Electrical Engineering (EE) Exam > Electrical Engineering (EE) Notes > Short Notes for Electrical Engineering > Short Notes: Induction Machines
Short Notes: Induction Machines | Short Notes for Electrical Engineering - Electrical Engineering (EE) PDF Download
| Download, print and study this document offline |
Please wait while the PDF view is loading
Page 1
Stator & Rotor Magnetic Fields
o When a 3-phase supply is connected to the stator, than a magnetic field is set up
whose speed of rotation is
S
120f
N =
P
f = frequency of supply
o If negative sequence currents are applied the rotating magnetic field rotates in
opposite direction as compared to magnetic field produced by positive sequence
currents.
o The rotor rotates in same direction as the stator magnetic field with a speed, .
?
sr
s
NN
slip s =
N
? ?
rs
N = N 1 s ??
o Speed of rotor magnetic field with respect to rotor
s
= sN
o speed of rotor magnetic field with respect to stator
s
= N .
Hence, stator & rotor magnetic fields are at rest with respect to each other.
o Frequency of emf & current in rotor = sf
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 N s N s(1-s) N s
Stator
Magnetic
Field
-Ns 0 -sNs 0
Rotor -N s(1-s) sN s 0 sN s
Rotor
Magnetic
Field
-N s 0 -sN s 0
Page 2
Stator & Rotor Magnetic Fields
o When a 3-phase supply is connected to the stator, than a magnetic field is set up
whose speed of rotation is
S
120f
N =
P
f = frequency of supply
o If negative sequence currents are applied the rotating magnetic field rotates in
opposite direction as compared to magnetic field produced by positive sequence
currents.
o The rotor rotates in same direction as the stator magnetic field with a speed, .
?
sr
s
NN
slip s =
N
? ?
rs
N = N 1 s ??
o Speed of rotor magnetic field with respect to rotor
s
= sN
o speed of rotor magnetic field with respect to stator
s
= N .
Hence, stator & rotor magnetic fields are at rest with respect to each other.
o Frequency of emf & current in rotor = sf
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 N s N s(1-s) N s
Stator
Magnetic
Field
-Ns 0 -sNs 0
Rotor -N s(1-s) sN s 0 sN s
Rotor
Magnetic
Field
-N s 0 -sN s 0
Inverted Induction Motor
o When a 3 ?? supply is connected to the rotor & stator terminals are shorted or are
connected to the resistive load.
o Then a rotor magnetic field is set up which rotates at speed
s
N with respect to rotor ;
where f is frequency of supply.
o If rotor rotates at speed , than slip
?
sr
s
NN
s =
N
Here, the rotor rotates in a direction opposite to the direction of rotation of stator
magnetic field.
o Speed of rotor magnetic field with respect to stator
? ?
s s s
= N N 1 s = sN ??
Speed of stator magnetic field
s
= sN
o Frequency of emf & current induced in stator = sf
f = supply frequency on rotor.
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 sN s N s(1-s) sN s
Stator
Magnetic
Field
-sN s 0 -N s 0
Rotor -Ns(1-s) Ns 0 Ns
Rotor
Magnetic
Field
-sNs 0 -Ns 0
Equivalent circuit of Induction Motor
Page 3
Stator & Rotor Magnetic Fields
o When a 3-phase supply is connected to the stator, than a magnetic field is set up
whose speed of rotation is
S
120f
N =
P
f = frequency of supply
o If negative sequence currents are applied the rotating magnetic field rotates in
opposite direction as compared to magnetic field produced by positive sequence
currents.
o The rotor rotates in same direction as the stator magnetic field with a speed, .
?
sr
s
NN
slip s =
N
? ?
rs
N = N 1 s ??
o Speed of rotor magnetic field with respect to rotor
s
= sN
o speed of rotor magnetic field with respect to stator
s
= N .
