b

7. BU loi cm ng thng thng

(in p thp)

8. u cc cao p

27

My bin in p (BU)









BU kiu t phn p

in khng b: c tnh ton trit tiu thnh phn dungkhng ca t phn p

Tng tr ngun nhn t pha ti l xp x 0 cng sut u ra ly raln nht

B dch pha do t phn p gy ra

Mch gim dao ng cng hng: l in tr ti, c th ni cuntam gic h

28

My bin in p (BU) Tham kho









Cc loi BU

H s gii hn in p Vf

Khi xy ra s c trong HT: Upha c th tng ln ti mt gi tr l Vf lnUdanh nh.

Tiu chun IEC a ra cc gi tr h s Vf nh sau: 1.9 i vi cc h thng c trung tnh khng ni t trc tip

1.5 i vi cc h thng c trung tnh ni t trc tip

Li t ca cc bin in p khng c php bo ho khi in p tngti cp in p gii hn theo h s Vf.

29

My bin in p (BU)









Cp chnh xc theo tiu chun IEC 60044-2

Cng sut danh nh (cos=0,8)

10, 15, 25, 30, 50, 75, 100, 150, 200, 300, 400, 500 VA

30

My bin in p (BU)

Cp chnh

xc

Sai s gii hn

Ti % in p nh mc

Sai s ln %

Sai s gc pha(pht)

ng dng

Chun ha dng c o trong cng nghip

ng h o

Ti % ti nh mc

Phng th nghim

o m chnh xc

Bo v rle

Vf: H s gii hn in p

Bo v rle

o m tiu chun









S cp

Th cp

B lc in p TTK (U0)

Dng 3 BU loi mt pha

31

My bin in p (BU)









B lc in p TTK (U0)

Dng BU loi 3 pha 5 tr in p TTK ly ra t cun tam gic h

32

My bin in p (BU)

S cp

Thccp

3V0

A

B

C

A B C N

o c in p th t khng:o Phi c ng dn cho t thng TTKo Cn thm 2 tr (khng qun dy)o Trung tnh cun s cp phi ni t (nu khng s ch o c thnh phn hi bc 3)

Chng 02

33

Cu trc rle k thut s









a chc nng, cng sut tiu th nh

Tit kim chi ph

Gim thao tc u ni

Cho php lp trnh logic lin ng, tip im u ra, hin th

Lp trnh c tnh tc ng, nhiu b gi tr ci t

iu khin ti ch, gim st kt ni t xa

Kh nng t gim st

Thu thp d liu

Bn ghi s c

Bn ghi s kin

Thng s vn hnh

34

u im









Kh nng gim st kt ni

35

u im









Cu trc chung

36

Cu trc

Xem din gii chi tit ti liu gi km









V d vi rle SIEMENS

37

Cu trc









V d

38

Cu trcD

IGIT

AL I/O

Sta

tus Inputs

/ C

ontr

ol O

utp

uts

Digital I/O Analog I/O

AN

AL

OG

I/O

Analo

g T

ransducer

I/O

Communications

CO

MM

UN

ICA

TIO

NS

(Pro

tection)

CT Shorting

Clips

Field Wiring

Undisturbed

Module

Keying

D dng nng cp (plug & play)

Plug n Play

Easy Module

Draw-out

Chng 03

39

Bo v qu dng

Bo v qu dng c thi gian (51)

Bo v qu dng in ct nhanh (50)

Bo v qu dng kt hp kha v hm in p thp (51V)

Bo v qu dng c hng









Bo v qu dng (I> hoc 50 & 51):

Chng li cc dng s c qu dng mt pha, hai pha & ba pha v s cchm t.

Bo v khi ng khi:

Dng in ca mt pha, hai pha hoc c ba pha vt qu mt gi tr c ci t trc trong rle.

