Advantages of speed control using thyristor

1. Fast Switching Characterstics than MOSFET, BJT, IGBT 
2. Low cost 
3. Higher Accuracy.

4. Low power consumption. The drive is voltage controlled one rather then rheostat control.So power loss will be reduced which will improve the efficiancy

5. Easy Operation

6. No rotating parts

7. Smoother control can be possible unlike step variation in the speed in the general rheostat control

8. Wide range of control is possible with the provision of firing angle control

9.Ssize of controller will be small and the heat dissipation provisions are also not much larger as in case of rheostat controllers.

10. With the advancement of electronic devices its manufacturing cost is very much reduced so will be cheaper than the rheostatic.