Hence, stator & rotor magnetic fields are at rest with respect to each other.
o Frequency of emf & current in rotor = sf
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 N s N s(1-s) N s
Stator
Magnetic
Field
-Ns 0 -sNs 0
Rotor -N s(1-s) sN s 0 sN s
Rotor
Magnetic
Field
-N s 0 -sN s 0
Inverted Induction Motor
o When a 3 ?? supply is connected to the rotor & stator terminals are shorted or are
connected to the resistive load.
o Then a rotor magnetic field is set up which rotates at speed
s
N with respect to rotor ;
where f is frequency of supply.
o If rotor rotates at speed , than slip
?
sr
s
NN
s =
N
Here, the rotor rotates in a direction opposite to the direction of rotation of stator
magnetic field.
o Speed of rotor magnetic field with respect to stator
? ?
s s s
= N N 1 s = sN ??
Speed of stator magnetic field
s
= sN
o Frequency of emf & current induced in stator = sf
f = supply frequency on rotor.
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 sN s N s(1-s) sN s
Stator
Magnetic
Field
-sN s 0 -N s 0
Rotor -Ns(1-s) Ns 0 Ns
Rotor
Magnetic
Field
-sNs 0 -Ns 0
Equivalent circuit of Induction Motor
If we refer all parameters on stator side
22
11
2 2 2 2
22
NN
r = r ; x = x
NN
? ? ? ?
? ? ? ?
? ? ? ?
? ? ? ?
??
??
??
1 1 1
N = N k
?
?
Where
1
N = no. of turns per phase on stator
1
k ? = winding factor of stator winding
2 2 2
N = N k
?
?
2
N = number of turns per phase on rotor
2
k ? = winding factor of rotor winding
Tests Conducted on Induction Motor
(i) No-Load Test
o Conducted on Stator with no-load on rotor side.
o It gives No-Load Losses ( Rotational Loss + Core Loss).
(ii) Blocked Rotor Test
o Conducted on stator side keeping rotor blocked
o It gives full load Copper Losses and equivalent resistance and equivalent reactance
referred to Stator Side.
Page 4
Stator & Rotor Magnetic Fields
o When a 3-phase supply is connected to the stator, than a magnetic field is set up
whose speed of rotation is
S
120f
N =
P
f = frequency of supply
o If negative sequence currents are applied the rotating magnetic field rotates in
opposite direction as compared to magnetic field produced by positive sequence
currents.
o The rotor rotates in same direction as the stator magnetic field with a speed, .
?
sr
s
NN
slip s =
N
? ?
rs
N = N 1 s ??
o Speed of rotor magnetic field with respect to rotor
s
= sN
o speed of rotor magnetic field with respect to stator
s
= N .
Hence, stator & rotor magnetic fields are at rest with respect to each other.
o Frequency of emf & current in rotor = sf
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 N s N s(1-s) N s
Stator
Magnetic
Field
-Ns 0 -sNs 0
Rotor -N s(1-s) sN s 0 sN s
Rotor
Magnetic
Field
-N s 0 -sN s 0
Inverted Induction Motor
o When a 3 ?? supply is connected to the rotor & stator terminals are shorted or are
connected to the resistive load.
o Then a rotor magnetic field is set up which rotates at speed
s
N with respect to rotor ;
where f is frequency of supply.
o If rotor rotates at speed , than slip
?
sr
s
NN
s =
N
Here, the rotor rotates in a direction opposite to the direction of rotation of stator
magnetic field.
o Speed of rotor magnetic field with respect to stator
? ?
s s s
= N N 1 s = sN ??
Speed of stator magnetic field
s
= sN
o Frequency of emf & current induced in stator = sf
f = supply frequency on rotor.
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 sN s N s(1-s) sN s
Stator
Magnetic
Field
-sN s 0 -N s 0
Rotor -Ns(1-s) Ns 0 Ns
Rotor
Magnetic
Field
-sNs 0 -Ns 0
Equivalent circuit of Induction Motor
If we refer all parameters on stator side
22
11
2 2 2 2
22
NN
r = r ; x = x
NN
? ? ? ?
