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.
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.
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.
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.
Investigation of Artificial Neural Network Based Direct Torque Control for PM...cscpconf
This paper investigates solution for the chronically and the biggest problem of direct torque control scheme: high torque ripple. Otherwise, another main problem faced in direct torque control method is difficulties due to complex algorithm to get high performance control for industrial motors. The purpose of this paper is to simplify the control structure by using artificial neural networks learning abilities and to investigate the affects of this structure on torque performance of motor. For this purpose, two different artificial neural networks have been suggested replacing the optimal switching vector selection and flux sector determination process of conventional direct torque control method. Matlab/Simulink based numerical simulations have been carried out to compare motor performances with conventional control structure and proposed artificial neural network based structure. It has been observed that the dynamic response of motor is faster and torque ripple and the controller complexity of the conventional control system has been reduced with the proposed technique.
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.
STATOR FLUX OPTIMIZATION ON DIRECT TORQUE CONTROL WITH FUZZY LOGIC cscpconf
This document summarizes a research paper that proposes a fuzzy logic based stator flux optimization technique for direct torque control (DTC) drives. The technique uses a fuzzy logic controller to self-regulate the stator flux reference based on the torque error and initial flux value without requiring motor parameters. Simulations show the proposed fuzzy logic approach reduces torque ripple compared to conventional DTC, especially at low loads. Key advantages of the fuzzy approach include improved performance and robustness to parameter changes without motor details.
Comparing of switching frequency on vector controlled asynchronous motorijscai
Nowadays, asynchronous motors have wide range use in many industrial applications. Field oriented
control (FOC) and direct torque control (DTC) are commonly used methods in high performance vector
control for asynchronous motors. Therefore, it is very important to identify clearly advantages and
disadvantages of both systems in the selection of appropriate control methods for many industrial
applications. This paper aims to present a new and different perspective regarding the comparison of the
switching behaviours on the FOC and the DTC drivers. For this purpose, the experimental studies have
been carried out to compare the inverter switching frequencies and torque responses of the asynchronous
motor in the FOC and the DTC systems under different working conditions. The dSPACE 1103 controller
board was programmed with Matlab/Simulink software. As expected, the experimental studies showed that
the FOC controlled motors has a lessened torque ripple. On the other hand, the FOC controlled motor
switching frequency has about 65-75% more than the DTC controlled under both loaded and unloaded
working conditions
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.
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.
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.
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.
Investigation of Artificial Neural Network Based Direct Torque Control for PM...cscpconf
This paper investigates solution for the chronically and the biggest problem of direct torque control scheme: high torque ripple. Otherwise, another main problem faced in direct torque control method is difficulties due to complex algorithm to get high performance control for industrial motors. The purpose of this paper is to simplify the control structure by using artificial neural networks learning abilities and to investigate the affects of this structure on torque performance of motor. For this purpose, two different artificial neural networks have been suggested replacing the optimal switching vector selection and flux sector determination process of conventional direct torque control method. Matlab/Simulink based numerical simulations have been carried out to compare motor performances with conventional control structure and proposed artificial neural network based structure. It has been observed that the dynamic response of motor is faster and torque ripple and the controller complexity of the conventional control system has been reduced with the proposed technique.
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.
STATOR FLUX OPTIMIZATION ON DIRECT TORQUE CONTROL WITH FUZZY LOGIC cscpconf
This document summarizes a research paper that proposes a fuzzy logic based stator flux optimization technique for direct torque control (DTC) drives. The technique uses a fuzzy logic controller to self-regulate the stator flux reference based on the torque error and initial flux value without requiring motor parameters. Simulations show the proposed fuzzy logic approach reduces torque ripple compared to conventional DTC, especially at low loads. Key advantages of the fuzzy approach include improved performance and robustness to parameter changes without motor details.
Comparing of switching frequency on vector controlled asynchronous motorijscai
Nowadays, asynchronous motors have wide range use in many industrial applications. Field oriented
control (FOC) and direct torque control (DTC) are commonly used methods in high performance vector
control for asynchronous motors. Therefore, it is very important to identify clearly advantages and
disadvantages of both systems in the selection of appropriate control methods for many industrial
applications. This paper aims to present a new and different perspective regarding the comparison of the
switching behaviours on the FOC and the DTC drivers. For this purpose, the experimental studies have
been carried out to compare the inverter switching frequencies and torque responses of the asynchronous
motor in the FOC and the DTC systems under different working conditions. The dSPACE 1103 controller
board was programmed with Matlab/Simulink software. As expected, the experimental studies showed that
the FOC controlled motors has a lessened torque ripple. On the other hand, the FOC controlled motor
switching frequency has about 65-75% more than the DTC controlled under both loaded and unloaded
working conditions
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparison of Estimated Torques Using Low Pass Filter and Extended Kalman Fil...IAES-IJPEDS
Torque calculation process is one of the major concerns for controlling induction motors in industry, which requires very accurate state estimation of unmeasurable variables of nonlinear models. This can be solved if the variables used for torque calculation is accurately estimated. This paper presents a torque calculation based on a voltage model represented with a low-pass filter (LPF), and an extended Kalman filter (EKF). The experimental results showed that the estimated torque at low speed based on EKF is more accurate in the expense of more complicated and larger computational time.
This document compares the switching behaviors of field oriented control (FOC) and direct torque control (DTC) for induction motors. Experimental tests using a dSpace 1103 controller board show that under no load conditions, FOC produces less torque ripple than DTC. However, the switching frequency of the inverter for a FOC controlled motor is about 75% higher than for a DTC controlled motor. Therefore, DTC may be preferable when fast dynamic performance is critical, while FOC provides better torque quality.
Performance Analysis of a DTC and SVM Based Field- Orientation Control Induct...IJPEDS-IAES
This study presents a performance analysis of two most popular control strategies for Induction Motor (IM) drives: direct torque control (DTC) and space vector modulation (SVM) strategies. The performance analysis is done by applying field-orientation control (FOC) technique because of its good dynamic response. The theoretical principle, simulation results are discussed to study the dynamic performances of the drive system for individual control strategies using actual parameters of induction motor. A closed loop PI controller scheme has been used. The main purpose of this study is to minimize ripple in torque response curve and to achieve quick speed response as well as to investigate the condition for optimum performance of induction motor drive. Depending on the simulation results this study also presents a detailed comparison between direct torque control and space vector modulation based field-orientation control method for the induction motor drive.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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.
Comparison of different controllers for the improvement of Dynamic response o...IJERA Editor
This document compares different fuzzy logic controllers for improving the dynamic response of an indirect vector controlled induction motor drive. It presents a new fuzzy PI controller with scaling factors and evaluates its performance against fuzzy PI and fuzzy MRAC (model reference adaptive control) controllers. Simulation results show that the proposed fuzzy PI with scaling factors has a faster settling time than fuzzy PI, and is less complex than fuzzy MRAC while still providing good parameter insensitivity. The proposed controller provides a compromise between complexity, accuracy and settling time for induction motor applications.
This document summarizes a research paper that proposes a novel method to improve direct torque control (DTC) for induction machine drives using a controlled rectifier. The paper begins with an overview of DTC and its limitations of torque and flux ripples. It then describes the proposed method of using a PI controller and controlled rectifier to adjust the DC bus voltage based on torque error, allowing selection of a voltage vector that reduces ripples. Simulation results presented in MATLAB/Simulink show the proposed method significantly reduces current distortion and torque/flux ripples compared to standard DTC.
