Equivalent circuits of three-phase induction motor

The equivalent circuits as in Fig. 1 can be represented the
steady state behavior of a three-phase induction motor.
Where
R1 : stator resistance
X1 : stator leakage reactance
Rc : core loss resistance,
Xm : magnetizing reactance,
R2 : rotor resistance referred to stator,
X2 : rotor leakage reactance referred to stator,
Xeq : equivalent leakage reactance ( X1 + X2 ),
s : slip

From the six-impedance and approximate equivalent circuits,
the equations of stator current ( I1 ) and power factor ( PF )
can be expressed as in (1) and (2) respectively.

Fig. 1. Equivalent circuits of three-phase induction motor
a) six-impedance b) approximate

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