? ? ? ?
? ? ? ?
? ? ? ?
??
??
??
1 1 1
N = N k
?
?
Where
1
N = no. of turns per phase on stator
1
k ? = winding factor of stator winding
2 2 2
N = N k
?
?
2
N = number of turns per phase on rotor
2
k ? = winding factor of rotor winding
Tests Conducted on Induction Motor
(i) No-Load Test
o Conducted on Stator with no-load on rotor side.
o It gives No-Load Losses ( Rotational Loss + Core Loss).
(ii) Blocked Rotor Test
o Conducted on stator side keeping rotor blocked
o It gives full load Copper Losses and equivalent resistance and equivalent reactance
referred to Stator Side.
o
01
R &
01
X are equivalent winding resistance & equivalent leakage reactor referred to
Stator side.
o Wattmeter reading =
2
sc 01
P = I R from this equation, we can calculate
01
R
o
sc
01
sc
V
Z =
I
&
22
01 01 01
X = Z R ?
o We obtain
01
R ,
01
X & full load copper losses from this test.
o
01
R = R 1+ R 2’ ;
01
X = X 1+ X 2’
Power Flow Diagram
Rotor i/p =
g
P (Airgap power) Mechanical Power Developed
in
P
Stator Stator Rotor Rotor Friction &
2
IR loss core loss
2
IR loss core loss windage loss
2
22
g
3I r
P =
s
2
I = rotor current
s = slip
2
r = rotor resistance per phase
Rotor
u
C Loss
2
2 2 g
= 3I r = sP
Mechanical power developed
? ?
g g g
= P sP = 1-s P ?
Developed Torque,
? ?
? ?
g g
m
e
rs
s
1-s P P
P
T = =
ww
1-s w
?
Page 5
Stator & Rotor Magnetic Fields
o When a 3-phase supply is connected to the stator, than a magnetic field is set up
whose speed of rotation is
S
120f
N =
P
f = frequency of supply
o If negative sequence currents are applied the rotating magnetic field rotates in
opposite direction as compared to magnetic field produced by positive sequence
currents.
o The rotor rotates in same direction as the stator magnetic field with a speed, .
?
sr
s
NN
slip s =
N
? ?
rs
N = N 1 s ??
o Speed of rotor magnetic field with respect to rotor
s
= sN
o speed of rotor magnetic field with respect to stator
s
= N .
Hence, stator & rotor magnetic fields are at rest with respect to each other.
o Frequency of emf & current in rotor = sf
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 N s N s(1-s) N s
Stator
Magnetic
Field
-Ns 0 -sNs 0
Rotor -N s(1-s) sN s 0 sN s
Rotor
Magnetic
Field
-N s 0 -sN s 0
Inverted Induction Motor
o When a 3 ?? supply is connected to the rotor & stator terminals are shorted or are
connected to the resistive load.
o Then a rotor magnetic field is set up which rotates at speed
s
N with respect to rotor ;
where f is frequency of supply.
o If rotor rotates at speed , than slip
?
sr
s
NN
s =
N
Here, the rotor rotates in a direction opposite to the direction of rotation of stator
magnetic field.
o Speed of rotor magnetic field with respect to stator
? ?
s s s
= N N 1 s = sN ??
Speed of stator magnetic field
s
= sN
o Frequency of emf & current induced in stator = sf
f = supply frequency on rotor.
With
respect
to
Relative Speed of
Stator Stator
Magnetic
Field
Rotor Rotor
Magnetic
Field
Stator 0 sN s N s(1-s) sN s
Stator
Magnetic
Field
-sN s 0 -N s 0
Rotor -Ns(1-s) Ns 0 Ns
Rotor
Magnetic
Field
-sNs 0 -Ns 0
Equivalent circuit of Induction Motor
If we refer all parameters on stator side
22
11
2 2 2 2
22
NN
r = r ; x = x
NN
? ? ? ?