C th lm vic vi thi gian tr m bo tnh chn lc

Thi gian tr:

c lp so vi dng in (c tnh c lp)

Ph thuc vo dng in (c tnh ph thuc)

40

Bo v qu dng c thi gian









Bo v qu dng vi c tnh thi gian c lp:

Thi gian lm vic (tr) ca bo v khng ph thuc vo ln dngngn mch

41


+

Iqua rle

Thi gian lm vic

Ikhi ng

tlm vic khng i theo dng in









Bo v qu dng vi c tnh thi gian ph thuc:

Thi gian lm vic: ph thuc t l nghch vo ln ca dng in ngn mch

Trong thc t th thi gian tc ng t l vi t s Ingn mch/ Ikhi ng

42










Bo v qu dng vi c tnh thi gian ph thuc

43

V d









c tnh ca rle s

C cc c tnh chun ha

Cho php t thit lp c tnh (custom)

44










Phm vi s dng ca cc c tnh

Standard Inverse (SI): s dng trong hu ht cc trng hp cn phigia cc bo v

Very Inverse (VI): c tnh rt dc thch hp s dng khi ln dngin s c dc ng dy cn bo v thay i mnh.

Extremely Inverse (EI): thi gian tc ng t l nghch vi bnh phngca dng in.

ng dy mang cc ti c dng khi ng t bin thi im uv d nh t lnh, my bm, ng c ln...

Phi hp vi cc cu ch hoc cc thit b t ng li.

45

La chn c tnh lm vic









S logic ca bo v qu dng c thi gian

46










Nguyn tc: m bo tnh chn lc bng phn cp dng in

S c ti phn on no: ch bo v ti c php khi ng

Cc bo v khng cn phi hp thi gian

Thi gian tc ng t xp x 0 giy (thng t 5080ms) tn gi:bo v qu dng ct nhanh (50 hay I>>)

Do cch chn lc bng dng in dng in khi ng tnh theo:

Ik=Kat*Ingn mch ngoi vng max (H s Kat=1,11,2)

Khng bo v c ton b i tng khng s dng lm bo vchnh

47

Bo v qu dng ct nhanh (50 hay I>>)









Vng c bo v ct nhanh

Ik=Kat*Ingn mch ngoi vng max (H s Kat=1,11,2)

Dng ngn mch gim dn khi im ngn mch i xa ngun

ln dng ngn mch ph thuc vo ch ca h thng

V ng cong biu din dng ngn mch Inmax & Inmin dc ng dy

48


L(km)

I> I>1 2

IN

Inmax

Inmax

Ik BV1

Ik BV2

Lct nhanh min

Lct nhanh max

Lct nhanh min=0

Lct nhanh max









S logic

49










c im

Chc nng bo v qu dng ct nhanh I>> S dng gi tr hiu dng (RMS) ca dng in

Chc nng bo v qu dng ct nhanh tc cao I>>> (bo v qu dng cp 3 - high speed stage)

Mt s rle trang b thm chc nng ny

S dng gi tr dng in tc thi gim thi gian lm vic ca bo v.

50










Tn gi khc 51V

L do s dng

S dng thm khu phn bit gia s c v qu ti bng in p(kha in p thp)

Khi s c: in p gim thp hn

Khi qu ti (nng): in p vn nm trong ngng cho php

51

Bo v qu dng c kha in p thp (51&27)

ng dy di

Mang ti nng

Dng ngn mch cui

ng dy nh

Dng khi ng

ca bo v ln

Bo v khng

nhy

Kat* Kmm*Ilv maxKtv

Ik=









Phn bit hai loi bo v

Bo v qu dng kt hp vi kha in p thp

51 & 27= Voltage Controlled Overcurrent

Bo v qu dng kt hp hm in p (51V)

Voltage-Restraint Overcurrent

T ng iu chnh gi tr dng khi ng theo in p

Khi in p gim dng khi ng c t ng gim i

52

Bo v qu dng c kha in p thp (51&27)

Chc nng ny s kha khi mt in p nh th









L do s dng

Cc phn t ca bo v qu dng c hng

S u ni phn t nh hng cng sut

La chn gc c tnh ca phn t nh hng

53

Bo v qu dng c hng (67)









Xt li in cp ngun t hai pha

S c xy ra ti N1: c th BV3 & BV2 khi ng m bo chn lc: yu cu BV3 tc ng trc BV2 phi t tBV3 5I>4 I>6I> 3I>2HT1 HT2

