The conditions of induction motor on load resemble those of a transformer whose secondary is
The conditions of induction motor on load resemble those of a transformer whose secondary is Supplying a variable resistive load.
When an induction motor is running under load, the rotor is subjected to mechanical torque and rotates at a speed slightly less than the synchronous speed.
The slip between the synchronous speed and the actual speed of the rotor determines the amount of mechanical torque developed by the motor.
Under these conditions, the stator current and voltage are not in phase, and the stator winding draws both active power (which is converted into mechanical power) and reactive power (which is required to create the magnetic field in the motor).
The active power drawn by the motor is equal to the mechanical power developed by the motor plus the losses in the motor.
From the transformer analogy, we can consider the rotor circuit as a secondary circuit supplied by the induced voltage, and the load torque as a variable resistive load.
The slip in the rotor circuit results in the development of rotor current, which creates the necessary magnetic field in the motor.
The rotor current also creates a voltage drop across the rotor resistance, which is analogous to the voltage drop across a variable resistive load.
The conditions of an induction motor under load resemble those of a transformer whose secondary is supplying a variable resistive load, where the active power is delivered to the load, and the reactive power is used to create the magnetic field in the motor.