An advanced direct torque control (DTC) technique using Model predictive control (MPC) is proposed for matrix converter (MC)-based permanent-magnet synchronous motor (PMSM) drive system, which reduces the torque ripples, does not need the duty cycle calculation, and ensures the fixed switching frequency. Analytical expressions of change rates of torque and flux of PMSM as a function of MC - dqo components are derived. The predictive model of PMSM and MC is realized by means of State model. Then, the advanced MC-fed DTC algorithm is implemented based on Cost function evaluation. The simulation results exhibit remarkable torque ripple reduction with the help of MPC. As a result, the proposed strategy is proved to be effective in minimizing the torque ripples for MC-based PMSM drives.
A NEW FUZZY LOGIC BASED SPACE VECTOR MODULATION APPROACH ON DIRECT TORQUE CON...csandit
The induction motors are indispensable motor types for industrial applications due to its wellknown
advantages. Therefore, many kind of control scheme are proposed for induction motors
over the past years and direct torque control has gained great importance inside of them due to
fast dynamic torque response behavior and simple control structure. This paper suggests a new
approach on the direct torque controlled induction motors, Fuzzy logic based space vector
modulation, to overcome disadvantages of conventional direct torque control like high torque
ripple. In the proposed approach, optimum switching states are calculated by fuzzy logic
controller and applied by space vector pulse width modulator to voltage source inverter. In
order to test and compare the proposed DTC scheme with conventional DTC scheme
simulations, in Matlab/Simulink, have been carried out in different speed and load conditions.
The simulation results showed that a significant improvement in the dynamic torque and speed
responses when compared to the conventional DTC scheme.
MODELLING AND IMPLEMENTATION OF AN IMPROVED DSVM SCHEME FOR PMSM DTCpaperpublications3
Abstract: A very widely used drive strategy for PMSM is the field oriented control (FOC), which was proposed in 1971 for induction motors (IMs). However, the FOC scheme is quite complex due to the reference frame transformation and its high dependence upon the motor parameters and speed. To mitigate these problems, a new control strategy for the torque control of induction motor was developed by Takahashi known as the direct torque control (DTC) and by Depenbrock as the direct self control (DSC). The basic direct torque control (DTC) scheme may cause undesired torque, flux and current ripples because of the small number of applicable voltage vectors. The control system should be able to generate any voltage vector, implying the use of space vector modulation (SVM) which complicates the control scheme. The discrete space vector modulation (DSVM) method was proposed for DTC to overcome this problem which replaces the simple switching table by several switching tables, to apply a combination of three voltage vectors in the same sampling period. In this paper, after a brief review of the primary concept of DSVM DTC technique, a new scheme of DSVM DTC for PMSM is proposed with a new set of switching tables taking into account the motor speed and the absolute values of torque and flux feedback errors. In one fixed sampling time interval, three vectors are applied to the motor including the two null vectors. Comparisons of the basic DTC and the improved DSVM DTC schemes are made based on the system performance and switching loss. For this purpose the DSVM technique uses prefixed time intervals within a sampling cycle to synthesize a higher number of voltage vectors than the basic DTC scheme. A set of switching table is carried out to minimize the torque error. An optimal vector selector is developed to reduce the switching loss and make the system more stable. The sampling period does not need to be doubled in order to achieve a mean switching frequency practically equal to that of the basic DTC scheme. For a comparable performance, the switching loss of the proposed scheme is less than that of the basic DTC method. The vector application sequence is investigated and an optimal algorithm is developed to reduce the switching loss and torque ripple. Simulation and experiments on the improved DSVM DTC are carried out and compared with those on the basic DTC scheme.
[9_CV] FCS-Model Predictive Control of Induction Motors feed by MultilLevel C...Nam Thanh
Ha Thanh Vo, Nam Thanh Hoang, Phuong Hoang Vu, Minh Trong Tran, Dich Quang Nguyen, “FCS-Model Predictive Control of Induction Motors feed by MultilLevel Casaded H-Bridge Inverter”, RCEEE-2018.
FLC-Based DTC Scheme for a New Approach of Two-Leg VSI Fed Induction MotorIJERA Editor
A new Direct Torque Control (DTC) strategy for Induction Motor (IM) drive fed by a two leg three phase
inverter (i.e., Four switches are used in VSI) was proposed in this paper. The proposed methodology is based on
the emulation of operation of the conventional Six-switch three phase inverter. The combination of four
unbalanced voltage vectors is generated by the two-leg three phase inverter, approaching to the synthesis of the
six balanced voltage vectors of the conventional DTC. This approach has been implemented in the design of the
vector selection table of the proposed DTC strategy. Further, Fuzzy Logic Controller (FLC) is proposed in the
speed controller for the improvement of torque ripples. Convention DTC with Six Switch three phase VSI, twoleg
three phase VSI with PI and Fuzzy Controller are implemented using MATLAB/SIMULINK. Simulation
results have shown that the proposed DTC strategy, two-leg inverter fed IM drive revealed an improved
performance.
DSP-Based Sensorless Speed Control of a Permanent Magnet Synchronous Motor us...IJPEDS-IAES
In this paper, experimental results of 3-phase permanent magnet synchronous motor (PMSM) sensorless speed control are presented. To estimate the rotor position, a sliding mode current observer (SMCO) was implemented. This observer estimates the back emfs of the motor in the stationary reference frame using only the measured voltages and currents of the motor. These emfs were utilized to obtain the rotor position. The speed of the motor was calculated by differentiating the rotor position angle. The stability of the proposed SMCO was verified using Lyapunov method to determine the observer gain. The saturation function was adopted in order to reduce the chattering phenomenon caused by the SMCO. A vector control method was employed to achieve the sensorless drive system. The control application was developed in C/C++ language and implemented using the Texas Instruments TMS320LF2812 digital signal processor (DSP). This new processor enables intelligent control for motors. We used to test the drive the MCK2812 which is a professional development kit available from Technosoft Company. The theoretical finding is validated with experimental results that show the effectiveness of the real-time implementation.
Simulation and Analysis of Modified DTC of PMSMIJECEIAES
This research paper describes the simulation and analysis of the modified DTC for Surface mounted Permanent Magnet Synchronous Motor (SPMSM) using PI controller. Among all of the various drive systems,PMSM is widely used for accurate speed and torque control, with greater efficiency, superior torque to inertia and high power density.The Conventional DTC secheme widely used for this purpose but it is failed to achieve desirable performance of the system for which the modified DTC secheme is propsed.The modified DTC algorithm controls the voltage vectors, directly from a simple look up table depending on outcome of the torque and indirectly flux controllers.The overall drive system can be implemented in SIMULINK/MATLAB environment.The modified DTC is validated with loading conditions.The simulated results are focused on the speed, settling time at loaded conditions, torque and flux linkages ripple and THD in the phase current for modified DTC applied to SPMSM.
The application of the direct torque control strategy for induction machine drives is mainly characterized by torque and flux distortions caused by voltage vector limitation. The goal of this paper is to perform the conventional DTC induction machine drives and reduce ripples of both flux and torque response. The proposed contribution is based on the control of the DC output side of the rectifier feeding the voltage source inverter by means of PI controller in order to adapt the voltage vector used in typical DTC switching table. Mathematic models are built using MATLAB Simulink and programming environment; the simulation results show the difference between the proposed method and classical DTC.
A NEW FUZZY LOGIC BASED SPACE VECTOR MODULATION APPROACH ON DIRECT TORQUE CON...csandit
The induction motors are indispensable motor types for industrial applications due to its wellknown
advantages. Therefore, many kind of control scheme are proposed for induction motors
over the past years and direct torque control has gained great importance inside of them due to
fast dynamic torque response behavior and simple control structure. This paper suggests a new
approach on the direct torque controlled induction motors, Fuzzy logic based space vector
modulation, to overcome disadvantages of conventional direct torque control like high torque
ripple. In the proposed approach, optimum switching states are calculated by fuzzy logic
controller and applied by space vector pulse width modulator to voltage source inverter. In
order to test and compare the proposed DTC scheme with conventional DTC scheme
simulations, in Matlab/Simulink, have been carried out in different speed and load conditions.
The simulation results showed that a significant improvement in the dynamic torque and speed
responses when compared to the conventional DTC scheme.
MODELLING AND IMPLEMENTATION OF AN IMPROVED DSVM SCHEME FOR PMSM DTCpaperpublications3
Abstract: A very widely used drive strategy for PMSM is the field oriented control (FOC), which was proposed in 1971 for induction motors (IMs). However, the FOC scheme is quite complex due to the reference frame transformation and its high dependence upon the motor parameters and speed. To mitigate these problems, a new control strategy for the torque control of induction motor was developed by Takahashi known as the direct torque control (DTC) and by Depenbrock as the direct self control (DSC). The basic direct torque control (DTC) scheme may cause undesired torque, flux and current ripples because of the small number of applicable voltage vectors. The control system should be able to generate any voltage vector, implying the use of space vector modulation (SVM) which complicates the control scheme. The discrete space vector modulation (DSVM) method was proposed for DTC to overcome this problem which replaces the simple switching table by several switching tables, to apply a combination of three voltage vectors in the same sampling period. In this paper, after a brief review of the primary concept of DSVM DTC technique, a new scheme of DSVM DTC for PMSM is proposed with a new set of switching tables taking into account the motor speed and the absolute values of torque and flux feedback errors. In one fixed sampling time interval, three vectors are applied to the motor including the two null vectors. Comparisons of the basic DTC and the improved DSVM DTC schemes are made based on the system performance and switching loss. For this purpose the DSVM technique uses prefixed time intervals within a sampling cycle to synthesize a higher number of voltage vectors than the basic DTC scheme. A set of switching table is carried out to minimize the torque error. An optimal vector selector is developed to reduce the switching loss and make the system more stable. The sampling period does not need to be doubled in order to achieve a mean switching frequency practically equal to that of the basic DTC scheme. For a comparable performance, the switching loss of the proposed scheme is less than that of the basic DTC method. The vector application sequence is investigated and an optimal algorithm is developed to reduce the switching loss and torque ripple. Simulation and experiments on the improved DSVM DTC are carried out and compared with those on the basic DTC scheme.