N1

I> 1 I> 5I>4 I>6I> 3I>2HT1 HT2

N2

tBV3tBV2









55

Bo v qu dng c hng (67) - S cn thit

I> = I> + W

I>

+

-

Gii php: s dng bo v qu dng loi c nh hng

Bo v qa dng c hng ch tc ng khi:

Dng in chy qua bo v theo hng qui nh (hng dng -thng qui c t thanh gp ng dy)

Dng in vt qua gi tr khi ng ca bo v

Vy: bo v qu dng c hng l

Bo v qu dng + B nh hng cng sut

B nh hng cng sut:

Thnh phn tham chiu

Thnh phn cn xc nh hng









S u ni b nh hng cng sut:

c u ni m bo Rle c nhy v tc ng ng trong mi

trng hp.

S u ni tiu chun i vi rle s S 900

i lng lm gc tham chiu: in p

Chi tit phng thc u ni: Dng in t mt pha

in p dy ca hai pha cn li

56


Gi thit cos=1 hay =00 in p tham chiu v dng in to vi nhau gc 900 tn gi ca s









L do chn in p l i lng tham chiu:

Khi xy ra s c ba pha: in p gim thp, nu s dng in p phath rle nh hng c th khng nhy, s dng in p dys tng c gi tr in p a vo rle.

Khi xy ra s c pha-pha v d gia pha 1 & 2: in p U12 c th rtthp (c th bng 0 nu s c gn bo v) rle nh hng khng nhy, trong khi in p U23 vn cn ln phi s dngin p dy vi pha khng s c cn li lm in p tham chiu.

57


Chng 04

58

Bo v so lch dng in

Bo v so lch dng in c hm

La chn h s hm

Ni t BI

Bo v chng chm t hn ch (87N)

Bo v so lch tng tr cao (87H)









Thit b

So snh tng dng in i vo & i ra ca i tng c bo v: tng dng in ny khc 0 bo v tc ng.

Ch bnh thng:

Dng in chy qua rle nh hnh v

Dng chy qua rle: l dng chnh lch do sai s ca BI cc pha

59

Nguyn l

Bnh thng

Irle= +









Ch s c ngoi vng:

Dng in l dng s c c gi tr ln sai s BI ln hn

Phn b dng in tng t ch bnh thng

Dng in chy qua rle s ln chnh nh rle khng tc ng dng khi ng ln, gim nhy

Vng bo v: gii hn bi v tr t cc BI

60

Nguyn l

S c ngoi

Thit b









Ch s c trong vng:

Dng in chy qua rle bng tng dng hai pha c gi tr ln rle s tc ng ngay

61

Nguyn l

S c trong vng

Thit b

Irle= +









Tng kt:

62

Nguyn l

Irle= +

S c trong

Thit b

Irle= +

S c ngoi

Irle= +

Bnh thng

Dng in chy qua rle l do sai s BI Dng in chy qua rle l tng dng s c









Bo v rle so lch thng thng cc rle c th tc ng nhm do:

Sai s ln ca cc BI khi ngn mch ngoi

Chuyn u p...

Bo v so lch c hm: hot ng da theo t hp ca hai loi dng in so lch (Isl) & hm (Ih):

S c ngoi vng: dng hm c gi tr ln dng so lch nh

S c trong vng: dng hm nh - Dng so lch ln.

63

Bo v so lch c hm









iu kin tc ng ca rle so lch c hm

Vi cc rle in c:

Rle c Lc hm lun khng i

Tnh ty bin km

Vi cc rle s Thc hin thut ton tng t

Mc hm thay i ty theo trng thi ca thit b

Linh ng vi cc trng thi vn hnh ca thit b

64

Bo v so lch c hm

Lc tc ng(do dng so lch gy ra) Lc hm(do dng hm gy ra)+ Lc hm l xo









Phn tch c tnh tc ng ca rle so lch c hm

Vi cc rle c

65

Bo v so lch c hm

Lc tc ng(do dng so lch gy ra) Lc hm(do dng hm gy ra)+ Lc hm l xo

Iso lch Khm*Ihm+ Ihm c nh (hng s)

y a*x+ b









Rle c: h s hm l c nh

Rle s: h s hm t ng thay i theo ch vn hnh

66

Bo v so lch c hm

c tnh lm vic ca rle bo v so lch- Loi in c -

c tnh lm vic ca rle bo v so lch- Loi s dng k thut s -

y a*x+ b

a b

c

d









T hp dng in hm v so lch trong cc rle k thut s

Dng in so lch: iso lch = i1(vo)-i2(ra)-i3(ra)

