LOSSES AND EFFICIENCY

Induction Motor Even if the machine is lossless we cannot ignore the electrical portion of airgap power which When we subtract friction and windage losses from the developed power then we obtain the shaft power. In Induction machine we do not merge core loss and mechanical loss as rotational loss because there location inside the […]

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 […]