In this topic, you study Reduced Voltage Starting of squirrel cage induction motors.
Increasing rotor resistance for limiting the starting current is not feasible in squirrel cage induction motors. However, in their case, reduction in starting current can be achieved by applying the reduced voltage to the stator terminals during the starting period. The voltage is then increased to its normal value when the motor picks up the full speed. The reduced-voltage starting causes the starting torque to reduce drastically as it is proportional to the square of the voltage. Hence, such starting can be carried out only under no or light-load conditions. Different types of starters used for starting squirrel cage induction motors with reduced voltage are :
- Stator Resistance Starter
- Auto Transformer Starter
- Star Delta Starter