A 440 V , 25 hp , 4 - pole , Y - connected three - phase wound - rotor induction motor has the following circuit parameters : R1 = 0.460 , R2 = 0.33 0 , x1 = 1.1 0 , x2 = 0.46 02 , and Xm = 25 22. ( stator referred ) Rotational losses ( including core loss ) = 500 W ( constant ) . If the terminal voltage and supply frequency are simultaneously reduced to 50 % , calculate the stator current , the developed air - gap torque , and the maximum torque at a slip of 0.04 .

A 440 V , 25 hp , 4 - pole , Y - connected three - phase wound - rotor induction motor has the following circuit parameters : R1 = 0.460 , R2 = 0.33 0 , x1 = 1.1 0 , x2 = 0.46 02 , and Xm = 25 22. ( stator referred ) Rotational losses ( including core loss ) = 500 W ( constant ) . If the terminal voltage and supply frequency are simultaneously reduced to 50 % , calculate the stator current , the developed air - gap torque , and the maximum torque at a slip of 0.04 .

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter32: Three-phase Motors

Section: Chapter Questions

Problem 6RQ: Name three factors that determine the torque produced by an induction motor.

See similar textbooks

Similar questions

2. Describe the Torque-Slip characteristics of a three phase induction motor.
1- To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be....... a) Reduced by 10%, b) Reduced by 20%, c) Increased by 10%, d) Increased by 20% 2. When maximum starting torqua ic ohtoinod
What are the various losses in an induction motor? On what factors do they depend? IV. V. List the different types of stray load losses in an induction motor.
An 3-phase induction motor(IM) has full load slip = 0.5%. If the rotor circuit resistance is increased so that R2new =2R2old, then the slip at which the motor develops the same full load torque is=.. * ......
L-1). The 3-phase wound-rotor induction motor has .... . a) high starting torque b) low starting current c) both "a" and "b" d) neither "a" nor "b" L-2). The 3-phase wound-rotor induction.........a) motor has a wire wound rotor b) motor's rotor can be connected to an external resistive load by way of slip rings and brushes c) motor requires more maintenance than the 3-phase squirrel-cage induction motor d) all of the above L-3). The 3-phase wound-rotor induction motor's rotor circuit's resistance should be adjusted so it is__________ during starting. a) low b) high c) either "a" or "b" d) neither "a" nor "b" L-4). Will a 3-phase wound-rotor induction motor start with no external circuit connected to its rotor leads? a) yes b) no
Design and develop equivalent circuit model of a single phase Induction motor with th consideration of core losses present with the parameter consideration of stator resistance R1 and reactance X1 and two rotor parameters which includes r2,x2 and magnetising reactance xm. (Illustration is required) Draw by hand please
6- In a stepper motor, how is the speed of rotation determined? a) By the current supplied to the motor. b) By the magnitude of the voltage applied. c) By the load applied to the motor. d) By the frequency of the waveforms used. 7- A transformer core is laminated to a) reduce hysteresis loss b) reduce eddy current losses c) reduce copper losses d) reduce all above losses 8- An induction motor with 580 r.p.m. speed at 60 Hz will have a) 8 poles b) 6 poles c) 4 poles d) 2 poles 9- If any two phases for an induction motor are interchanged a) the motor will run in reverse direction b) the motor will run at reduced speed c) the motor will not run d) the motor will burn 10- No-Load speed of which of the following motor will be highest? a) Shunt motor b) Series motor c) Short-Shunt compound motor d) Long-Shunt compound motor
An 8 pole, 50 Hz slip ring induction motor runs at a slip of 2.67% on full load. The rotor resistance per phase of the winding is 0.2 ohm. What external resistance per phase must be added in the rotor circuit so that the motor now runs ate a slip of 17.33% such that the torque remains same in both the cases. (Ans: 1.1 ohm)
Three Phase Induction Mot... The relative speed of stator magnetic field with respect to rotor of a 30 induction motor with 4 pole, 50 Hz frequency. If the slip is 0.05.
6- Which of the following supply is given to the rotor winding of 3-Phase Induction Motor: a) DC Supply b) AC Supply c) No Supply d) Pulsating Supply 7- 3-Phase Induction Motor will have Starting Torque and Starting Current a) High, High b) Low, Low. c) High, Low d) Low, High 8- Which of the following method is used for controlling the speed of an induction motor: a) Changing number of stator poles b) Supply voltage control c) Frequency control d) All the options are correct 9- Which of the following method cannot be used for starting of 3-Phase Squirrel Induction Motor: a) Star-Delta Starting b) Line resistor startling c) transformer Starter d) Rotor Resistance Starting 10- The rotor of a stepper motor has no: a) windings b) commutator c) brushes d) all of the above
A freewheeling DC motor is driven with 1000 rpm and a nominal load torque of 80Nm. The field circuit resistance is 200 and the armature circuit resistance is 0.2 O. The field coils are fed with a zero degree transmission angle through a single-phase fully controlled converter connected to a single-phase 240V source. The armature circuit is fed from a single phase 400V source through another fully controlled converter. Magnetic saturation has been neglected, the motor constant is given as 0.8 V - s / A - rad. Assuming that there is no fluctuation in armature and field current, find the control angle of the converter feeding the armature at nominal load. If you want to leave the question blank, click again on the option you marked.
Q.14. What is slip in an induction motor? Q.15. What is the value of slip at start in an induction motor?