MMF Balancing In an Induction machine due to air gap between stator and rotor the magnetizing current drawn by the Stator is must be higher as compare to magnetizing current drawn by the transformer. hence So usually we ignore and only consider in the shunt branch. The magnetizing Reactance of a Induction motor is […]
Month: September 2021
ROTOR (Equivalent Circuit)
Under running condition the rotor frequency is scaled by a factor of “s” due to which all the parameters that are directly proportional to frequency such as emf and reactance also scaled by a factor of “s”. We considered the resistance to be independent of the frequency hence the rotor resistance remain same under standstill […]
PHASOR DIAGRAM OF INDUCTION MOTOR
In Induction machine both the stator and rotor winding carry current and produce flux due to which the resultant air gap flux is obtained by sum of the flux of the 2 winding and this resultant flux is responsible for inducing an e.m.f in stator as well as rotor winding. In an Induction machine rotor […]
INVERTED INDUCTION MOTOR
When an Induction motor is supplied by 3 phase AC source on the rotor side and the stator terminals are short circuited through resistances the Induction motor is called as Inverted Induction motor or rotor fed Induction motor. This configuration is only possible for Slip ring Induction motor (SRIM) and not for Squirrel cage Induction […]
ROTOR FREQUENCY
Induction Motor Speed of Stator magnetic field = Ns Speed of rotor = Nr Slip, S = (Ns-Nr) / Nr As the stator magnetic field rotates at Ns and the rotor rotates at Nr in the same direction the relative speed of magnetic field with respect to conductor is Ns-Nr In case of Induction motor […]
Rotor Construction Of an Induction Motor Squirrel Cage Rotor
Silicon steel is used for stator as well as rotor construction and in rotor as well as stator it is laminated to reduce eddy current losses. The stator frequency is generally higher then rotor frequency hence to reduce eddy current loss we make use of thinner lamination in stator and thicker lamination in rotor The […]