Induction Motor


A motor with only armortisseur windings is called an induction motor. An induction motor is the most modest electrical machine from constructional point of view, in the majority of the cases. Induction motor works on the principle of induction where electro-magnetic field is induced into the rotor when rotating magnetic field of stator cuts the stationary rotor. Induction machines are by far the most common type of motor used in industrial, commercial or residential settings. It is a three phase AC motor. Its characteristic features are:
  1. Simple and rugged construction
  2. Low cost and minimum maintenance
  3. High dependability and sufficiently high proficiency
  4. Needs no additional starting motor and necessity not be synchronized

What are the basic parts of an Induction Motor?

An induction motor has basically two parts: 
Stator and Rotor.
Stator:
The stator is made up of various stampings with slots to carry three phase windings. It is wound for a distinct number of poles. The windings are geometrically divided 120 degrees separated. Two sorts of rotors are used in Induction motors: Squirrel cage rotor and Wound rotor. No DC field current is required to run the machine. Rotor voltage is induced in the rotor windings rather than being physically connected by wires.


Rotor:
The rotor is the rotating part of the electromagnetic circuit. The most common type of rotor is the squirrel cage rotor. The rotor comprises of a cylindrical laminated core with axially placed parallel slots for carrying the conductors. Each slot carries a copper, aluminum, or alloy bar. The rotor of three-phase induction motors frequently is likewise implied as an anchor. The purpose behind this name is the anchor shape of the rotors used within quite early electrical devices. In electrical equipment the anchor’s winding would be induced by the magnetic field, although the rotor takes this part in three-phase induction motors.
Induction motor has the same physical stator as a synchronous machine with an alternate rotor development. Induction motor might be worked as either motors or generator. On the other hand, they are fundamentally used as induction motors.



Two Types of Induction Motors
Single phase induction motor: The single-phase induction motor is not self-starting. When the motor is connected to a single-phase power supply, the main winding carries an alternating current. It is logical that the least expensive, most reduced upkeep sort engine ought to be utilized most regularly. These are of different types based on their way of starting since these are of not self starting. Those are split phase, shaded pole and capacitor motors. Again capacitor motors are capacitor start, capacitor run and permanent capacitor motors. Permanent capacitor motor is shown below.
In these types of motors the start winding can have a series capacitor and/or a centrifugal switch. When the supply voltage is applied, current in the main winding lags the supply voltage because of the main winding impedance. And current in the start winding leads/lags the supply voltage depending on the starting mechanism impedance. The angel between the two windings is sufficient phase difference to provide a rotating magnitude field to produce a starting torque. The point when the motor reaches 70% to 80% of synchronous speed, a centrifugal switch on the motor shaft opens and disconnects the starting winding.

MUHAMMAD NAEEM
ABA ENGINEERING
                       


Comments

Post a Comment

Popular posts from this blog

AIR CIRCUIT BREAKER AND PARTS

Image
AIR CIRCUIT BREAKER  ① Front cover ② Arc extinguish chamber ③ Control circuit terminal ④ Electronic trip relay ⑤ Counte ⑥ Closing button ⑦ Charging handle ⑧ Name plate ⑨ Caution mark ⑩ position indicator ⑪ Pushing/Drawing lever hole ⑫ Charging indicator ⑬ Extension rail ⑭ Trip button ⑮ ON/OFF indicator (16) Draw-out profile (17) Main body profile (18) Handle MUHAMMAD NAEEM ABA ENGINEERING
Read more

WORKING OF SERVOMOTOR AND CONTROL

Image
Working of servomotors :                                      Servo motors control position and speed very precisely. Now a potentiometer can sense the mechanical position of the shaft. Hence it couples with the motor shaft through gears. The current position of the shaft is converted into electrical signal by potentiometer, and is compared with the command input signal. In modern servo motors, electronic encoders or sensors sense the position of the shaft . We give command input according to the position of shaft . If the feedback signal differs from the given input, an error signal alerts the user. We amplify this error signal and apply as the input to the motor, hence the motor rotates. And when the shaft reaches to the require position , error signal become zero , and hence the motor stays standstill holding the position. The command input is in form of electrical puls...
Read more

HISTORY OF PLC PROGRAMMING

Image
            HISTORY OF PLC PROGRAMMING History Industrial automation began long before PLCs. In the early to mid 1900s, automation was usually done using complicated electromechanical relay circuits. However, the amount of relays, wires and space needed to create even simple automation was problematic. Thousands of relays could be necessary to automate a simple factory process! And if something in the logical circuit needed to be changed? Oh boy! NOTE: On a basic level, electromechanical relays function by magnetically opening or closing their electrical contacts when the coil of the relay is energized. The are very useful devices and still play a major role in industrial automation (for a more in-depth lesson on electromechanical relays check out this  post ). In 1968 the first programmable logic controller came along to replace complicated relay circuitry in industrial plants. The PLC was designed to be easily programmable by plant eng...
Read more