A New Induction Motor Adaptive Robust Vector Control based on Backstepping IJECEIAES
In this paper, a novel approach to nonlinear control of induction machine, recursive on-line estimation of rotor time constant and load torque are developed. The proposed strategy combines Integrated Backstepping and Indirect Field Oriented Controls. The proposed approach is used to design controllers for the rotor flux and speed, estimate the values of rotor time constant and load torque and track their changes on-line. An open loop estimator is used to estimate the rotor flux. Simulation results are presented which demonstrate the effectiveness of the control technique and on-line estimation.
Novelty Method of Speed Control Analysis of Permanent Magnet Brushless DC MotorIRJET Journal
This document summarizes a study on speed control of permanent magnet brushless DC motors (PMBLDC). It begins with an introduction to PMBLDC motors and their closed-loop speed control system using a PI controller. It then presents the mathematical model developed to simulate the motor drive system in LabVIEW. Key aspects of the model include the motor equations, torque equation, voltage and current relationships, and mechanical model relating speed, position, load torque and friction. Simulation results are used to analyze the motor's dynamic response and tune the PI controller gains.
On tracking control problem for polysolenoid motor model predictive approach IJECEIAES
The Polysolenoid Linear Motor (PLM) have been playing a crucial role in many industrial aspects due to its functions, in which a straight motion is provided directly without mediate mechanical actuators. Recently, with several commons on mathematic model, some control methods for PLM based on Rotational Motor have been applied, but position, velocity and current constraints which are important in real systems have been ignored. In this paper, position tracking control problem for PLM was considered under state-independent disturbances via min-max model predictive control. The proposed controller forces tracking position errors converge to small region of origin and satisfies state including position, velocity and currents constraints. Further, a numerical simulation was implemented to validate the performance of the proposed controller.
TORQUE CONTROL OF AC MOTOR WITH FOPID CONTROLLER BASED ON FUZZY NEURAL ALGORITHMijics
Nowadays in the complicated systems, design of proper and implementable controller has a most importance. With respect to ability of fractional order systems in complicated systems identification as a first order fractional system with time delay, usage of fractional order PID has a proper result. From one side flexibility of fractional calculus than integer order has been topics of interest to the researchers. From another side, PMSM motors which are one the AC motor types, has been allocated largely accounted position in industry and used in variety applications. Therefore in this paper torque direct control of PMSM motors with FOPID based on model is proposed. Also fuzzy neural controllers are widely considered. Reason of this is success of fuzzy neural controller in control and identification of uncertain and complicated systems. The proposed method in this paper is combination of FOPID controller with fuzzy neural supervision system which with coefficients setting of this controller, control operation of PMSM will improve. Results of proposed method show the ability of proposed technique in reference signal tracking, elimination of disturbances effects and functional robustness in presence of noise and uncertainty. The results show the error averagely in three condition, nominal form, step disturbance and noise and uncertainly will decrease 11.66% in proposed method (FNFOPID) with Integral Square Error criterion and 7.69% with Integral Absolute Error criterion in comparison to FOPID.
Comparative Study of the Success of PI and PI-Fuzzy Controller for Induction ...inventionjournals
Asynchronous motors have a wide range of applications in the industry.Therefore, speed control of asynchronous motors is of great importance.Speed control of asynchronous motors based on vector control techniques to achieve high performance.The vector control technique, motor flux and moment variables can be controlled independently of each other.Because of the nonlinear and complex model of asynchronous motors, the speed control applications of these motors are not provided with great efficiency by classical control methods.Fuzzy logic controllers (FLC), which were successful in many areas, present great performance in speed control of an asynchronous motor.In this study, a simulation study regarding speed control of a threephase squirrel cage asynchronous motor was carried out with a PI-Fuzzy type FLC and a conventional PI type controller.The data obtained by simulation are evaluated and the performances of the control methods are compared.
Output feedback trajectory stabilization of the uncertainty DC servomechanism...ISA Interchange
This work proposes a solution for the output feedback trajectory-tracking problem in the case of an uncertain DC servomechanism system. The system consists of a pendulum actuated by a DC motor and subject to a time-varying bounded disturbance. The control law consists of a Proportional Derivative controller and an uncertain estimator that allows compensating the effects of the unknown bounded perturbation. Because the motor velocity state is not available from measurements, a second-order sliding-mode observer permits the estimation of this variable in finite time. This last feature allows applying the Separation Principle. The convergence analysis is carried out by means of the Lyapunov method. Results obtained from numerical simulations and experiments in a laboratory prototype show the performance of the closed loop system.
Analysis of Direct Torque Control of Industrial Drives using Zone-Shifting SVMIJPEDS-IAES
Direct Torque Control of Induction Motor has gained popularity in industrial applications mainly due to its simple control structure from its first introduction in 1986. Here the direct torque control (DTC) of induction motor with zone shifting space vector modulation (SVM) has been done. It uses a simple phase current re-construction algorithm for three phase induction motor (IM). The phase current re-construction algorithm is done by using information from the current that is from the phases between the inverter and the induction motor. The proposed algorithm is robust and very simple. It uses the AC current to get the stator current for estimating the motor flux and the electromagnetic torque. By evaluating through the torque value and the current the controlling of induction motor is done. The simulation results are also given which supports the direct torque control strategy of the induction motor (IM).
Майорка является одним из лучших гольф назначения. Остров имеет 24 полей для гольфа, хороший климат, отличные условия проживания и многое другое. Узнайте, почему!
The document contains a series of letters arranged in a grid-like pattern, with no other text. The letters are "V", "S", "D", "L", "M", and "X", "J", and "T". There are no punctuation marks or spaces between letters.
Este documento discute la importancia de la educación multicultural en las escuelas primarias. Propone que los maestros deben aceptar y celebrar la diversidad cultural para garantizar que todos los niños se sientan valorados e incluidos. También aboga por la creación de un centro educativo multicultural que sirva como modelo de integración cultural y pluralismo, y donde los maestros estén capacitados para comprender y respetar diferentes culturas.
Este documento presenta diferentes perspectivas sobre el concepto de dirección empresarial, incluyendo coordinar el esfuerzo de los empleados para alcanzar las metas de la empresa, guiar y supervisar a los subordinados, e influir en ellos interpersonalmente. También describe los grados de dirección, estilos de dirección, el proceso de dirección que incluye planificación y control, y la toma de decisiones en situaciones de certeza, riesgo e incertidumbre. Finalmente, distingue entre dirigir y liderar, señalando
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparison of Estimated Torques Using Low Pass Filter and Extended Kalman Fil...IAES-IJPEDS
Torque calculation process is one of the major concerns for controlling induction motors in industry, which requires very accurate state estimation of unmeasurable variables of nonlinear models. This can be solved if the variables used for torque calculation is accurately estimated. This paper presents a torque calculation based on a voltage model represented with a low-pass filter (LPF), and an extended Kalman filter (EKF). The experimental results showed that the estimated torque at low speed based on EKF is more accurate in the expense of more complicated and larger computational time.
This document compares the switching behaviors of field oriented control (FOC) and direct torque control (DTC) for induction motors. Experimental tests using a dSpace 1103 controller board show that under no load conditions, FOC produces less torque ripple than DTC. However, the switching frequency of the inverter for a FOC controlled motor is about 75% higher than for a DTC controlled motor. Therefore, DTC may be preferable when fast dynamic performance is critical, while FOC provides better torque quality.
