UPS Nghich Luu

7/31/2019 UPS Nghich Luu

1/29

Nhim v thit k

1. Nhim v thit k.

Thit k b UPS phn nghch lu vi cc thng s sau:

in p ngun 220V, 50Hz (10%)

Cng sut 15kVA

Thi gian lu in 10 pht.

2. Ni dung:

- Tnh ton la chn cc thit b mch ng lc (dng Transitor IGBT)

- Thit k s iu khin van nghch lu.

3. Cc bn v:

- S nguyn l mch ng lc v mch iu khin.

- Cc biu thi gian.


2/29

n mn hc in t cng sut

- 1 -

Ti liu tham kho

1. PGS. TS. Nguyn Trng Thun - iu khin logic v ng dng - Nh

xut bn Khoa hc Kthut, H Ni 2000.

2. in t cng sut -Nguyn Bnh.

3. Vi mch v mch to sng - Tng Vn On.

4. Master Replacement Guide (ECG is ISO - 9002 register).


3/29


- 2 -

Chng i

Gii thiu v b ups

1. Gii thiu chung

Mt ngun in tt s m bo kh nng lm vic lin tc v c tin

cy cao c bit l i vi cc thit b, cc h tiu th in nhy cm nh: h

thng mng my tnh, cc i pht thanh, cc trm thng tin lin lc, h thng

chiu sng sn bay v cc h thng quan trng khc. i vi h thng nhy

cm vin ny, vic xy ra mt s c nh c th gy ra nhng thit hi lnv chnh tr v kinh t.

H thng lu in chuyn i tnh c thit k cung cp cho cc

thit b nhy cm mt in p n nh, lin tc, thot khi nhng nhiu lon

ng in nh s gin on in th tc thi

H thng lu in vi d tr nng lng trong pin (c quy) s tip tc

cung cp nng lng in cho ti trong mt khong thi gian, khong thi

gian ny thng cho ngi dng thc hin nhng hnh ng cn thit v

trnh nhng hu qu xu i vi thit b. V vy ngy nay UPS c mt trong

tt c cc h thng in.

ii. phn loi h thng lu in

* Nguyn l hot ng ca thit b lu in.

UPS l mt thit b ngun, c ngun u vo c ni vi li in,

u ra ni vi thit b tiu th in. Bn trong UPS c mt b c quy dng

d tr nng lng. Khi c in li n cp in thng t in li cho thit

b. Khi mt in li n s a in t c quy ln. Mc ch l cho hot

ng ca thit b in khng b gin on.

Cc khu chc nng ca UPS.- Chnh lu/np in


4/29


- 3 -

-Nghch lu

- c quy

Trong khun kh ti l Thit k phn nghch lu ca b UPSnn

em ch i su v phn ny.

Khi nghch lu: Cu to bi cc van in t (bng cc quy lut ng

m s to ra in p xoay chiu gn sin c tn s 50Hz) bin i ngun in

mt chu t c quy cung cp cho ti. UPS ny khi nghch lu c lp song

song vi li v khng tham gia vo bt k hot ng no khi li n nh.

Khi ngun xy ra s c mt in, th lc ny ti c ngt ra khi li

in v ni ti nghch lu bt u hot ng bin i in p mt chiu t c

quy sang xoay chiu cung cp cho ti.

iii. s cu trc ngun lu in d phng

Trong n ny nhim v thit k mt ngun cp in d phng hot

ng ch ch c kh nng cung cp mt cng sut thit k l 15kVA

m bo n nh dng in p trong thi gian gin on cp in khi

ngun in li b mt, in p ny l mc in p bnh thng ca mng

in 220V/50Hz dao ng 10%. Thi gian cp inc th duy tr c

trong khong 10 15 pht l khong thi gian cn thit khi ng my

pht d phng.

1. c quy.

L ni tch tr nng lng in mt chiu cung cp ngun cho bnghch lu khi mt ngun in li. Tham gia cp in ca b nghch lu do

dung lng ca c quy quyt nh.

2. B nghch lu.

Bin i in p mt chiu ly t ngun c quy thnh in p xoay

chiu 1 pha. B nghch lu c u song song vi li v ch hot ng khi

ngun vo chnh c s c.