[9_CV] FCS-Model Predictive Control of Induction Motors feed by MultilLevel C...Nam Thanh
Ha Thanh Vo, Nam Thanh Hoang, Phuong Hoang Vu, Minh Trong Tran, Dich Quang Nguyen, “FCS-Model Predictive Control of Induction Motors feed by MultilLevel Casaded H-Bridge Inverter”, RCEEE-2018.
FLC-Based DTC Scheme for a New Approach of Two-Leg VSI Fed Induction MotorIJERA Editor
A new Direct Torque Control (DTC) strategy for Induction Motor (IM) drive fed by a two leg three phase
inverter (i.e., Four switches are used in VSI) was proposed in this paper. The proposed methodology is based on
the emulation of operation of the conventional Six-switch three phase inverter. The combination of four
unbalanced voltage vectors is generated by the two-leg three phase inverter, approaching to the synthesis of the
six balanced voltage vectors of the conventional DTC. This approach has been implemented in the design of the
vector selection table of the proposed DTC strategy. Further, Fuzzy Logic Controller (FLC) is proposed in the
speed controller for the improvement of torque ripples. Convention DTC with Six Switch three phase VSI, twoleg
three phase VSI with PI and Fuzzy Controller are implemented using MATLAB/SIMULINK. Simulation
results have shown that the proposed DTC strategy, two-leg inverter fed IM drive revealed an improved
performance.
DSP-Based Sensorless Speed Control of a Permanent Magnet Synchronous Motor us...IJPEDS-IAES
In this paper, experimental results of 3-phase permanent magnet synchronous motor (PMSM) sensorless speed control are presented. To estimate the rotor position, a sliding mode current observer (SMCO) was implemented. This observer estimates the back emfs of the motor in the stationary reference frame using only the measured voltages and currents of the motor. These emfs were utilized to obtain the rotor position. The speed of the motor was calculated by differentiating the rotor position angle. The stability of the proposed SMCO was verified using Lyapunov method to determine the observer gain. The saturation function was adopted in order to reduce the chattering phenomenon caused by the SMCO. A vector control method was employed to achieve the sensorless drive system. The control application was developed in C/C++ language and implemented using the Texas Instruments TMS320LF2812 digital signal processor (DSP). This new processor enables intelligent control for motors. We used to test the drive the MCK2812 which is a professional development kit available from Technosoft Company. The theoretical finding is validated with experimental results that show the effectiveness of the real-time implementation.
Simulation and Analysis of Modified DTC of PMSMIJECEIAES
This research paper describes the simulation and analysis of the modified DTC for Surface mounted Permanent Magnet Synchronous Motor (SPMSM) using PI controller. Among all of the various drive systems,PMSM is widely used for accurate speed and torque control, with greater efficiency, superior torque to inertia and high power density.The Conventional DTC secheme widely used for this purpose but it is failed to achieve desirable performance of the system for which the modified DTC secheme is propsed.The modified DTC algorithm controls the voltage vectors, directly from a simple look up table depending on outcome of the torque and indirectly flux controllers.The overall drive system can be implemented in SIMULINK/MATLAB environment.The modified DTC is validated with loading conditions.The simulated results are focused on the speed, settling time at loaded conditions, torque and flux linkages ripple and THD in the phase current for modified DTC applied to SPMSM.
The application of the direct torque control strategy for induction machine drives is mainly characterized by torque and flux distortions caused by voltage vector limitation. The goal of this paper is to perform the conventional DTC induction machine drives and reduce ripples of both flux and torque response. The proposed contribution is based on the control of the DC output side of the rectifier feeding the voltage source inverter by means of PI controller in order to adapt the voltage vector used in typical DTC switching table. Mathematic models are built using MATLAB Simulink and programming environment; the simulation results show the difference between the proposed method and classical DTC.
International Refereed Journal of Engineering and Science (IRJES)irjes
a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications.
Field-Oriented Control of PMSM Drive Based on SVPWM Using MATLABIJERA Editor
The space vector PWM has the character of wide linear range, little higher harmonic and easy digital
realization. The FOC theory and SVPWM technique make the PMSM can achieve the performance as well as
DC motor. The mathematical model of PMSM is analyzed and the system model of FOC vector control has
been established. The control system has been also simulated by MATLAB/Simulink. The simulation results
accord with the real motor’s performance and provide the theory basis for the designing of real system.
A Survey on Quality Changes in Positive, Negative and Combined Switching Stra...IJAPEJOURNAL
In this paper uses positive, negative and combined switching strategies for three phase ac/ac matrix converter .the author compares these strategies. The performance comparison of these three strategies is made under balanced operation. The simulation of three phase matrix converter feeding a three phase load was accomplished by means of the matlab/simulink software. After the simulation the comparison of the waveforms THD in three switching sequence is done. It must be mentioned that the duty cycle of the whole switches in the converter is according to Venturini switching algorithm
Voltage profile Improvement Using Static Synchronous Compensator STATCOMINFOGAIN PUBLICATION
Static synchronous compensator (STATCOM) is a regulating device used in AC transmission systems as a source or a sink of reactive power. The most widely utilization of the STATCOM is in enhancing the voltage stability of the transmission line. A voltage regulator is a FACTs device used to adjust the voltage disturbance by injecting a controllable voltage into the system. This paper implement Nruro-Fuzzy controller to control the STATCOM to improve the voltage profile of the power network. The controller has been simulated for some kinds of disturbances and the results show improvements in voltage profile of the system. The performance of STATCOM with its controller was very close within 98% of the nominal value of the busbar voltage.
Implementation of Space Vector Modulator for Cascaded H-Bridge Multilevel Inv...IJPEDS-IAES
The Space Vector Modulation (SVM) technique has gained wide acceptance
for many AC drive applications, due to a higher DC bus voltage utilization
(higher output voltage when compared with the SPWM), lower harmonic
distortions and easy digital realization. In recent years, the SVM technique
was extensively adopted in multilevel inverters since it offers greater
numbers of switching vectors for obtaining further improvements of AC
drive performances. However, the use of multilevel inverters associated with
SVM increases the complexity of control algorithm (or computational
burden), in obtaining proper switching sequences and vectors. The
complexity of SVM computation causes a microcontroller or digital signal
processor (DSP) to execute the computation at a larger sampling time. This
consequently may produce errors in computation and hence degrades the
control performances of AC motor drives. This paper presents a
developement of SVM modulator for three-level Cascaded H-Bridge
Multilevel Inverter (CHMI) using a hybrid controller approach, i.e. with
combination between the DS1104 Controller Board and FPGA. In such way,
the computational burden can be minimized as the SVM tasks are distributed
into two parts, in which every part is executed by a single controller. This
allows the generation of switching gates performed by FPGA at the
minimum sampling time ܦܶଶ ൌ 540 ݊ݏ to obtain precise desired output
voltages, as can be verified via simulation and experimental results.
Simplified Space Vector Pulse Width Modulation Based on Switching Schemes wit...IJAAS Team
This paper presents a simplified control strategy of SVPWM with a three segment switching sequence and 7 segment switch frequency for high power multilevel inverter. In the proposed method, the inverter switching sequences are optimized for minimization of device switching sequence frequency and improvement of harmonic spectrum by using the three most derived switching states and one suitable redundant state for each space vector. The proposed 3-segment sequence is compared with conventional 7-segment sequence similar for five level Cascaded H-Bridge inverter with various values of switching frequencies including very low frequency. The output spectrum of the proposed sequence design shows the reduction of device switching frequency and states current and line voltage. THD this minimizing the filter size requirement of the inverter, employed in industrial applications. Where sinusoidal output voltage is required.
Direct Torque Control of Four Switch Three Phase Inverter Fed Induction Motor...IAES-IJPEDS
This paper presents sensorless speed control of induction motor (IM) using four switch three phase inverter (FSTPI) with direct torque and flux control (DTFC). The proposed sensorless DTFC system consists of an adaptive observer of rotor flux to accurately estimate stator resistance and speed simultaneously, without affecting drive performances. The switching technique for DTFC of IM using FSTPI in low power application is based on the principle of similarity between FSTPI and SSTPI (six switch three phase inverter), where the αβ plan is divided into 6 sectors and the formation of the voltage space vector is done in the same way as for SSTPI by using effective (mean) vectors. This approach allows using the well-known established switching table of SSTPI for FSTPI. The simulation results indicates that the sensorless speed control of FSTPI fed IM with DTFC and adaptive observer provides accurate estimate, good trajectory tracking with different dynamics performance. The experimental results verify the effectiveness of the proposed method at different operating points.
An Implementation Mechanisms of SVM Control Strategies Applied to Five Levels...IJPEDS-IAES
In the area of the energy control with high voltage and power, the multilevel inverters constitute a relatively recent research orientation. The current applications of this technology are in the domains of the high voltage (over hundred kV), variable speed drives, transport and distribution of a good quality of electrical energy (HVDC, FACTS system, ....). To improve the output voltage for such inverters, many different modulation strategies have been developed. Among these strategies, the SVM (Space Vector Modulation). The technique provide the nearest switching vectors sequence to the reference vector without involving trigonometric functions and provide the additional advantages of superior harmonic quality. In this paper, we analyze different mechanisms of the output voltage synthesis and the problem of even order harmonic production. With the proposed a new trajectory SVM, which can eliminate all the even order harmonics for five levels inverter. Show clearly how to deduce the trajectories from the sequences allowing to have better performances among several possible trajectories. It is dedicated to the application of two particular trajectories.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Nonlinear control of WECS based on PMSG for optimal power extraction IJECEIAES
This paper proposes a robust control strategy for optimizing the maximum power captured in Wind Energy Conversion Systems (WECS) based on permanent magnet synchronous generators (PMSG), which is integrated into the grid. In order to achieve the maximum power point (MPPT) the machine side converter regulates the rotational speed of the PMSG to track the optimal speed. To evaluate the performance and effectiveness of the proposed controller, a comparative study between the IBC control and the vector control based on PI controller was carried out through computer simulation. This analysis consists of two case studies including stochastic variation in wind speed and step change in wind speed.
