Production of RMF in 3 Phase Induction Machine скачать в хорошем качестве

Production of RMF in 3 Phase Induction Machine

The rotating magnetic field (RMF) in a three-phase induction motor is a fundamental concept where a magnetic field of constant magnitude rotates in space within the stator. This RMF is produced by the three-phase balanced supply fed to the stator windings, which are placed 120 electrical degrees apart. The three-phase currents flowing through these windings produce sinusoidal magnetic fluxes that are also 120 degrees out of phase.The resultant effect of these three alternating fluxes is a magnetic field that has a constant magnitude and rotates around the stator at synchronous speed, denoted as [ Ns ]. This synchronous speed depends on the supply frequency [ f ] and the number of poles [ P ] of the motor, calculated as:The rotating magnetic field induces a current in the rotor, causing it to rotate in the direction of the RMF. The direction of the RMF depends on the phase sequence of the supply, and reversing any two supply lines reverses the rotation direction of the motor.Key points about RMF in a three-phase induction motor:The RMF has a constant magnitude, equal to 1.5 times the maximum flux produced by any one phase.It rotates at synchronous speed, which is fixed by supply frequency and number of poles.This rotating field produces the necessary torque by inducing rotor currents.The RMF allows the rotor to rotate without physical movement of the stator windings, enabling efficient motor operation.Thus, RMF is the operating principle of the three-phase induction motor, making it an essential concept to understand its functioning and performance .