6.8 A three-phase, 250 hp, 2300 V, 60 Hz, Y-connected nonsalient rotor synchronous motor has a synchronous reactance of 11 ohms per phase. When it draws 165.8 kW, the power angle is 15 electrical degrees. Neglect ohmic losses. (a) Determine the excitation voltage per phase, Ef. (b) Determine the supply line current, Ia. (c) Determine the supply power factor. (d) If the mechanical load is thrown off and all losses become negligible, (i) Determine the new line current and supply power factor. (ii) Draw the phasor diagram for the condition in (i). (iii) By what percent should the field current I be changed to minimize the line current?
6.8 A three-phase, 250 hp, 2300 V, 60 Hz, Y-connected nonsalient rotor synchronous motor has a synchronous reactance of 11 ohms per phase. When it draws 165.8 kW, the power angle is 15 electrical degrees. Neglect ohmic losses. (a) Determine the excitation voltage per phase, Ef. (b) Determine the supply line current, Ia. (c) Determine the supply power factor. (d) If the mechanical load is thrown off and all losses become negligible, (i) Determine the new line current and supply power factor. (ii) Draw the phasor diagram for the condition in (i). (iii) By what percent should the field current I be changed to minimize the line current?
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...
Related questions
Concept explainers
Synchronous Generator
In comparison to an asynchronous generator, it is a machine where the rotor speed is equal to the rotating magnetic field produced by the stator, i.e., mechanical speed is equal to the electrical speed, thus called synchronous, and not asynchronous.
Salient Pole Rotor
Salient pole rotor includes a large number of exposed poles mounted on a magnetic wheel. The construction of a bright pole is as shown in the image on the left. The proposed poles are made of metal laminations. The rotor winding is provided on these poles and is supported by pole shoes.
Question
Please help solve with explanation
Transcribed Image Text:6.8
A three-phase, 250 hp, 2300 V, 60 Hz, Y-connected nonsalient rotor synchronous motor has a
synchronous reactance of 11 ohms per phase. When it draws 165.8 kW, the power angle is 15
electrical degrees. Neglect ohmic losses.
(a) Determine the excitation voltage per phase, Ef.
(b) Determine the supply line current, Ia.
(c) Determine the supply power factor.
(d)
If the mechanical load is thrown off and all losses become negligible,
(i) Determine the new line current and supply power factor.
(ii) Draw the phasor diagram for the condition in (i).
(iii) By what percent should the field current I be changed to minimize the line current?
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 3 steps with 3 images
Knowledge Booster
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.Recommended textbooks for you
Introductory Circuit Analysis (13th Edition)
Electrical Engineering
ISBN:
9780133923605
Author:
Robert L. Boylestad
Publisher:
PEARSON
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:
9781337900348
Author:
Stephen L. Herman
Publisher:
Cengage Learning
Programmable Logic Controllers
Electrical Engineering
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education
Introductory Circuit Analysis (13th Edition)
Electrical Engineering
ISBN:
9780133923605
Author:
Robert L. Boylestad
Publisher:
PEARSON
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:
9781337900348
Author:
Stephen L. Herman
Publisher:
Cengage Learning
Programmable Logic Controllers
Electrical Engineering
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education
Fundamentals of Electric Circuits
Electrical Engineering
ISBN:
9780078028229
Author:
Charles K Alexander, Matthew Sadiku
Publisher:
McGraw-Hill Education
Electric Circuits. (11th Edition)
Electrical Engineering
ISBN:
9780134746968
Author:
James W. Nilsson, Susan Riedel
Publisher:
PEARSON
Engineering Electromagnetics
Electrical Engineering
ISBN:
9780078028151
Author:
Hayt, William H. (william Hart), Jr, BUCK, John A.
Publisher:
Mcgraw-hill Education,