Dng in hm: Cch thc t hp thay i ty theo hng sn xut

67

Bo v so lch c hm

Trung bnh cng

TngnR iiiii ...321

nR iiiin

i ...1

321

Siemens

Areva

I1(vo) I2(ra)

I3(ra)









L do h s hm nn t thay i theo ch vn hnh

68

Bo v so lch c hm Rle s

Tng dng sai lch

Dng sai lch do BI

Dng sai lch do chuyn i u phn

p, khng ph hp t s BI

Dng t ha my bin p









Ni t BI

69

Vn ni t BI vi bo v so lch

Bo v so lch MF

Bo v so lch MBA

BI trunggian

BI trung gianRle c

Rle s









Ni t BI

70


Bo v so lch tng tr cao

Rle









Ni t BI

71


Bo v so lch tng tr cao









Bo v so lch c th tc ng nhm khi BI b bo ha

V d hin tng bo ha ca cc BI vi bo v thanh gp

72

Nguyn l{ bo v so lch tng tr cao (87H)

Vng bo v

S c trong vng bo v

Vng bo v

S c ngoi vng bo v

Bo ha









L do s dng 87H

Vi cc rle so lch tng tr thp: trng hp rle b bo ha honton th d rle c c trang b hm nhng vn c kh nng tcng nhm

Nguyn l lm vic ca bo v so lch tng tr cao m bo lmvic tin cy trong trng hp xu nht: BI b bo ha hon ton.

Vi BV thanh gp th hin tng bo ha BI cng d xy ra do: Ti ca cc BI khng ging nhau mt BI c dng s c tng chy qua v dng

s c ny s phn chia qua cc BI cn li.

Vi bo v REF hin tng xy ra tng t:

BI trung tnh v BI pha mang dng khc nhau trong ch s c mc bo ha khc nhau. D gp hin tng bo ha my bin dng

73











Dng khi tnh ton bo v so lch tng tr cao

Khi BI b bo ha:

Dng u vo tng cao

Dng u ra c dng xung nhn gi tr hiu dng rt nh

Nh vy: c th coi l c dng u vo BI nhng khng c dng ura dng u vo khp mch qua nhnh t ha tng ngvi vic tng tr nhnh t ha gim rt thp, coi nh xp x bng 0

74


BI l tng

X=0

Zs cp Zth cp










Xt s n gin: thanh gp ch gm hai ngn l

75


IBI1 BI2

Bo ha

IBI1L tng

Zs cp Zth cp

X>>0 X=0

Zs cpZth cp

BI2L tng

Gi tr rt ln(coi l h mch)

Gi tr xp x 0(ni tt)









Xt s n gin: thanh gp ch gm hai ngn l

76


IBI1L tng

Zs cp Zth cp Zs cpZth cp

BI2L tng

Nhnh song song

BI b bo ha: khng c dng th cp

BI cn li: dng cp ra khp mch qua rle v tng tr th cp BI b boha c dng qua rle rle s tc ng (tc ng sai)

Gii php: hn ch dng qua rle bng cch ghp ni tip mt in trc gi tr ln rle so lch tng tr cao

I

Zth cp Zth cp

R>>

Rle so lch tng tr cao









Cc yu t cn ch

Hiu chnh gc pha do t u dy my bin p

Loi b thnh phn dng in TTK

Hiu chnh t s bin dng

Hm theo sng hi Khi ng xung kch my bin p

Khi qu t thng li t

77

Bo v so lch cho my bin p (87T)

I

I1 I2









nh hng ca t u dy my bin p

MBA t u dy hai pha khc nhau dng in cc pha b lchgc nhau

T u dy Y0/-11 th dng s cp v th cp lch nhau 11x300=3300.