Direct Torque Control (DTC) is widely applied for ac motor drives as it offers high performance torque control with a simple control strategy. However, conventional DTC poses some disadvantages especially in term of variable switching frequency and large torque ripple due to the utilization of torque hysteresis controller. Other than that, performance of conventional DTC fed by two-level inverter is also restricted by the limited numbers of voltage vectors which lead to inappropriate selection of voltage vectors for different speed operations. This research aims to propose a Constant Switching Frequency (CSF) torque controller for DTC of induction motor (IM) fed by three-level Neutral-Point Clamped (NPC) inverter. The proposed torque controller utilizes PI controller which apply different gain for different speed operation. Besides, the utilization of NPC inverter provides greater number of voltage vectors which allow appropriate selection of voltage vectors for different operating condition. Using the proposed method, the improvement of DTC drives in term of producing a constant switching operation and minimizing torque ripple are achieved and validated via experimental results.
This paper presents a novel structure combining the port-controlled Hamiltonian (PCH) and Backstepping (BS) nonlinear control for the vector control of the six-phase induction motor (SPIM). In this new scheme, to improve the outer loop’s robustness, the BS technique using the integral tracking errors action is proposed in the speed and flux controllers design. The advantage of this proposed control law is not to increase the complexity of differential equation resolution due to being not increased system states numbers. To enhance more the performance of SPIM drives (SPIMD), port-controlled Hamiltonian (PCH) scheme is used in the inner current loop controllers. In this proposed PCH current controller, the stabilization of controller is achieved via system passivity. In that, the interconnection and damping matrix functions of PCH system are shaped so that the physical (Hamiltonian) system structure is preserved at the closed loop level and the closed loop energy function is equal to the difference between the physical energy of the system and the energy supplied by the controller. The proposed control design is based on combination PCH and BS techniques improve significantly performance and robustness. The proposed speed control scheme is validated by Matlab-Simulink software.
Model Predictive Current Control of a Seven-phase Voltage Source Inverteridescitation
The paper elaborate finite set model based predictive
current control of a seven-phase voltage source inverter. The
current control is carried out considering a finite set of control
actions. The space vector model of a seven-phase voltage source
inverter (VSI) yields 27 = 128 space voltage vectors, with 126
active and two zero vectors. The control method described in
this paper discard some switching states from the whole set
and employs reduced number of switching states to track the
commanded current. Three sets of space vectors are used for
switching actuation, in one case only 15 vectors are used (14
active and one zero), in second case 29 vectors are used (28
active and one zero) and finally 43 vectors (42 active and one
zero) are employed. Optimal algorithm is employed to find
the vector which minimizes the chosen cost function. The
effect of selecting the cost function, the number of space
vectors and the sampling time is investigated and reported.
The developed technique is tested for RL load using simulation
and experimental approaches.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
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Transmission Congestion Management by Using Series Facts Devices and Changing...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Artificial Neural Network Controller for Reducing the Total Harmonic Distorti...IJAEMSJORNAL
A neural network based space vector modulation (SVM) of voltage source inverter is proposed. The voltage source converter (VSC) is highly used in high voltage direct current (HVDC) transmission so that a detailed analysis and transmission of this system is carried out. In addition, a non-linear neural network controller is proposed to control the space vector pulse width modulation (SVPWM) to reduce the total harmonic distortion (THD) of the converter (inverter) output voltage. The inverter outputcurrent is analyzed with two switching frequency 1050Hz and1450Hz with and without proposed ANN controller. The results show a THD enhancement about 0.74 % for 1050Hz and 0.68 % for 1450Hz.
The induction motors are indispensable motor types for industrial applications due to its wellknown advantages. Therefore, many kind of control scheme are proposed for induction motors over the past years and direct torque control has gained great importance inside of them due to fast dynamic torque response behavior and simple control structure. This paper suggests a new approach on the direct torque controlled induction motors, Fuzzy logic based space vector
modulation, to overcome disadvantages of conventional direct torque control like high torque ripple. In the proposed approach, optimum switching states are calculated by fuzzy logic
controller and applied by space vector pulse width modulator to voltage source inverter. In order to test and compare the proposed DTC scheme with conventional DTC scheme
simulations, in Matlab/Simulink, have been carried out in different speed and load conditions. The simulation results showed that a significant improvement in the dynamic torque and speed responses when compared to the conventional DTC scheme.
International Refereed Journal of Engineering and Science (IRJES)irjes
a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications.
Field-Oriented Control of PMSM Drive Based on SVPWM Using MATLABIJERA Editor
The space vector PWM has the character of wide linear range, little higher harmonic and easy digital
realization. The FOC theory and SVPWM technique make the PMSM can achieve the performance as well as
DC motor. The mathematical model of PMSM is analyzed and the system model of FOC vector control has
been established. The control system has been also simulated by MATLAB/Simulink. The simulation results
accord with the real motor’s performance and provide the theory basis for the designing of real system.
A Survey on Quality Changes in Positive, Negative and Combined Switching Stra...IJAPEJOURNAL
In this paper uses positive, negative and combined switching strategies for three phase ac/ac matrix converter .the author compares these strategies. The performance comparison of these three strategies is made under balanced operation. The simulation of three phase matrix converter feeding a three phase load was accomplished by means of the matlab/simulink software. After the simulation the comparison of the waveforms THD in three switching sequence is done. It must be mentioned that the duty cycle of the whole switches in the converter is according to Venturini switching algorithm
Voltage profile Improvement Using Static Synchronous Compensator STATCOMINFOGAIN PUBLICATION
Static synchronous compensator (STATCOM) is a regulating device used in AC transmission systems as a source or a sink of reactive power. The most widely utilization of the STATCOM is in enhancing the voltage stability of the transmission line. A voltage regulator is a FACTs device used to adjust the voltage disturbance by injecting a controllable voltage into the system. This paper implement Nruro-Fuzzy controller to control the STATCOM to improve the voltage profile of the power network. The controller has been simulated for some kinds of disturbances and the results show improvements in voltage profile of the system. The performance of STATCOM with its controller was very close within 98% of the nominal value of the busbar voltage.
Implementation of Space Vector Modulator for Cascaded H-Bridge Multilevel Inv...IJPEDS-IAES
The Space Vector Modulation (SVM) technique has gained wide acceptance
for many AC drive applications, due to a higher DC bus voltage utilization
(higher output voltage when compared with the SPWM), lower harmonic
distortions and easy digital realization. In recent years, the SVM technique
was extensively adopted in multilevel inverters since it offers greater
numbers of switching vectors for obtaining further improvements of AC
drive performances. However, the use of multilevel inverters associated with
SVM increases the complexity of control algorithm (or computational
burden), in obtaining proper switching sequences and vectors. The
complexity of SVM computation causes a microcontroller or digital signal
processor (DSP) to execute the computation at a larger sampling time. This
consequently may produce errors in computation and hence degrades the
control performances of AC motor drives. This paper presents a
developement of SVM modulator for three-level Cascaded H-Bridge
Multilevel Inverter (CHMI) using a hybrid controller approach, i.e. with
combination between the DS1104 Controller Board and FPGA. In such way,
the computational burden can be minimized as the SVM tasks are distributed
into two parts, in which every part is executed by a single controller. This
allows the generation of switching gates performed by FPGA at the
minimum sampling time ܦܶଶ ൌ 540 ݊ݏ to obtain precise desired output
voltages, as can be verified via simulation and experimental results.
Simplified Space Vector Pulse Width Modulation Based on Switching Schemes wit...IJAAS Team
This paper presents a simplified control strategy of SVPWM with a three segment switching sequence and 7 segment switch frequency for high power multilevel inverter. In the proposed method, the inverter switching sequences are optimized for minimization of device switching sequence frequency and improvement of harmonic spectrum by using the three most derived switching states and one suitable redundant state for each space vector. The proposed 3-segment sequence is compared with conventional 7-segment sequence similar for five level Cascaded H-Bridge inverter with various values of switching frequencies including very low frequency. The output spectrum of the proposed sequence design shows the reduction of device switching frequency and states current and line voltage. THD this minimizing the filter size requirement of the inverter, employed in industrial applications. Where sinusoidal output voltage is required.
Direct Torque Control of Four Switch Three Phase Inverter Fed Induction Motor...IAES-IJPEDS
This paper presents sensorless speed control of induction motor (IM) using four switch three phase inverter (FSTPI) with direct torque and flux control (DTFC). The proposed sensorless DTFC system consists of an adaptive observer of rotor flux to accurately estimate stator resistance and speed simultaneously, without affecting drive performances. The switching technique for DTFC of IM using FSTPI in low power application is based on the principle of similarity between FSTPI and SSTPI (six switch three phase inverter), where the αβ plan is divided into 6 sectors and the formation of the voltage space vector is done in the same way as for SSTPI by using effective (mean) vectors. This approach allows using the well-known established switching table of SSTPI for FSTPI. The simulation results indicates that the sensorless speed control of FSTPI fed IM with DTFC and adaptive observer provides accurate estimate, good trajectory tracking with different dynamics performance. The experimental results verify the effectiveness of the proposed method at different operating points.
