What is dc induction motor ? and how to control its speed ?



What is dc induction motor ? and how to control its speed ?..

Answer / engr. kashif

Induction motors are AC motors and they rely on the principle of Induction thus called induction motors. The stator is given a three phase supply and with the help of the revolving magnetic field produced by it, current is induced in the rotor. This then itself generates a magnetic field opposite to the one generated by the stator. These two fields react with each other to produce rotor movement.

Speed may be controlled either by varying input frequency or by changing the no. of poles of the motor. Obviously changing the no. of poles of the motor is not possible unless u alter the motor design or its a specialized multi winding motor. So we have to settle for the other option i.e. change the input frequency. This can be accomplished with the help of VFD (Variable Frequency Drives). They allow u to control the input frequency and thus the speed of the motor.

Is This Answer Correct ?    10 Yes 2 No

Post New Answer

More Electrical Engineering Interview Questions

Upload data by LSMW via BAPI in SAP system.

1 Answers  


in alternator what is use of AVR ? how AVR is operating either AC or DC?

1 Answers  


If a motor of 8.5 KW with same load and using in both Star & Delta one by one,then which will take more current in star connected or in delta connected

4 Answers  


what is difference b/w HT & LT and the range of HT & LT ?

22 Answers   AF, Schneider,


If the load is 10Kw and power factor has to improve from 0.5 to 0.8,how can we select the capacitor rating accordingly.Illustrate by showing formula?

9 Answers  






cause of failure of transformer bushes

3 Answers  


what is the difference between multimeter and megger?

3 Answers   Bhel, Metro,


how to wiring it with contactor and timer together

0 Answers  


can i use the six sigma method which is used in management area, in state estimation of power systems?

0 Answers  


What is working of Trip Ckt.Supervision Relay?

1 Answers  


Does all the output contacts (N/O as well as N/C) of a Numerical relay operate when relay receives a binary input/inputs or contacts are designated to specific logic input/inputs and only these contacts operate?

0 Answers  


While elctrical load on DG,capacitor banks kept off why so? If capacitor banks on is their any effect DG?

4 Answers   IL&FS Infrastructure Leasing Financial Services,


Categories
  • Civil Engineering Interview Questions Civil Engineering (5085)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4452)
  • Electrical Engineering Interview Questions Electrical Engineering (16638)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1095)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (239)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (259)
  • Instrumentation Interview Questions Instrumentation (3014)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (124)
  • Power Plant Engineering Interview Questions Power Plant Engineering (172)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (25)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1379)