INDUCTION MOTOR

59

mutual inductive part of the synchronous impedance, or the
effective reactance of armature reaction, x'y is not contained in XQ.

The effective reactance of armature reaction of the synchro-
nous machine, x', represents the field excitation consumed by the
armature m.m.f., and is the voltage corresponding to this field
excitation, divided by the armature current which consumes this
field excitation.

b, the exciting susceptance, is the magnetizing armature
current, divided by the voltage induced by it, thus, x', the effect-
ive reactance of synchronous-motor armature reaction, is the
reciprocal of the exciting susceptance of the induction machine.

The total or synchronous reactance of the induction machine
as synchronous motor thus is:

x = XQ + x'

= *„ + [•

The exciting conductance, g} represents the loss by hysteresis,
etc., in the iron of the machine. As synchronous machine, this
loss is supplied by the mechanical power, and not electrically,
and the hysteresis loss in the induction machine as synchronous
motor thus is : e*g.

We thus have :

The induction motor of the constants, per phase:
Exciting admittance : Fo = g — jby

Primary self-inductive impedance : ZQ = TO + j
Secondary self-inductive impedance : Z\ = r\ + j

by passing direct current through the secondary or rotor, be-
comes a synchronous motor of the constants, per phase :

Armature resistance : r0, -

Synchronous impedance: x = XQ + r-

Total power consumed in field excitation:

P = 2 <*r,,

where i = field exciting current.

Power consumed by hysteresis :

P = e*g.

(1)

(2)'

(3)