An Implementation Mechanisms of SVM Control Strategies Applied to Five Levels...IJPEDS-IAES
In the area of the energy control with high voltage and power, the multilevel inverters constitute a relatively recent research orientation. The current applications of this technology are in the domains of the high voltage (over hundred kV), variable speed drives, transport and distribution of a good quality of electrical energy (HVDC, FACTS system, ....). To improve the output voltage for such inverters, many different modulation strategies have been developed. Among these strategies, the SVM (Space Vector Modulation). The technique provide the nearest switching vectors sequence to the reference vector without involving trigonometric functions and provide the additional advantages of superior harmonic quality. In this paper, we analyze different mechanisms of the output voltage synthesis and the problem of even order harmonic production. With the proposed a new trajectory SVM, which can eliminate all the even order harmonics for five levels inverter. Show clearly how to deduce the trajectories from the sequences allowing to have better performances among several possible trajectories. It is dedicated to the application of two particular trajectories.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Nonlinear control of WECS based on PMSG for optimal power extraction IJECEIAES
This paper proposes a robust control strategy for optimizing the maximum power captured in Wind Energy Conversion Systems (WECS) based on permanent magnet synchronous generators (PMSG), which is integrated into the grid. In order to achieve the maximum power point (MPPT) the machine side converter regulates the rotational speed of the PMSG to track the optimal speed. To evaluate the performance and effectiveness of the proposed controller, a comparative study between the IBC control and the vector control based on PI controller was carried out through computer simulation. This analysis consists of two case studies including stochastic variation in wind speed and step change in wind speed.
Direct Torque Control (DTC) is widely applied for ac motor drives as it offers high performance torque control with a simple control strategy. However, conventional DTC poses some disadvantages especially in term of variable switching frequency and large torque ripple due to the utilization of torque hysteresis controller. Other than that, performance of conventional DTC fed by two-level inverter is also restricted by the limited numbers of voltage vectors which lead to inappropriate selection of voltage vectors for different speed operations. This research aims to propose a Constant Switching Frequency (CSF) torque controller for DTC of induction motor (IM) fed by three-level Neutral-Point Clamped (NPC) inverter. The proposed torque controller utilizes PI controller which apply different gain for different speed operation. Besides, the utilization of NPC inverter provides greater number of voltage vectors which allow appropriate selection of voltage vectors for different operating condition. Using the proposed method, the improvement of DTC drives in term of producing a constant switching operation and minimizing torque ripple are achieved and validated via experimental results.
This paper presents a novel structure combining the port-controlled Hamiltonian (PCH) and Backstepping (BS) nonlinear control for the vector control of the six-phase induction motor (SPIM). In this new scheme, to improve the outer loop’s robustness, the BS technique using the integral tracking errors action is proposed in the speed and flux controllers design. The advantage of this proposed control law is not to increase the complexity of differential equation resolution due to being not increased system states numbers. To enhance more the performance of SPIM drives (SPIMD), port-controlled Hamiltonian (PCH) scheme is used in the inner current loop controllers. In this proposed PCH current controller, the stabilization of controller is achieved via system passivity. In that, the interconnection and damping matrix functions of PCH system are shaped so that the physical (Hamiltonian) system structure is preserved at the closed loop level and the closed loop energy function is equal to the difference between the physical energy of the system and the energy supplied by the controller. The proposed control design is based on combination PCH and BS techniques improve significantly performance and robustness. The proposed speed control scheme is validated by Matlab-Simulink software.
Model Predictive Current Control of a Seven-phase Voltage Source Inverteridescitation
The paper elaborate finite set model based predictive
current control of a seven-phase voltage source inverter. The
current control is carried out considering a finite set of control
actions. The space vector model of a seven-phase voltage source
inverter (VSI) yields 27 = 128 space voltage vectors, with 126
active and two zero vectors. The control method described in
this paper discard some switching states from the whole set
and employs reduced number of switching states to track the
commanded current. Three sets of space vectors are used for
switching actuation, in one case only 15 vectors are used (14
active and one zero), in second case 29 vectors are used (28
active and one zero) and finally 43 vectors (42 active and one
zero) are employed. Optimal algorithm is employed to find
the vector which minimizes the chosen cost function. The
effect of selecting the cost function, the number of space
vectors and the sampling time is investigated and reported.
The developed technique is tested for RL load using simulation
and experimental approaches.
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Transmission Congestion Management by Using Series Facts Devices and Changing...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Artificial Neural Network Controller for Reducing the Total Harmonic Distorti...IJAEMSJORNAL
A neural network based space vector modulation (SVM) of voltage source inverter is proposed. The voltage source converter (VSC) is highly used in high voltage direct current (HVDC) transmission so that a detailed analysis and transmission of this system is carried out. In addition, a non-linear neural network controller is proposed to control the space vector pulse width modulation (SVPWM) to reduce the total harmonic distortion (THD) of the converter (inverter) output voltage. The inverter outputcurrent is analyzed with two switching frequency 1050Hz and1450Hz with and without proposed ANN controller. The results show a THD enhancement about 0.74 % for 1050Hz and 0.68 % for 1450Hz.
The induction motors are indispensable motor types for industrial applications due to its wellknown advantages. Therefore, many kind of control scheme are proposed for induction motors over the past years and direct torque control has gained great importance inside of them due to fast dynamic torque response behavior and simple control structure. This paper suggests a new approach on the direct torque controlled induction motors, Fuzzy logic based space vector
modulation, to overcome disadvantages of conventional direct torque control like high torque ripple. In the proposed approach, optimum switching states are calculated by fuzzy logic
controller and applied by space vector pulse width modulator to voltage source inverter. In order to test and compare the proposed DTC scheme with conventional DTC scheme
simulations, in Matlab/Simulink, have been carried out in different speed and load conditions. The simulation results showed that a significant improvement in the dynamic torque and speed responses when compared to the conventional DTC scheme.
Fuzzy logic based direct torque control of induction motor with space vector ...ijscai
The induction motors have wide range of applications for due to its well-known advantages like brushless
structures, low costs and robust performances. Over the past years, many kind of control methods are
proposed for the induction motors and direct torque control has gained huge importance inside of them due
to fast dynamic torque responses and simple control structures. However, the direct torque control method
has still some handicaps against the other control methods and most of the important of these handicaps is
high torque ripple. This paper suggests a new approach, Fuzzy logic based space vector modulation, on
the direct torque controlled induction motors and aim of the approach is to overcome high torque ripple
disadvantages of conventional direct torque control. In order to test and compare the proposed direct
torque control method with conventional direct torque control method simulations, in Matlab/Simulink,
have been carried out in different working conditions. The simulation results showed that a significant
improvement in the dynamic torque and speed responses when compared to the conventional direct torque
control method.
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onlinear Compensation Empyoing Matrix Converter with DTC Controller Yayah Zakaria
This paper describes a nonlinear harmful speed and torque controller for fourth order induction motor model. The investigation of optimality and cost function for that base on estimation of Hammerstein-Wiener model with the compensated mathematical model. The matrix converter with direct torque
control combination is efficient way to get better performance specifications in the industry.The MC and the DTC advantages are combined together. The reduction of complexity and cost of DC link in the DTC since it has no capacitors in the circuit. However, the controlling torque is a big problem it in DTC because of high ripple torque production which results in vibrations response in the operation of the IM as it has no PID to control the torque directly. The combination of MC with DTC is applied to reduce the fluctuation in the output torque and minimize the steady state error. This paper presents the simulation analysis of induction machine drives using
Maltlab/Simulink toolbox R2012a. Design of constant switching frequency MCDTC drive,stability investigation and fault protection as well as controllability and observability with minimum steady state error has been carried out which proved the effectiveness of the proposed technique.
Nonlinear Compensation Empyoing Matrix Converter with DTC Controller IJECEIAES
This paper describes a nonlinear harmful speed and torque controller for fourth order induction motor model. The investigation of optimality and cost function for that base on estimation of Hammerstein-Wiener model with the compensated mathematical model. The matrix converter with direct torque control combination is efficient way to get better performance specifications in the industry.The MC and the DTC advantages are combined together.The reduction of complexity and cost of DC link in the DTC since it has no capacitors in the circuit. However, the controlling torque is a big problem it in DTC because of high ripple torque production which results in vibrations response in the operation of the IM as it has no PID to control the torque directly. The combination of MC with DTC is applied to reduce the fluctuation in the output torque and minimize the steady state error. This paper presents the simulation analysis of induction machine drives using Maltlab/Simulink toolbox R2012a. Design of constant switching frequency MCDTC drive,stability investigation and fault protection as well as controllability and observability with minimum steady state error has been carried out which proved the effectiveness of the proposed technique.
Simulation of 3 Phase to 3 Phase Power Conversion Using Matrix Converter with...IJERA Editor
This paper proposes a new approach of design and implementation of 3 phase to 3 phase conversion using
matrix converter. It includes the design, modeling and implementation. The entire matrix converter circuits are
developed by mathematical model so as to reduce computational time and performances of the converter are
evaluated using MATLAB/SIMULINK for RL Load. The mathematical expressions relating the input and
output of the three phase matrix converter are implemented by using simulink block set. The duty cycles of the
matrix converter bidirectional switches are calculated using modified venturini algorithm for maximum (0.866)
and minimum (0.5) voltage transfer ratio.
SPEED CONTROL OF INDUCTION MACHINE WITH REDUCTION IN TORQUE RIPPLE USING ROBU...IAEME Publication
In this paper a novel and simple algorithm for three-phase induction motor(IM) under Direct Torque Control (DTC) scheme using Classic DTC switching table for dynamic torque ripple reduction and space-vector modulation scheme for steady state torque and flux control is proposed. The proposed scheme having the advantages of low torque ripples as well as constant switching frequency.
Simulation results are given to prove the ability of the proposed method obtaining good speed control bandwidth while overcoming classic DTC and DTC-SVM drawbacks.
