Overview
Closeup |
A wound rotor induction motor is a motor that produces torque in the secondary
coil through the interaction of the rotating magnetic field and the current
induced in the secondary coil by the rotating magnetic field of the stator
coil. Because an induced current flows through the coil, the electromagnetic
force can be utilized and regenerated through a slip ring.
The current induced in the secondary coil effects the performance of the
wound rotor induction motor.For this reason, it is important to evaluate
the current that is induced.
This example presents the use of a magnetic field analysis to obtain the
current density distribution and the slip versus torque curve of a three-phase
wound rotor induction motor. |
Current Density Distribution
The current density distribution at a 0.5 slip is indicated in Fig. 1.
Current is induced in the rotor coil by the rotating magnetic field of
the stator coil. The induced current largely effects the torque characteristics
because the torque is a result of the interaction between the rotating
magnetic field and the magnetic flux produced by the induced current. |
Closeup |
Slip vs. Torque Curve
Closeup |
The slip versus torque curve is indicated in Fig. 2.
The amount of torque that can be produced with this induction motor increases
as the slip gets larger. The external resistance of the rotor can be investigated
to produce a higher amount of torque at a lower slip because the current
induced in the secondary coil determines the torque for each slip. |
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