What will happen if we increase the air gap in the induction motor power factor?

Detailed Solution. If the air gap of an induction motor increases, 1) The permeability of the magnetic circuit rotor-to-stator will decrease. 2) The magnetizing inductance of the motor thus decreases.

What is the effect of the induction motors to the power factor?

The power factor can be controlled by manipulating either of active or reactive power. In induction motors, active power is proportional to the motor load that variation of motor load results in increase or decrease in power factor.

How is Gap power calculated?

Calculation of Air Gap Power From the above expression, it is clear that per phase rotor power input is equal to I22(r2/s) as reactance x2 do not consume any power. Pg is the power transferred from stator to the rotor across the air gap. Therefore it is called the Air Gap Power.

What happens if the air gap length is doubled?

What happens if the air gap length is doubled? If the air gap of an induction motor is doubled then the mmf and magnetizing current approximately doubles. Also increase in air gap length increases the overload capacity, offers better cooling, reduces noise and reduces unbalanced magnetic pull.

Why do induction motors need air gaps?

The air gap needs to be large enough to prevent contact between the rotor and stator, taking into account tolerances related to their respective dimensions, loose bearings, and movement that results from deflection during operation.

What is the effect of airgap on efficiency of induction motor?

Airgap of the induction motor is inversely proportional to the power factor and efficiency. The Airgap between stator and rotor decides amount of energy transferred from stator to rotor. Airgap incteases the loss of fluxes transferred from stator to rotor. Thus efficiency decreases if Airgap increases ,

What is the effect of air gap on no-load power factor?

As the air-gap increases no-load current increases and no-load power factor goes very low. When compared to low air-gap, a larger air-gap machine requires considerable amount of energy to transfer the power from stator to rotor, to attain this, stator has to draw more power from mains to pump in rotor, there by increase in losses.

What size air gap do I need for my induction motor?

Few design guidelines exist for selecting the air gap size best suited to any rotating machine. For induction motors, in power ratings from 3/4 to 750 kilowatts, practical values from 0.2 to 5 mm are typical; the higher the motor speed, the larger the gap.

What is the air gap power of a rotors?

From the above expression, it is clear that per phase rotor power input is equal to I22(r2/s) as reactance x2 do not consume any power. Pg is the power transferred from stator to the rotor across the air gap. Therefore it is called the Air Gap Power.