Nguyn l bo v so lch yu cu dng in hai pha cn so snhphi trng pha khi xy ra lch pha c dng cn bng chyqua bo v s tc ng nhm phi hiu chnh gc pha.

Rle s: hiu chnh gc pha c thc hin bng phn mm:

BI c th u hnh Y cho mi cun dy

Khai bo vo rle cc t du dy ca my bin p v my bin dng(nu cn thit).

78










V d xc nh vecto dng in theo t u dy (Y/-11)

79

V d









Loi b thnh phn dng in TTK

S c chm t ngoi vng

Nu khng loi b: tc ng nhm

80


Dng qua rle ln hn 0Rle c th tc ng nhm

BI trung gian khng c cun tam gic









Loi b thnh phn dng in TTK trong rle s

S dng nguyn l Ipha so lch = Ipha o I0

V d thut ton trong rle s

81


Dngpha oc

Dng so lch loi tr I0

Gii thch









Hiu chnh t s bin dng

Dng cn bng c th sinh ra khi:

BI cc pha c t s bin khc t s bin p

Hoc khi dng in th cp ca cc BI khng ging nhau

Rle s t ng tnh ton h s hiu chnh

82










Hm theo thnh phn sng hi

Chng hot ng nhm do dng t ha xung kch khi ng khng ti

ng my bin p khng ti

Khng c ti

ng in my bin p t mt pha

Khi ng khng ti:

Dng t ha xung kch chy vo t mt pha

Pha u ra khng ti: khng c dng in

Bo v so lch c th tc ng nhm

83


I1

I

I2










Cch x l dng t ha xung kch khi ng khng ti vi rle s

Dng t ha xung kch c dng mo sng, tt nhanh

Phn tch ph: c sng hi bc 2 ly lm tn hiu hm bo vso lch hm theo sng hi

84


Dng xung kch

in p

Phn tch ph

Bc c bn (50Hz)

Bc hai (100Hz)

Bc cao hn

Sng hi










L do chn thnh phn sng hi bc 2 hm bo v khi ng xungkch

ng my bin p khng ti (ng xung kch) Dng t ha xung kch: lun cha thnh phn 2nd

Dng s c: khng c 2nd & bc chn

Dng t ha xc lp: khng c sng hi bc chn.

Sng hi bc 2: c trng ring bit ca dng t ha xung kch sdng thnh phn sng hi bc 2 ny t ng hm bo v so lch khing khng ti my bin p.

85











Chng hot ng nhm khi MBA b qu t thng

Li my bin p b qu t thng

Dng in cc pha khng ging nhau

Khi MBA b qu t thng: dng in c cha thnh phn snghi bc 3th & 5th

Thnh phn bc 3: c th b loi bi cun tam gic dng thnh phn hi bc 5 kha tm thi chc nng bo v so lch

86










Vng hm b sung

pht hin tnh trng bo

ha my bin dng khi xy ra

ngn mch ngoi.

Hot ng

S c trong vng: Hin tng bo ha my bin

dng do s c trong vng bo v khng gy nh hng nhiu ti s lm vicca bo v 87T v mc bo ha ca BI cc pha l gn tng t nhau.

S c ngoi vng Cc BI c mc bo ha khc nhau: bo v c th tc ng nhm do dng so

lch rt ln

87










Vng hm b sung Chi tit

Khi bin dng b bo ha dng in u ra ch tn ti trong mt phn nh ca chu kz (c dng xung)

88


S c trong vng S c ngoi vng









Qu o ca im lm vic khi BI c/khng b bo ha

89


Khi BI bo ha

Khi BI l tng









Qu o ca im lm vic khi BI c/khng b bo ha

90


Khi BI bo ha

Khi BI l tng

S c ngoi & BI bo ha:

Thi im u: dng hm tng mnh

ng thi khi : cc BI cha bo ha dng so lch nh qi o ca im lm vic i theo on 0-1-2

Sau BI bt u b bo ha dng so lch tng dn

Dng hm gim mt cht: im lm vic di chuyn theo qu o 2-3 c th ri vo vng lm vic rle tc ng nhm.

