Q1Electrical Machines II
Question
2 marks
Give the importance of airgap in rotating machines.
Answer
A small airgap minimizes the reluctance of the magnetic circuit, lowering the required magnetizing current and improving the power factor.
The airgap in a rotating machine separates the stationary stator from the rotating rotor, providing necessary mechanical clearance.
Air has a much higher magnetic reluctance than the iron core. Therefore, the airgap must be kept as small as physically possible. A smaller airgap reduces the magnetizing current required to establish the necessary magnetic flux. This in turn significantly improves the operating power factor and efficiency of the machine, particularly in induction motors.