This question uses construction skills to determine the machine characteristics. A three-phase delta-connected synchronous induction motor is connected to a 415 volt, 50 Hz supply. The winding resistance is negligible and the synchronous reactance per phase is 4 ohms. The input power is 25 kW and the motor has a leading power factor of 0.8. a) find i) Calculate phase current ii) Calculate the stator reactive voltage drop IXs b) Draw the phasor diagram for this machine to scale (use graph paper) i) draw the generated voltage V ii) use the IXs phasor and the V phasor to construct the phasor for E. iii) measure or calculate the magnitude of E iv) By construction and/or by calculation find the load angle c)If the excitation and, as a consequence the generated emf, is reduced by 10%: i)Calculate the new value of the generated emf E’ ii)Construct the new phasor for E’ on the same diagram, using the same value for reactive volt drop iii)Calculate or measure the new load angle iv)Draw the new stator current phasor from the new reactive power phasor, and measure or calculate the new power factor d)Comment very briefly on the effect that reducing the excitation has on the power factor and the load angle

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.
icon
Related questions
Question

This question uses construction skills to determine the machine characteristics. A three-phase delta-connected synchronous induction motor is connected to a 415 volt, 50 Hz supply. The winding resistance is negligible and the synchronous reactance per phase is 4 ohms. The input power is 25 kW and the motor has a leading power factor of 0.8. a) find

i) Calculate phase current ii) Calculate the stator reactive voltage drop IXs

b) Draw the phasor diagram for this machine to scale (use graph paper)

i) draw the generated voltage V

ii) use the IXs phasor and the V phasor to construct the phasor for E.

iii) measure or calculate the magnitude of E

iv) By construction and/or by calculation find the load angle

c)If the excitation and, as a consequence the generated emf, is reduced by 10%:

i)Calculate the new value of the generated emf E’ ii)Construct the new phasor for E’ on the same diagram, using the same value for reactive volt drop

iii)Calculate or measure the new load angle

iv)Draw the new stator current phasor from the new reactive power phasor, and measure or calculate the new power factor

d)Comment very briefly on the effect that reducing the excitation has on the power factor and the load angle.

Expert Solution
steps

Step by step

Solved in 7 steps with 9 images

Blurred answer
Follow-up Questions
Read through expert solutions to related follow-up questions below.
Follow-up Question

Dear experts, regarding the question below can you elaborate as requested please, and indicate all the angels and voltages, please? The question is re written below 

 

b) Draw the phasor diagram for this machine to scale (use graph paper)

i) Draw the generated voltage V
ii) use the IXs phasor and the V phasor to construct the phasor for E.

Solution
Bartleby Expert
SEE SOLUTION
Knowledge Booster
Three phase Induction Motor
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Delmar's Standard Textbook Of Electricity
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:
9781337900348
Author:
Stephen L. Herman
Publisher:
Cengage Learning