What are the Characteristics, Power Ranges and Applications of different types of AC & DC Motors?

Characteristics, Power Range and Applications of some AC & DC Motors:

Motor Types	Characteristics	Power Range	Applications
DC Motors
DC shunt motor	Constant flux constant speed motor creates moderate torque at start.	Up to 200 hp	Machine tools like lathes, milling machines, grinding machines, centrifugal and reciprocating pumps, blowers, and fans.
DC series motor	Creates dangerously high torques at low speeds and should be always connected to the load; speed can be varied.	Up to 200 hp	Preferred for traction-type loads; employed in electric locomotives, conveyors, cranes, elevators, trolleys.
Permanent magnet DC motor	Higher efficiency, smaller size and simpler architecture; magnets can become demagnetized due to excessive use and overheating; produces lower torque.	Up to 10 hp	Power windows in automobiles, computer peripherals.
Separately excited motors	Can be controlled either by varying the voltage applied to the field winding or by varying the voltage applied to the armature; can produce high torques.	Up to 100 hp	Traction applications, to control the speed and torque of the motor by changing both armature voltage and stator current.
AC Motors
Three-phase induction motor (Squirrel cage rotor)	Moderate starting torque. Simple robust and maintenance free construction. Speed control by addition of rotor resistance is not possible.	1–5000 hp	Lathe machines, water pumps, grinders, printing machines, large refrigeration and air-conditioning units, small compressors.
Three-phase induction motor (Slip ring rotor)	Very high starting torque. Speed control by rotor resistance possible. High cost. Complicated construction which requires maintenance due to use of slip rings and brush.	1–5000 hp	Cranes, hoists, elevators, large compressors, industrial fans and blowers.
Three-phase synchronous motor	Constant speed irrespective of load, need of a starting device, need for two different excitation sources, variable frequency drives required for speed control.	Up to 50,000 hp	Motor generator sets, timing devices, centrifugal pumps, textile mills, cement mills, rolling mills.
Special Types of Motors
Single-phase induction motor	Simple and rugged construction.	Up to 5 hp	Fans, water pumps, and refrigerators.
Stepper motor	Smooth rotation, linear relation between electrical input and step rotation.	Sub-fractional horsepower rating	Used for precise position control in printers, floppy disk drives, robotics, process control, machine tools.
Brushless DC motor	No maintenance required, long life, high reliability and efficiency, low inertia and friction, low starting torque and high costs, ability to run at speeds as high as 50,000 rpm.	Up to 300 hp	Video recorders, computer peripherals, biomedical instruments, commercial ovens, film processing equipment, printing technology, and material handling equipment.
Universal motor	High-power-to-weight ratio, can produce high starting torque, can operate at very high speeds, suits wide variety of applications demanding different torques, shorter lifespan.	Used exclusively in fractional horsepower range	Small appliances like mixers, blenders, drills, saws, vacuum cleaners, sewing machines.

Read more: Discuss Different types of Motors & their Uses.

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