This document discusses direct torque control of a three-phase induction motor using a four-switch inverter. It begins by reviewing existing literature on direct torque control methods and their limitations. The author then proposes using direct torque control with space vector modulation to control a four-switch inverter for improved dynamic response, reduced torque ripple, and lower harmonic distortion compared to existing methods. Simulation and hardware results demonstrate the benefits of the proposed method, such as lower torque ripple and current harmonic distortion.
DIRECT TORQUE CONTROL OF THREE PHASE INDUCTION MOTOR USING FOUR SWITCH THREE PHASE INVERTER
1. DIRECT TORQUE CONTROL OF 3
PHASE INDUCTION MOTOR USING
4 SWITCH INVERTER
By:
S.Madhumitha
Reg no:311612415006-MNM Jain Engineering College,Chennai
Guide:
Prof.S.Muthurajan,M.E., M.B.A.,
Associate Professor/EEE
1madhumitha.santhiraj@gmail.com
2. OBJECTIVE
Variable Speed control of three
phase induction motor using a four
switch inverter by Direct Torque
Control.Control.
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3. LITERATURE SURVEY
M.Azab and A.L.Orille IEEE Trans. Ind.
Appl., vol. 22, no. 5, pp. 820-827, 2010.
• “Novel Flux and torque control of
induction motor drive using four switch
inverter”inverter”
• This strategy is penalized by low dynamic
and high ripple of the torque.
• The reason for this is due to the
application of unbalanced voltage vector
to control flux and torque.
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4. LITERATURE SURVEY
B.Bouzidi,B.EL.Basidi,A.Masmoudi,
IEEE Trans. Magn., vol. 48, no. 8, pp.
3133–3136, Aug. 2011.
• Investigation of the performance of a
DTC strategy dedicated to the controlDTC strategy dedicated to the control
induction motor drives”.
• It has been noted that the drive
performance remains relatively low due to
the increase of the CPU time .
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5. LITERATURE SURVEY
J.K.Kang, D.W.Chang and S.K.Sul,IEEE
Trans.Power Electron.,vol.27,no. 5,pp. 2566-
2575,May 2012.
• “Direct torque control of induction machine
with variable amplitude control of flux and
torque hysteresis bands”.torque hysteresis bands”.
• The major drawback in this paper is
uncontrolled switching frequency and high
torque ripple resulting from the use of flux and
torque hysteresis controllers.
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6. LITERATURE SURVEY
M. D. Hennen, M. Niessen, C. Heyers, H. J.
Brauer, and R.W. DeDoncker,
• “Development and control of an integrated and
distributed inverter for a fault tolerant five-
phase switched reluctance traction drive,”
• A concept of an integrated and distributed• A concept of an integrated and distributed
inverter for switched reluctance machines is
introduced. The distribution is achieved by
supplying each phase coil with its own modular
inverter. Each inverter module is placed evenly
around the end of the stator stack next to its
dedicated coil.
• The main drawback of this is increased losses
and cost.
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7. EXISTING METHOD
• The speed control of three phase induction
motor from stator side are further classified as:
• V / f control or frequency control
• changing the number of stator poles
• controlling supply voltage
• adding rheostat in the stator circuit
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16. DISADVANTAGES OF
EXISTING METHOD
• Harmonic content in motor current
increases at low speed.
• The machine saturates at light loads due
to high V/f ratio.
• These effects overheat the machine at
low speed.
• Smooth speed control of induction motor
is not possible.
• The cost of the method is high but less
efficient.
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17. PROPOSED METHOD
• The speed control of induction motor
is done using direct torque control
with four switch three phase inverter.
• The switching technique used is space• The switching technique used is space
vector modulation technique.
• The two phases are connected to the
two legs of the inverter, while the third
phase is connected to the mid point of
the dc-bus voltage.
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21. SPACE VECTOR
MODULATION
• Technique to generate PWM load line voltages that
are in average equal to a given load line voltage.
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22. SPACE VECTORS GENERATED
USING FSTPI
•The four vectors are
generated are unbalanced so
in order to generate balance
voltage vectors Vij the
voltage vectors resulting
from the sums of successive
voltage vectors Vi and Vj is
used.used.
•This makes the operation of
FSTPI similar to SSTPI.
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23. SPACE VECTOR
MODULATION
• The active voltage generated by SSTPI has a amplitude
equal to
• Where is the DC bus voltage
• For the same value the FSTPI produces voltages with
different amplitudedifferent amplitude
• With and
• Note that the voltage vector resulting from the sum of
successive voltage vector and with
and
• can be expressed as follows,
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24. DIRECT TORQUE
CONTROL
• Stator flux linkage is estimated by
integrating the stator voltages.
• Torque is estimated as a cross
product of estimated stator fluxproduct of estimated stator flux
linkage vector and measured motor
current vector.
• The estimated flux magnitude and
torque are then compared with their
reference values.
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25. ADVANTAGES OF SVM DTC
• SVM-DTC technique gives ripple free
operation for entire speed range.
• Improvement in flux, torque, speed
response.response.
