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DIRECT TORQUE CONTROL OF 3
PHASE INDUCTION MOTOR USING
4 SWITCH INVERTER
By:
S.MadhumithaReg no:311612415006-MNM Jain Engineering College,Chennai
Guide:
Prof.S.Muthurajan,M.E., M.B.A.,
Associate Professor/EEE
OBJECTIVE
Variable Speed control of three phase induction motor using a four switch inverter by Direct Torque Control.Control.
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.3
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 aDTC strategy dedicated to the controlDTC strategy dedicated to the controlinduction motor drives”.
• It has been noted that the driveperformance remains relatively low due tothe increase of the CPU time .
4madhumitha.santhiraj @gmail.com
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.
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 distributedinverter for switched reluctance machines isintroduced. The distribution is achieved bysupplying each phase coil with its own modularinverter. Each inverter module is placed evenlyaround the end of the stator stack next to itsdedicated coil.
• The main drawback of this is increased lossesand cost.
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
DISADVANTAGES OF
EXISTING METHOD• Harmonic content in motor current
increases at low speed.
• The machine saturates at light loads dueto high V/f ratio.
• These effects overheat the machine atlow speed.
• Smooth speed control of induction motoris not possible.
• The cost of the method is high but lessefficient.
PROPOSED METHOD
• The speed control of induction motoris done using direct torque controlwith four switch three phase inverter.
• The switching technique used is space• The switching technique used is spacevector modulation technique.
• The two phases are connected to thetwo legs of the inverter, while the thirdphase is connected to the mid point ofthe dc-bus voltage.
CONCEPTUAL DESIGN
EXISTING METHOD PROPOSED METHOD
HARDWARE FABRICATION
MODULES TESTING
SIMULATION BY MATLAB
PIC 16 BIT CONTROLER MOSFET 4 SWITCH INVERTER
EXISTING METHOD PROPOSED METHOD
SPACE VECTOR
MODULATION
• Technique to generate PWM load line voltages that
are in average equal to a given load line voltage.
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.
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,
DIRECT TORQUE
CONTROL• Stator flux linkage is estimated by
integrating the stator voltages.
• Torque is estimated as a crossproduct of estimated stator fluxproduct of estimated stator fluxlinkage vector and measured motorcurrent vector.
• The estimated flux magnitude andtorque are then compared with theirreference values.
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
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.
ADVANTAGES OF DTC SVM
• Constant switching frequency SVM-DTC schemes improve
• Therefore, SVM-DTC is an excellent• Therefore, SVM-DTC is an excellentsolution for general purpose IM drivesin a very wide power range.
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.
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.
COMPARISON
CONVENTIONAL
METHOD
PROPOSED METHOD
•Exhibits torque ripples of higher amplitude and
•Exhibits torque ripple which has the lowest higher 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%
APPLICATIONS
• Fans, Compressor, Pumps, blowers, machine tools like lathe, drilling machine, lifts, conveyer belts etc.
MICROCONTROLLER
• PIC16F877A used
• 40 pin device having five I/O having five I/O ports
• Have 8 A/D input channels
• Parallel slave port is implemented
TLP250 - DRIVER CIRCUIT
• TLP250 is an opto isolated gate driver
• 8−lead DIP • 8−lead DIP package
• Fast gate switching
HARDWARE CIRCUIT
U4
TLP250
2
81
6
5
7
3
4
U6
TLP250
2
81
6
5
7
3
4
U11
TLP250
2
81
6
5
7
3
4
U13
TLP250
2
81
6
5
7
3
4
1
MOSFET DUAL G/N
4
MOSFET DUAL G/N
3
MOSFET DUAL G/N
6
MOSFET DUAL G/N
BT1
BATTERY ELEM
M~3
MO1
MOTOR AC
U7
PIC16F877A
VDD2
RB010
RB111
RB212
RB313
RB414
RB515
RB616
RB717
RC018
RC119
RC220
RC321
RC422
RC523
RC624
RC725
OSC2/CLKOUT26
TOCKI1
OSC1/CLKIN27
MCLR28
RA06
RA17
RA28
RA39
C1
CAPACITOR
C2
CAPACITOR
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.
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.
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
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 voltage investigation 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.
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