A Review of Matrix Converter and Novel Control Method of DC-AC Matrix Converteridescitation
For the past three decades, research work in matrix
converter has increased much. This paper presents a new
topology of DC-AC matrix converter, starting with a brief
historical review of different modulation and control strategies
which was developed recently. The purpose of the Paper is to
generate a multilevel output voltage equal to multilevel
inverter with reduced switches. An important part of the paper
is to design a dedicated DC-AC matrix converter and some
new arrays of bidirectional switches in a single module are
also presented. To find the performance of the module the
entire module is designed with MATLAB simulation and tested
with three phase induction motor.
A Novel Direct Torque Control for Induction Machine Drive System with Low Tor...IAES-IJPEDS
The conventional Direct Torque Control (DTC) is known to produce a quick and robust response in AC drives. However, during steady state, stator flux and electromagnetic torque which results in incorrect speed estimations and acoustical noise. A modified Direct Torque Control (DTC) by using Space Vector Modulation (DTC-SVM) for induction machine is proposed in this paper. Using this control strategy, the ripples introduced in torque and flux are reduced. This paper presents a novel approach to design and implementation of a high perfromane torque control (DTC-SVM) of induction machine using Field Programmable gate array (FPGA). The performance of the proposed control scheme is evaluated through digital simulation using Matlab\Simulink and Xilinx System Generator. The simulation results are used to verify the effectiveness of the proposed control strategy.
Constant Frequency Torque Controller for DTC with Multilevel Inverter of Indu...IJPEDS-IAES
Direct Torque Control using multilevel inverter (DTC-MLI) with hysteresis
controller suffers from high torque and flux ripple and variable switching
frequency. In this paper, a constant frequency torque controller is proposed to
enhance the DTC-MLI performance. The operational concepts of the
constant switching frequency torque controller of a DTC-MLI system
followed by the simulation results and analysis are presented. The proposed
system significantly improves the DTC drive in terms of dynamic
performance, smaller torque and flux ripple, and retains a constant switching
frequency.
An Improved Repetitive Control for Circulating Current Restraining in MMC-MTDCTELKOMNIKA JOURNAL
The modular multilevel converter (MMC) is widely used in many important application fields such
as high voltage DC transmission system. And the multi-terminal architecture of it attracts many attentions.
However, the circulating current of MMC is an inherent problem which is mainly caused by the voltage
mismatch between arms and DC bus. In this paper, an advanced repetitive control method is proposed.
This method is based on the even-harmonic characteristic of the circulating current and the potential
feature of repetitive control that it has an internal integration part. The pole diagram of the closed loop
transform function of the proposed control system proves the stability of the proposed method. And
according to the simulation results of a three-terminal MMC-MTDC model in PSCAD/EMTDC, the
improved repetitive control presents better circulation repression ability and superior anti-interference
capability by comparing with traditional PI control method. Additionally, the simulation results also indicate
that the proposed repetitive controller can restrain the fluctuation of SM voltage more effectively than PI
control.
A Novel Optimal PI Parameter Tuning Strategy to Improve Constant Switching Pe...IJPEDS-IAES
This paper presents a novel method of optimal Propotional-Intergral (PI)
controller’s parameter tuning strategy in-order to improve the constant
switching performance of 3-phase direct torque control (DTC) shceme. The
DTC sheme is acknowledged to provide fast decoupled control over the
torque output and stator flux via a simple control structure. However, DTC
sheme has two major downsides, which are the inconsistent inverter
switching frequency and high torque output ripple. The main reason that
contributes to these tribulations is the usage of hysteresis comparators in
order to control the output torque. The realization of PI based controller
method as replacement of hyterisis controller in DTC system able to provide
significant solutions to over come the fall back while retaining the simple
control structure of conventional DTC. The combination usage of higher
sampling controller DS1004 and also 3-level cascaded H-bridge multilevel
inverters (CHMI) in this system can further minimize the output torque ripple
by providing higher resolution with lower digital error and greater number of
vectors. This paper presents detail explanation and calculation of optimal PI
parameter tuning strategy consecutively to enhance the performance of 3-
level DTC system. In order to verify the feasibility of the proposed method
experimentation, the proposed method is compared with convention DTC
system via simulation and experiment results.
OPTIMAL TORQUE RIPPLE CONTROL OF ASYNCHRONOUS DRIVE USING INTELLIGENT CONTROL...elelijjournal
The dynamic performance of an asynchronous machine when operated with cascaded Voltage Source Inverter using Space Vector Modulation (SVM) technique is presented in this paper. A classical model of Induction Motor Drive based on Direct Torque Control (DTC) method is considered which displays
appreciable run-time operation with very simple hysteresis control scheme. Direct control of the torque and flux variables is achieved by choosing suitable inverter voltage space vector from a lookup table. Under varying torque conditions the performance of the drive system is verified using MATLAB/Simulink software tool. The ripple content in the torque parameter is significant when traditional PI controller and Fuzzy approach are configured in the proposed system. Finally, by replacing the PI-Fuzzy controller with Hybrid Controller the torque ripple minimization can be achieved during no-load and loaded conditions.
Basically, the direct torque control (DTC) drive system is operated at light load. At light load, supplying the drive system with rated flux will decrease the efficiency of the system. To maximize the efficiency of drive system, an optimal flux has been applied during steady-state but when a torque is suddenly needed, for example during acceleration, the dynamic of the torque response would be degraded. Therefore, a modification to the voltage vector as well as look-up table has been proposed for the torque response improvement. The proposed voltage vector is generated by adding two adjacent conventional voltage vectors and implemented by using duty ratio. The duty ratio is used to estimate the activation time of each conventional voltage vector in order to produce the proposed voltage vector.
The main objective of the present work is to describe the sensorless control of interior permanent magnet synchronous motor (IPMSM) for embeded systems in traction applications using the Model Reference Adaptive System (MRAS) method for speed estimation. The algorithm of this method has been adapted with the mathematical model of the motorized wheels electric vehicle. The command used is the DTC. Sensorless DTC of IPMS in-wheel motor based on MRAS for electric vehicle is simulated by Matlab/Simulink. The simulation results show the effectiveness of this proposed sensorless DTC control used for embedded system applications.
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TORQUE RIPPLE MINIMIZATION OF MATRIX CONVERTER-FED PMSM DRIVES USING ADVANCED DIRECT TORQUE CONTROL
1. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
DOI : 10.14810/ijscmc.2014.3404 51
TORQUE RIPPLE MINIMIZATION OF MATRIX
CONVERTER-FED PMSM DRIVES USING
ADVANCED DIRECT TORQUE CONTROL
S.Kannan1
, S.Chinnaiya2
and S.U.Prabha3
1, 2 Department of Electrical and Electronics Engineering, K.S.R. College of Engineering
Tiruchengode, India
3 Department of Electrical and Electronics Engineering, Sri Ramakrishna Engineering
College,Coimbatore, India
ABSTRACT
An advanced direct torque control (DTC) technique using Model predictive control (MPC) is proposed for
matrix converter (MC)-based permanent-magnet synchronous motor (PMSM) drive system, which reduces
the torque ripples, does not need the duty cycle calculation, and ensures the fixed switching frequency.
Analytical expressions of change rates of torque and flux of PMSM as a function of MC – dqo components
are derived. The predictive model of PMSM and MC is realized by means of State model. Then, the
advanced MC-fed DTC algorithm is implemented based on Cost function evaluation. The simulation results
exhibit remarkable torque ripple reduction with the help of MPC. As a result, the proposed strategy is
proved to be effective in minimizing the torque ripples for MC-based PMSM drives.
Keywords
Direct torque control (DTC), matrix converter (MC), permanent-magnet synchronous motor (PMSM),
Model predictive control (MPC), and Cost function
1. INTRODUCTION
The Matrix converter is a single-stage power converter, which consists of m x n bidirectional
power switches in an array form. The bidirectional switches in the converter are composed by
means of two IGBTs and two diodes connected in anti-parallel. Generally, the number of input
phases, m must be at least three, and the number of output phases, n can be chosen from one to
infinity. Currently, research works on commutation techniques [1], operation stability [2], and
control/modulation strategy [4]–[12] of MCs increase the usage of Matrix converter in many
fields like elevators, wind power generation, and mechanical manufacture [13].
A tremendous research work focusing on control and modulation strategies of MCs can be
divided into four types. They are scalar techniques, pulse width modulation (PWM), predictive
control, and direct torque control (DTC) [3].The Venturini method [4] is the first scalar technique,
which obtains the duty ratio of each switch directly by calculating the function of the
instantaneous value of the input voltage and the reference value of the output voltage. The Space
vector modulation [5] (SVM) is based on the instantaneous space vector representation of input
and output voltages and currents and it exploits the pulse width modulation, which was developed
and improved in the 1990s. The modern technique, predictive control [6], [7] evaluates the effect
2. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
52
of each possible switching state by a cost function. The switching state which minimizes the cost
function will be selected to output. The DTC exploits the hysteresis comparators and SVM
switching tables to obtain high-performance ac drives, was extended to MC-fed induction
machines (MC-DTC) in 2001 [8]. Normally, MC-DTC adopts hysteresis comparators and
switching tables which experiences the two major shortcomings: significant torque ripples and
variable switching frequency [14]. To overcome these drawbacks, [15] is implemented which
utilizes the duty cycle calculation. Since it reduces the torque ripples up to 30 %, it has some
disadvantages:
• It uses multilevel hysteresis and subdivided voltage vectors to reduce torque ripple.
o Discrete SVM should be produced to obtain 56 virtual voltage vectors with
different amplitude.
• Formation of switching table is offline & requires more accurate calculation.
• Exploits the duty cycle control.
o Complicated to implement &depends on motor parameters.
To avoid all these drawbacks an advanced DTC technique is proposed in this paper.
• The Model predictive control strategy is implemented with the MC – DTC fed PMSM
motor to minimize the torque ripples.