5/29


- 4 -

3. B iu khin nghch lu.

C nhim v iu khin thi gian dn dng ca cc van trn b nghch

lu to ra din p xoay chiu c n nh cao cp cho ph ti.

4. Kho chuyn mch.

C chc nng ng hoc ct chuyn ch lm vic ca h thng

cung cp in p t ngun in li sang ngun in d phng lu in v

ngc li.


6/29


- 5 -

Chng ii

Thit k mch lc ca b lu in

i. thit k mch lc ca b nghch lu

I.1. La chn s nghch lu.

Trong cc b ngun lu in nghch lu thc hin chc nng chnh l

ly in t c quy cho thit b khi mt in ngun.

Ngi ta thng s dng mt trong hai b nghch lu l:+ Nghch lu ngun dng

+ Nghch lu ngun p.

Trong khun kh ti l thit k b nghch lu ngun p v phn

mch lc dng transistor IGBT nn chng ta s i su v phn ny.

Ngy nay, trong cc b lu in ngun ta thng s dng cc van bn

dn trong s nghch lu l transistor IGBT, bi n c nhiu tnh u vit

nh tc chuyn mch nhanh. Cng sut iu khin yu cu rt nh. Vic

s dng cc transistorIGBT lm n gin ng k vic thit k cc b bin

i v lm cho kch thc ca h thng iu khin ngy cng thu nh.

T yu cu ca ti ta chn s nghch lu l s nghch lu

mt pha ngun p dng transistor IGBT. Vi s ny ta c th nng cao

c cht lng in p u ra ca b nghch lu bng phng php iu

bin rng xung va iu khin c in p ra v vn gim nh c

nh hng ca sng hi.


7/29


- 6 -

I.2. S nghch lu 1 pha ngun p dng transistor IGBT.

II.1.3. Tnh chn van cho b nghch lu.

B nghch lu c thit k cung cp cho ti c cng sut ti a l

1,5kVA. Gi s hiu sut ca b nghch lu l 0,80 th cng sut vo b

nghch lu l.

3

1

S 15.10S VA 18750VA

0,80 0,80

Gi tr dng in phng ca c quy l:

(Do inp t c quy ti ta chn 240V)

1p ngS 18750vA

I I 78,5 AE 240vA

Dng in trung bnh qua van b nghch lu l:

tbv t

1I I sin tdt 51

2

T1d 1

T4d 4 T3d 3

T2d 2

UPh ti


8/29


- 7 -

in p mi van phi chu: CEU E 240 V

Chn h s an ton v dng cho van l: k1 = 1,4

H s an ton v in p cho van l: ku = ,12

Khi dng in trung bnh qua van ln nht l:

Ivmax = Itbv. 1,4 = 51 (A) x 1,4 = 71,4 (A)

in p t ln van ln nht l:

UCE =UCE. 1,2 = 240 . 1,2 = 288 (V)

Chn van transistor IGBT loi k hiu ECG3328 ca PHILIPS ch toc thng s nh sau:

Icmax UCEbh UCEmax uGEmax UCE ton toff IGE

80A 6V 400v 20V 80ns 400ns 1mA

Tnh chn diod cho b nghch lu.

Diod m cho b nghch lu phi chu c in p ngc bng gi tr

in p ln nht t ln mi van. Dng in m diot chu c cng bng

dng in ln nht chy qua van do Ungmax = 144V

Cn c vo cc thng s ca van ta chn loi diot l loi ECG6064 do

PHILIPS ch to c thng s nh sau:

Itb Ungmax U

85A 400V 0,7V


9/29


- 8 -

Chng iv

Thit k mch iu khin nghchlu.

i. gii thiu nguyn tc iu bin rng xung

in p xoay chiu c to ra t b nghch lu l in p khng c

dng hnh sin nh mong mun m ch c dng gn hnh sin ch nht hoc gn

nh ch nht c cha rt nhiu trng thi lm nh hng ncht lng in

p u ra cp cho ti.

iu mong mun l lm th no va iu chnh c in p ra m

vn gim nh c s hu ca cc sng hi bc thp.

lm c iu c rt nhiu bin php thc hin nh: s dng b

lc LC. Nh vy, trng lngv gi thnh ca thit b bin tn s cao. V

vy, phng php iu bin rng xung PWM Pulse Width Modulation

c th p ng c yu cu trn hiu qu nht.

iu bin rng xung c nguyn l c bn sau:

To mt sng dng hnh sin Umc gi l sng iu bin (xung mu)

c tn s ln hn nhiu tn s sng iu bin thng l bi ba (t 1 10Khz).

