Homework Help is Here – Start Your Trial Now!
Engineering
Electrical Engineering
laging (6) A 4 MW, 0.707 industrial plant is supplied from a 6 MVA three-phase power transformer. A 1.0 MW, 11 kV, 0.8 leading power factor, 88 % efficient, 3-phase synchronous motor is to be installed in the plant. Answer the following questions: Case) (a) What is the new overall power factor of the plant. (b) Is the 6 MVA transformer over-loaded after connecting the synchronous motor. (c) If yes find the over-loading percentage. fynchronous motor has an EMF of 600 V. The rotational losses are

laging (6) A 4 MW, 0.707 industrial plant is supplied from a 6 MVA three-phase power transformer. A 1.0 MW, 11 kV, 0.8 leading power factor, 88 % efficient, 3-phase synchronous motor is to be installed in the plant. Answer the following questions: Case) (a) What is the new overall power factor of the plant. (b) Is the 6 MVA transformer over-loaded after connecting the synchronous motor. (c) If yes find the over-loading percentage. fynchronous motor has an EMF of 600 V. The rotational losses are

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

please solve question 6

3-phase A-connected induction motor has a direct starting current of 800 % of rated current and a full-load slip of 4 %. Answer the following questions: (a) Under direct starting conditions, calculate the percentage of the starting torque compared to rated torque. (b) If an autotransformer is used to reduce the starting current of the motor to 250 % of rated value, calculate the transformation ratio of the transformer, and the corresponding percentage value of the new starting torque. (c) If the motor is to be started using Y-A starting method, calculate the new percentage of the starting current and the corresponding starting torque. laging (6) A 4 MW, 0.707 industrial plant is supplied from a 6 MVA three-phase power transformer. A 1.0 MW, 11 kV, 0.8 leading power factor, 88 % efficient, 3-phase synchronous motor is to be installed in the plant. Answer the following questions: Case (a) What is the new overall power factor of the plant. (b) Is the 6 MVA transformer over-loaded after connecting the synchronous motor. (c) If yes find the over-loading percentage. (7) A 500 V, A-connected, three-phase synchronous motor has an EMF of 600 V. The motor synchronous impedance is (0.4+j5) 02/ph, and the rotational losses are neglected. Calculate the maximum power output that can be delivered, the corresponding line current, the input power factor and efficiency of the motor. (8) A 3300 V, A-connected synchronous motor has a synchronous reactance of 18 0/ph. It operates at a 0.707 leading power factor when drawing 800 kW from the mains. Answer the following questions: (a) Calculate the motor EMF and torque angle. (b) If the field current in increased by 20 % while the load power is unchanged calculate the new value of the line current and the corresponding input power factor.
Transcribed Image Text:3-phase A-connected induction motor has a direct starting current of 800 % of rated current and a full-load slip of 4 %. Answer the following questions: (a) Under direct starting conditions, calculate the percentage of the starting torque compared to rated torque. (b) If an autotransformer is used to reduce the starting current of the motor to 250 % of rated value, calculate the transformation ratio of the transformer, and the corresponding percentage value of the new starting torque. (c) If the motor is to be started using Y-A starting method, calculate the new percentage of the starting current and the corresponding starting torque. laging (6) A 4 MW, 0.707 industrial plant is supplied from a 6 MVA three-phase power transformer. A 1.0 MW, 11 kV, 0.8 leading power factor, 88 % efficient, 3-phase synchronous motor is to be installed in the plant. Answer the following questions: Case (a) What is the new overall power factor of the plant. (b) Is the 6 MVA transformer over-loaded after connecting the synchronous motor. (c) If yes find the over-loading percentage. (7) A 500 V, A-connected, three-phase synchronous motor has an EMF of 600 V. The motor synchronous impedance is (0.4+j5) 02/ph, and the rotational losses are neglected. Calculate the maximum power output that can be delivered, the corresponding line current, the input power factor and efficiency of the motor. (8) A 3300 V, A-connected synchronous motor has a synchronous reactance of 18 0/ph. It operates at a 0.707 leading power factor when drawing 800 kW from the mains. Answer the following questions: (a) Calculate the motor EMF and torque angle. (b) If the field current in increased by 20 % while the load power is unchanged calculate the new value of the line current and the corresponding input power factor.
Expert Solution
Step 1

Given data,

The rating for the industrial load,

PL=4 MWcosφL=0.707 lag

The rating for the transformer,

Ptransformer=6 MVA

The rating for the synchronous motor,

P0=1.0 MWcosφm=0.8 leadV=11 kVη=88%

To find: 

(a) What is the new overall power factor of the plant?

(b) Is the 6 MVA transformer overloaded after connecting the synchronous motor?

(c) If yes find the overloading percentage.

steps

Step by step

Solved in 4 steps

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Single phase transformer
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
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