n p Buck - ConverterNhm 3
BO COBI TP LN IN T CNG SUT TI :THIT K MCH GIM P BUCK
CONVERTERGVHD : TS Hn Huy Dng Sinh vin thc hin:Trn Hi Bnh -
20125403V Cng Hon - 20125542L Th Long - 20125644Nguyn Tin Quang -
20125728Nguyn Vit Thanh - 20125770
H Ni 6/2015
MC LCLI NI U3I.GII THIU TI41.Tng quan v n p Buck42.Ch hot
ng42.1Ch dn lin tc42.2Ch dn khng lin tc5II.PHN TCH MCH51.S tng quan
cc khi52.Mch Buck l tng63.Nguyn l hot ng ca mch6III.TNH TON GI TR V
MCH BUCK71.Chu k chuyn mch72.Chu k nhim v ( rng xung )73.Tnh ton gi
tr in p ra ( Uout )83.1Khi van m :83.2Khi van kha ta c :84.Tnh ton
gi tr cun cm9IV.THIT K B TO XUNG VI TN S 10KHZ DNG IC 555101.S
nguyn l mch to xung102.Tnh ton gi tr ca tn s10V.TNH TON CC GI TR
TIN HNH M PHNG V LM MCH111.Tnh ton cc gi tr trong mch Buck111.1Chu
k chuyn mch T:111.2Thi gian van ng t1:111.3 rng xung D111.4Gi tr
cun cm L:112.M phng122.1S m phng trn Psim122.2Kt qu m phng132.3 th
dng xung iu khin to ra bng IC555163.Tin hnh lm mch163.1S nguyn l
:163.2S mch in173.3Mch thc t18VI.NHN XT181.u im:182.Nhc im:18KT
LUN19
LI NI U Chng ta ang sng trong th k 21,th k ca cch mng khoa hc v
cng ngh. in, in t pht trin ngy cng mnh m v mang li nhng ng dng v
cng to ln cho s pht trin kinh t trn ton th gii. in t cng sut l cng
ngh bit i in nng t dng ny sang dng khc trong cc phn t bn dn cng sut
ng vai tr trung tm. in t cng sut c ng dng rng ri trong hu ht cc
ngnh cng nghip hin i. Trong cc my mc thit b cng nghip,cng nh i sng
hng ngy u phi s dng in nng, c nhng thit b hot ng trong di in p ln,
cng c thit b hot ng trong di in p nh. cho cc thit b hot ng trong di
in p thp chng ta cn rt nhiu b chuyn i khc nhau p ng di in p cho cc
thit b . Trong bi tp ln ln ny, chng em la chn mt b chuyn i c chc
nng l Mch gim p Buck Converter.
Bng phn cng cng vicSTTH v tnNi dung cng vic
1L Th LongLm m phng v v mch in
2Trn Hi BnhTm hiu nguyn l v mua linh kin
3V Cng HonVit bo co
4Nguyn Tin QuangThit lp cng thc
5Nguyn Vit ThanhLm mch in
I. GII THIU TI Tng quan v n p Buck Buck Converter l b bin i m in
p u ra nh hn in p u vo hay cn c gi l b bin i gim p.Mch Buck l mch c
chc nng gim in p u vo ca b chuyn i xung in p thp hn v n nh hn ng
dng : + Trong cc ng c m t 1 chiu .+ Cho cc thit b hot ng trong di
tn thp+ Mch n gin + Cung cp in mt chiu v iu khin tc ng c mt chiu Ch
hot ng Dng IL khng i Dng IL khng lin tc vi VD l hng s Dng IL khng
lin tc vi VO l hng s 1.1 Ch dn lin tc
L ch : dng dn lin tc v IL bng 0 ti hai u mt 1.2 Ch dn khng lin
tc
L ch : trong mt chu k IL = 0 trong khong 2.TSII. PHN TCH MCH1. S
tng quan cc khi
2. Mch Buck l tng
Cu to mch: Diode : bo v kha T trong gia khong thi gian Ton v
Toff trnh c dng d chy ngc li nh thng kha T Kha T : iu chnh in p u
ra bng cch thay i chu k ng ngt B lc thng thp : gm cun cm v mt t in
c chc nng n nh in p u ra Vd : in p u vo ca mch Nguyn l hot ng ca
mchGi T l chu k chuyn mch, t1(ton) l thi gian ng mch (on-time) v
t2(toff) l thi gian m mch (off-time) Trong khi on-time th in p u vo
c a vo mch Vin=V1, Diode s b phn c ngc v b kha li, khi dng in s qua
cun cm v cun cm L1 s np nng lng. Chiu dng in nh hnh v:
Trong khi van off-time th cun cm L phng in chng li s gim t ngt
dng in trong mch v tip tc dn dng in i qua ti, i qua R v Diode,kt qu
in p V1=0. Trong thi gian van off-time th in p V1=0 nhng dng in L I
vn khng gim v 0. y c gi l ch Continuous mode. Chiu dng in nh hnh
v:
III. TNH TON GI TR V MCH BUCK1. Chu k chuyn mch
Trong : t1 l thi gian van ng mch (on time ) t2 l thi gian van m
mch (off time)2. Chu k nhim v ( rng xung )
3. Tnh ton gi tr in p ra ( Uout )
3.1 Khi van m :
Thi gian : 0t