Dng mt khu so snh 2 tn hiu Um v Up, t cc giao im ca 2

sng ny ta xc nh c khong tc ng ca xung iu khin thyristor

hoc transistor cng sut (gc chuyn mch). Nu sng tam gic c tn s

cng ln th mn ca in p u ra cng cao, cht lng m bo bi theo

yu cu ca ph ti.

-iu bin rng xung n cc.

in p trn ti l mt chui xung, rng khc nhau, c tr s 0 v E


10/29


- 9 -

-iu bin rng xung lng cc.

in p ra trn ti l mt chui xung, rng khc nhau, c tr s E.

T s gia bin sng iu bin v bin sng mang, k hiu l M

c gi l h s iu bin.

Khi ta iu chnh ln Am cng chnh l iu chnh rng xung.

Khi M = 1 th in p ra ti c bin l ln nht v mun gim nh in p

ra th ta gim nh Am.

I.1. iu ch rng xung n cc 1 pha.

Transistor T1c kch m bi xung chm, trong na chu k dng

ca sng iu bin Up, cn transistor T4trong na chu k am ca Uv.

Dng ti i, chm pha so vi in p ti U, trong khong U v i khc

du, dng ti ngun e qua 2 dit.

Trong khong U = 0, th dng ti chy qua mt transistor ca nhnh

ny v mt it ca nhnh khc, ti b ngn mch, dng in ngun is = 0.

Sng hi trong in p ti. Nu chuyn gc to sang 0, in p ti

U l mt hm chu k l. Khai trin Fourier ca n ch cha cc thnh phn

sng sin.

Bin ca sng hi c tnh theo cng thc.

m 0

2

U E sin d

Khi n = 1 th


11/29


- 10 -

2 4 5 4 2

m

1 3 5 3 1

m

2m

2EU sin d sin d sin d sin d sin d

4EU cos 1 cos 2 cos 3 cos 4 cos 5

U 0

Khi n = 3.

3 3 3 23 2 3

3m

3 1 3 3 3 3 1

2EU sin .d sin .d sin .d sin .d sin .d

2

3m4E

U cos3 1 cos3 cos3 cos3 cos33

Bin sng hi c dng tng qut nh sau:

k

i 1cosn 1

m1

4EU 1

n

Trong : n = 1, 3, 5

il gc chuyn trng thi, i bin thin t 1 n k

kl gc chuyn trng thi cui cng trc /2

Nh vy, i vi iu bin rng xung n cc, in p ti khng

cha cc sng hi bc 3, 5 v 7 cn phi c.

i 1

3m

1....k

i 1

5m1....k

i 1

7m

1....k

4EU 1 cos3 1 0

3

4E

U 1 cos5 1 0

4EU 1 cos7 1 0

* iu bin rng xung lng cc.

T s iu bin M > 1, cc transistor c iu khin tng cp T 1, T3

v T2, T4. Ngun E lun lun c ni vi ti, thng qua hoc T 1, T3 v T2,


12/29


- 11 -

T4. Do in p gm 1 chui xung, rng khc nhau, khng c nhng

khong u = 0.

* Sng hi trong in p ti.

Nu chuyn gc to sang 0, d thy rng in p ti c dng hm

chu k l, ch cha cc thnh phn sin.