• Response is fast and controller is
robust like BASIC DTC
• Switching frequency is high and
controllable
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26. ADVANTAGES OF SVM DTC
• When load is changed from no load to rated value,
torque changes to rated value with staring
transients and ripples are less and 10 % variation
from base torque value is observed.from base torque value is observed.
• Speed attains its base value smoothly.
• Ripples are less observed in stator flux only
4%variations from the reference flux value.
• Ripples are less in stator phase currents.
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27. ADVANTAGES OF DTC SVM
• Constant switching frequency SVM-
DTC schemes improve
• Therefore, SVM-DTC is an excellent• Therefore, SVM-DTC is an excellent
solution for general purpose IM drives
in a very wide power range.
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28. ADVANTAGES OF DTC
• DTC strategy is used to control the
switching frequency.
• Harmonic distortion in the motor• Harmonic distortion in the motor
phase current is reduced.
• Inverter switching losses are reduced.
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29. ADVANTAGES OF
PROPOSED METHOD
• The number of switches are reduced.
• Switching losses are reduced.
• Harmonics are also reduced.
• The efficiency is increased.
• Overall cost of the system is reduced.
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30. COMPARISON
CONVENTIONAL
METHOD
PROPOSED METHOD
•Exhibits torque ripples of
higher amplitude and
•Exhibits torque ripple
which has the lowesthigher amplitude and
frequency.
which has the lowest
amplitude and frequency.
•THD of Ias is equal to
17.4%
•THD of Ias is equal to
11%
•THD of Ics is equal to
14.6%
•THD of Ics is equal to
12.5%
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31. APPLICATIONS
• Fans, Compressor, Pumps, blowers,
machine tools like lathe, drilling machine,
lifts, conveyer belts etc.
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35. MICROCONTROLLER
• PIC16F877A used
• 40 pin device
having five I/Ohaving five I/O
ports
• Have 8 A/D input
channels
• Parallel slave port is
implemented
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36. TLP250 - DRIVER CIRCUIT
• TLP250 is an
opto isolated gate
driver
• 8−lead DIP• 8−lead DIP
package
• Fast gate
switching
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42. REFERENCES
1] Takahashi, and T. Noguchi, “A new quick-response
and high-efficiency control strategy of an induction
motor,” IEEE Trans. Ind. Appl., vol. 22, no. 5, pp.
820-827, 2012.
2] F. Khoucha, S.M.Lagoun, K. Marouani, A. Kheloui,2] F. Khoucha, S.M.Lagoun, K. Marouani, A. Kheloui,
and M.E. H. Benbouzid, “Hybrid cascaded h-bridge
multi level inverter induction-motor drive direct
torque control for automotive applications,” IEEE
Trans. Ind. Electron., vol. 57, no. 3, pp. 892-899,
2010.
42
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43. REFERENCES
3] A. Dey, B. Singh, D. Chandra, and B. Dwivedi, “A
novel approach to minimize torque ripples in DTC
induction motor drive,” Proc. IEEE Int. Conf.
Power, Control and Embedded SystemsPower, Control and Embedded Systems
(ICPCES’10), pp. 1-6, Allahabad, India, November-
December, 2010.
43
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44. REFERENCES
4] L. Gao, J. E. Fletcher, and L. Zheng, “Low-speed control
improvements for a two-level five-phase inverter-fed induction
machine using classic direct torque control,” IEEE Trans. Ind.
Electron., vol. 58, no. 7, pp. 2744-2754, 2011.Electron., vol. 58, no. 7, pp. 2744-2754, 2011.
5] A. Jidin, N. R. N. Idris, A. H. M. Yatim, T. Sutikno, and M. E.
Elbuluk, “An optimized switching strategy for quick dynamic
torque control in DTC-hysteresis-based induction machines,”
IEEE Trans. Ind. Electron., vol. 58, no. 8, pp. 3391-3400, 2011
44
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45. REFERENCES
6] M. N. Uddin and M. Hafeez, “FLC-based DTC
scheme to improve the dynamic performance of an
IM drive,” IEEE Trans. Ind. Appl., vol. 48, no. 2, pp.
823–831, Mar./Apr. 2012.
7] R. Wang, J. Zhao, and Y. Liu, “A comprehensive
investigation of four switch three-phase voltageinvestigation of four switch three-phase voltage
source inverter based on double fourier integral
analysis,” IEEE Trans. Power Electron., vol. 26, no.
10, pp. 2774–2787,Oct. 2011.
45madhumitha.santhiraj@gmail.com
46. REFERENCES
8] Z. Zhifeng, T. Renyuyan, B. Boadong, and X.
Dexin, “Novel direct torque control based on
space vector modulation with adaptive stator flux
observer for induction motors,” IEEE Trans.
Magn., vol. 48, no. 8, pp. 3133–3136, Aug. 2010.
9] Y.Zhang and J. Zhu, “Direct torque control of
permanent magnet motor with reduced torque
ripple and commutation frequency” IEEE Trans.
Power Electron., vol. 26, no. 1, pp. 235–248, Jan.
2011
46santhiraj.madhumitha@gmail.com