Thdi gian : 120 phtit. Sinh Vien dUEc phep sfi dgng tdi lieu.
1 . oong cd mot chidu kich trr song song 10 HP ( 1 HP = 746 w ), 230 v, 1O0O viph, hi6u sudt 46.
= 0,86, di6n tr6 dAy qudn phdn rrng ru = 0,26 a, diOn trd dAy qudn kich tr) r11 = 22s a.
a/ Tinh dong di6n dinh mrlc ti6u thu td ludi di6n vd tdng c6c tdn thdt cfra dQng cd trong didu ki6n
tAi dinh mrlc (1di6m)
Trong cdc cAu b/ vA c/ dttdi dAy, xem moment cAn do ma sdt, qu4t gi6 ld khdng ddng k€.
b/ D6ng cd v5n keo tAi co moment cAn dinh mfc, nhr.tng ti th6ng kich trlr bi giAm dot ngOt cdn 50%
gid tri dinh muc. Sau giai dgan qu6 dQ, qu6 trinh s6 xdc lap. Tinh strc diQn dQng cAm ung, ddng
ti6u thrl vir tdc dQ trong di6u ki6n xdc lAp. (1di6m)
c/Di6n trd cdn mdc nditidp phdn rlng sao cho t6c dQ dOng cd giam cdnYz gid tri dinh mfc, trong
2.tvtotm6yphdtddngb6turbinekhf ,3pha,rotocuctiJd,n,2OMVA, 138OOV,50Hz,4cuc, day qudn stato ndi Y, dien khdng d6ng b0 xdb=.11,0 a ipha, cos edm= 0, 85 tr6.
ai Tinh tdc d0 quay cr3 a tu rbine khi. Dong phdn rrng k hi m6y phdt lam vi6c 6 tAi din h m,itc? (1 di6m)
bl MAy ldm vi6c song song vdi ludi di6n vO cung ldn, di6n 6p 13 800 V va cung cdp cong sudt MVA dinh mfc ra l$6i 6 cosrp = 0,8 tr6. V6 gi&n dd vecto m6 tA hoat dQng vd tfnh di6n ap ( day ) 6
ddu cUc mdy ph6t khi d6t nhi6n m6y cit Odu cuc lam vi6c , cit mdy phat tr6n ra kh6i ludi tliQn,
trong khi dong kich til khdng kip thay d6i . ( ldi6m )
cl May ldm vi6c song song vdi lrJdi di6n v6 cung ldn, di6n 6p 13 800 V , turbine k6o mdy phdt bi
cat tninn linh kh6i m6y phdt. Dong kfch tJ vAn co gid tri kh6ng thay ddi nhu trong cAu b/ , tuy nhi6n
tr6n trqrc maiy bay gid c6 tAi co hqc, c6 gi6 tri bing 60% gid tri moment dinh muc khi turbine k6o
mdy phdt. May khi d6 ldm vi6c trong chd dO ndo ? Tfnh trong didu ki6n niiy, dong phdn ung lu ,
g6c tAi 0 vd, costp. ( I didm )
Bd qua diQn tr1 dAy qudn phdn 1ng, vd cdc tdn hao trong miiy. MAy tdm viQc 6 di6u ki6n mqch ttl
kh1ng bAo hda.
3. OOng cd kh6ng ddng bO 3 pha roto ddy qudn , 40 kW, 220/g8O V, 50 Hz, 1425 vlphut, day qudn
stato ndi A/Y, c6 ddc tinh cd M ( n )lM: momenttr6n trqc mdy N.m; n;tdc dO v/ph ldLrqc xem lir
tuydn tinh trong:khu vgc lam vi6c. Cho bidt tl sd Mrnzx/M67nlMmax.. Moment cuc dai, Mam: Moment dinh mfc lc0a dQng cd la 2,5. DAy qudn roto ndiY, di6n trd roto tit 12- 0,05 O ( pha ) .
a/ Tinh tdc d0 n*"11lngvdi moment Mr* ( 1 di6m )
Tinh di6n trd phq rphy cdn phAi mic ndi tidp tren mach r6to trong cdc didu ki6n ldm vi6c khilc
nhau c0a cdc cAu bl vit cl sau ddy :
b/ dQng co md mdy vdi moment trdn trqc ldn nhdt (1di6m) ci dong cd lirm viec trong chd d0 hdm ngrrgc ( bing c6ch ddi thti tU pha dAy qudn stato ), tdm c6ng
vi6-c ha mQt khdi hang ndng M= 136 kg, duQc m6c vdo ddu day cdp qudn quanh mdt poulie c6
dudng kinh D= 0,4 m. VAn tcic ddric0a khdihang khidixudng le y= 10 m/s . (adsbygoogle = window.adsbygoogle || []).push({});
khi moment cAn vd dong kich td vAn ld cdc gi6 tri dinh mric. Tfnh cOng sudt tren trr,rc m6y vdr hiQu sudt d6ng co khi do ?
86 qua hien uEng philn 1ng phdn 1ng, diQn trd tidp xic cIa ch6ithan.
Cho bidt 1 kg = 9,9 11
Dong co lirm vi6c vdi tAi ddi h6i m6t cOng sudt P = 50 kW .
d/ Tinh tdc dO dOng co ndu cdc vernh truqt Otrqc ndi ngin mach
( 0,5 di6m ) ( 0,5 di6m ) (1di6m) (1di6m) l+ r
\
DE rHr rV rnuAr DICN 2 - D12000 l oo.zoozy
Thdi gian ldm bAi : 120 phut. SV duoc phdp s(I dqng titi liQu.
