DC motors are employed in various industrial applications. As per the characteristics of d.c. motors, different types of d.c. motors are applied for various applications. These applications are explained below:-
Separately Excited Motors
Very accurate speeds can be obtained by these motors. Moreover, these motors are best suited where speed variation is required from very low value to high value. These motors are used for paper machines, diesel-electric propulsion of ships, in steel rolling mills etc.
DC Series Motors
The characteristics of a series motor reveals that it is variable speed motor i.e. the speed is low at higher torques ( upto 500%) and vice versa. However, at light or no-load, the motor tends to attain dangerously high speed. The motor has a high starting torque. It is, therefore, used
- Where large starting torque is required.
- Where the load is subjected to heavy fluctuations and the speed is automatically required to reduce at high torques and vice-versa.
As such the dc series motors are most suitable for electric traction, hoists, cranes, elevators, vacuum cleaners, sewing machine etc.
DC Shunt Motors
The characteristics of a shunt motor reveal that it is an approximately constant speed motor. It is, therefore, used
- Where the speed is required to remain almost constant from no-load to full-load.
- Where the load has 10 be driven at a number of speeds and any one of which is required to remain nearly constant.
As such the dc shunt motors are most suitable for industrial drives such as lathes, centrifugal pumps, reciprocating pumps, fans blowers, drills grinders etc.
DC Compond Motors
Differential-compound motors are rarely used because of their poor torque characteristics. However, cumulative-compound motors are used where a fairly constant speed is required with irregular loads or suddenly applied heavy loads.
As such the dc compound motors are most suitable for Presses, shears, reciprocating machines etc.