This document summarizes a research paper on implementing smooth transitions between optimal control modes in a switched reluctance motor (SRM). It begins with introductions to SRM technology and an overview of the paper contents. It then covers the operating principles, characteristics, control strategies, and modes of operation of SRMs. The document describes the development of a Simulink model for a proposed optimal controller, including subsystems for pulse width modulation and single pulse control. Simulation results are presented and analyzed for no-load operation, with load, and under speed and torque dynamics. The analysis shows the controller varies turn-on and turn-off angles optimally under different operating conditions to reduce ripple and enable smooth transitions between control modes. The conclusion
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1. Smooth transition between optimal
control modes in
SWITCH RELUCTANCE MOTOR
By- Badal Patnaik - 1001227260
Sanjit Debta - 1001227317
D. Gouri Sankar - 1001227269
Debendra Kido - 1001227267
Ananya Subhadarsinee - 1001227255
2. Content
Introduction
Principle of operation
Characteristics
General control strategy
Modes of operation
Simulink model for proposed controller
Simulation results and Analysis
Conclusion
References
3. Introduction
Concept of SRM-1938
Practical realization-mid 1960s,after the evolution of power
electronics & computer aided EM design
Also known as : -Variable Reluctance Motor
-Brushless Reluctance Motor
-Commutated Reluctance Motor
4. Construction
Its a doubly-salient, singly-
excited, independent stator
exited motor
The stator is same as PM
motor but the rotor is
simpler having no permanent
magnet
Stator windings on
diametrically opposite poles
are connected in series or
parallel to form one phase
6. Content
Introduction
Principle of operation
Characteristics
General control strategy
Modes of operation
Simulink model for proposed controller
Simulation results and Analysis
Conclusion
References
8. Principle of Operation
Inductance of stator phase winding varies with rotor
position
Torque is produced only during variation of inductance
Current is made available only during this variation, hence
the need for rotor position feed back sensor
9. Periodic change of inductance with
Rotor position
Rotor
Unaligned Position
Lu
La
Inductance Profile
Stator
Aligned
PositionRotor
慮1 慮3慮2 慮4
慮
L
10. Content
Introduction
Principle of operation
Characteristics
General control strategy
Modes of operation
Simulink model for proposed controller
Simulation results and Analysis
Conclusion
References
11. Characteristics of SRM
All these characteristics cannot be obtained at a
single operating point.
HENCE THE NEED OF OPTIMAL CONTROL STRATEGY
12. Content
Introduction
Principle of operation
Characteristics
General control strategy
Modes of operation
Simulink model for proposed controller
Simulation results and Analysis
Conclusion
References
14. Voltage Source control
Both transistors are switched on at 慮0and both are switched off at 慮cConducts through D2 and D1 when negative voltage is applied between 慮c and 慮q
17. Hysteresis current control
Power switches are switched off or on according to the current is
greater than or less than a reference current.
The instantaneous phase current is measured and fed back to
summing junction.
The error is used directly to control the states of power
transistors.
19. SRM with hysteresis current controller
iref
Hysteresis Current
Controller
Converter
6/4
SRM
V
i
i
20. Content
Introduction
Principle of operation
Characteristics
General control strategy
Modes of operation
Simulink model for proposed controller
Simulation results and Analysis
Conclusion
References
22. Optimum Performance in Single Pulse mode
L, 率
La
L
Lu
率c
率
慮
慮u慮a慮q慮c慮1
慮u
慮0
慮01
慮
硫s
硫r
留p
慮q慮c慮1
慮u
慮0
慮e1 慮e2
-Vdc
Vdc
23. Optimum turn-on & turn-off angle in
single Pulse mode
11 e
opt
o c 縁縁
11 1 e
opt
c c 縁縁
24. Optimum Performance in PWM mode
La
Lu
L
慮
慮
慮1慮u
慮01
i
慮0 慮c 慮q
慮e
慮a
Vdc
iref
率c
-Vdc
慮u
硫s
硫r
留p
25. Optimum turn-on & turn-off angle in
PWM mode
dc
refu
V
iL
縁 10
e
esk
opt
c
縁縁縁 01
1 12
26. Content
Introduction
Principle of operation
Characteristics
General control strategy
Modes of operation
Simulink model for proposed controller
Simulation results and Analysis
Conclusion
References
31. Parameters of the 6/4 SRM
Voltage = 240V dc,
Current = 450A max,
Rating of the SRM = 60 kw
No. of phases = 3
No. of stator poles =6
No. of stator poles =4
Rotor pole pitch = 90 deg
Stator pole arc = 36.00 deg
Rotor pole arc = 38.50 deg
Rotor position at which stator
and rotor pole corners starts
overlap =52.50 deg
Aligned inductance =23.6x10-
03 H
Unaligned
inductance=0.67x10-03 H
Max flux linkage=0.486 V.s
Stator resistance=0.05 ohm
Inertia=0.05 Kg.m.m
Friction=0.02 N.m.s
Base speed = 3100 rpm
32. Content
Introduction
Principle of operation
Characteristics
General control strategy
Modes of operation
Simulink model for proposed controller
Simulation results and Analysis
Conclusion
References
39. Analysis of simulation results on No-load
Type of controller
at steady state rpm
0f 6560
PWM mode Single pulse mode
Turn-on
(degree)
Turn-off
(degree)
Current
ripple
(Amps)
Torque
ripple
(Nm)
Turn-on
(degree)
Turn-off
(degree)
Current ripple
(steady state)
(Amps)
Torque ripple
(steady state)
(Nm)
Basic 45 75 0 to 200
(200)
36 to 148
(112)
45 75 0 to 30.5 (30.5) 10 to 18
(8)
Developed 52.5 to
52.3
104 to 81 0 to 230
(230)
30 to 100
(70)
45.2 72 to 75 0 to 30
(30)
10 to 17.5
(7.5)
40. Analysis on No-load
The developed controller operates with varied turn-on and turn-of
angles.