Cdu 1 : Ddng co 1 chidu kich ttJ ndi tidp 22BV,ldm vi6c 6 tai dinh mfc ti6u thr; dong dinh muctdm = 25 A, toc o..
dinh mUc ld n6p = 1400 vong /phut. Cdc gid tric0a di6n trd phdn rlng vd c0a dAy qudn kich trl ldn tuot lA
lU = 0,17 Q vd lktnt = 0,11 Q .
GiA s& dQng co dang ldm vi6c trdn do4n tuydn tinh cia dic tinh td hod c0a vAt li6u trl, va b6 qua hi6n trrong phAn
rtng phdn Ung vir di6n 6p roi tren chdi than, c0ng nhU tdn hao co hec.
a/ T(nh tdc d0 vA moment c0a d6ng cd khi ddng di6n I = 40 A ( 1 didm ).
b/ Tim bidu thrlc tinh to6n moi quan h6 c0a tdc dd vA moment theo dong tai va ve m6i quan he dy ( 1 didm ).
cl XAc dinh dong tAi vir toc d0 khi moment tr6n truc mdy li 20 N.m ( 1 didm ).
Ciu 2 : MAy ph6t di6n ddng bo c{c trl dn, dAy qudn stato noi Y, cung cdp di6n cho m6t hldi di6n ti6u thU th6ng qua 2 mdy bien dp vd dltong dAy truydn t6i nhtJ hinh sau :
-,t C)c_ MAY BIEN AP T1 l_ F-l-r t- D DUONG DAY TRUYEN TAI
MAY LUOI DIENBIEN AP TIEU THU BIEN AP TIEU THU
r2
C6c th6ng sd cfia c6c phdn t0 :
MAy phAt ; Supdm = 380 MVA, UUpom = 22 KY; Xdb = 1 ,528 fl
Maybi6nap(T1 vdT2 gi6ngnhau) :SeROm=4BOMVA,U1dm(sdcdp) = 22KV, U266(thr-icdp) = 340KV,Xnm (di6n khdng ngdn mach) = 15"h
DUdng d|y truy6n fdi : chidu ddi Lx = 45 km, x66 ( di6n khdng dudng dAy truydn tai, b6 qua di6n tr6 duong dAy) =
0,5 ohm/km.
86 qua tdt ca cac di6n dung c0a drlong dAy.
a/ Tinh di6n 6p kh6ng tAi Eo (ddy) c&a miiy phdt, khi may ph6t ldm vi6c d cdng sudt dinh mrlc, 6 dien dp dinh
mfc, vd hd sd c6ng sudt cosq - 0,88 tr6 ( 1 didm ).
b/ V6 so dd mach dirSn tUdng dudng cOa h6 th6ng , v6i c6c thdng sd crla ciic phdn tft dugc qui vd mrlc di6n 6p th6ng nhdt 22 KV ( 1 didm ). (adsbygoogle = window.adsbygoogle || []).push({});
c/ Gi0 nguy6n gi6 tri di6n 5p kh6ng tAi Eo nhu trong cAu a/, nhulng goc pha 6 gi0a Eo vd U1 c0a ludi dien duqc thay ddi. Vidt bidu thrlc vd v6 moi quan hO c0a c6ng sudt tac dqng Px c6 thd truydn tAi qua dudng dAy ddn lrrdi
di6n ti6u thu theo g6c 5 . Di6n dp dinh mrjc c0a h.toi di6n ti6u thU khi ay ld Ug = 21 KV. Tinh g6c 6 niry, khi cong sudt truydn tAi Px la 350 MW ( 2 didm ).
Ciu 3: DOng co khong ddng b0 3 pha, stato ndi Y, 380 V, 50 Hz, 4 cqlc. Di6n tr6 dAy qudn stato R1 = 0,40 a /pha.
Thl nghiim kh6ng tAi :l6c dO ddng cd - 1500 vdng/phtit, cdng sudtti6u thU po = 1150 W, dong di6n (ddy) lo= 11,2 A.
Thinghilm vdi tAi dinh m1c:di6n dp cung cdp 380 V,50 Hz, vdi cdc s6 ti6u do drlec:
- d0 trUdt S = 4"/o
- cong suat di6n ti6u thg = 18,1 kW
- dong di6n (ddy) ti6u thq = 32 A. Tinh :
al cAc tdn hao Joule trong dAy qudn stato khi khOng tAi. Tdn hao Joule trong r6to khi ldm thi nghiGm kh6ng tAi ?
(0,5 didm )
b/ tdn hao sdt, UiSt ring tdn hao cd hqc ld 510 W (0,5 didm ). c/ h6 sd cdng sudt dinh mr;c va tdc dO dinh mtlc(0,5 didm ).
d/ tdn sd dong di6n trong r6to 6 OO trrrgt s = 4o/o. Tdn hao sdt trong r6to ?(0,5 didm ).
e/ tdn hao Joule trong ddy quan stato vd rdto trong didu ki6n tei dinh mrtc (0,5 didm ). f/ c6ng sudt tr6n truc mdy, hi6u sudt, moment khi tai lir dinh mrlc (0,5 didm ).
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