INDUCTION MOTOR

35

current in the middle squirrel cage:

current in the outer squirrel cage:

li = ~

primary current:

/o = /a + /2 +
The voltages are related by:

+

(2)

(3)

(4)

JT' — TT I rt/y. 7" /'Cv^

# = #1 + ja?i (/i + /2 + /3), (7)

#0 = E + ZQ!Q, (8)

where x$ is the reactance due to the flux leakage between the
third and the second squirrel cage; #2 the reactance of the leak-
age flux between second and first squirrel cage; x3 the reactance
of the first squirrel cage and XQ that of the primary circuit, that
is, xi + XQ corresponds to the total leakage flux between primary
and outer most squirrel cage.

$3, $2 and $1 are the true induced voltages in the three squirrel
cages, $ the mutual inductive voltage between primary and
secondary, and $0 the primary impressed voltage

25. From equations (1) to (8) then follows:

(9)

(10)

where:

a2 =

_ « p ,

--&,

r3

(ID
(12)
(13)