2 4 5 4 2

m

1 3 5 3 1

m

2m

2EU sin d sin d sin d sin d sin d

4EU 1 2cos 1 2cos 2

U 0

3m4E

U 1 2cos3 1 2cos 23

Biu thc tng qut ca bin sng hi ca iu bin rng xung

lng cc.

i 1

nm 1...k

4EU 1 2 1 cosn i

n

Khi u bt u bng mt xung dng

i 1

nm1...k

4EU 1 2 1 cosn i

n

Khi u bt u bng mt xung m

i vi trng hp ang xt, mun loi tr sng hi bc 3 v 5 cn

phi c:

1 2cos3 1 2cos3 2 01 2cos5 1 2cos5 2 0

Bng phng php tnh gn ng tm c 0 01 223 616, 33 3 nh

vy, in p ra ch cha sng c bn v cc sng hi bc cao 7, 9, 11 c th

xem nm4E

U sin tn


13/29


- 12 -

Um

Ur

0 2

t

t

0

t0

t0

t0

D2 t1D1 t2 D2 t1D2 t1 t2 D1 t2

D3 t3D3 t4 D4 t3 t2D4 t3 D3 t4


14/29


- 13 -

1.2. S khi v chc nng cc khi trong h thng iu khin nghch

lu mt pha theo nguyn tc iu khin PWM.

Mch iu khin gm nhng khi chnh nh sau:

- Khi 1: Khi to in p gn hnh sin Um(tn s 50Hz)

Chc nng ca khi ny l to in p hnh sin mt pha c tn s 50Hz

v bin c th iu chnh c (gi l sng iu bin) a ti u vo

ca b so snh.

- Khi 2: Khi to in p tam gic

C nhim v to mt sng tam gic c bin ln hn (thng l bi

3) tn s ca sng iu bin a ti b so snh cng vi sng iu bin.

- Khi 3: Khi so snh.

Thc hin vic so snh 2 tn hiu sng iu bin v sng mang, ti cc

giao im ca 2 sng mang ny ta xc nh c thi im pht xung iu

khin m cc transistor IGBT trn mch lc.

- Khi 4: Khi khuch i xung.

m bo cho transistor lm vic ch bo ho th ta phi a

dng iu khin vo cc B c 10%, dng qua transistor nn b khuch i

xung c chc nng khuch i tn hiu iu khin m bo cho vic m

cc transistor mt cch chc chn.

- Khi 4: Khi ngun

To mt ngun nui n nh v cng sut cung cp cho mch iu

khin.


15/29


- 14 -

I.3. Tnh ton v chn linh kin cho mch iu khin.

I.3.1. Mch to in p hnh sin cho mt pha tn s 50Hz.

S dng mch dao ng cu vin

u

RfK 1 3

Ra

in tr Rf v Ra l nhit in tr sao cho 2,9 < Kumax < 3,1

Chn Ra = 10K ta c Rf= 30 K

Ly R = R1 = R2 = 10K th

f0 = 1/6,28C1. 1000 = 50Hz CH = 0,3F

Dng khuch i thut ton A 741 vi ngun cung cp 15V

Ura = Ubh = 80% Vcc = 12V

-

+

RF

R1

Ra

C1

C2R2

6

U1+VC

7

4

-VC

3

2

C1 = C2 = CR1 = R2 = RRf = 3RaF0 = 1/2pi RC


16/29


- 15 -

I.3.2.Mch to in p tam gic tn s cao (xung rng ca)

Cc thng s c chn nh trn s

Chn IC1 v IC2 l A 741 trong IC1 c ni thnh mch dao

ng t phc hi to ra dng sng rng ca trn t C1 v sng vung ng ra

chan 6 ca IC2 (mc theokiu khuch i khng o c h s khuch i K =

1) n c tc dng nh mch m gia sng trn t C1 v mch ti bn ngoi.

Hot ng ca mch nh sau:

T C1 c np in theo hm m v pha in p dng ng ra ca

IC1 qua R1RV6 cho n khi t in p kch khi (xc nh bi phn p

R2-R3). Lc ny ng ra ca OMRAMP chuyn xung trng thi mc thp

ca t C1 phng in v phi in p m ca IC1 qua R1 RV6 cho n khi

t n in p kch khi ln th 2 (cng xc nh bi phn p R2 R3) lm

ng ra ca OP chuyn trng thi ban u v chu k li c lp li.

