EE0309
DESIGN OF ELECTRICAL APPARATUS
Prerequisite
EE 0201,EE 0202
L T P
3 1 0
C
4
PURPOSE
To enable the students gain fair knowledge on design of magnetic circuits and electrical
Machines.
INSTRUCTIONAL OBJECTIVES
At the end of the course the students will be able to:
1. Understand basics of design considerations for rotating and static electrical machines
2. Design the single phase and three phase transformers
3. Design rotating DC electrical machines
4. Design rotating AC electrical machines (3 Phase and Single phase Induction motor,
Synchronous motor)
STUDENT OUTCOMES FOR THE PROGRAM
(a) an ability to apply knowledge of mathematics, science, and engineering
(b) an ability to design and conduct experiments, as well as to analyze and interpret data
(c) an ability to design a system, component, or process to meet desired needs within
realistic constraints such as economic, environmental, social, political, ethical, health and
safety, manufacturability, and sustainability
(e) an ability to identify, formulate, and solve engineering problems
(k) an ability to use the techniques, skills, and modern engineering tools necessary for
engineering practice.
BASIC CONSIDERATION IN DESIGN
Classification of Areas of Design, Electrical Engineering materials – conducting, insulating
& magnetic materials, design limitations and specifications, modes of Heat dissipation,
Internal temperature, temperature gradient in cores & slots, thermal resistively of winding.
TRANSFORMERS
Output equation of single phase and three phase transformers – window space factor – overall
dimensions – design of core and windings, design of tank with cooling tubes – core area
factor.
DESIGN OF DC MACHINES
Magnetic circuit calculations – total gap contraction factor, net length of Iron, MMF for air
gap, MMF for teeth, real and apparent flux densities. Output equation for DC machine,
choice of specific loadings, selection of number of poles, separation of D and L, Armature
Design – selection of number of slots, number of conductors, number of coils, Design of
commentator and brushes.
DESIGN OF THREE PHASE INDUCTION MOTORS
Output equation for induction motor – choice of specific loadings, separation of D and L, L/τ
criteria, Armature Design – selection of number of slots, number of conductors,
determination of depth of core and other dimensions. Design of squirrel cage rotor, design of
wound rotor.
DESIGN OF SYNCHRONOUS MACHINES
Pole construction – run away speed – output equation, choice of specific loading, separation
of D and L, design of armature – number of slots, number of conductors. Determination of
depth of core and other dimensions, Estimation of air gap length, short circuit ratio – Design
of field system.
TEXT BOOKS
1. Mittle V.M. and Mittle.A, Design of Electrical Machines, standard publishers Distribution,
Fourth edition, 1996.
2. Sawhney, A.K. A course in Electrical Machine Design, Dhanpat rai & sons, 1993.
REFERENCE BOOKS
1. Rai, H.M. Electrical Machine Design, Sathiya Prakashan Publications, Third edition, 1992.
2. Say M.G., The Performance & Design of Alternating current Machines Isaac Pitman &
sons Ltd., London 1995.
3. Clayton, A.E., Performance & Design of Direct current Machines, English Language Book
society & Sri Isaac Pitman & sons Ltd., London 1995
Hour
.No
1
2
3
4
5
6
7
8
Topics covered
Conducting, insulating & magnetic materials
Design limitations and specifications
A,C
Understand basics of
design considerations
for rotating and static
electrical machines
Modes of Heat dissipation
Internal temperature
Temperature gradient in cores & slots,
Thermal resistively of winding
Output equation of single phase transformers
10
Output equation of three phase transformers
11
Window space factor
12
Overall dimensions
13
Design of core and windings
Design of tank with cooling tubes – core area
factor
15
Magnetic circuit calculations
16
Total gap contraction factor,
17
Program
Outcome
Classification of Areas of Design
Electrical Engineering materials
9
14
Instructional
OBJECTIVES
Net length of Iron
18
MMF for air gap, MMF for teeth,
19
Real and apparent flux densities
Design the single
phase and three phase
transformers
C,E,K
Design rotating DC
electrical machines
C,E,K
20
Output equation for DC machine
21
Choice of specific loadings
22
23
Selection of number of poles
Armature Design
24
Selection of number of slots
25
Number of conductors, number of coils
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Design rotating DC
electrical machines
C,E,K
Design of commentator
Design of brushes
Output equation for induction motor
Choice of specific loadings, separation of D
and L, L/ criteria,
Armature Design
Selection of number of slots
Number of conductors
Determination of depth of core and other
dimensions
Design rotating AC
electrical machines (3
Phase and Single
phase Induction motor,
Synchronous motor
C,E,K
Design rotating AC
electrical machines (3
Phase and Single
phase Induction motor,
Synchronous motor
A,B,E
Design of squirrel cage rotor,
Design of wound rotor
Pole construction – run away speed
Output equation of synchronous machine,
Choice of specific loading, separation of D and L
Design of armature
Number of slots
Number of conductors
Determination of depth of core and other
dimensions
Estimation of air gap length
Short circuit ratio
Design of field system