? ? ? ?
? ? ? ?
? ? ? ?
??
??
??
1 1 1
N = N k
?
?
Where
1
N = no. of turns per phase on stator
1
k ? = winding factor of stator winding
2 2 2
N = N k
?
?
2
N = number of turns per phase on rotor
2
k ? = winding factor of rotor winding
Tests Conducted on Induction Motor
(i) No-Load Test
o Conducted on Stator with no-load on rotor side.
o It gives No-Load Losses ( Rotational Loss + Core Loss).
(ii) Blocked Rotor Test
o Conducted on stator side keeping rotor blocked
o It gives full load Copper Losses and equivalent resistance and equivalent reactance
referred to Stator Side.
o
01
R &
01
X are equivalent winding resistance & equivalent leakage reactor referred to
Stator side.
o Wattmeter reading =
2
sc 01
P = I R from this equation, we can calculate
01
R
o
sc
01
sc
V
Z =
I
&
22
01 01 01
X = Z R ?
o We obtain
01
R ,
01
X & full load copper losses from this test.
o
01
R = R 1+ R 2’ ;
01
X = X 1+ X 2’
Power Flow Diagram
Rotor i/p =
g
P (Airgap power) Mechanical Power Developed
in
P
Stator Stator Rotor Rotor Friction &
2
IR loss core loss
2
IR loss core loss windage loss
2
22
g
3I r
P =
s
2
I = rotor current
s = slip
2
r = rotor resistance per phase
Rotor
u
C Loss
2
2 2 g
= 3I r = sP
Mechanical power developed
? ?
g g g
= P sP = 1-s P ?
Developed Torque,
? ?
? ?
g g
m
e
rs
s
1-s P P
P
T = =
ww
1-s w
?
Torque – Slip Characteristics
If core loss is neglected then equivalent circuit looks like as shown
? ?
? ?
m 1
e
m 11
V jX
V =
r j X X ??
? ?
mm 11
ee
m 1
m 1
r X X X
R = ; X =
XX
XX
?
?
Torque developed,
2
e 2
c
2
2
2
s e e 2
r mV
T =
s
r
w R X X
s
??
??
??
??
??
??
??
????
?? ??
??
?
?
?
?
? ? ?
For Approximate analysis,
Stator impedance is neglected;
2
12
c
2
s
2
2
2
Vr
3
T =
ws
R
X
s
??
??
??
??
??
??
??
??
??
?
?
?
?
?
Read More
Related Exams
About this Document
|
4.80/5 Rating |
|
Dec 22, 2024 Last updated |
Document Description: Short Notes: Induction Machines for Electrical Engineering (EE) 2024 is part of Short Notes for Electrical Engineering preparation.
The notes and questions for Short Notes: Induction Machines have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Short Notes: Induction Machines covers topics
like and Short Notes: Induction Machines Example, for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises and tests below for Short Notes: Induction Machines.
Introduction of Short Notes: Induction Machines in English is available as part of our Short Notes for Electrical Engineering
for Electrical Engineering (EE) & Short Notes: Induction Machines in Hindi for Short Notes for Electrical Engineering course.
