Three Phase Induction Motor
The three phase induction motor is commonly used electric motor in the industry. These motor basically runs from no load to full load at constant speed. Though, the speed of the motor is dependent on the frequency. Normally we prefer DC motors whenever the required speed variation is large. On the other hand the three phase induction motors are simple, rugged, and low cost; maintenance is easy and can be manufactured with the suitable characteristics for the requirement of industries.
Similar to any electric motor, three phase induction motors also have a rotor and stator. The stator is a static and it carries a 3 phase windings named as stator winding and the rotor is a rotating one and it carries the short circuited windings names as rotor winding. The three phase source is supplied to the stator winding only. The stator winding externally energized through electromagnetic induction and develops voltage and power on the rotor winding. The stator winding energized due to electromagnetic induction and it is named as induction motor. An induction motor might be deliberated to a transformer with a rotational secondary and it can, hence, it can be described as a transformer type AC machine in that the electrical energy is transformed into mechanical energy.
- The construction is simple and rugged.
- It is comparatively cheap.
- It requires very less maintenance
- Efficiency is high and the power factor is good
- It has self-starting torque
- Basically the motor speed is constant and to change the speed it is not possible so easily.
- Its starting torque is lesser to DC Shunt motor