The electric drive systems used in industrial applications are increasingly required to meet the higher performance and reliability requirement. Today about 90% of all industrial motor applications are induction motors because they are simple in design, easy to maintain, and less costly than other types of motors. The load on induction motor is not constant, and varies as per load requirement. So speed must change as per load. The speed of induction motors can be controlled by the stator frequency (fs) and voltage (Vs). Although there are different methods of speed control of induction motors,

Keywords : induction motor, speed control, frequency, voltage, flux.