The torque ripple is reduced in both PWM and single pulse mode
when the SRM is used with the developed controller.
This is one aspect of the optimal performance of the SRM with the
developed controller.
While operating at steady state in single pulse mode, the
maximum current/current ripple is less when the SRM is used with
the developed controller.
The transition is smooth in terms of flux, current, torque or speed
when the motor shifts its operation from PWM mode to single
pulse mode.
SRM delivers better performance when used with a controller
having varied turn-on and turn-off angles
The turn-on and turn-off angles are varied at every instant in
synchronization with the formulae for optimal condition.
50. With torque dynamics : turn-off angle
Tu
rn
off
an
gle
(de
g)
Time (sec)
1 2 3 4 5 6 7
60
70
80
90
100
110
51. Analysis of Simulation results on Load
Application PWM mode Single-pulse mode
Turn-on
angle (degree)
Turn-off
angle(degree)
Turn-on
angle (degree)
Turn-off
angle(degree)
80 Nm of load at 6560 rpm ref speed 52.5 to 52 128 to 72 43 to 32.2 64 to 78
Steep increase of load from 5 to 20
Nm at 6560 rpm ref speed
52.5 to 52.2 104 to74 41.2 to 40 to 40.2
to 35.8
66 to 68 to73
Steep increase of speed from 6560 to
8000 rpm at 5 Nm of load
52.5 to 52.2 104 to74 41.2 to 40 to 40.2
to 34.4 to 36
67 to 68 to 75 to
73
52. Analysis on Load
The controller operates by varying the turn-on and turn-off angles at every
instant as per the requirement of that operating point.
When the operation of the motor shifts from PWM mode to single pulse
mode, the turn-on angle is advanced to cater to the torque demand as the
overlapping of the phases is reduced.
When there is a sudden increase of load from 5 Nm to 20 Nm or sudden
increase of speed from 5650 rpm to 8000 rpm the turn-on angle is advanced
and the turn-off angle is retarded to balance the new torque demand.
The emphasis is made to show that to maintain optimal operating condition
the turn-on and turn-off angles vary to make the transition smooth between
the two optimal control modes
It is proved now that the developed controller is able to control the SRM
over its entire speed and torque range.
53. Content
Introduction
Principle of operation
Characteristics
General control strategy
Modes of operation
Simulink model for proposed controller
Simulation results and Analysis
Conclusion
References
54. CONCLUSION
This project studies optimal control modes of the SRM by striking
a balance between maximum efficiency and minimum torque
ripple and thus calculates the optimum switch on angles and
switch off angles.
The turn on and turn off angles are calculated through simple
formulas and implemented through Simulink building blocks.
The optimum controller determines the turn-on and turn-off
angles at every instant and accordingly the converter switches are
fired to cater to the torque and speed demand of that instant.
To validate the effectiveness of the controller, simulation is carried
out on a variety of load and speed combination and the
effectiveness is verified.
55. REFERENCES
[1] C.J. Van Duijn, Development of methods, algorithms and soft wares for optimal design of
switched reluctance drives
[2] F. Soares and P.J. Costa Branco, Simulation of a 6/4 switched reluctance motor based on
Matlab/Simulink environment
[3] R Krishnan, Switched Reluctance Motor Drives; Modeling, Simulation, Analysis, Design and
Applications
[4] Han-Kyung Bae, Control of Switched Reluctance Motors considering mutual inductance
[5] Ardeshir Motomedi-Sedeh, Speed control of switched reluctance motors
[6] M. T. DiRenzo, "Switched Reluctance Motor Control Basic Operation and Example Using the
TMS320F240, Texas Instruments Application Note," 2000.
[7] C. Mademlis and I. Kioskeridis, Performance optimization in switched reluctance motor drives
with online commutation angle control, IEEE
[8] C. Mademlis and I. Kioskeridis, Maximum efficiency in Single Pulse Controlled switched
reluctance motor drives, IEEE
[9] C. Mademlis and I. Kioskeridis, Smooth Transition between Optimal Control Modes in switched
reluctance motoring, IEEE
[10] Matlab R 2008a, Version 7.6