3 Phase motor drives and DC drives dominate the industry in most applications from low to high power. (Single phase drives usually take care of the low power end.)
Basic 3Phase motors are:
3Phase induction cage rotor motor
3Phase induction wound rotor motor
3Phase synchronous motor
3Phase induction motors are used widely to serve general purpose applications, both adjustable speed and servo drives. 3Phase synchronous motor is found in special applications, mostly as servo drives. Some very large power adjustable speed drives also prefer synchronous motors because of the possibility of using low cost load-commutated-inverters (LCI) built from thyrestors.