4

27

3+

-

+9V

6

-9V 741

RV2

10k out

IC2

4

-9V 741

IC1

72

3+

-6

+9V

15kR3

100k

R2

R1

10k

100kRV6

C1

22n

0


17/29


- 16 -

Thay i tr s bin tr RV6 ta c th hiu chnh c tn s ra mong

mun (800Hz n 8000Hz).

I.3.3. Mch so snh: (Um v Up)

B so snh tn hiu gia rng ca v xung hnh sin, ch ny

khuch i thut ton lm vic ch bo ho. Ta chn khuch i thut

ton A741 vi ngun cung cp 15V.

Khi ta c: U = V+

- V

Khi V+

> V th Ura = + USAT

Khi V+

< V th Ura = -USAT

Vi USATl in p ca IC, vi USAT= 80%U ngun cp cho IC. Xung

u ra ca mch so snh l xung ch nht vi cc rng khc nhau.

Chn khuch i thut ton A741 lm mch so snh, c cc thng s.

Vcc = 12V Ira = 25mA

Chn Um = Up= 12V hay t s iu bin bng l mt th in p trn ti

t max.

4

-V

72

3+

-

+V

6

U3

LM7131

Ura

10k

R1Um

Up R2 10k


18/29


- 17 -

1.3.4. Mch khuch i xung.

Nguyn l hot ng:

Tn hiu in p u ra sau b so snh l dng xung vung vi bin

xung l USc a vo u vo ca mch khuch i xung l Usc

a vo u vo ca mch khuch i xung qua ph t quang. Tu theo cch

mc u vo phto quang m ta cho xung dng hoc xung m qua. Khi

ph t m th s c s st p trn R1 v R4m transitor Q v c dng chy

qua R3 v R4. St p trn R4 chnh l in p m cho T.

Chn thit b cho mch khuch i xung.

+ Ph t quang chn loi EGC 3081 c cc thng s:

- u ra kiu NPN transitor.

- in p cch ly: 6000V.

- Cng sut tiu tn: Pht trin = 250mW.

- Dng chuyn mch u vo 60mA

- Dng Collector u ra 100mA

Us

Ra

Rb

FT

R1

R2

+E2

R4

R3

R6

R5C2

Q

TiC1

T


19/29


- 18 -

- in p u vo thun: 3V.

+ St p trn RB= 3V, vi US = 12V.

Chn RB = 150.

RA = 12 3 .150

4503

+ Chn transistor Q c tn s lm vic cao, kho, m chc chn. Ta

chn loi EGC397 c cc thng s:

in p chu ng:

CB

CE

BE

Cmax

0max

U = 350V

U 300V

U 6V

I 1A

P 10W

in p m cho transistor Q nh nht l 0,6V m chc chn ta chn

UBE= 1,5V. Nh vy st p trn R1 l 1,5V.

Chn R1 = 1,5 K

R2 = 100 K

+ Chn T l loi EGC3328 c in p m t vo cc G U Gemax = 6V

m cho T m chc chn ta chn Um= 2V.

Chn R3 = 100 K

R2 = 2 K

Nh vy in p st p trn R42,2V c phn p qua R5 v R6t

vo cc G ca T.

R5 hn ch dng IGca T chn = 100nh vy nu chn UGE = 2V

th


20/29


- 19 -

62

R 1000 1K2,2 2

100

T C1, C2 m bo cho hng s thi gian tc ng nhanh ca Q v T .Chn C1 = C2 = 102p.

I.3.5. Khi ngun nui mch iu khin.

V mch iu khin v mch lc c cch ly bi photo quang nhng

v in p cp cho mch lc l in p 1 chiu. V vy ta c th ly 1 phn

in p trn c quy cp mch lc cp cho mch iu khin in p mch

iu khin l 15V v vy ta chn c quy 12V v c cp qua IC7815 v

7915. Mch cp nh sau:

in p u vo IC n p nh nht l 18V do st p trn R1 v R2

s l 24 18 = 6V.

Dng tiu th ton b mch iu khin 500mA.

m bo in p lun n nh 15V th ta chn dng cc i Idkmax

= 1A.