• The generalized MP-DTC [16] is approached to reduce the switching losses.
• The Branch and Bound algorithm [17] for PMSM is carried out to reduce the
computational time of Cost function.
2. MC-DTC TOPOLOGY
2.1. Principle of Matrix converter
The matrix converter having 9 bi-directional switches that allow any output phase to be connected
to any input phase. The circuit configuration is shown in Fig.1. The input terminals of the
converter are connected to a three phase power supply, while the output terminal are connected to
a three phase load, like an induction motor. The relationship between the input and output voltage
and current of MC can be expressed as
( ) ( ) ( )
( ) ( ) ( ) .
( ) ( ) ( )
a Aa Ab Ac A
b Ba Bb Bc B i
c Ca Cb Cc C
v S t S t S t v
v S t S t S t v M v
v S t S t S t v
= =
and
( ) ( ) ( )
( ) ( ) ( ) .
( ) ( ) ( )
a Aa Ba Ca A
T
b Ab Bb Cb B o
c Ac Bc Cc C
i S t S t S t i
i S t S t S t i M i
i S t S t S t i
= =
where spq(t) is the state of switch Spq, p ∈ {A,B,C}, q ∈ {a, b, c}, and MT
is the transpose of
transfer matrix M. Theoretically, the nine bi-directional switches of the matrix converter can
assume 512 (29
) different switching states . But all of them cannot be employed usefully.
(1)
(2)
3. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
53
Irrespective to the control method of the matrix converter, the choice of switching states
combinations must obey with two basic rules.
Fig. 1. Schematic representation of a matrix converter.
If the converter is supplied by a voltage source and feeds an inductive load, the input phases
should never be short-circuited and the output currents should not be interrupted. From a practical
point of view these rules imply that one and only one bi-directional switch per output phase must
be switched on at any instant. Because of this oblige, the matrix converter can follow 27
switching combinations only.
Fig. 2. Output line-to-neutral voltage vector configuration
In the 27 successive switching states, only 21 can be practically exploited in the DTC algorithm.
These configurations are presented in Table 1. The first 18 switching configurations have the
same feature of connecting two output phases to the same input phase. The corresponding output
line-to-neutral voltage vector and input line current vector, have fixed directions, as represented
4. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
54
in Figs. 2 and 3, and will be named “active configurations.” The magnitude of these vectors
depends upon the instantaneous values of the input line-to-neutral voltages and output line
currents respectively as shown in Table 1. Three switching configurations regulate zero input
current and output voltage vectors and will be named “zero configurations.” The remaining six
switching configurations have the three output phases connected to a different input phase.
Fig. 3. Input line current vector configuration
2.2. Existing MC-DTC
Normally, the VSI-DTC employs one switching state from the VSI switching table during one
sampling period to increase or decrease motor torque or flux [18]. The output voltage vectors of
MC have the same direction as those delivered by a VSI (V1 − V6), as shown in Fig. 2. Hence,
MC-DTC based on VSI-DTC can adjust the input power factor on the grid side and torque and
flux on the motor side at the same time, by means of the second selection of switching states. In
Fig. 2, the space is equally divided into six sectors, which are indexed by hα (α = 1, 2, . . . , 6),
with the first sector covering from−π/6 to π/6. As a result, in each sector, there are two output
voltage vectors that have the same direction as that of the VSI vector, and their related input
current vectors just lie on different sides of the input voltage vector, in which way the phase
between input voltages and currents could be controlled.
The schematic diagram of the Existing MC-DTC [15] is presented in Fig. 4. One desired virtual
VSI voltage vector is selected from the VSI switching table (see Table 2). Then, one MC
switching state is employed [15] from Table 3 based on the virtual VSI voltage vector. When a
zero-voltage vector is required from Table 2, the zero configuration of the MC, which minimizes
the number of commutations, is selected. The torque and flux are estimated, as shown in the
lower part of Fig. 4, in which the required output voltage and input current can be obtained from
the input voltage, output current, and transfer matrix M.
2.3. Duty cycle calculation
It can be seen that an enhanced switching table and a duty cycle calculation part are added based
on the standard method as shown in fig. 4. At first, an active voltage vector is chosen using the
5. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
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standard method; then, pτ is obtained by referring to the enhanced switching table. At last, the
duty cycle is calculated by substituting pτ and motor speed as,
e e
Tp
T p
d
K pτ τ
∆
= +
As the online calculation of the functions of τ and λ according to Table 1 will bring undesirable
calculation burden, a lookup table with the average values of τ and λ can eliminate the burden by
explicitly showing the effects of MCs voltage vectors on torque and flux.It can be seen from
Fig. 4. Block diagram of existing MC-DTC
Table 1 that the functions of τ and λ of all switching states are obtained by multiplying the two
terms.
(3)
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Table 1. Switching configurations used in MC-DTC scheme
MC
State
Switches
Output Input
Vo αo Ii βi
+1 SAa SBb SCb 2/3vab 0 2/√3iA -π/6
-1 SAb SBa SCa -2/3vab 0 -2/√3iA -π/6
+2 SAb SBc SCc 2/3vbc 0 2/√3iA π/2
-2 SAc SBb SCb -2/3vbc 0 -2/√3iA π/2
+3 SAc SBa SCa 2/3vca 0 2/√3iA 7π/6
-3 SAa SBc SCc -2/3vca 0 -2/√3iA 7π/6
+4 SAb SBa SCb 2/3vab 2π/3 2/√3iB -π/6
-4 SAa SBb SCa -2/3vab 2π/3 -2/√3iB -π/6
+5 SAc SBb SCc 2/3vbc 2π/3 2/√3iB π/2
-5 SAb SBc SCb -2/3vbc 2π/3 -2/√3iB π/2
+6 SAa SBc SCa 2/3vca 2π/3 2/√3iB 7π/6
-6 SAc SBa SCc -2/3vca 2π/3 -2/√3iB 7π/6
+7 SAb SBb SCa 2/3vab 4π/3 2/√3iC -π/6
-7 SAa SBa SCb -2/3vab 4π/3 -2/√3iC -π/6
+8 SAc SBc SCb 2/3vbc 4π/3 2/√3iC π/2
-8 SAb SBb SCc -2/3vbc 4π/3 -2/√3iC π/2
+9 SAa SBa SCc 2/3vca 4π/3 2/√3iC 7π/6
-9 SAc SBc SCa -2/3vca 4π/3 -2/√3iC 7π/6
0a SAa SBa SCa 0 - 0 -
0b SAb SBb SCb 0 - 0 -
0c SAc SBc SCc 0 - 0 -
The one containing αi is related to time, which will be referred to as time-dependent expression in
the following sections, and the other containing θs is related to the relative position of the stator
flux vector to output voltage vector. The enhanced switching table of all the positive vectors can
be obtained by moving the numbers of lα and lθ.
Table 2. VSI switching table
Cψ CT
Stator Flux Sectors hθ
① ② ③ ④ ⑤ ⑥
+1
+1 V2 V3 V4 V5 V6 V1
0 V7 V0 V7 V0 V7 V0
-1 V6 V1 V2 V3 V4 V5
-1
+1 V3 V4 V5 V6 V1 V2
0 V0 V7 V0 V7 V0 V7
-1 V5 V6 V1 V2 V3 V4
7. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
57
Table 3. MC switching table
hα Cφ
VSI Vectors
V1 V2 V3 V4 V5 V6
①①①①
+1 -3 +9 -6 +3 -9 +6
-1 +1 -7 +4 -1 +7 -4
②②②②
+1 +2 -8 +5 -2 +8 -5
-1 -3 +9 -6 +3 -9 +6
③③③③
+1 -1 +7 -4 +1 -7 +4
-1 +2 -8 +5 -2 +8 -5
④④④④
+1 +3 -9 +6 -3 +9 -6
-1 -1 +7 -4 +1 -7 +4
⑤⑤⑤⑤
+1 -2 +8 -5 +2 -8 +5
-1 +3 -9 +6 -3 +9 -6
⑥⑥⑥⑥
+1 +1 -7 +4 -1 +7 -4
-1 -2 +8 -5 +2 -8 +5
3. MATHEMATICAL MODELLING OF PMSM
In the rotating d-q frame, the dynamics of the surface mounted PMSM is described as [19]
( ) 1
( ) ( ( ) )mr
r e m
m m
Bd t
t T t T
dt J J
ω
ω= − + −
( ) 1
( ) ( ) ( ) ( )d s
d e d d
di t R
i t t i t v t
dt L L
ω= − + +
( ) 1 1
( ) ( ) ( ) ( ) ( )
q s
q e d e m q
di t R
i t t i t t v t
dt L L L
ω ω λ=− − − +
where ωr(t) is the rotor speed, ωe(t) is the electrical rotational rotor speed, id(t) and iq(t) are the
stator current in d-q frame, respectively. The electromagnetic torque of PMSM is expressed as
[20]
3 | |
2 sin | | ( )sin 2
4
s
e f q s q d
d q
p
T L L L
L L
ψ
ψ δ ψ δ = − −
where δ is the displacement angle between the stator and permanent-magnet flux linkage, ψf is the
permanent-magnet flux, Ld and Lq are the direct and quadrature stator inductances, respectively,
and p is the number of pole pairs. From (7), the change rate of torque can be derived as
3 | |
cos | | ( )cos2
2
s
e f q s q d
d q
pd d
T L L L
dt L L dt
ψ δ
ψ δ ψ δ = − −
The derivative of δ is given by
(4)
(5)
(6)
(7)
(8)
8. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
58
( )s r
s r
dd
dt dt
θ θδ
ω ω
−
= = −
where θs and θr are the stator and rotor positions, respectively, and ωr is the rotor electrical
angular velocity.
4. ADVANCED DTC
In this paper, the generalized DTC scheme with Model Predictive control is approached in Fig.5.