Performance Analysis of a DTC and SVM Based Field- Orientation Control Induct...IJPEDS-IAES
This study presents a performance analysis of two most popular control strategies for Induction Motor (IM) drives: direct torque control (DTC) and space vector modulation (SVM) strategies. The performance analysis is done by applying field-orientation control (FOC) technique because of its good dynamic response. The theoretical principle, simulation results are discussed to study the dynamic performances of the drive system for individual control strategies using actual parameters of induction motor. A closed loop PI controller scheme has been used. The main purpose of this study is to minimize ripple in torque response curve and to achieve quick speed response as well as to investigate the condition for optimum performance of induction motor drive. Depending on the simulation results this study also presents a detailed comparison between direct torque control and space vector modulation based field-orientation control method for the induction motor drive.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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.
Comparison of different controllers for the improvement of Dynamic response o...IJERA Editor
This document compares different fuzzy logic controllers for improving the dynamic response of an indirect vector controlled induction motor drive. It presents a new fuzzy PI controller with scaling factors and evaluates its performance against fuzzy PI and fuzzy MRAC (model reference adaptive control) controllers. Simulation results show that the proposed fuzzy PI with scaling factors has a faster settling time than fuzzy PI, and is less complex than fuzzy MRAC while still providing good parameter insensitivity. The proposed controller provides a compromise between complexity, accuracy and settling time for induction motor applications.
This document summarizes a research paper that proposes a novel method to improve direct torque control (DTC) for induction machine drives using a controlled rectifier. The paper begins with an overview of DTC and its limitations of torque and flux ripples. It then describes the proposed method of using a PI controller and controlled rectifier to adjust the DC bus voltage based on torque error, allowing selection of a voltage vector that reduces ripples. Simulation results presented in MATLAB/Simulink show the proposed method significantly reduces current distortion and torque/flux ripples compared to standard DTC.
A New Induction Motor Adaptive Robust Vector Control based on Backstepping IJECEIAES
In this paper, a novel approach to nonlinear control of induction machine, recursive on-line estimation of rotor time constant and load torque are developed. The proposed strategy combines Integrated Backstepping and Indirect Field Oriented Controls. The proposed approach is used to design controllers for the rotor flux and speed, estimate the values of rotor time constant and load torque and track their changes on-line. An open loop estimator is used to estimate the rotor flux. Simulation results are presented which demonstrate the effectiveness of the control technique and on-line estimation.
Novelty Method of Speed Control Analysis of Permanent Magnet Brushless DC MotorIRJET Journal
This document summarizes a study on speed control of permanent magnet brushless DC motors (PMBLDC). It begins with an introduction to PMBLDC motors and their closed-loop speed control system using a PI controller. It then presents the mathematical model developed to simulate the motor drive system in LabVIEW. Key aspects of the model include the motor equations, torque equation, voltage and current relationships, and mechanical model relating speed, position, load torque and friction. Simulation results are used to analyze the motor's dynamic response and tune the PI controller gains.
On tracking control problem for polysolenoid motor model predictive approach IJECEIAES
The Polysolenoid Linear Motor (PLM) have been playing a crucial role in many industrial aspects due to its functions, in which a straight motion is provided directly without mediate mechanical actuators. Recently, with several commons on mathematic model, some control methods for PLM based on Rotational Motor have been applied, but position, velocity and current constraints which are important in real systems have been ignored. In this paper, position tracking control problem for PLM was considered under state-independent disturbances via min-max model predictive control. The proposed controller forces tracking position errors converge to small region of origin and satisfies state including position, velocity and currents constraints. Further, a numerical simulation was implemented to validate the performance of the proposed controller.
TORQUE CONTROL OF AC MOTOR WITH FOPID CONTROLLER BASED ON FUZZY NEURAL ALGORITHMijics
Nowadays in the complicated systems, design of proper and implementable controller has a most importance. With respect to ability of fractional order systems in complicated systems identification as a first order fractional system with time delay, usage of fractional order PID has a proper result. From one side flexibility of fractional calculus than integer order has been topics of interest to the researchers. From another side, PMSM motors which are one the AC motor types, has been allocated largely accounted position in industry and used in variety applications. Therefore in this paper torque direct control of PMSM motors with FOPID based on model is proposed. Also fuzzy neural controllers are widely considered. Reason of this is success of fuzzy neural controller in control and identification of uncertain and complicated systems. The proposed method in this paper is combination of FOPID controller with fuzzy neural supervision system which with coefficients setting of this controller, control operation of PMSM will improve. Results of proposed method show the ability of proposed technique in reference signal tracking, elimination of disturbances effects and functional robustness in presence of noise and uncertainty. The results show the error averagely in three condition, nominal form, step disturbance and noise and uncertainly will decrease 11.66% in proposed method (FNFOPID) with Integral Square Error criterion and 7.69% with Integral Absolute Error criterion in comparison to FOPID.
Comparative Study of the Success of PI and PI-Fuzzy Controller for Induction ...inventionjournals
Asynchronous motors have a wide range of applications in the industry.Therefore, speed control of asynchronous motors is of great importance.Speed control of asynchronous motors based on vector control techniques to achieve high performance.The vector control technique, motor flux and moment variables can be controlled independently of each other.Because of the nonlinear and complex model of asynchronous motors, the speed control applications of these motors are not provided with great efficiency by classical control methods.Fuzzy logic controllers (FLC), which were successful in many areas, present great performance in speed control of an asynchronous motor.In this study, a simulation study regarding speed control of a threephase squirrel cage asynchronous motor was carried out with a PI-Fuzzy type FLC and a conventional PI type controller.The data obtained by simulation are evaluated and the performances of the control methods are compared.
Output feedback trajectory stabilization of the uncertainty DC servomechanism...ISA Interchange
This work proposes a solution for the output feedback trajectory-tracking problem in the case of an uncertain DC servomechanism system. The system consists of a pendulum actuated by a DC motor and subject to a time-varying bounded disturbance. The control law consists of a Proportional Derivative controller and an uncertain estimator that allows compensating the effects of the unknown bounded perturbation. Because the motor velocity state is not available from measurements, a second-order sliding-mode observer permits the estimation of this variable in finite time. This last feature allows applying the Separation Principle. The convergence analysis is carried out by means of the Lyapunov method. Results obtained from numerical simulations and experiments in a laboratory prototype show the performance of the closed loop system.
Analysis of Direct Torque Control of Industrial Drives using Zone-Shifting SVMIJPEDS-IAES
Direct Torque Control of Induction Motor has gained popularity in industrial applications mainly due to its simple control structure from its first introduction in 1986. Here the direct torque control (DTC) of induction motor with zone shifting space vector modulation (SVM) has been done. It uses a simple phase current re-construction algorithm for three phase induction motor (IM). The phase current re-construction algorithm is done by using information from the current that is from the phases between the inverter and the induction motor. The proposed algorithm is robust and very simple. It uses the AC current to get the stator current for estimating the motor flux and the electromagnetic torque. By evaluating through the torque value and the current the controlling of induction motor is done. The simulation results are also given which supports the direct torque control strategy of the induction motor (IM).
Майорка является одним из лучших гольф назначения. Остров имеет 24 полей для гольфа, хороший климат, отличные условия проживания и многое другое. Узнайте, почему!
