What is dc induction motor ? and how to control its speed ?
Answer Posted / 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 View All Answers
HOW WE CAN REDUCE THE CIRCUIT COMPLEX OF STAR-DELTA STARTER .BECAUSE NOW WE USING ONE TIMER RELAY & THREE CONTACTOR FOR MAIN,STAR & DELTA ?IF ANY IDEAS PLZ POST.THANK U
Thumb rule of cable size(rm>30 rm)X multiplying factor=ampere
What is the formula to calculate distribution transformer De-rating on iron losses basis
which one is more efficient, torq, power & ecnomy with the same frame size AC motor / DC motor?
how ct burden,magnetising current,ratio and knee point voltage are related & derived
how we can calculate 2 phase welding transformer rating or total power?
How time response of the system is divided?
For an induction motor wat is the loading/unloading cycle duration or interms of L/UL ratio/ percentage?
what is the use of vcb & isolator in substation?
why power factor is important?
If Neutral Grounding Resistor (GR) failed/shorted. Is it repairable.
how synchronous condenser is used in place of synchronous generator with out negotiating IEEE standards? Can i use 3 generators as synchronous generators and 2 generators as a synchronous condensers in an IEEE 14 bus system with out disturbing the standards?
could an induction motor be used for regenerative braking in electric-train control? in this type of application would some scheme have to be devised to obtain low synchronous speeds while braking? would induction-motor drive, therefore, be suitable for passenger service?
what is formula to cal cute earth pit numbers and size of earth strip used in earthing?
How to do fabrication , busbar and wiring cost for : 1. LT Panels 2. C& R Panel