SOLUTION

Application of Synchronous motor

1. A polyphase synchronous motor has an inherent disadvantage of low-starting torque and sensitivity to system disturbance when sometimes it falls out of step.
2. The advantages of using a synchronous motor for industrial applications are the ease of controlling the power factor and also the constant speed.
3. At lower speeds and higher frequencies, synchronous motors are cheaper than induction motors.
4. With an improved design of their damper windings, the synchronous motors do not encounter any difficulty in handling sudden applications of load, and this does not affect their steady-state operation.
5. Synchronous motors were mainly used in constant speed applications.
6. Synchronous motors are particularly attractive for low speed (< 300 rpm) because the power factor can always be adjusted to unity and efficiency is high.
7. Over excited synchronous motor can be used to improve the power factor.
8. Synchronous motors are used to improve the voltage regulation of transmission lines.
9. Synchronous motors can always be adjusted to operate at the unity power factor.
10. Synchronous motor only runs at synchronous speed, therefore it is used in textile, paper mill, etc.
11. Due to constant speed characteristics, it is used in:

(a) Machine tools

(b) Motor-Generator set

(c) Synchronous clocks

(d) Timing devices

(e) Fans and blowers

(f) Cement industries