1 26

R R 6

1

2 x 12v 2 x 12v

R17815 +15V

R2-15V7915

+-+-


21/29


- 20 -

FT 1

R4 R6

R3R5

Ti

+E1

R2

R1

Q1

T1

T4

R8R9

FT 2

R12R10

R11 T2

R7

Q2

T3

+E2

FT 3

R16 R18

+E2

Q3

R15R14

R17

R13

R24R22

FT4

R21R23

R20

Q4

R19

+E3

RB

RA

RS

+Ed= 120V

a b

-Ed = 0V


22/29


- 21 -

Nguyn l hot ng ca s .

in p sau b so snh l Usdng xung vung c cc tnh i du.

Khi Us < 0 lm FT1 v FT3m lm Q1 v Q3m cp p vo chn G T1 v T3

lm T1 v T3m dn dng chy t +E2(120V) qua T1, qua ti, qua T3v E2

(0V). Trn ti ta c dng chy t a b.

Khi Us > 0 th FT2 v FT4min p UBE Q2 v Q4thp lm Q2 v

Q4m cp p vo chn G T2 v T4 lm T2 v T4m dn dng chy t +E2

(120V) qua T4qua ti, qua T2v -E2. Trn ti c dng chy t b a nh vy

trn ti nhn c dng in o chiu lin tc.


23/29


- 22 -

IC MPC 3842: iu ch rng xung. u ra IC l dng xung vung

c rng thay i, c a vo cc G ca MOSFET K2545.

MOSTET K2545 lm vic ngt m theo xung iu khin lm dng qua

s cp bin p xung thay i gy ra cm ng song bn th cp BAX. Cui

cng bn th cp BAX tat thu c cc mc in p khc nhau ph thuc vo

s vng dy ca cun th cp.

y in p th cp v s cp c csach ly hon ton, cc ngun bn

th cp cng ring bit khng ph thuc nhau.

+15V

-15V

_

+

-

+

-

+

E1

E2

E3

+Ed

240VBAX

RS

MDC

3842

+Ed

-Ed

SG

K2545D

Uht


24/29


- 23 -

Chng iii

La chn c quy.

i. gii thiu v c quy.

c quy l thit b quan trng trong b ngun d phng UPS c chc

nng d tr nng lng in lm vic da trn nguyn l in ho hoc, c

quy sn xut ra cn phi m bo c cc tnh nng v in nh sau:

Sut in ng ln, t thay i khi phng hay np in

c quy phi lm vic thun nghch ngha l hiu sut nng lng cao

Dung lng cho mt n v trng lng v mt n v th tch phi ln

Qu trnh t phng in nh

Tui th s dng cao.

c quy c rt nhiu loi khc nhau: c quy axit hoc c quy kim

song thch hp dng UPS cng sut ln vn l c quy ch axit do c gi thnh

h.

Cu to c bn ca c quy ch axit gm cc bn cc dng lm bng

oxit ch (Pb2O) v bn cc m lm bng ch (Pb) c nhng trong dung dch

axit. tng din tch trao i gia cc bn cc m, cc bn cc m c ci

rng lc vi cc bn cc dng. Mi bnh c quy gm mt bn cc m v

dng ni trn c gi l mt n nguyn hay gi l mt ngn. Mi c quy

ch axit cho in p h mch l 2,1V. Dung lng v dng in cho php ca

mi ngn c quy ph thuc vo din tch v hp cht cc bn cc. Dung dc

in mi axit H2O vi t trng l D =1,2 1,3 g/cm3.

Khi np v phng in ti cc bn cc xy ra cc phn ng thun

nghch nh sau:


25/29


- 24 -

Ti cc bn cc m:

Ti cc bn cc dng

Qu trnh phng in xy ra khi cc bn cc dngv m khc nhau v

thnh phn ho hc c nhng trong dung dch axit sunfuric tham gia v kt

thc khi thnh phn ho hc ca hai bn cc ging nhau. Axit sunfuric tham

gia vo phn ng lm cho dung dch in mi dn dn, cc phn ng ho hc

yu dn v c quy mt dn kh nng phng in.