S c trong vng:

im lm vic ngay lp tc ri vo trong vng tc ng

Rle c thm vng hm b sung: s pht hin hin tng bo ha BI khi thy im lm vic ri vo vng hm ny. Khi chc nng so lch s b tm thi kha li trnh tc ng nhm.









L do dng bo v so lch th t khng 87N

S c ti im gn trung tnh cun dy u hnh sao, trung tnh ni t: dngs c c th rt b (do in p gn trung tnh c gi tr nh)

Bo v qu dng TTK (50N & 51N):

C th khng nhy bo v cho cun dy my bin p

Bo v so lch:

C th khng nhy dng bo v so lch th t khng (87N)

Phm vi bo v: cc cun dy u sao, trung tnh ni t (phm vi bo v b hn ch).

91

Bo v so lch th t khng (87N)










V d v nh hng n nhy ca BVSL 87T

92


Dng in pha trong cun Y0

Dng in dy ca cun

Gi thit BVSL t ngngkhi ng l 20% (0,2In):

Khong 59% cun dykhng c bo v

bo v khong 80% cun dy ngng khi ng 2,3%In khng thc t










Xt dng in chy qua trung tnh cun dy Y0 ni t trc tip

Khi s c gn trung tnh (v d cch 10%) dng qua dy trung tnh In lun ln hn rtnhiu ln dng in pha Ip bo v ly dng in In s c nhy

93










Bo v so lch th t khng 87N

Phn b dng in khi s c trong/ngoi vng

Lun c dng qua dy trung tnh dng dng in ny nh i lng tcng

Cn c thnh phn hm:

Khi s c ngoi cc BI c th b bo ha vi mc khc nhau khi s c pha-pha

94


S c ngoi vng S c trong vng









Nguyn l thc hin chc nng 87N ca cc rle SEL

95


S c ngoivng

S c trongvng

S dng vic so snh hng ca tng dng ba pha

Dng tc ng: 3I0=Ia+Ib+Ic

So vi dng tham chiu: dng trung tnh In

Dng trun tnh c s dng v khng i hngvi c s c trong v ngoi

S c trong vng: dng tc ng v dng trung tnhcng pha

S c ngoi vng: dng tc ng v dng trung tnhngc pha 1800

a









Nguyn l thc hin chc nng 87N ca cc rle SIEMENS

96


T hp dng hm v tc ng

Dng tc ng: Itc ng=3In

Dng hm: Ihm=k*(|3In-3I0|-|3In+3I0|)

k: h s hm

Gi thit k=1

S c ngoi vng: 3In v 3I0 bng nhau, ngcpha


Dng hm: Ihm= (|3In-3I0|-|3In+3I0|)=2*|3In|

Rle s hm an ton

S c trong vng: dng cp ch t pha cun Y0 Ch c 3In cn 3I0=0


Dng hm: Ihm= (|3In-3I0|-|3In+3I0|)=0

Khng c hiu ng hm rle s tc ng vi nhy cao nht

S c trong vng: dng cp c t pha hthng (gi thit cng ln)


Dng hm:

Ihm= (|3In-3I0|-|3In+3I0|)= -2*|3In|

Dng hm m rle coi l bng khngKhng c hiu ng hm rle s tc ngvi nhy cao nht

S c ngoi, dng hm tnh ton da trn slch pha 1800 ca 3In v 3I0

Tuy nhin: BI b bo ha gc lch gim thphn 1800 lm gim ln dng hm

m bo rle khng tc ng nhm: khi gcgia dng tc ng v dng hm ln hn 1000

rle s b kha bt k dng tc ng









Cc vn cn quan tm

T hp tn hiu cho bo v so lch

c tnh tc ng ca bo v so lch ng dy thng dng

nh hng ca in dung ng dy

tr ng truyn tin

Bo v cc ng dy r nhnh

Bo v chng tt lo

97

Bo v so lch cho ng dy (87L)









ng dy c chiu di ln phi dng knh truyn gi tn hiu dng in gia cc pha.