Here predictive control consists a model of the whole converter and PMSM in order to predict the
system behaviour after a computation period for each possible MC configuration. After that a cost
function will be used to determine the configuration which is to be applied for the next computing
period.
4.1. Model Predictive control
In Model Predictive Control [21], the current control input is attained by solving at each sampling
instant an inhibited optimal control problem based on the predictions delivered by an internal
model of the controlled process. Generally the optimal control problem is formulated over a finite
or infinite horizon. The underlying optimization procedure profits an optimal control sequence
which minimizes an objective function. The first control input of this sequence is applied in
accordance with the so called receding horizon policy. At the next sampling instant, the control
sequence is recomputed over a shifted horizon, thus providing feedback.
4.2. Receding horizon policy
The MPC algorithm finds the sequence of optimal input u(k) that satisfies given constraints [22].
From that sequence of optimal input u(k), only the first input is applied to plant for next sampling
interval. The whole process is repeated for next samples. This method of optimization of u is
known as online optimization. The prediction horizon keeps on shifting towards right after each
sample and the size of prediction horizon remains constant as shown in fig. 6. So that this
mechanism is termed as receding horizon policy.
(9)
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Fig. 5. Block diagram of Advanced MC-DTC.
4.3. Modelling of MP-DTC scheme
4.3.1. Permanent Magnet Synchronous Machine Model
The PMSM can be modelled with the help of state space equations in the dq rotor frame (10)
where Id, Iq and Vd, Vq are stator currents and voltages expressed in the dq frame, R and L are the
stator winding resistor and inductance respectively, ω is the rotor angular speed and φ is the flux
produced by permanent magnets [22].
( )
1
( ) 0 0( )( )
. . ( ) ( )
( )( ) 1 ( )
( ) 0
tdd
d q
qq
R
t I tI t L L
V t V t
I tI t R t
t
L L L
ω
φ
ω
ω
−
= + − − −
&
&
The Model parameters (R, L and φ) can be considered as constant and rotor electrical speed (ω)
variations can be abandoned for a short sampling period T of the algorithm. Hence the following
model can be found with a first order Euler integration.
01 ( ) 0( 1) ( ) ( )
. .
( 1) ( ) ( ) ( )
( ) 1 0
d d d
q q q
RT T
T kI k I k V kL L
T
I k I k V kRT T k
T k L
L L
ω
φ
ω
ω
− + = + + + − − −
( )
( 1) ( ). ( ) ( )
( )
d
q
V k
X k A k X k B k
V k
+ = + + Φ
(10)
(11)
(12)
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60
where X(k) = [Id(k) Iq(k) ]t
B is a constant matrix, and normally A and Φ depend on rotation
speed. Vd, Vq must be expressed as functions of converter switching states in order to obtain a
model of the whole converter - machine.
4.3.2. Matrix Converter Model
The dq-voltages Vd and Vq can be expressed as functions of output voltages [Va Vb Vc]t
by using
rotation matrix as,
cos( ( )) sin ( ( ))
( ( ))
sin ( ( )) cos( ( ))
k k
R k
k k
θ θ
θ
θ θ
=
−
1 1
( )1
( ) 2 2 2
( ( )). . ( )
( ) 3 3 3
( )0
2 2
a
d
b
q
c
V k
V k
R k V k
V k
V k
θ
− − = − −
Also the output voltage can be expressed as function of input voltages with the following
intellectual. Let λκ (λ = A,B,C and κ = a, b, c) as the switch between phases λ and κ. Let define uλκ
as an integer that represent the switch state with the following convention: if uλκ = 0 then the
switch λκ is open; if uλκ = 1 then the switch λκ is closed. In a matrix converter, between the three
switches connected to an output phase, one and only one switch can be closed. Certainly if more
than one switch is closed, there will be a short circuit of the voltage supply and if none is closed,
there is no path for the output phase current. For example, for the phase a, this lead to
1Aa Ba Cau u u+ + =
and
1
1
1
Aa a A
Ba a B
Ca a C
u V V
u V V
u V V
= → =
= → =
= → =
Then
a Aa A Ba B Ca CV u V u V u V= + +
As a result output voltages can be expressed as function of input voltages with (18).
( ) ( ) ( ) ( ) ( )
( ) ( ) ( ) ( ) . ( )
( ) ( ) ( ) ( ) ( )
a Aa Ba Ca A
b Ab Bb Cb B
c Ac Bb Cc C
V k u k u k u k V k
V k u k u k u k V k
V k u k u k u k V k
=
(13)
(14)
(15)
(18)
(16)
(17)
11. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
61
Also the Eqn (15) can be written for phase b and c; by the way there are 27 allowable switching
configurations for a three-phase to three-phase matrix converter. These converter configurations
can be divided into three groups. In the first one, each output phase is connected to a different
input phase (e.g. uAa = uBb = uCc = 1). The corresponding output voltage vectors (in the αβ stator
frame) have a constant amplitude and a variable direction. There is six configurations in this
group. In the second group, each output phase is connected to the same input phase (e.g. uAa = uBb
= uCc = 1) There is three configurations in this group. They lead to a null output voltage vector.
Finally the eighteen other configurations are in the third group. Two outputs are connected to the
same input (e.g. uAa = uBb = uCc = 1). The corresponding output voltage vectors (in the αβ stator
frame) have a constant direction and a variable amplitude. It is worth to note that, for each paper
cited in reference, the six configurations from the first group are not considered. Predictive
control can use these configurations.
4.3.3. Model of the whole converter – machine
Firstly with (1), (2) and (18), if output currents, input voltages (V in = [VA VB Vc ]T
) , angular
position and speed are measured, it is possible to predict every possible state vector after a
sampling period Xn(k + 1) (1 ≤ n ≤ 27) for each possible converter configuration Un (19).
( 1) ( ). ( ) . ( ( )). . ( ). ( ) ( )n n inX k A k X k B R k C U k V k kθ+ = + +Φ
Secondly as it is possible to achieve for currents a similar reasoning than the one used to
demonstrate (18), it is also possible to predict input currents in a fixed frame AB after a sampling
period for each converter configuration (20).
1
1 1 1 1
1 1
( 1) 2 2 2 2 2
. ( ).
( 1) 3 3 3 3 3
0 0
2 2 2 2
( 1)
. ( ) .
( 1)
An t
n
Bn
An
Bn
I k
U k
I k
I k
R k
I k
−
− − − − +
=
+ − −
+
+
4.3.4. Cost Function
A cost function is used to determine which configuration must be applied. As the main goal of the
control scheme is to control output currents, a first cost function is proposed as the sum of
differences between the reference currents Id
#
, Iq
#
and the predicted currents (21).
' # #
| ( 1)| | ( 1)| .|sin( ( 1))|n d dn q qn inG I I k I I k c kφ= − + + − + + +
With this cost function, only output currents are controlled. However the matrix converter
structure also allows to control input power factor. So input currents are computed with (20) in
order to compute the angle between input current vector and input voltage vector if the
configuration n is applied (φin). Then a third term is added in (21) to take into account input
power factor and in order to make it as close to unity as possible (22).
(19)
(20)
(21)
12. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
62
' # #
| ( 1)| | ( 1)| .|sin( ( 1))|n d dn q qn inG I I k I I k c kφ= − + + − + + +
(a)
(b)
Fig.6. MPC operating principle. (a)Theoretical case. (b) Implementation case
In (22) c is a weighting factor. Actually the instantaneous angle between input current vector and
input voltage vector is used as a way to act on input power factor. With c, it is possible to obtain a
trade-off between output current control and input power factor controls.
5. BRANCH AND BOUND ALGORITHM FOR MPC
The Prediction of future behaviour is not very simple from computational cost point of view. It
becomes really complex when prediction is to be made for few samples. The B&B approach [17]
is based on the total set of feasible solutions that can be partitioned into subset of solutions which
are estimated to get the finest solution [24]. Bounding value is the maximum cost at which the
particular solution will be discarded and should not be branched further. Branch and bound
scheme reduces the computational cost in three ways:
• Previous switching position of the MC is considered as the root node which is further
branched to its eight possible positions. Then each of the eight possible switching positions
(22)
13. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
63
is to be further branched to next eight possible positions. But using the branch and bound
algorithm, if any switching position at first level is found to be unfeasible, it is not branched
i.e.it has reached the allowable bound so that node will not be further branched. One
particular case is explained in Fig. 7. Here the minimum size of N is 2. The root node is {11
0}. Suppose that four nodes at first level {10 0}, {0 1 1}, {0 0 1} and {1 0 1} are not feasible
due to violating either torque or flux limits. So these switching positions are not further
branched. It saves computational efforts at level 2 and next levels if N is greater than 2.
• If at stage during the scan, a sequence is found with minimum cost, the scanning process is
stopped and that sequence is decided as the most suitable one.
• Before enumerating any node, the minimum possible cost of its child node sequences is
calculated from maximum switching sequence length. It is compared with minimum cost
obtained so far. If it is greater than the minimum cost till that stage, that particular node is
discarded.
Fig.7. An Example of Branch & Bound
6. FLOW CHART OF MPC ALGORITHM
The flowchart for the proposed MPC methodology is derived as per the Branch and Bound
Algorithm and it is illustrated in the fig.8
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64
Fig.8. Flow Chart of Proposed MPC – Branch & Bound Algorithm
7. SIMULATION RESULT
The Simulation studies are carried out in MATLAB/Simulink to validate the proposed MC-DTC
scheme for a 600 W PMSM drive system. The considerations of the PMSM are given as follows.