Qu trnh np in nh mt dng in cng bc vo c quy lm cho

phn ng xy ra theo chiu ngc li vi qu trnh phng in. Kt qu l cc

cc m v cc dng c hot ho v mang cc thnh phn ho hc khc

nhau, cc ion 24SO kt hp vi 2H+lm cho nng dung dch in mi tng

ln dung lng ca c quy li c khi phc, ngi ta ni c quy c np

no.

Dung lng ca c quy c tnh bng ampe gi (Ah) xc nh dng

phng in c th trong mt khong thi gian phng in cho trc mt

nhit v ch phng in nht nh.

Phng in

Np in

Pb + SO4 PbSO4 + 2e

Phng in

Np in

PbO2 + 4H+

+SO-4 + 2e

-PbSO4 + 2H2O


26/29


- 25 -

Dung lng ca c quy ph thuc vo ch phng in. Di ch

phng in su (hay phng in chm), dng in nh, thi gian phng

in di th dung lng c quy ln. Khi phng in vi dng in ln, thi

gian phng in ngn (thi gian phng in nng) th dung lng c quygim.

Nhit c nh hng trc tip n dung lng ca c quy, dung

lng ca c quy thp khi nhit thp bi khi cc phn ng ho hc xy

ra chm hn. Xong nhit t nh hng n ch phng in su hay

cn gi l ch phng in chm.

Tui th ca c quy c tnh theo s chu k phng np. Tui th

ca c quy tng trong ch phng in nhanh v gim i trong ch phng

in chm v cc hot cht trong ch phng in chm c s dng trit

hn. Thng tui th ca c quy khong t 500 2000 chu k ty thuc

vo ch phng in v cch bo qun.

Trong qu trnh phng in, in p ca c quy thay i, khng nn

c quy phng in in pthp hn 1,8V/1 n nguyn.

Qu trnh np in th in p ca c quy cng thay i theo quy lut

nht nh. Cui qu trnh np in p lm vic ca n, ngng trn in p

np in c chn mc sinh kh va trn vo dung dch in mi v

lm gim s ng lp trn b mt in cc. Ngng di ca in p phng

in phi m bo dung lng s dng l ln nht nhng vn gi c tui

th c quy theo yu cu.

i vi ngng trn ca in p np in ca c quy ch axit l:

Ch d phng in nng: 2,6 + 2,54V/ngn c quy.

Ch d phng in su: 2,6 + 2,65V/ngn c quy.

i vi ngng di ca in p phng in ca c quy ch axit l:

Ch d phng in nng: 1,9 V/ngn c quy.


27/29


- 26 -

Ch d phng in su: 1,7V/ngn c quy.

La chn c quy v cch ghp ni

Ngun c quy c tnh ton cung cp in p 1 chiu l 240V trong

thi gian khong 10 pht. Trn th trng hin nay c quy dng cho UPS ph

bin l cc loi 12/20Ah v 6V/7Ah c in p 240V cn phi ni tip cc

c quy c in p b vi nhau.

S lng c quy cung cp mt in p 240V l khong 10 bnh

loi 12V/20Ah. Cc c quy c u ni tip vi nhau.


28/29


- 27 -

3

-V

4

+ LM7131

+V

2 7-

6

U3R1 10k

3

C2 R2

-15VR4

4

+

R1

C1+15V

RF

72

-

U10

61kLM741

Um

Up

R2 10k

3

-9V

22n

C1

+

4

741

+9VIC1

-2

7

6

RV6100k

10k

R1

0

3

-9V

15kR3

R2100k

4

741

+

10k out

RV2

IC2+9V

27

-6


29/29


Kt lun

Sau khong thi gian nghin cu, tm hiu v thit k, n nay nca em c hon thnh. Ni dung ca n ny nu ln c hai vn

chnh sau:

+ Nghin cu tm hiu v b ngun d phng.

+ Thit k b ngun d phng 15kVA (phn nghch lu).

Tuy nhin do trnh cn hn ch, khong thi gian lm n ngn b

phn thit k ch l nhng khu c bn ca b ngun d phng. Do c

tnh kh thi trong thc t cn phi nghin cu thm v b ngun d phng

t a ra c phng n ti u.

Documents

UPS Nghich Luu