, Un111 %= 55 Cong suat tong S= 300KVA Tfnh tai cua moi may.
3 tk u nh6 hO'n
2.9.4 May bien ap chinh ILPu: A
A Cl c::::J c::::J bl/ . Cl! c::::J c::::J C B (-) (+)
Hinh 2.42. Sa <16 may bien ap chlnh IU'u
MBA chTnh IU'u c6 d~c diem la tai cua cac pha khong d6ng thai ma luan phien nhau theo Sl,I' lam vi$c cua cac dU'O'ng Cl,I' cua cac bQ chTnh ILI'u thuy ngan ban dan d~t a thLI' cap cua mba nhLI' hinh 2.42. NhLI' v~y mba luon luon lam vi$c trong t1nh tr,;mg khong d<Si XLl'ng, do d6 phai chQn SO' d6 n<Si day sao cho dam bao dU'Q'C dieu ki$n tLI' hoa b1nh thU'ang cua cac tn,1 thep va giam nh6 dLI'Q'C Sl,I' d~p m9ch cua di$n ap va dong di$n chTnh ILI'u. Mu<Sn v~y phai tang s6 pha cua day quan thLI' cap (chQn s6 pha bang 6) va & phfa thLI' cap c6 d$t them cu¢n cam can bang K giO,a cac diem trung tfnh cua cac pha thu<;1n (a'b'c') va 3 pha ngLI'Q'C (a"b"c"). Tac d1,mg cua cu9n cam K la lam can bang di$n ap trong m9ch cua 2 pha c6 g6c !$ch 60° lam vi$c song song. Vf d1,1 nhLI' cua a' va c" hinh 2.42.
Khi day quan thLI' cap lam vi$c song song v6i nhau, bQ chTnh IU'u 6 pha lam vi$c tLI'O'ng ht nhLI' bQ chinh ILI'u 3 pha va m6i dU'O'ng Cl)'C lam vi$c khong phai trong thai
gian m¢t ph~n sau ma trong 1 ph~n ba chu kL
gian m¢t ph~n sau ma trong 1 ph~n ba chu kL Sam
Cong suat dinh mLl'c mba 3 pha Sam = ff. U1am 11am = ff. U2ctm 12am Sam
Sdd day quan SO' cap E1 E1 = 4,44.f.W1<I>m Sad day quan thl.l' cap E2 E2 = 4,44.f.W2<I>m
H$ s6 bi§n ap k K= w1Jw2
PhLI'O'ng tr1nh di$n ap SO' cap U1 = - E1 + l1(r1 + jx1) PhLI'O'ng tr1nh di~n ap thLI' cap U2 = E2 - '2(r2 + jx2)
PhU'O'ng tr1nh SLl'C tU' d¢ng 11 = lo - Ii