The document contains a series of letters arranged in a grid-like pattern, with no other text. The letters are "V", "S", "D", "L", "M", and "X", "J", and "T". There are no punctuation marks or spaces between letters.
Este documento discute la importancia de la educación multicultural en las escuelas primarias. Propone que los maestros deben aceptar y celebrar la diversidad cultural para garantizar que todos los niños se sientan valorados e incluidos. También aboga por la creación de un centro educativo multicultural que sirva como modelo de integración cultural y pluralismo, y donde los maestros estén capacitados para comprender y respetar diferentes culturas.
Este documento presenta diferentes perspectivas sobre el concepto de dirección empresarial, incluyendo coordinar el esfuerzo de los empleados para alcanzar las metas de la empresa, guiar y supervisar a los subordinados, e influir en ellos interpersonalmente. También describe los grados de dirección, estilos de dirección, el proceso de dirección que incluye planificación y control, y la toma de decisiones en situaciones de certeza, riesgo e incertidumbre. Finalmente, distingue entre dirigir y liderar, señalando
This document summarizes a research paper that assesses collaboration frameworks in multi-cloud environments. It explores the viability of cloud service providers collaborating to offer diverse services without heavy infrastructure spending. The paper reviews several proposed collaboration models and frameworks, including a proxy-based framework using different types of proxies, a unified multi-cloud infrastructure using open service models and configurable federations, and a proxy-as-cloud-broker model using dynamic scheduling algorithms. The paper concludes that multi-cloud environments can eliminate vendor lock-in for consumers and allow services to be accessed based on preference and need rather than a single provider. Key challenges to collaboration include standardization and security across provider platforms and services.
This listening activity involves changing colored spaces on a page based on directions. The student will listen to instructions and modify the colored spaces by replacing them in the correct locations that are specified. The goal is to end up with the intended design after following the spoken directions.
O documento discute riscos e incertezas associados com raspadinhas, necessidades versus desejos de um videogame, e como economizar dinheiro durante o Halloween comprando itens reutilizáveis em vez de novos a cada ano.
Emma E. Conroy has experience in urban gardening education, horticulture, nonprofit work, teaching English abroad, and human rights advocacy. She received a Bachelor of Arts in Latin American Studies and Anthropology from Colby College in 2011. Her roles have included garden educator, greenhouse intern, sales and education outreach, teacher and coordinator in Peru, workshop facilitator, and assistant/interpreter for a human rights worker in Colombia. She is proficient in Spanish and has skills in translation, Microsoft Office, and developing educational programming.
This document discusses legal issues related to industrial action in the education sector. It outlines what types of industrial action are lawful and unlawful under UK law. Lawful industrial action, such as strikes, must meet certain ballot and notification requirements. Picketing can be lawful if it takes place at an employee's own workplace, but unlawful if it disrupts other organizations. The document provides guidance on distinguishing lawful picketing from peaceful protests and on preparations employers can make in anticipation of potential strikes.
I would distribute my opening film sequence on either Vimeo or YouTube to gain wide viewership and recognition for my work. Warner Brothers would be the ideal media company to partner with as they have experience distributing similar fantasy and sci-fi films like Harry Potter due to the genres similarities. Their past successes distributing comparable films indicates they understand how to market a film like mine effectively.
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.
Improvements the direct torque control performance for an induction machine u...IJECEIAES
This article examines a solution to the major problems of induction machine control in order to achieve superior dynamic performance. Conventional direct torque control and indirect control with flux orientation have some drawbacks, such as current harmonics, torque ripples, flux ripples, and rise time. In this article, we propose a comparative analysis between previous approaches and the one using fuzzy logic. Results from the simulation show that the direct torque control method using fuzzy logic is more effective in providing a precise and fast response without overshooting, and it eliminates torque and flux fluctuations at low switching frequencies. The demonstrated improvements in dynamic performance contribute to increased operational efficiency and reliability in industrial applications.
In this paper, DTC is applied for two-level inverter fed IM drives based on neuronal hysteresis comparators and The Direct Torque Control (DTC) is known to produce quick and robust response in AC drive system. However, during steady state, torque, flux and current ripple. An improvement of electric drive system can be obtained using a DTC method based on ANNs which reduces the torque and flux ripples, the estimated the rotor speed using the KUBOTA observer method based on measurements of electrical quantities of the motor. The validity of the proposed methods is confirmed by the simulation results.The THD (Total Harmonic Distortion) of stator current, torque ripple and stator flux ripple are determined and compared with conventional DTC control scheme using Matlab/Simulink environment.
Enhanced Torque Control and Reduced Switching Frequency in Direct Torque Cont...IJPEDS-IAES
Direct Torque Control (DTC) of induction machine has received wide
acceptance in many adjustable speed drive applications due to its simplicity
and high performance torque control. However, the DTC using a common
two-level inverter poses two major problems such as higher switching
frequency (or power loss) and larger torque ripple. These problems are due to
inappropriate voltage vectors which are selected among a limited number of
voltage vectors available in two-level inverter. The proposed research aims to
formulate an optimal switching strategy using Dual-Inverter Supplied Drive
for high performances of DTC. By using dual-inverter supplied, it provides
greater number of voltage vectors which can offer more options to select the
most appropriate voltage vectors. The most appropriate voltage vectors
should able to produce minimum torque slope but sufficient to satisfy torque
demands. The identification is accomplished by using an equation of rate of
change of torque which is derived from the induction machine equations. The
proposed strategy also introduces a block of modification of torque error
status which is responsible to modify the status such that it can determine the
most optimal voltage vectors from a look-up table, according to motor
operating conditions. The improvements obtained are as follows; 1)
minimization of switching frequency (reduce power loss), and 2) reduction of
torque ripple. Some improvements obtained in the proposed strategy were
verified via experimentations.
This document describes a direct torque control (DTC) scheme for an induction motor that uses a fuzzy logic controller (FLC) to reduce torque ripples. The DTC controls the motor torque and flux by selecting inverter voltage vectors. Typically this results in torque ripples. The FLC is designed to adaptively adjust the bandwidth of the torque hysteresis controller based on changes in motor torque and current over time. This helps minimize torque ripples and improve dynamic response. Simulation results using MATLAB/Simulink confirm that the FLC-based DTC scheme effectively controls the induction motor with reduced torque ripples compared to conventional DTC.
A Novel Direct Torque Control for Induction Machine Drive System with Low Tor...IAES-IJPEDS
This document describes a novel direct torque control method for induction machine drives using space vector modulation (DTC-SVM) to reduce torque and flux ripples. Simulation results show the proposed DTC-SVM control achieves lower ripples compared to the conventional DTC method. The DTC-SVM control strategy is designed and simulated using Matlab/Simulink and implemented on an FPGA using Xilinx System Generator. Simulation results verify the DTC-SVM control is effective at minimizing torque and flux ripples for induction machine drives.
