Homework Help is Here – Start Your Trial Now!
Engineering
Electrical Engineering
7-19. A460-V, four-pole, 50-hp, 60-Hz, Y-connected, three-phase induction motor devel- ops its full-load induced torque at 3.8 percent slip when operating at 60 Hz and 460 V. The per-phase circuit model impedances of the motor are R = = 0.33 N XM = 30N %3D X = 0.42 N X = = 0.42 N %3D Mechanical, core, and stray losses may be neglected in this problem. (a) Find the value of the rotor resistance R2. (b) Find Tmat. Smar and the rotor speed at maximum torque for this motor. (c) Find the starting torque of this motor.

7-19. A460-V, four-pole, 50-hp, 60-Hz, Y-connected, three-phase induction motor devel- ops its full-load induced torque at 3.8 percent slip when operating at 60 Hz and 460 V. The per-phase circuit model impedances of the motor are R = = 0.33 N XM = 30N %3D X = 0.42 N X = = 0.42 N %3D Mechanical, core, and stray losses may be neglected in this problem. (a) Find the value of the rotor resistance R2. (b) Find Tmat. Smar and the rotor speed at maximum torque for this motor. (c) Find the starting torque of this motor.

Introductory Circuit Analysis (13th Edition)
Introductory Circuit Analysis (13th Edition)
13th Edition
ISBN:9780133923605
Author:Robert L. Boylestad
Publisher:Robert L. Boylestad
Chapter1: Introduction
Section: Chapter Questions
Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...
See similar textbooks
icon
Related questions
Question
7-19. A460-V, four-pole, 50-hp, 60-Hz, Y-connected, three-phase induction motor devel- ops its full-load induced torque at 3.8 percent slip when operating at 60 Hz and 460 V. The per-phase circuit model impedances of the motor are R : X, = 0.42 N 0.33 N XM = 30 2 %3D %3D X2 = 0.42 2 %3D %3D Mechanical, core, and stray losses may be neglected in this problem. (a) Find the value of the rotor resistance R2. (b) Find Tmax, Smar and the rotor speed at maximum torque for this motor. (c) Find the starting torque of this motor. (d) What code letter factor should be assigned to this motor? 7-20. Answer the following questions about the motor in Problem 7-19. (a) If this motor is started from a 460-V infinite bus, how much current will flow in the motor at starting? (b) If transmission line with an impedance of 0.35 + j0.25 per phase is used to connect the induction motor to the infinite bus, what will the starting current of the motor be? What will the motor's terminal voltage be on starting? (c) If an ideal 1.4:1 step-down autotransformer is connected between the transmis- sion line and the motor, what will the current be in the transmission line during starting? What will the voltage be at the motor end of the transmission line dur- ing starting?
Transcribed Image Text:7-19. A460-V, four-pole, 50-hp, 60-Hz, Y-connected, three-phase induction motor devel- ops its full-load induced torque at 3.8 percent slip when operating at 60 Hz and 460 V. The per-phase circuit model impedances of the motor are R : X, = 0.42 N 0.33 N XM = 30 2 %3D %3D X2 = 0.42 2 %3D %3D Mechanical, core, and stray losses may be neglected in this problem. (a) Find the value of the rotor resistance R2. (b) Find Tmax, Smar and the rotor speed at maximum torque for this motor. (c) Find the starting torque of this motor. (d) What code letter factor should be assigned to this motor? 7-20. Answer the following questions about the motor in Problem 7-19. (a) If this motor is started from a 460-V infinite bus, how much current will flow in the motor at starting? (b) If transmission line with an impedance of 0.35 + j0.25 per phase is used to connect the induction motor to the infinite bus, what will the starting current of the motor be? What will the motor's terminal voltage be on starting? (c) If an ideal 1.4:1 step-down autotransformer is connected between the transmis- sion line and the motor, what will the current be in the transmission line during starting? What will the voltage be at the motor end of the transmission line dur- ing starting?
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
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
Introductory Circuit Analysis (13th Edition)
Introductory Circuit Analysis (13th Edition)
Electrical Engineering
ISBN:
9780133923605
Author:
Robert L. Boylestad
Publisher:
PEARSON
Delmar's Standard Textbook Of Electricity
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:
9781337900348
Author:
Stephen L. Herman
Publisher:
Cengage Learning
Programmable Logic Controllers
Programmable Logic Controllers
Electrical Engineering
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education
Fundamentals of Electric Circuits
Fundamentals of Electric Circuits
Electrical Engineering
ISBN:
9780078028229
Author:
Charles K Alexander, Matthew Sadiku
Publisher:
McGraw-Hill Education
Electric Circuits. (11th Edition)
Electric Circuits. (11th Edition)
Electrical Engineering
ISBN:
9780134746968
Author:
James W. Nilsson, Susan Riedel
Publisher:
PEARSON
Engineering Electromagnetics
Engineering Electromagnetics
Electrical Engineering
ISBN:
9780078028151
Author:
Hayt, William H. (william Hart), Jr, BUCK, John A.
Publisher:
Mcgraw-hill Education,
SEE MORE TEXTBOOKS