- YJ =P2 =P1 LP= 1_LP =P
d. T6n hao phµ Pt: sinh ra trong thep cOng nhLI' 6' trong d6ng cua may di$n.
Ton hao phl) trong thep do tll' trU'ang phan b6 khong d§u tren b§ m$t phan (mg, anh hLI'&ng cua rang va ranh lam xu§t hi$n tll' tmang dc;1p m9ch dQc trl)c.
Ton hao phl) trong d6ng: dong di$n phan b5 khong d§u tren choi than, khi doi chi§u, tll' trLI'ang phan b5 khong d§u trong ranh lam cho trong day qu§n sinh ra dong di$n xoay, ton hao trong day n6i can bang v.v ... ThLI'ang trong may di$n m(>t chi§u I§.y:
Pf = 1 % P dm n~u may khong c6 day quan bu.
= 0,5% Pdm neu may c6 day quan bu. Tong ton hao trong may la:
2:p = Pery + PFe + PcuU' + Pcut + Pf Neu gQi P1 la cong suat dU'a vao may
P2 la cong suat dU'a ra cua may th1
p 1 = P2 + 2:p P2 = p 1 - 2:p
Hi$U suat cua may dU'Q'C tfnh theo %
YJ¾=p2 100= p2 100=P1-LP100=(1_LPJ100
P1 P2 + LP P1 l P1
5.2.3.2. Qua trinh nang ILI'gng trong may di~n DC va cac phLI'O'ng trinh can bang
a. May phat di~n:
Ta hay xet qua tr1nh bien doi nang ILI'qng. Vf dl,l nhU' cua may phat di$n m(>t chi§u kich thfch d(>c lc;1p dU'Q'C quay v&i t6c d(> n = cte. Khi kich thfch d(>c lc;1p th1 ton hao trong m9ch kfch thfch khong tinh vao cong suat P1 dLI'a tll' d(>ng CO' SO' cap vao may phat di$n. Khi bien doi nang ILI'Q'ng 1 phan P1 tieu phf vao cac ton hao Pery, PFe, Pf va phan con 19i
bien thanh nang ILI'Q'ng di$n tU', do d6: Pdt = ELI'.ILI' = P1 - (Pery+ PFe+ Pf)
Cong suat c6 fch P2 = U.ILI' do may phat di$n dU'a vao ILI'&i nho hO'n P dt m(>t tri s6 bang tf>n hao d6ng trong may:
P2 = Pdt- PcuU' = EU'.IU' - RU'= U.IU' Chia 2 ve tren cho Ill' ta c6:
U = ELI' - ILI'.RLI'
06 la phU'O'ng tr1nh can bang SU'C di$n d(>ng cua may phat di$n.
Gian d6 nang IU'Q'ng cua may phat di$n 1 chi§u: Ta c6 th§ viet cong th(rc:
P1 = Pdt + PO Hay
M1 .ro = Mdt.ro + MO.ro Chia 2 ve cho ro M1 = Mdt + MO
•
Pcu
Hinh 5.14 Gian a6 nang lll'Q'ng cua may
phat c!i?n 1 chi{Ju
06 la phU'O'ng trlnh can bang moment cua may phat di$n 1 chi§u v&I M1: Moment CO' dU'a vao trl)c MF di$n; Mdt: moment di$n tll' phat ra cua may phat.