In a constant V/f control of induction motor, the ratio V/f is maintained constant from 0 to base frequency, where V is the voltage applied to the motor at fundamental frequency f.

Which of the following statements relating to low frequency operation of the motor is TRUE? (A) At low frequency, the stator flux increases from its rated value. (B) At low frequency, the stator flux decreases from its rated value. (C) At low frequency, the motor saturates. (D) At low frequency, the stator flux remains unchanged at its rated value.

• Surbhi
• 18061 दृश्य
• 21 उत्तर

• B

  • M.Jeenath
  • 27 मई
  • 0 टिप्पणी

  0

  ---

• B

  • Venigalla
  • 06 फरवरी
  • 0 टिप्पणी

  -1

  ---

• b

  • Arjun
  • 08 दिसम्बर
  • 0 टिप्पणी

  -1

  ---

• Hi,br /I think the answer is D,because V/f ratio is kept constant so the flux will remains unchanged.

  • Rani
  • 29 नवम्बर
  • 0 टिप्पणी

  -1

  ---

• B.the stator flux decreases

  • Vaishali
  • 20 नवम्बर
  • 0 टिप्पणी

  1

  ---

• b

  • Anup
  • 12 अक्तूबर
  • 0 टिप्पणी

  1

  ---

• flux inversly promotional to frequency... so freq decreases so that flux increases....and(A)

  • Prem
  • 09 अक्तूबर
  • 0 टिप्पणी

  -1

  ---

• B

  • Sangeetha
  • 30 सितम्बर
  • 0 टिप्पणी

  0

  ---

• (C)

  • Gopi
  • 15 सितम्बर
  • 0 टिप्पणी

  0

  ---

• c

  • Rasu
  • 26 जुलाई
  • 0 टिप्पणी

  0

  ---

• (B)

  • Akkala
  • 16 जुलाई
  • 0 टिप्पणी

  0

  ---

• If you keep V/f constant , then field flux remains constant , hence the generated torque now depends only on rotor current , there is a relation of electromagnetic torque generated in motors ,Te = (3/2)*(P/2) *Fs*Fr *sin(delta) , by keeping Fs constant , you remove the coupling between flux and the armature current , hence Torque response will be instantaneous with change in rotor current and response will not get delayed ,with smooth control, so flux vs time should be a parallel line to time axis.br /At low frequencies once you try to maintain V/f constant , stator applied voltage also reduces , and hence the stator impedance drop becomes significant , hence flux value reduces from rated . At high frequencies impedance drop is negligible compared to the applied voltage ,so we take V =E .br /strongD. At low frequency, the stator flux remains unchanged at its rated value./strongbr /br /

  • Sadaqat
  • 16 जुलाई
  • 0 टिप्पणी

  -1

  ---

• correct answer is D bcz V/f= 4.44phi*N*kd*kp so if V/f is maintained constant then flux phi will also remain constant.

  • Archana
  • 03 दिसम्बर
  • 1 टिप्पणी

  -2

  ---

• A

  • Rinku
  • 18 अक्तूबर
  • 0 टिप्पणी

  0

  ---

• B

  • Damodar
  • 15 अक्तूबर
  • 0 टिप्पणी

  1

  ---

• A

  • Doriet
  • 08 सितम्बर
  • 1 टिप्पणी

  -2

  ---

• Ans is B

  • Akash
  • 03 सितम्बर
  • 0 टिप्पणी

  1

  ---

• B

  • Ankeshwarapu
  • 02 सितम्बर
  • 0 टिप्पणी

  0

  ---

• D

  • P ganesh
  • 30 अगस्त
  • 0 टिप्पणी

  0

  ---

• At low fre

  • Krupananda
  • 30 अगस्त
  • 0 टिप्पणी

  -2

  ---

• can the alternator be self excited ,,if so how
• I am appearing for this year gate. What Should i prepare in 2 week? I m Avg. student. Can anyone give some suggestions Plss. I m very worried 😔
• How does sigma delta adc work?
• I want ECE test papers please change the papers
• For a regenerative braking with DC series motor it's field windings are.... .... excited
• Gate syllabus for electrical engineering
• what is the cheapest method of pf improvement..
• What is the highest possible monthly salary that a person securing an AIR 1 in GATE electrical engineering can get from a PSU?
• I'm currently from second year ..how should I Carry out the pre preparation of gate EE .
• hi everyone! well i am first year eee student I have I have more fear about gate please help how to prepare gate