COMPARING OF SWITCHING FREQUENCY ON VECTOR CONTROLLED ASYNCHRONOUS MOTORijscai
Nowadays, asynchronous motors have wide range use in many industrial applications. Field oriented
control (FOC) and direct torque control (DTC) are commonly used methods in high performance vector
control for asynchronous motors. Therefore, it is very important to identify clearly advantages and
disadvantages of both systems in the selection of appropriate control methods for many industrial
applications. This paper aims to present a new and different perspective regarding the comparison of the
switching behaviours on the FOC and the DTC drivers. For this purpose, the experimental studies have
been carried out to compare the inverter switching frequencies and torque responses of the asynchronous
motor in the FOC and the DTC systems under different working conditions. The dSPACE 1103 controller
board was programmed with Matlab/Simulink software. As expected, the experimental studies showed that
the FOC controlled motors has a lessened torque ripple. On the other hand, the FOC controlled motor
switching frequency
ADAPTIVE BANDWIDTH APPROACH ON DTC CONTROLLED INDUCTION MOTORijcisjournal
Induction motors are most commonly used motor type in industrial applications because of its well-known advantages like robust structure, cheaper prices etc. Today, field oriented control (FOC) and direct torque control (DTC) methods, also called vector control, are most famous control methods in high-performance applications. The main structural and behavioural differences between the both methods can be summarized as: the FOC has parameter dependence while the DTC has high torque ripples. In this study, a new adaptive bandwidth approach was presented to reduce torque ripples in DTC controlled induction motor drives. With the proposed method, instead of fixed bandwidth, adaptive bandwidth approach was investigated in hysteresis controllers on the DTC method. Both the conventional DTC(C-DTC) method and adaptive bandwidth DTC (AB-DTC) for induction motor were simulated in MATLAB/SIMULINK and the results were presented and discussed to verify the proposed control. The comparisons shown that, torque ripples were reduced remarkably with the proposed AB-DTC method.
ADAPTIVE BANDWIDTH APPROACH ON DTC CONTROLLED INDUCTION MOTORijics
Induction motors are most commonly used motor type in industrial applications because of its well-known
advantages like robust structure, cheaper prices etc. Today, field oriented control (FOC) and direct torque
control (DTC) methods, also called vector control, are most famous control methods in high-performance
applications. The main structural and behavioural differences between the both methods can be
summarized as: the FOC has parameter dependence while the DTC has high torque ripples. In this study, a
new adaptive bandwidth approach was presented to reduce torque ripples in DTC controlled induction
motor drives. With the proposed method, instead of fixed bandwidth, adaptive bandwidth approach was
investigated in hysteresis controllers on the DTC method. Both the conventional DTC(C-DTC) method and
adaptive bandwidth DTC (AB-DTC) for induction motor were simulated in MATLAB/SIMULINK and the
results were presented and discussed to verify the proposed control. The comparisons shown that, torque
ripples were reduced remarkably with the proposed AB-DTC method.
T ORQUE R IPPLES M INIMIZATION ON DTC C ONTROLLED I NDUCTION M OTOR WITH A DA...csandit
The conventional direct torque control (DTC) method for induction motors suffers from high torque ripples. This document proposes an adaptive bandwidth approach for the hysteresis controllers in DTC to reduce torque ripples. With the adaptive bandwidth approach, the hysteresis bandwidth is determined by the error values from the previous step for stator flux and torque, rather than using a fixed bandwidth. Simulation results show the proposed adaptive bandwidth DTC (AB-DTC) method can reduce torque ripples by around 60% compared to conventional DTC under both unloaded and loaded motor conditions.
CONTROL OF AN INDUCTION MOTOR WITH DOUBLE ANN MODEL BASED DTCcsandit
Direct torque control (DTC) is preferably control method on high performance control of induction motors due to its dvantages such as fast dynamic response, simple and robust control structure. However, high torque and current ripples are mostly faced problems in this control method. This paper presents artificial neural network (ANN) based approach to the DTC method to overcome mentioned problems. In the study, by taking a different perspective to ANN and DTC integration, two different ANN models have been designed, trained and implemented. The first ANN model has been used for switch selecting process and the second one has been used for sector determine process. Matlab/Simulink model of the proposed ANN based DTC method has created in order to compare with the conventional DTC and the proposed DTC
methods. The simulation studies have proved that the induction motor torque and current
ripples have been reduced remarkably with the proposed method and this approach can be a
good alternative to the conventional DTC method for induction motor control
OPTIMAL TORQUE RIPPLE CONTROL OF ASYNCHRONOUS DRIVE USING INTELLIGENT CONTROL...elelijjournal
This document summarizes a research paper on optimizing torque ripple in an asynchronous drive using intelligent controllers. It describes using a hybrid controller combining PI and fuzzy logic control with direct torque control and space vector modulation of a three-level cascaded inverter to power an induction motor drive. Simulation results showed the hybrid controller approach minimized torque ripple compared to using just PI or fuzzy logic control alone under no-load and loaded conditions. The optimized torque control method provides benefits for general purpose induction motor applications.
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.
Review of the DTC Controller and Estimation of Stator Resistance in IM DrivesIAES-IJPEDS
In recent years an advanced control method called direct torque control
(DTC) has gained importance due to its capability to produce fast torque
control of induction motor. Although in these systems such variables as
torque, flux modulus and flux sector are required, resulting DTC structure is
particularly simplistic. Conventional DTC does not require any mechanical
sensor or current regulator and coordinate transformation is not present, thus
reducing the complexity. Fast and good dynamic performances and
robustness has made DTC popular and is now used widely in all industrial
applications. Despite these advantages it has some disadvantages such as
high torque ripple and slow transient response to step changes during start
up. Torque ripple in DTC is because of hysteresis controller for stator flux
linkage and torque. The ripples can be reduced if the errors of the torque and
the flux linkage and the angular region of the flux linkage are subdivided into
several smaller subsections. Since the errors are divided into smaller sections
different voltage vector is selected for small difference in error, thus a more
accurate voltage vector is selected and hence the torque and flux linkage
errors are reduced. The stator resistance changes due to change in
temperature during the operation of machine. At high speeds, the stator
resistance drop is small and can be neglected. At low speeds, this drop
becomes dominant. Any change in stator resistance gives wrong estimation
of stator flux and consequently of the torque and flux. Therefore, it is
necessary to estimate the stator resistance correctly. This paper aims to
review some of the control techniques of DTC drives and stator resistance
estimation methods.
TORQUE RIPPLE MINIMIZATION OF MATRIX CONVERTER-FED PMSM DRIVES USING ADVANCED...ijscmcj
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.
The aim of this article is propose a method to improve the direct torque control and design a Fuzzy Logic based Controller which can take necessary control action to provide the desired torque and flux of an asynchronous machine. It’s widely used in the industrial application areas due to several features such as fast torque response and less dependence on the rotor parameters. The major problem that is usually associated with DTC control is the high torque ripple as it is not directly controlled. The high torque ripple causes vibrations to the motor which may lead to component lose, bearing failure or resonance. The fuzzy logic controller is applied to reduce electromagnetic torque ripple. In this proposed technique, the two hysteresis controllers are replaced by fuzzy logic controllers and a methodology for implementation of a rule based fuzzy logic controller are presented. The simulation by Matlab/Simulink was built which includes induction motor d-q model, inverter model, fuzzy logic switching table and the stator flux and torque estimator. The validity of the proposed method is confirmed by the simulative results of the whole drive system and results are compared with conventional DTC method.
Improved Torque Control Performance in Direct Torque Control using Optimal Sw...IJPEDS-IAES
This paper presents the significant improvement of Direct Torque Control (DTC) of 3-phases induction machine using a Cascaded H- Bidge Multilevel Inverter (CHMI). The largest torque ripple and variable switching frequency are known as the major problem founded in DTC of induction motor. As a result, it can diminish the performance induction motor control. Therefore, the conventional 2- level inverter has been replaced with CHMI the in order to increase the performance of the motor either in dynamic or steady-state condition. By using the multilevel inverter, it can produce a more selection of the voltage vectors. Besides that, it can minimize the torque ripple output as well as increase the efficiency by reducing the switching frequency of the inverter. The simulation model of the proposed method has been developed and tested by using Matlab software. Its improvements were also verified via experimental results.