98


ng dy 2 ngun cp

ng dy r nhnh

Knh truyn c th kt ni theo mch vng tng tnh d phng ng nt t









Hai loi bo v so lch dng in

99


ng dy cp in t mt pha

ct my ct u khng ngun cn truyn tn hiu ct t u i din









Phng thc trao i dng in

T hp dng in 3 pha theo t lmt tn hiu so snh cc tnhiu ny ca hai pha.

nhy b thay i

La chn t s theo tng iu

kin c th

Ly mu dng in ca c 3 pha chuyn thnh tn hiu schuyn n so snh cng vi u i din.

Knh truyn ch yu l cp quang (PLC khng m bo bng thng)

100


S dng nguyn l ny:Rle 7SD502

Bin dng tng hp tch hp trong rle

Ty theo yu cu v nhy i vi s cchm t th cch t hp dng in cth khc nhau









S tun hon dng in

Bnh thng: dng in chy tun hon qua knh truyn tin

c im: H mch knh truyn: tc ng nhm

Ngn mch knh truyn: kha, khng tc ng nhm

101


S dng nguyn l ny:Rle 7SD503 (Siemens)Khong cch ti 15km









S cn bng in p

Bnh thng: dng in khng chy qua knh truyn tin

c im: H mch knh truyn: kha, khng tc ng nhm

Ngn mch knh truyn: tc ng nhm

102


S dng nguyn l ny:Rle 7SD502/7SD600 (Siemens)Khong cch ti 15km









c tnh tc ng

Ch bnh thng, dng in so lch c th xut hin do:

Sai khc c tnh BI cc pha ng dy

Sai s do tr trn ng truyn (knh truyn tn hiu s)

Sai s do ly mu tn hiu

Dng in so lch v hm c t hp ty theo hng ch to, tuy nhin thng da theo nguyn tc chung

103


L: localR: Remote

iu kintc ng









c tnh lm vic ca mt s rle ph bin

104


P546 MiCOM









c tnh lm vic ca mt s rle ph bin

105

c tnh tc ng

LFCB









X l nh hng ca in dung ng dy

in dung ng dy lm dng in hai u ng dy khc nhau

ng dy truyn ti: c th b qua in dung ng dy

Cp in lc: in dung ln phi c bin php b Tng dng khi ng (c th p dng v ng cp thng c dng ngn mch ln)

B bng thut ton: ng cp thng t/khng trang b BU kh tnh ton b trongrle

106










V d: dng in dung ng dy c th sinh ra

107










108










Thut ton b in dung ng dy vi rle s

a thm: mt thnh phn m phng thnh phn dng in dung ny vo trong tnh ton dng so lch

Tr i: thnh phn ny t gi tr dng in o c

Dng in dung: tnh ton gn ng bng cch o in p ng dy v chia cho dung khng ca ng dy

109


Rle MiCOM









Thut ton b in dung ng dy vi rle s

Khi ng khng ti: c dng in dung t mt pha ng dy

Nu in p i xng v ng dy c o pha: ch c dng in dung TTT ch cn tng gi tr chnh nh cho phn t so lch pha

Nu ng dy khng o pha: cn thay i gi tr chnh nh c chophn t so lch TTK v TTN

Khi s c ngoi, khng i xng:

Thnh phn dng in dung nh hng ti tt c cc phn t so lchpha, so lch TTK, so lch TTN

Tuy nhin do dng hm lc ny ln nn nh hng ny c th b qua

110










X l vn tr ng truyn tin

Bo v dng dy dn ph

Vn hnh trong thi gian thc

Tn hiu tng t o lng ti cc u ng b v mt thi gian

Bo v dng knh truyn k thut s

Ly mu tn hiu

X l v gi qua knh truyn k thut s c tr

tr v mt thi gian th hin thnh mc dch pha ca tn hiu

111












Gii php: o v b tr ng truyn da theo c ch ping-pong Rle mt pha gi tn hiu Rle u kia nhn c v gi tr li

Xc nh tr ng truyn da theo thi gian t lc gi n lc nhn li tn hiu

112












Xc nh tr ng truyn theo nguyn tc ping-pong c chnh xc cao

Tuy nhin cn ch ti khng i xng ca knh truyn (Channel unsymmetry): Knh truyn thng c thit k vi knh d phng

Nu khng chnh nh ng: tn

Documents

Bao ve va dieu khien cac he thong dien - Cao hoc.pdf