The rated power is 600 W;maximum speed is 3000 RPM; Rs = 0.165 ; Ld = 0.268 mH; Lq =
0.342 mH; the voltage constant Ke = 8.7 V/kRPM; the number of pole pairs is p = 4; and the
momentum of inertia is J = 0.000008 kg·m2
. The switching frequency of MC-SVM scheme is 10
kHz, which is typically used in practical motor drive systems. The Simulink diagram is shown in
fig.9. Firstly, at 0 sec. the PMSM is operated at 10 Nm Load Torque and then sudden changes of
15 Nm, 20 Nm and 5 Nm are applied at 0.5 sec, 1 sec and 1.5 sec respectively. The steady-state
performances of the proposed MC-DTC are shown in fig.10. Moreover, the proposed DTC can
output a larger mean torque at the same operating condition, which is important for drive systems
15. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
65
Fig. 9 . Simulink Diagram of Proposed MC-DTC
.
0 0.5 1 1.5
-400
-300
-200
-100
0
100
200
300
400
Time in Sec
RotorSpeedinwm
ROTOR SPEED
(a)
0 0.5 1 1.5
-400
-300
-200
-100
0
100
200
300
400
ELECTROMAGNETIC TORQUE
Time in Sec
ElectromagneticTorqueTm
(b)
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
-500
-400
-300
-200
-100
0
100
200
300
400
500
Time in Sec
Current(A)
STATOR CURRENT ( ia, ib, ic )
(c)
Fig.10.Steady state response.(a)Rotor speed,(b)Electromagnetic Torque, (c) Stator current ia& ib
16. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
66
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
-500
-400
-300
-200
-100
0
100
200
300
400
500
INPUT RESPONSE OF THE MATRIX CONVERTER
Time in Sec
Voltage(V)&Current(A)
(a)
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
-800
-600
-400
-200
0
200
400
600
800
OUTPUT RESPONSE OF THE MATRIX CONVERTER
Time in Sec
Voltage(V)&Current(A)
(b)
0 2 4 6 8 10 12 14 16 18 20
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Harmonic order
Fundamental (50Hz) = 295.1 , THD= 6.02%
Mag(%ofFundamental)
(c)
Fig.11. Steady state response. (a)Input Voltage & Current,(b) Output Voltage & Current, (c) THD analysis of MC
current
8. CONCLUSION AND FUTURE WORK
In this paper, an advanced DTC scheme for MC fed PMSM has been introduced. The method
retains advantages inherited from the conventional Enhanced table- Duty cycle estimation
technique of DTC, and decreases the torque ripples with the help of MPC algorithm by
employing Branch and Bound method. This method is more direct and able to adopt with online
estimation. In the future, this control method will be improved by deriving more accurate
algorithm, in order to reach a milestone by which the torque ripple can be reduced fairly.
17. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
67
REFERENCES
[1] H. She, H. Lin, B. He, X. Wang, L. Yue, and X. An, “Implementation of voltage-based commutation
in space-vector-modulated matrix converter,” IEEE Trans. Ind. Electron., vol. 59, no. 1, pp. 154–166,
Jan. 2012.
[2] C. Xia, P. Song, T. Shi, and Y. Yan, “Chaotic dynamics characteristic analysis for matrix converter,”
IEEE Trans. Ind. Electron., vol. 60, no. 1, pp. 78–87, Jan. 2013.
[3] J. Rodriguez, M. Rivera, J. Kolar, and P. Wheeler, “A review of control and modulation methods for
matrix converters,” IEEE Trans. Ind. Electron., vol. 59, no. 1, pp. 58–70, Jan. 2012.
[4] M. Venturini, “A new sine wave in sine wave out, conversion technique which eliminates reactive
elements,” in Proc. Powercon 7, 1980, pp. E3/1–E3/15.
[5] X. Wang, H. Lin, H. She, and B. Feng, “A research on space vector modulation strategy for matrix
converter under abnormal input-voltage conditions,” IEEE Trans. Ind. Electron., vol. 59, no. 1, pp.
93–104, Jan. 2012.
[6] M. Rivera, A. Wilson, C. A. Rojas, J. Rodriguez, J. R. Espinoza, P. W. Wheeler, and L. Empringham,
“A comparative assessment of model predictive current control and space vector modulation in a
direct matrix converter,” IEEE Trans. Ind. Electron., vol. 60, no. 2, pp. 578–588, Feb. 2013.
[7] S. Kouro, P. Cortes, R. Vargas, U. Ammann, and J. Rodriguez, “Model predictive control, a simple
and powerful method to control power converters,” IEEE Trans. Ind. Electron., vol. 56, no. 6, pp.
1826–1838, Jun. 2009.
[8] D. Casadei, G. Serra, and A. Tani, “The use of matrix converters in direct torque control of induction
machines,” IEEE Trans. Ind. Electron., vol. 48, no. 6, pp. 1057–1064, Dec. 2001.
[9] C. Ortega, A. Arias, C. Caruana, J. Balcells, and G. Asher, “Improved waveform quality in the direct
torque control of matrix-converter-fed PMSM drives,” IEEE Trans. Ind. Electron., vol. 57, no. 6, pp.
2101–2110, Jun. 2010.
[10] K.-B. Lee and F. Blaabjerg, “Sensorless DTC-SVM for induction motor driven by a matrix converter
using a parameter estimation strategy,” IEEE Trans. Ind. Electron., vol. 55, no. 2, pp. 512–521, Feb.
2008.
[11] J. Wang and J. Jiang, “Variable-structure direct torque control for induction motor driven by a matrix
converter with over modulation strategy,” in Proc. 6th IEEE IPEMC, May 2009, pp. 580–584.
[12] D. Xiao and M. F. Rahman, “Sensorless direct torque and flux controlled IPM synchronous machine
fed by matrix converter over a wide speed range,” IEEE Trans. Ind. Informat., vol. 9, no. 4, pp. 1855–
1867, Nov. 2013.
[13] E. Yamamoto, H. Hara, T. Uchino, M. Kawaji, T. J. Kume, J.-K. Kang, and H.-P. Krug,
“Development of MCs and its applications in industry,” IEEE Ind. Electron. Mag., vol. 5, no. 1, pp.
4–12, Mar. 2011.
[14] G. S. Buja and M. P. Kazmierkowski, “Direct torque control of PWM inverter-fed ac motors—A
survey,” IEEE Trans. Ind. Electron., vol. 51, no. 4, pp. 744–757, Aug. 2004.
[15] C.Xia, J.Zhao, Y.Yan, and T.Shi , “A Novel Direct Torque Control of Matrix Converter-Fed PMSM
Drives Using Duty Cycle Control for Torque Ripple Reduction,” IEEE Trans.Ind.Electron, vol. 61,
no. 6, pp. 2700-2713, Jun. 2014.
[16] T.Geyer, and G.Papafotiou, “Model Predictive Direct Torque Control of a Variable Speed Drive with
a Five-Level Inverter”, IEEE Industrial Electronics, 35th Annual Conference , pp.1203-1208, Nov.
2009
[17] M. A. Naeem, and K. M. Hasan , “Direct Torque Control (DTC) of Three Phase Induction Motor
using Model based Predictive Control (MPC) scheme deploying Branch and Bound Algorithm”,
ICRERA 2013, Madrid, Spain, Oct. 2013
[18] I. Takahashi and T. Noguchi, “A new quick response and high efficiency control strategy for an
induction motor,” IEEE Trans. Ind. Electron., vol. IE-22, no. 5, pp. 820–827, Sep. 1986.
[19] J. Zhoua and Y. Wang, “Real-time nonlinear adaptive back stepping speed control for a PM
synchronous motor,” Control Eng. Pract., vol. 13, pp. 1259– 1269, 2005.
[20] L. Zhong, M. Rahman, W. Hu, and K. Lim, “Analysis of direct torque control in permanent magnet
synchronous motor drives,” IEEE Trans. Power Electron., vol. 12, no. 3, pp. 528–536, May 1997.
[21] C. E. Garcia, D. M. Prett, and M. Morari, “Model predictive control: Theory and practice – a survey,”
Automatica, vol. 25, no. 3, pp. 335–348, Mar. 1989.
18. International Journal of Soft Computing, Mathematics and Control (IJSCMC), Vol. 3, No. 4, November 2014
68
[22] M.Fan, H.Lin , and T.Lan , “Model Predictive Direct Torque Control for SPMSM with Load Angle
Limitation”, Progress In Electromagnetics Research B, Vol. 58, 245 -256, Mar.2014
[23] M. Pacas and J. Weber, “Predictive direct torque control for the PM synchronous machine,” IEEE
Trans. Ind. Electron., vol. 52, no. 5, pp. 1350–1356, Oct. 2005.
[24] T. Geyer, “Low complexity model predictive control in power electronics and power systems,” Ph.D.
dissertation, Automatic Control Laboratory ETH Zurich, 2005.
Authors
Mr.S.Kannan , He completed his B.E in Electrical and Electronics Engineering from
Sasurie College of Engineering, Tirupur, India and currently doing M.E in K.S.R. College of
Engineering ,Tiruchengode, India. He worked as a Lecturer in M.Kumarasamy College of
Engineering, Karur, India for 2 years. His area of interest includes Electrical Machines,
Power Electronics & Soft computing Techniques.
Mr.S.Chinnaiya, He completed his M.E in Power Electronics and Drives from Anna
University, Chennai, India and pursuing Ph.D under Anna University, Chennai. He is a
lifetime member in ISTE. At present he is working as an Assistant Professor in EEE
Department at KSR College of Engineering, Tiruchengode, India. His area of interest includes
Matrix Converter, Power Quality, and Intelligent Controllers.
Dr.S.U.Prabha, She completed her M.E. in Electrical Machines from Bharathiar University,
Coimbatore, India and her Ph.D in Power Systems from Multimedia University, Malaysia. She
is a lifetime member in ISTE and also a member of IEEE. At present she is working as a
Professor and Head in EEE Department at Sri Ramakrishna Engineering College, Coimbatore,
India. She is a reviewer for various International Journals. She has published more than 20 research papers
in various International Journals and Conferences. Her areas of interest are Power Systems and Electrial
Machines.