QUICK DYNAMIC TORQUE CONTROL IN DTC-HYSTERESIS-BASED INDUCTION MOTOR BY USING...ijiert bestjournal
Induction machines are widely employed in industries due to their r ugged structure,high maintainability and economy than DC motors. There has been constant development in the i nduction motor drive system and their implementation in industrial applications. The improvement of switching speed of power electronic devices has enabled control techniques which possess high switching f requency and feasibility of high efficiency drive systems. In this pretext,Direct Torque Contr ol (DTC) was introduced to obtain quick and better dynamic torque response. The DTC scheme in its basic c onfiguration comprises torque and flux estimator DTC controller,stator voltage vector selector and voltage source inverter. Direct Torque Control of induction motor has increasingly become the best alternative to Field- Oriented Control methods. The performance of an induction motor under the classical Direct Torque Control method and improved scheme have been studied and confirmed by simulation using MATLAB.
1) The document proposes an enhanced direct torque control strategy for induction motor drives based on an imaginary swapping instant concept.
2) Simulation results show the proposed technique improves performance over conventional direct torque control, reducing torque and flux ripples by over 60% and speeding transient response times.
3) Benefits of the proposed technique include better robustness against parameter and load variations across low and high speed ranges.
The Nine-Switch Inverter(NSI) is a recently developed dual output converter. It can be used to drive two three-phase loads independently. As a substitute to two separate conventional voltage source inverters, the NSI has been, already, proposed in various industrial applications to reduce the numberof semiconductor switches and its associated energy losses and drive circuitry. On the other hand, the Direct Torque Control(DTC) is a robust control scheme of AC motors, which consist of selecting proper state vectors of a conventional voltage source inverter. The NSI, having a different working principle from the conventional voltage source inverter and taking into account the varying influence of active space vectors on motor’s torque and stator flux, a Direct Torque Control is suggested in this paper to, efficiently, drive two induction motors independently, while minimizing the torque and stator flux ripples of both motors. Simulations results confirm the effectiveness of the proposed algorithm. In addition, application of this newly proposed control scheme in operation of an Electric Vehicule (EV) is demonstrated.
Similar to Fuzzy logic based direct torque control of induction motor with space vector modulation (20)
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
How information systems are built or acquired puts information, which is what they should be about, in a secondary place. Our language adapted accordingly, and we no longer talk about information systems but applications. Applications evolved in a way to break data into diverse fragments, tightly coupled with applications and expensive to integrate. The result is technical debt, which is re-paid by taking even bigger "loans", resulting in an ever-increasing technical debt. Software engineering and procurement practices work in sync with market forces to maintain this trend. This talk demonstrates how natural this situation is. The question is: can something be done to reverse the trend?
In the realm of cybersecurity, offensive security practices act as a critical shield. By simulating real-world attacks in a controlled environment, these techniques expose vulnerabilities before malicious actors can exploit them. This proactive approach allows manufacturers to identify and fix weaknesses, significantly enhancing system security.
This presentation delves into the development of a system designed to mimic Galileo's Open Service signal using software-defined radio (SDR) technology. We'll begin with a foundational overview of both Global Navigation Satellite Systems (GNSS) and the intricacies of digital signal processing.
The presentation culminates in a live demonstration. We'll showcase the manipulation of Galileo's Open Service pilot signal, simulating an attack on various software and hardware systems. This practical demonstration serves to highlight the potential consequences of unaddressed vulnerabilities, emphasizing the importance of offensive security practices in safeguarding critical infrastructure.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Programming Foundation Models with DSPy - Meetup SlidesZilliz
Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
"Choosing proper type of scaling", Olena SyrotaFwdays
Imagine an IoT processing system that is already quite mature and production-ready and for which client coverage is growing and scaling and performance aspects are life and death questions. The system has Redis, MongoDB, and stream processing based on ksqldb. In this talk, firstly, we will analyze scaling approaches and then select the proper ones for our system.
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
"Frontline Battles with DDoS: Best practices and Lessons Learned", Igor IvaniukFwdays
At this talk we will discuss DDoS protection tools and best practices, discuss network architectures and what AWS has to offer. Also, we will look into one of the largest DDoS attacks on Ukrainian infrastructure that happened in February 2022. We'll see, what techniques helped to keep the web resources available for Ukrainians and how AWS improved DDoS protection for all customers based on Ukraine experience
Northern Engraving | Nameplate Manufacturing Process - 2024Northern Engraving
Manufacturing custom quality metal nameplates and badges involves several standard operations. Processes include sheet prep, lithography, screening, coating, punch press and inspection. All decoration is completed in the flat sheet with adhesive and tooling operations following. The possibilities for creating unique durable nameplates are endless. How will you create your brand identity? We can help!
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/how-axelera-ai-uses-digital-compute-in-memory-to-deliver-fast-and-energy-efficient-computer-vision-a-presentation-from-axelera-ai/
Bram Verhoef, Head of Machine Learning at Axelera AI, presents the “How Axelera AI Uses Digital Compute-in-memory to Deliver Fast and Energy-efficient Computer Vision” tutorial at the May 2024 Embedded Vision Summit.
As artificial intelligence inference transitions from cloud environments to edge locations, computer vision applications achieve heightened responsiveness, reliability and privacy. This migration, however, introduces the challenge of operating within the stringent confines of resource constraints typical at the edge, including small form factors, low energy budgets and diminished memory and computational capacities. Axelera AI addresses these challenges through an innovative approach of performing digital computations within memory itself. This technique facilitates the realization of high-performance, energy-efficient and cost-effective computer vision capabilities at the thin and thick edge, extending the frontier of what is achievable with current technologies.
In this presentation, Verhoef unveils his company’s pioneering chip technology and demonstrates its capacity to deliver exceptional frames-per-second performance across a range of standard computer vision networks typical of applications in security, surveillance and the industrial sector. This shows that advanced computer vision can be accessible and efficient, even at the very edge of our technological ecosystem.
Fueling AI with Great Data with Airbyte WebinarZilliz
This talk will focus on how to collect data from a variety of sources, leveraging this data for RAG and other GenAI use cases, and finally charting your course to productionalization.
Your One-Stop Shop for Python Success: Top 10 US Python Development Providersakankshawande
Simplify your search for a reliable Python development partner! This list presents the top 10 trusted US providers offering comprehensive Python development services, ensuring your project's success from conception to completion.
Introduction of Cybersecurity with OSS at Code Europe 2024Hiroshi SHIBATA
I develop the Ruby programming language, RubyGems, and Bundler, which are package managers for Ruby. Today, I will introduce how to enhance the security of your application using open-source software (OSS) examples from Ruby and RubyGems.
The first topic is CVE (Common Vulnerabilities and Exposures). I have published CVEs many times. But what exactly is a CVE? I'll provide a basic understanding of CVEs and explain how to detect and handle vulnerabilities in OSS.
Next, let's discuss package managers. Package managers play a critical role in the OSS ecosystem. I'll explain how to manage library dependencies in your application.
