Gio trnh My đin Trang 28 6:  (Dynamo .D.C Generator) I. ĐA ̣ I CƯƠNG:   : 4 .  1         (Separated Dynamo)  :  : ( Shunt Dynamo)       //     : (series dynamo)          .  : (Compound Dynamo) II. CC ĐC TNH CA MY PHT ĐIN MT CHIU: : 4     : U, I  , I t , n ,       ( n = const) 1. Đc tnh không ti: U 0 = f (I t ) = E ư ; I = 0 ; n = const. + U kt R  I t - F  U I = I  + - R  G  U I = I  I t + - + G  U I =I t = I  - G  U R  + - I  I ts I I = I  -I t Gio trnh My đin Trang 29             . I t (A) 0 I to U o (V) 0 U o () 1       :       ,             t  0                 ,      trên 2              (2  3)% U m          (I t R  ),       2                   .  t , U 0         ,      U o U o = f(I t ) 0 I t U o I t 0 - I t My kch thch đc lp c 2 nhnh I t R dc + - U kt G V + - n Gio trnh My đin Trang 30  ,   t , U 0 .                 . 2. Đc tnh ngn mch: I n = f ( I t ) khi U = 0 , n = const. I t (A) 0 I tn I n (A) 0 I  U = E   I  R  O = E   I  R   E  = I  R           :                                  I tn = OC I t1 = OD : . (I tn  I t1 ) = DC :         . U = E   I  R   (I tn  I t1 ) I n I t I  I tn O I t I n = I  I  R  0 B A D C I t1 I tn U o , I n U 0 = f(I t ) I n = f(I t ) I t R dc + - U kt F + - n I n U   A V Gio trnh My đin Trang 31                                   . Khi I = I          . 3. Đc tnh lm vic ca my pht đin mt chiu kch t đc lp: a) Đc tnh ngoi: U = f ( I ) I t = const ; n = const I t (A) I  0 U (V) U  U o  khi I t = , n = .            ,              ,      .              = 0    .          kt       . , ,        ( I  R  ),      do  .                  .  (I = 0)      (I =I  )                         .  U  % = 100. U UU ñm ñmo  (    (5  15)% U         )  U  = (5  15)% U U U = f(I) U o U  I  I I t I  I to I t = f(I) I t R dc + - U kt F + - n I n U A  I V Gio trnh My đin Trang 32 b) Đc tnh điu chnh: I t = f( I) khi U= const , n = const I (A) I  0 I t (A) I  I to                                                          .  :           ( I  , R  )  .  U  = const  I t .                ,            (15  25)% I t0 .                   . 4. My pht đin mt chiu t kch thch : kch t song song , kch t ni tiê ́ p, kch t hn hp: a) Điê ̀ u kiê ̣ n đ t kch t:   (  ),                (acquy, ) .   ,  chi,                          .                                  b) Qu trnh thnh lp đin p:  :              ,                            = (2  3)% U  ; E           .       ,                                 ,               .  ,             ,                    .  ,                         .   :  (I t = I  = I)             ,  ,    . I Gio trnh My đin Trang 33   :            = I t = 0.  .      ,               ,                            . 5. Đc tnh ca my pht mt chiu kch thch song song: a) Đc tnh ngoi: U = f(I) khi R t = const ; n = const. I (A) I  0 U (V) U  U o       ,                                            ,         . ,        ( )            0       ,          t ,      t   .                       . b) Đc tnh điu chnh: I t = f(I) khi U = const , n = const. I t F + - n  U A  I A V N S + - U DC U o U  I o I  I n I           U MF U DC - + ö dö o R E I  Gio trnh My đin Trang 34 I (A) I  0 I t (A) I  I to                      .   ,                ,           . 6. Đc tnh ca my pht mt chiu kch thch ni tip:  Đc tnh ngoi: U = f(I) khi n = const I (A) 0 I  U (V) E  U           ,    1    . I  I t = f(I) I  I I t I to 0 I  U  U U = f(I) E  N S + - U DC MF U DC - + MF + - A  I V I  . Gio trnh My đin Trang 35         t = I  = I nên khi n =     2            ,      = f( I ).  :      t = I nên                ,                    (   I t )                                      . 7. Đc tnh ca my pht mt chiu kch thch hn hp: N S + - U DC U DC - MF + MF + - A  I V Short shunt MF + - A  I V long shunt Gio trnh My đin Trang 36              2 n:   .  ,   2                .     2     ,             ,                          1 . a) Đc tnh ngoi: U = f (I) khi I t = const , n = const                       .   nt >    .    ,             .  ,       .    , ,                                   .   ,               xuyên n    . b) Đc tnh điu chnh: I t = f(I)     I (A) U (V)  0 I   0 I     0 I   U o  const  U o > U o    U o < U o      nt  ss  nt U U o (1)  (1)  (1)    I     ()    I t I 0 Gio trnh My đin Trang 37 III. MY PHT ĐIN MT CHIU LM VIC SONG SONG:       : 1                .   2        1 :        2 1 (        ).  E2     (  2 ). Quay F2     ,     2  E  = 0  2   .    t2 ( 2),      2  1  2  2 0.  E  = U     K 2 , 2  1. I  = 2 2 ö ö R UE  = 0,           , 2        (I 1 = I ; I 2 = 0). 2        2 > U (I t2 ),                          E 2  E 1 (I t1 ) ( 1  1' ; 2  2')    1 I t2 , I t1 sao cho I 1 = 0, I 2 = I    1  V 1 F 1 + - K 1 F 2 + - K 2 A A V 2    (bus bar) I  I 2 I 1 ' I 1 = I  I 1 I 2 1" 1' 1 2 2' 2" U : 2     . R  I t - F  U I = I  + - R  G  U I = I  I t + - + G  U I =I t = I  - G  U R  + - I . 100. U UU ñm ñmo  (    (5  15) % U         )  U  = (5  15) % U U U = f(I)