Feb 28, 2011

Different type of Electrical Motors

Motors are the heart of any plant or industry. The origin of Motor was to convert electrical energy to mechanical energy. DC motor was the first one to be invented and was result of concepts of electromagnetism by Michael Faraday. Today DC Motors , AC Motors - Induction , Squirrel Cage , Servo and Stepper Motor are used widely. We will see in brief about all these different types of Motors used in Automation Industry.

Electrical Motors In Industries :-

1) AC Motor :- We have already discussed the history of AC Motor in our earlier post. There is two broad classification of AC motors first Induction Motor and second as Synchronous Motors.
AC Induction Motor can viewed as Transformer for easy understanding. When voltage is applied to primary of Transformer a current flows and as a result current is induced in secondary winding of transformer.

The primary can be considered as Stator and Secondary as Rotor of AC Induction Motor. The magnetic field set up in the Stator results in Induced Magnetic Field in Rotor and results in Motion. Working of AC Induction Motor discussed already.

Synchronous Motor is same as Induction motor but with different Rotor configuration. The rotor is constructed in such a way that the Rotor is able to rotate with exactly same speed as of stator field. There are two variants of Synchronous Motor - self excited and Directly excited.

2) DC Motors :- DC Motors have been used in Past over the AC motors for applications demanding Speed and Position Control . Until the Introduction of Power electronics the speed variation of DC Motor was easier. In DC Motors the field in stationary in stator and rotor field, is set up by passing current through a commutator and into the rotor assembly. There are different types of DC motors as Shunt Wound Motor, Series Wound Motor and Compound Wound Motor.Subscribe to Automation-Talk by Email

3) Stepper Motor :- As the name indicates Step Motors are used for Converting the Digital Inputs commands in to Analog motion with the help of motor controller electronics.
Stepper Motor Rotates in angular positions according to the digital pulses Inputs. There are different types of Stepper Motors namely as solenoid activated, variable reluctance,permanent magnet and synchronous inductor stepper Motor.

4) PMDC Motor :- PMDC stands for permanent magnet DC , and is mostly used in closed loop system with effective feedback system. In these Motors there is linear speed-torque curve due to permanent magnet which provide provide constant field flux at all speeds. This Motor generates high starting or acceleration torque with light weight and thus used for rapid positioning applications.

5) Servo Motor :- Servo Motor works on servo-mechanism , best for closed loop applications . A controller issue commands for position/speed/torque control of motor shaft. "Servo" is a very big word to understand and we will be discussing more about servo drives, controllers and closed loop system in details in our further posts.

Till then you can subscribe to get all updates in yours In-box. Subscribe to Automation-Talk by Email.

Advertisements :-


Post a Comment

Receive all updates via Facebook. Just Click the Like Button Below