I'll share insights into how the Ruby and RubyGems core team works to keep our ecosystem safe. By the end of this talk, you'll have a better understanding of how to safeguard your code.
[OReilly Superstream] Occupy the Space: A grassroots guide to engineering (an...Jason Yip
The typical problem in product engineering is not bad strategy, so much as “no strategy”. This leads to confusion, lack of motivation, and incoherent action. The next time you look for a strategy and find an empty space, instead of waiting for it to be filled, I will show you how to fill it in yourself. If you’re wrong, it forces a correction. If you’re right, it helps create focus. I’ll share how I’ve approached this in the past, both what works and lessons for what didn’t work so well.
Dandelion Hashtable: beyond billion requests per second on a commodity serverAntonios Katsarakis
This slide deck presents DLHT, a concurrent in-memory hashtable. Despite efforts to optimize hashtables, that go as far as sacrificing core functionality, state-of-the-art designs still incur multiple memory accesses per request and block request processing in three cases. First, most hashtables block while waiting for data to be retrieved from memory. Second, open-addressing designs, which represent the current state-of-the-art, either cannot free index slots on deletes or must block all requests to do so. Third, index resizes block every request until all objects are copied to the new index. Defying folklore wisdom, DLHT forgoes open-addressing and adopts a fully-featured and memory-aware closed-addressing design based on bounded cache-line-chaining. This design offers lock-free index operations and deletes that free slots instantly, (2) completes most requests with a single memory access, (3) utilizes software prefetching to hide memory latencies, and (4) employs a novel non-blocking and parallel resizing. In a commodity server and a memory-resident workload, DLHT surpasses 1.6B requests per second and provides 3.5x (12x) the throughput of the state-of-the-art closed-addressing (open-addressing) resizable hashtable on Gets (Deletes).
Dandelion Hashtable: beyond billion requests per second on a commodity server
Fuzzy logic based direct torque control of induction motor with space vector modulation
1. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
FUZZY LOGIC BASED DIRECT TORQUE CONTROL OF
INDUCTION MOTOR WITH SPACE VECTOR
MODULATION
Fatih Korkmaz1, smail Topaloğlu2 and Hayati Mamur3
1,2,3
Department of Electrical and Electronics Engineering
Çankırı Karatekin University, 18200, Çankırı, TURKEY
ABSTRACT
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.
KEYWORDS
Direct torque control, Fuzzy logic control, Space vector modulation, Induction motor control.
1. INTRODUCTION
In many industrial applications, Direct torque control (DTC) of induction motor is well-known
control method which provides fast dynamic response compared with other control methods like
field oriented control (FOC). The DTC has been proposed for induction motor control in 1985 by
Takahashi [1] and similar idea that the name of Direct Self Control devoloped in 1988 by
Depenbrock [2].
Over the past years, the DTC has gained great attention due to its advantages like simple control
structure, robustness to parameters variations, fast dynamic response, not need to current
regulators...etc. However, DTC has still some disadvantages and they can be summarized as
follows; high current and torque ripples, difficulty to control torque and flux at very low speed,
variable switching frequency behavior and high sampling frequency needed for digital
implementation.
On the other hand, intelligent control methods like fuzzy logic have been explored by several
researchers for its potential to incorporate human intuition in the design process. The FL has
gained great attention in the every area of electromechanical devices control due to no need
DOI :10.5121/ijscai.2013.2603
31
2. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
mathematical models of systems unlike conventional controllers[3]. A fuzzy logic controller is
used to select voltage vectors in conventional DTC in some applications [4-6]. In parameter
estimation applications, a fuzzy logic stator resistance estimator is used and it can estimate
changes in stator resistance due to temperature change during operation[7]. For duty ratio control
method, a fuzzy logic controller is used to determine the duration of output voltage vector at each
sampling period [8]. These fuzzy logic controllers can provide good dynamic performance and
robustness. In recent publications, we see that some flux optimization method is proposed for the
DTC method for induction motor drives and the effects of the optimization algorithm is
investigated. In these publications, three flux control methods are used for optimization and
essentially we can classified according to control structure as following: flux control as a function
of torque [9], flux control based on loss model [10] and flux control by a minimum loss search
controller [11].
In this paper, to reduce the torque ripples of the induction motor on the DTC method, a new
approach has been proposed which named as, fuzzy logic based space vector modulation
method(FL-SVM). The fuzzy logic controller, in this proposed method, rates of flux and torque
errors as input and describes optimum space vector as output to minimize flux and torque errors.
The numerical simulation studies have performed with Matlab/Simulink to performance testing
of the proposed control method.
2. DIRECT TORQUE CONTROL
The basic idea of the DTC technique is to choosing the optimum vector of the voltage, which
makes the flux rotate and produce the desired torque. In conventional DTC method, the control of
an induction motor involves the direct control of stator flux vector by applying optimum voltage
switching vectors of the inverter. For this control, the stator current should be decoupled two
independent components as flux and torque components like dc motors. The clarke
transformation method is uses in this decoupling process in the DTC method. The DTC allows for
very fast torque responses, and flexible control of the induction motor.
The DTC bases on the selection of the optimum voltage vector which makes the flux vector rotate
and produce the demanded torque. In this rotation, the amplitude of the flux and the torque errors
are kept within acceptable limits by hysteresis controllers [12]. The rotation of the stator flux
vector and an example for the effects of the applied inverter switching vectors are given in the
Fig. 1.
Figure 1. The rotation of the stator flux vector and an example for the effects of the applied inverter
switching vectors
32
3. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
The stator flux linkage vector is estimated by using Eq. (1)-(3).
λα = ∫ (Vα − Rs iα )dt ,
(1)
λ β = ∫ (V β − R s i β )dt ,
(2)
2
λ = λα + λ 2 .
β
(3)
Where λ is stator flux vector, vα and v β stator voltages two phase components, iα and iβ line
currents in α-β reference frame and Rs describes stator resistance. After the calculation of the α-β
components of the stator flux vector electromagnetic torque of the induction motor can be
calculated as given in Eq. 4.
Te =
3
p (λα i β − λ β iα ).
2
(4)
Where, p is the number of pole pairs. In DTC method, stator flux rotate trajectory devided six
region and well-defined of stator flux region is directly affects on control performance. The stator
flux α-β components that calculated can be use the defining of the stator flux region as given in
Eq. 5.
θ λ = tan −1 (
λβ
λα
).
(5)
These observed values of the flux and the torque errors are compared to reference the flux and the
torque values and the resultant errors are applied to the hysteresis comparators as inputs. Two
different hysteresis comparators, as flux and torque comparators, generate other control
parameters on the DTC method. According to the hysteresis comparators outputs, the observed
angle of flux linkage and using a switching table, optimum voltage vectors are selected and
applied to the inverter.
3. BASICS OF THE FUZZY LOGIC BASED DTC
The objective of space vector pulse width modulation technique is to obtain the demanded output
voltage by instantaneously combination of the switching states corresponding the basic space
vectors (Figure 2.)[13].
Figure 2. Basic space vectors
33
4. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
U out can be obtained as Eq. 6. by applying the inverter in switching states U x and U x + 60 or
U x −60 for the time periods, T1 and T2 periods of time respectively.
U out ( nT ) =
1
(T1U x + T2U x ± 60 )
T
(6)
It must be pointed out that the sum of T1 and T2 periods should be less than or equal to total
sampling time period, T. If T1 + T2 〈T , than the inverter needs to be in pasive vectors,
0 000 or 0111 states, for the rest of the total time period that pasive time period can be named T0 .
