Understanding Rotor RMF in Squirrel Cage & Slip Ring Induction Motors

In summary, the rotor rotating magnetic field (R-RMF) is present in both squirrel cage induction motors (SCIM) and slip ring induction motors (SRIM). In SRIM, the 3 phase supply to the stator winding generates the rotor RMF, which then cuts the rotor winding and induces an emf. In SCIM, the rotor RMF is generated through the short-circuiting of the rotor bars and end rings. While the principles are similar, there are significant differences between the two types of motors.
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nik235
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is the rotor rotating magnetic field(R-RMF) present in squirrel cage induction motor (SCIM).

Is it same as in 3 phase ROTOR winding of slip ring induction motor (SRIM), generating rotor RMF.

* THE 3 phase, supply given to stator 3 phase winding of SRIM, generates (RMF), which cuts the rotor 3 phase winding of SRIM, now this flux cutting action results in emf induction and thus current flow in 3 phase rotor winding of SRIM, due to current, the rotor winding generates its own RMF, this RMF is stationery with respect to stator RMF, thus torque production.

so now, is the above described pattern same in SCIM too, if yes, then how is ROTOR RMF generated, with just rotor bars short circuited with end rings (ie in absence of 3 phase rotor winding).
 
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1. What is a rotor RMF in squirrel cage and slip ring induction motors?

A rotor RMF (rotating magnetic field) is an electromagnetic field that is created in the rotor of an induction motor. This field interacts with the stator's magnetic field to produce rotational motion in the motor.

2. How does a rotor RMF affect the performance of an induction motor?

The presence of a rotor RMF is essential for the proper functioning of an induction motor. It ensures that the motor can start and operate smoothly, with minimal vibration and noise. It also helps to maintain a constant speed and provides torque to drive the load.

3. What causes a rotor RMF in an induction motor?

A rotor RMF is created due to the principle of electromagnetic induction. When an alternating current is passed through the stator winding, it generates a rotating magnetic field. This field induces an electric current in the rotor, which in turn creates a magnetic field that interacts with the stator's field to produce rotation.

4. How does the design of a rotor affect the RMF in an induction motor?

The design of the rotor, specifically the number of rotor bars and their arrangement, can affect the strength and distribution of the rotor RMF. A higher number of rotor bars can result in a stronger and more uniform RMF, while a skewed rotor can help reduce noise and vibration.

5. Can a rotor RMF be controlled or adjusted in an induction motor?

The strength and distribution of a rotor RMF can be controlled by adjusting the number and arrangement of rotor bars, as well as the stator winding configuration. However, once the motor is in operation, the rotor RMF cannot be adjusted and remains constant.

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