induction motor Definition and Topics - 17 Discussions

An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor. An induction motor's rotor can be either wound type or squirrel-cage type.
Three-phase squirrel-cage induction motors are widely used as industrial drives because they are self-starting, reliable and economical. Single-phase induction motors are used extensively for smaller loads, such as household appliances like fans. Although traditionally used in fixed-speed service, induction motors are increasingly being used with variable-frequency drives (VFD) in variable-speed service. VFDs offer especially important energy savings opportunities for existing and prospective induction motors in variable-torque centrifugal fan, pump and compressor load applications. Squirrel-cage induction motors are very widely used in both fixed-speed and variable-frequency drive applications.

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  1. G

    Engineering Induction motor no load magnetisation loss

    The study material says under 'Estimation of magnetising losses' : On no-load, the rotor current is very small and the slip almost zero. Therefore, R′2s is very high and virtually no current flows through the branch of the circuit containing R′2s. Consequently, the no-load current is virtually...
  2. D

    Citation for origins of the Kloss formula

    The Kloss formula (from Dr. Max Kloss) is apparently widely used in Europe and Russia to approximate the relation between slip and motor torque in a squirrel cage induction motor, but I've never seen it in an American paper or book. Does anyone have a source citation for this?
  3. rishi kesh

    Engineering Resultant magnetic flux in a 3-phase induction motor

    Homework Statement I have some attachements below from my textbook. According to it the value of resultant flux is constant in magnitude and 1.5 times the maximum value of flux. But i have a doubt regarding how it is proved. The magnetic flux waveforms are 120° apart from each other and at...
  4. R

    Ansys Maxwell- Transient torque fluctuating problem

    Hii Friends, I was trying to model an Induction motor 5 KW in ANSYS Maxwell. The final output of Transient torque looks like shown below. It fluctuates with average torque almost equal to zero Nm. The input passed is a sine wave current with 120 deg phase shift. Any Suggestion will be highly...
  5. Noaha

    Rotor and stator flux in 3 phase Induction motor

    The rotor and stator flux speed are stationary with respect to each other in 3 phase induction motor. What will happen if there is relative speed between them? How these two fluxes interact with each other to develop a torque?
  6. Vikas Kasireddy

    Single Phase Induction motor winding phase difference

    Q1: So I'm trying to extract the electrical properties of a single phase induction motor. First off, how am I supposed to measure the phase difference between the start and run windings? I have L and R of start and run windings too! Q2: I have a torque vs slip curve up until 130% of rated load...
  7. O

    Induction Motor Ratings

    Hi.... Need help understanding 1MW, 6kV, 1600 RPM,Cage Rotor Asynchronous Motor, 3 Phase, 4 Poles. I have the basic understanding of all ratings but have received very low price for this motor but when i searched on the internet it looked huge and had very high price as compared to what i have...
  8. T

    Design choices for running an Electric train (and network)?

    Hi, I'm going to pose my questions with a number of assumptions, so please pick me up on any that are wrong. I want to know the design choices behind electric trains historically and current, this will mostly require some context of induction motors and inverters. I don't know exactly how EMUs...
  9. T

    Electric Trains (in general)

    Hi I thought I remember reading that transmitting power over 800km's is passed the break even point for DC vs AC. And I read that modern rail is starting to use 25KV AC, but aren't many networks bigger than that, specifically in NSW Australia, the according to wikipedia it's 815km, I'm not sure...
  10. L

    Equivalent circuit of an Induction Motor

    Hi, I have attached two circuits of an induction motor, one for steady state(1st circuit) and a dynamic model(2nd circuit). My question is: Why don't we include the induced emf in the steady state circuit? Looking at the dynamic circuit we include it, but not in the steady state circuit. Is the...
  11. srinaath

    Why slip is more in low HP induction motor?

    am doing a comparative study of induction motors (both single and three phase) based on cost, size, efficiency,etc.... while analyzing 1/4Hp and 5 HP motors, i read that 1/4HP motor has high slip than 5HP motor because 1/4HP motor has greater rotor winding resistance than efficiency is...
  12. B

    Induction motor control by DTC method

    I´m simulating an induction motor control using DTC (direct torque control). I want to tune my PI controller to achieve a fast start up, but I don't have a transfer function to make an analysis. How can I set this controller?
  13. srinaath

    Cost of three phase and single phase induction motor

    hi guys.... which will be costlier-single phase induction machine or three phase induction machine for same power rating, same rpm speed, same input voltage and current.???
  14. srinaath

    Driving three phase induction motor with single phase supply

    hi guys, am working on variable speed drive system. My aim is to make a low cost drive system for three phase induction motor. Current system employs three phase AC-DC and DC-AC converters, which has 12 switches in total. I have one idea...i found three phase inverter topology which has 4...
  15. J

    Engineering Magnetising circuit parameters in a 3ph induction motor

    Homework Statement Homework Equations The Attempt at a Solution Stator Line voltage 220 164 112 88 42 Stator Line Current 6.8 5.4 3.9 3.8 3.7 Stator power 470 360 278 244 232 By plotting a suitable graph from these results, determine the total of windage and...
  16. Z

    Why does q-axis stator current control torque in 3-ph IM?

    I know that decoupling the 3 phase currents we get the id and iq (in rotor frame) currents which control the flux and torque respectively. But where does the relation come from?
  17. Z

    Flux is not controllable in Direct Torque Control of IM

    Hi all, I was trying to simulate a direct torque and flux controlled induction motor in simulink. Even though ive managed to control torque within the band, i can't seem to be able to control the flux. It stays for a while within its hysteresis band and escapes after about 0.1 sec and keeps on...