Download more important topics related with notes, lectures and mock test series for Electrical Engineering (EE)
Exam by signing up for free. Electrical Engineering (EE): Short Notes: Induction Machines | Short Notes for Electrical Engineering - Electrical Engineering (EE)
Description
Full syllabus notes, lecture & questions for Short Notes: Induction Machines | Short Notes for Electrical Engineering - Electrical Engineering (EE) - Electrical Engineering (EE) | Plus excerises question with solution to help you revise complete syllabus for Short Notes for Electrical Engineering | Best notes, free PDF download
Information about Short Notes: Induction Machines
In this doc you can find the meaning of Short Notes: Induction Machines defined & explained in the simplest way possible. Besides explaining types of
Short Notes: Induction Machines theory, EduRev gives you an ample number of questions to practice Short Notes: Induction Machines tests, examples and also practice Electrical Engineering (EE)
tests
|
Explore Courses for Electrical Engineering (EE) exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
Related Searches
MCQs
,Short Notes: Induction Machines | Short Notes for Electrical Engineering - Electrical Engineering (EE)
,Previous Year Questions with Solutions
,past year papers
,Semester Notes
,Important questions
,Viva Questions
,Short Notes: Induction Machines | Short Notes for Electrical Engineering - Electrical Engineering (EE)
,practice quizzes
,study material
,Exam
,Sample Paper
,Extra Questions
,Short Notes: Induction Machines | Short Notes for Electrical Engineering - Electrical Engineering (EE)
,mock tests for examination
,Summary
,Objective type Questions
,shortcuts and tricks
,video lectures
,Free
,ppt
,
Additional Information about Short Notes: Induction Machines for Electrical Engineering (EE) Preparation
Short Notes: Induction Machines Free PDF Download
The Short Notes: Induction Machines is an invaluable resource that delves deep into the core of the Electrical Engineering (EE) exam.
These study notes are curated by experts and cover all the essential topics and concepts, making your preparation more efficient and effective.
With the help of these notes, you can grasp complex subjects quickly, revise important points easily,
and reinforce your understanding of key concepts. The study notes are presented in a concise and easy-to-understand manner,
allowing you to optimize your learning process. Whether you're looking for best-recommended books, sample papers, study material,
or toppers' notes, this PDF has got you covered. Download the Short Notes: Induction Machines now and kickstart your journey towards success in the Electrical Engineering (EE) exam.
Importance of Short Notes: Induction Machines
The importance of Short Notes: Induction Machines cannot be overstated, especially for Electrical Engineering (EE) aspirants.
This document holds the key to success in the Electrical Engineering (EE) exam.
It offers a detailed understanding of the concept, providing invaluable insights into the topic.
By knowing the concepts well in advance, students can plan their preparation effectively.
Utilize this indispensable guide for a well-rounded preparation and achieve your desired results.
Short Notes: Induction Machines
Short Notes: Induction Machines Notes offer in-depth insights into the specific topic to help you master it with ease.
This comprehensive document covers all aspects related to Short Notes: Induction Machines.
It includes detailed information about the exam syllabus, recommended books, and study materials for a well-rounded preparation.
Practice papers and question papers enable you to assess your progress effectively.
Additionally, the paper analysis provides valuable tips for tackling the exam strategically.
Access to Toppers' notes gives you an edge in understanding complex concepts.
Whether you're a beginner or aiming for advanced proficiency, Short Notes: Induction Machines Notes on EduRev are your ultimate resource for success.
Short Notes: Induction Machines Electrical Engineering (EE) Questions
The "Short Notes: Induction Machines Electrical Engineering (EE) Questions" guide is a valuable resource for all aspiring students preparing for the
Electrical Engineering (EE) exam. It focuses on providing a wide range of practice questions to help students gauge
their understanding of the exam topics. These questions cover the entire syllabus, ensuring comprehensive preparation.
The guide includes previous years' question papers for students to familiarize themselves with the exam's format and difficulty level.
Additionally, it offers subject-specific question banks, allowing students to focus on weak areas and improve their performance.
Study Short Notes: Induction Machines on the App
Students of Electrical Engineering (EE) can study Short Notes: Induction Machines alongwith tests & analysis from the EduRev app,
which will help them while preparing for their exam. Apart from the Short Notes: Induction Machines,
students can also utilize the EduRev App for other study materials such as previous year question papers, syllabus, important questions, etc.
The EduRev App will make your learning easier as you can access it from anywhere you want.
The content of Short Notes: Induction Machines is prepared as per the latest Electrical Engineering (EE) syllabus.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup