316

ELECTRICAL APPARATUS

Hence, at synchronism, the secondary current of the single-
phase induction motor does not become zero, as in the polyphase
motor, but both components of secondary current become equal.

At standstill, S = 0, SQ = 1, it is:

ZZ$ -f" ZZi +

z

= 0.

That is, primary and secondary current corresponding thereto
have the same values as in the polyphase induction motor, as
was to be expected.

179. Introducing as parameter the counter e.m.f., or e.rn.f. of
mutual induction:

777 __ 777 r/ r

Jli == ll/Q — Z/o/0,

and substituting for 70 from (49), it is:
Primary impressed e.m.f.:

"7 f r72n I O 'y' "7 I ?/ 2"\ I ty HT ( *"? \ "7

,-r Y-, Z/o (£ SQ ~r ^ A&I ~\~ &\ ) T" ^-^i \& "T~ &i

Primary current:
Secondary energy circuit:

ZZl (Z +

r(z +

Secondary magnetizing circuit:

And:

(55)
(56)

(57)
(58)

(59)
(60)

(61)

These equations differ from the equations of the polyphase
induction motor by containing the term SQ = (I — S2), instead

O Tyf

of s = (1 — S), and by the appearance of the terms, -^--_r «--

& T" -^1

Df frequency (1 + 5), in the secondary circuit.

t