Q5. A 400V, 6-poles, 3-phases, A-connected, 50HZ wound rotor induction motor has R1=0.50, R:=0.20, X1-0.SO, X;-0.40, X-200. 1. Find the Pullout torque of this motor. 2. Find slip and speed at Pullout torque. 3. Find the starting torque of this motor. 4. Find Res that should be connected to the rotor in order to start the motor at maximum torque. 5. If a 1.4:1 autotransformer starter is used during starting, find the new starting torque

Q5. A 400V, 6-poles, 3-phases, A-connected, 50HZ wound rotor induction motor has R1=0.50, R:=0.20, X1-0.SO, X;-0.40, X-200. 1. Find the Pullout torque of this motor. 2. Find slip and speed at Pullout torque. 3. Find the starting torque of this motor. 4. Find Res that should be connected to the rotor in order to start the motor at maximum torque. 5. If a 1.4:1 autotransformer starter is used during starting, find the new starting torque

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter35: Harmonics 916

Section: Chapter Questions

Problem 3RQ: Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction...

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Similar questions

Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction motor? Explain your answer.
B/ Fill in the blanks: TV ezur 1- In a three-phase induction motor iron losses in stator will be..... that in rotor. 2- In three-phase induction motors sometimes copper bars are placed deep in the rotor to........... 3- Blocked rotor test on induction motors is used to find out. R..., ke, X. 4- The maximum torque in an induction motor depends on .............and .....
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
Torque-speed characteristics for three phase induction motor 4. Discuss the following (rated torque, starting torque, break down torque).
200 +21. If maximum torque of an induction motor is kg-m at a slip of 12%, the torque at 6% slip would be...... kg-m. 1 (a) 100 (b) 160 (c) 50 (d) 40 B, 1993)
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=.. * ......
Draw the typical speed-torque characteristic of the induction motor and expain it.
1.why the slip of induction motor is never zero, 2.what happens if the slip of induction motor is one, 3.what is the value of the slip for an induction motor at on load and full load
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
3. A 440V 60-hp six pole 60 hz A connected induction motor has the following parameters R1=0.048 R2= 0.035 Xm= 9.50 X1= 0.33 0 X2= 0.37 0 Pcore= 600W PF&W= 350W Use the Thevenin's Equivalent circuit concept to find: (a)Vth and Zth seen by the rotor circuit (b)The slip at which maximum torque occurs (c) the value of Max/pullout Torques (d) The starting torque.
1. 2. 4. 4. •.. .... ..... .... E.g. • 2. A 3 phase, 460 V, 10hp, 60 Hz, four-pole induction machine delivers rated output power at a slip of 0.05. determine the a. Synchronous speed and motor speed b. speed of the rotating air gad field c. frequency of the rotor circuit d. Slip in rpm e. Speed of the rotor field relative to the i. rotor structure ii. Stator structure iii Stator rotating field f. haft torque of this motor at the rated load? ... .... Equivalent Circuit • The induction motor consists of a two magnetically connected systems: Stator and rotor • This is similar to a transformer that also has two magnetically connected systems: primary and secondary windings. • The induction motor is similar to the transformer with the excention that its secondarv windings are free to.
A 50-KW, 220V, 50 Hz, squirrel-cage three-phase induction motor is needed to rotate a mine conveyor belt drive. The motor starts sometimes under load, but most of the time is needed to run at rated speed and slip of 3.5%. Propose an appropriate design of this drive motor in order to suit the application. Motivate and then illustrate your design with suitable drawings and speed (slip)-torque graphs.