GUIDE: Prof. Jiji K S • Amal Joseph K • Anoop S • Asish Jacob James • Faheem Ali T • Hosni K • Jacob Mathew K
Jul 06, 2015
GUIDE: Prof. Jiji K S
• Amal Joseph K
• Anoop S
• Asish Jacob James
• Faheem Ali T
• Hosni K
• Jacob Mathew K
CONTENTS
INTRODUCTION
BLDC MOTOR
WORKING
PROJECT OVERVIEW
SCHEDULE
COST
REFERENCE
2
INTRODUCTION
DC motors – permanent magnet stator and armature is an electromagnet
They need brushes as the supply is given to rotating armature.
Disadvantages- wearing of brushes, noise, sparking, limitations in max speed and no of poles.
Brushless DC (BLDC) motor- permanent magnet rotor and supply is given to stator.
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WHY BLDC..???
Better speed versus torque characteristics
High dynamic response
High efficiency
Long operating life
Noiseless operation
Higher speed ranges
Compact form
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BLDC MOTOR
No commutators or brushes
Position of coils with respect to the magnetic field is sensed electronically.
Current is commutated through electronic switches to appropriate phases. 5
WORKING
6
PROJECT OVERVIEW
Design
Analysis
Fabrication
Control circuit
Testing
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DESIGN
110 V, 25W, 600RPM
STATOR
• No. of phases : 3• No. of slots : 6• No. of turns : 435-480• Stack length : 11.5 ± 0.5• Stack outer dia : 87mm• Stack inner dia :56.2 ± 0.2mm
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• Width of stator teeth
• Total no of conductors
• No of conductors per slot
• Area of stator slot
9
DESIGN EQUATIONS
10
11
ROTOR
12
13
14
SHAFT
ANALYSIS
From the design constraints of RDSO, analysis was done using MAXWELL 2D
15
Torque vs Speed curve
0.00 10000.00 20000.00 30000.00 40000.00n (rpm)
0.000
0.001
0.002
0.003
0.004
0.005
0.006
(N
.m)
ANSOFT
Curve Info
Output Torque
16
0.00 125.00 250.00 375.00ElectricalDegree [deg]
-3.75
-2.50
-1.25
0.00
1.25
2.50
3.75
Ph
ase
Cu
rre
nt1
a [A
]
RMxprtDesign1XY Plot 1 ANSOFT
Curve Info
PhaseCurrent1aSetup1 : Performance
0.00 125.00 250.00 375.00ElectricalDegree [deg]
-3.75
-2.50
-1.25
0.00
1.25
2.50
3.75
Ph
ase
Cu
rre
nt1
b [A
]
RMxprtDesign1XY Plot 2 ANSOFT
Curve Info
PhaseCurrent1bSetup1 : Performance
0.00 125.00 250.00 375.00ElectricalDegree [deg]
-3.75
-2.50
-1.25
0.00
1.25
2.50
3.75
Ph
ase
Cu
rre
nt1
c [A
]
RMxprtDesign1XY Plot 3 ANSOFT
Curve Info
PhaseCurrent1cSetup1 : Performance
Phase A
Phase B
Phase C
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FABRICATION
TESTINGASSEMBLING
ANALYSISDESIGN
PROCUREMENT OF RAW MATERIALS
MOTOR ASSEMBLY
18
STAMPING STACKINGSTACK
INSULATIONWINDING PREPPING
STATOR ASSEMBLY
19
24
ROTOR ASSEMBLY
SHAFT MACHINING
HUB MACHINING
MAGNET GLUING
BEARING PRESS
29
ASSEMBLED MOTOR
30
CONTROL CIRCUIT
Open loop control
Motor is started at a slower speed and slowly brought to its rated speed
Power circuit – 3 phase inverter using mosfet
Gate driving circuit – using optocoupler
4 isolated gate driver circuits are used to drive the mosfets
31
POWER CIRCUIT
32
33
GATE DRIVING CIRCUIT
34
12 V
G
35
8051 SIMULATION RESULT
36
TESTING
Heating test on permanent magnet
Insulation resistance
Dielectric test
37
RESULT
38
FUTURE DEVELOPMENTS
For motors of rating above 300 watts specialized sensor less driver ic’s can be used.
Back emf detection principle
One of the windings will always be in floating state
Back emf in the floating winding can be used to know which phase has to be excited
39
BLOCK DIAGRAM
A4960
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SCHEDULE
DATE WORK PROGRESS
8/10/2012 Collected required study materials
14/11/2012 Started design procedure
23/1/2013 Technical assistance from KEL
26/2/2013 Placed order for motor components
10/4/2013 Completed winding process
26/4/2013 Completed motor assembly
29/4/2013 Final submission
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MANUFACTURING COST
ITEM PRICE QUANTITY TOTAL
M-45 CRNGO silicon steel
400/kg 680 gm. 272
Rotor magnet 125 1 125
Stamping 300/ hr. 5 hr. 1500
29 SWG Cu wire 740/kg 175 gm. 130
6000 2RS bearing 35 1 35
Lathe work 3000 1 3000
IC 8051 75 1 75
Circuit components 1785 1 1785
Total 6972
42
REFERENCE
• RDSO spec sheet for 400mm sweep bldc fan
• Brushless DC (BLDC) Motor Fundamentals-Padmaraja Yedamale Microchip
• Design and Development of Three Phase Permanent Magnet Brushless DC (PM BLDC)-Srinivas Mallapalli-GE Global Research, GE India Technology Centre
• Design of a Compact BLDC motor for Transient Applications Y.K. Chin, W.M. Arshad, T. Bäckström & C. Sadarangani
• A4960 data sheet by allegro micro systems43
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