. 5.12. ZA ≠ Z B ≠ZC (I ≠ IB≠ IC), , . 5.5, IN = Ia + 1 + I . ; INZN .
Nun , U'c Uc. , .
Zc ( ) U′c = IcZc . .
, , UA U'b Uca Ubc . , , . , .
, . ,
Z = 0 .
, , , , :
1) ;
2) () ; 3) ( ) ; 4) ( ) . , .
? - .
: , , , . . .
, , , - .
:
= + + .
, (5.2) (5.1), :
|
|
= =3U I cos φ = 3(U / √3)I cos φ, . .
=√3 UI cos φ. (5.5)
:
Q=√3UI sinφ; (5.6)
S = √3UI (5.7)
(5.3) (5.4),
P=3P = 3U I cos φ= 3U (I / √3)cosφ= √3U I cosφ.
, (5.5), (5.6), (5.7).
, , , , cosφ (, ):
s φ = /(√3U I )
, 127, 220, 380 660 .
(2) 5.3. .
, √ , . - , √ , . , ( ) .
I :