reducing mechanical friction
increasing supply voltage
increasing number of poles
increasing supply frequency
squirrel cage induction motor
synchronous motor
slip ring induction motor
D.C. shunt motor
phase sequence is reversed
a D.C. source is connected to stator
one phase is open circuited
power is fed back to mains
improving the power factor
improving the starting torque
starting the motor
reducing the harmonics
hoists
rolling mills
mining
refrigerator