Thus, the calculation of total time period is given in Eq. 7.
T1 + T2 + T0 = T
(7)
Therefore, Eq. 6 becomes Eq. 7 in the following,
TU out = T1U x + T2U x ±60 + T0 (0 000 or 0111 )
(8)
From Eq. 8., we get Eq. 9. for T1 and T2 .
[T1
τ
T2 ] = T [U x
where [U x
U x ± 60 ] U out
−1
U x ± 60 ]
−1
(9)
is the normalized decomposition matrix for the sector.
Assume the angle between U out and U x is α from Figure 3, it can be also obtained Eq. 10. and
Eq. 11. for the T1 and T2 [13].
T1 = 2T U out cos(α + 30°)
(10)
T2 = 2T U out sin(α )
(11)
Figure 3. The Simulink block diagram the proposed method
34
5. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
In the C-DTC method, while the stator flux vector rotation, we have to use six active voltage
vector to keep stator flux vector in defined error limits, any other option. But, as described above,
in SVM method, we have many options to obtain the vector what we need to control stator flux
vector. The proposed fuzzy based SVM-DTC method includes a fuzzy logic controller block to
produce optimum control vector. The optimum control vector angle is calculated by fuzzy logic
controller with using instantaneously flux and torque errors. On this calculation, fuzzy logic rates
flux and torque errors and produces necessary change in stator flux vector angle for next step.
Then, calculated optimum vector angle applied to discrete space vector pulse width modulation
block (DSV-PWM) and DSV-PWM generates switching signals. The Simulink block diagram of
the proposed system is given in Figure 3.
The membership functions of fuzzy logic controller flux-torque inputs and angle output can be
seen in Figure 4. Table 1. describes rule table of fuzzy logic controller.
Figure 4. Flux, torque and angle membership functions
35
6. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
Table 1. Rule table of fuzzy logic controller
Torque
Rules
BD
SD
0
SI
BI
BD
-135
-165
0
165
135
SD
-105
-135
0
135
105
Flux
SI
-75
-45
0
45
75
BI
-45
-15
0
15
45
4. SIMULATION STUDIES
Numerical simulations have been carried out to evaluate the effectiveness of the proposed fuzzy
logic based SVM-DTC. Its developed using Matlab/Simulink. The DTC method and the
induction machine that used in the simulation works, have the parameters given in Table 2.
Table 2. Induction Machine and Simulation parameters
IM and Simulation Parameters
Inverter bus voltage (V)
400V
Rated Power (kW)
4
Stator resistance ( )
1.405
Stator inductance(H)
0.0058
Pole pairs
2
Sampling time (µs)
50
Flux reference (Wb)
0.8
Some tests have been carried out to compare the performances of the proposed fuzzy logic based
dSV-PWM DTC (FL-dSV-PWM) with conventional DTC (C-DTC). In order to fair compare the
performances with the C-DTC and the proposed FLSVM-DTC on induction motor drive,
different speed and load range applied to the induction motor. The dynamic performances of the
methods are performed by applying step change on load, 0Nm to 5 Nm, at 0,5. sec.
In first step of the simulation studies, the induction motor has been tested at rated speed with
unloaded and loaded working conditions. The simulation results of speed and torque responses at
1500 rpm reference are shown in Figure 5. and Figure 6., respectively.
36
7. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
(a)
(b)
Figure 5. Speed curves of motor at 1500 rpm (with zoom view)
a) C-DTC
b) FLSVM-DTC
According to the speed and torque curves which given in Figure 5. and Figure 6., the motor has
reached the reference speed at about 0,075. sec. for both control method. So, it can be said that
there are no difference between C-DTC and FLSVM-DTC methods speed rising times and the
motor has almost same performance at transient conditions for both control method. It means,
proposed control method has still fast transient conditions performance.
(a)
(b)
Figure 6. Torque curves of motor at 1500 rpm(with zoom view)
a) C-DTC
b) FLSVM-DTC
However, the main differences have appeared at torque responses of both control methods at
steady state conditions. It can be seen that, with the FLSVM-DTC instantaneous speed
fluctuations and torque ripples of the motor are reduced significantly.
In the second step of simulation studies, the motor has been at low speed with two different load
conditions. The aim of this tests is investigating of performances for both methods in low speed
37
8. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
conditions. The simulation results of speed and torque responses at 250 rpm reference are shown
in Figure 7. and Figure 8., respectively.
(a)
(b)
Figure 7. Speed curves of motor at 250 rpm(with zoom view)
a) C-DTC
b) FLSVM-DTC
According to the speed and torque curves which given in Figure 7. and Figure 8., the motor has
reached the reference speed at 0,02. sec for both control method and still no difference at transient
conditions.
(a)
(b)
Figure 8. Torque curves of motor at 250 rpm(with zoom view)
a) C-DTC
b) FLSVM-DTC
38
9. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
If we need to compare of steady state conditions of the motor for both control method, it must be
pointed out that the FLSVM-DTC controlled motor has better performance as lesser torque
ripples and speed fluctuations.
5. CONCLUSIONS
In this paper, a new fuzzy logic based space vector modulation technique has been proposed for
the DTC controlled induction motor drivers and the simulation studies have been carried out with
Matlab/Simulink to compare the proposed system behaviors at vary load and speed conditions. In
the study, the induction motor has been tested for low speed (250 rpm reference) and rated speed
(1500 rpm reference) working conditions to obtain fairy comparisons for both control methods.
The numerical simulations prove that torque and speed responses of the motor are significantly
improved with the proposed technique for both working conditions. The torque ripples of the
motor are lesser about % 40, in parallel, the speed fluctuations are reduced according to
conventional direct torque control technique. Moreover, the hyseteresis controllers and look-up
table that used in conventional method are removed.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
Takahashi and T. Noguchi , “A new quick-response and high efficiency control strategy of an
induction motor” IEEE Transactions on Industrial Applications, vol.I A-22 , no.5, pp. 820–827, 1986.
M. Depenbrock, “Direct self control of inverter-fed induction machines” IEEE Transactions in Power
Electronics, vol. PE-3, vo. 4, pp. 420–429, 1988.
Li, H., “Fuzzy DTC for induction motor with optimized command stator flux,” Intelligent Control and
Automation (WCICA), 2010, pp. 4958–4961.
Bacha, F., Dhifaoui, R., Buyse, H., Real-time implementation of direct torque control of an induction
machine by fuzzy logic controller, International Conference on Electrical Machines and Systems
(ICEMS),2001. – Vol. 2, P. 1244–1249.
Mir, S., Elbuluk, M.E., Zinger, D.S., PI and fuzzy estimators for tuning the stator resistance in direct
torque control of induction machines, IEEE Trans. Power Electron. 1998. – Vol.13 – P. 279–287.
Arias, A., Romeral, J.L., Aldabas, E., Jayne, M.G., Fuzzy logic direct torque control,
IEEE
International Symposium on Industrial Electronics (ISIE), 2000. – Vol.1 – P. 253–258.
Holtz, J., Quan, J., Sensorless vector control of induction motors at very low speed using a nonlinear
inverter model and parameter identification, IEEE Trans. Ind. Appl., 2002. Vol. 38 – No. 4 – P. 1087–
1095.
Casadei, D., Serra, G., Tani, A., Zarri, L., Profumo, F., Performance analysis of a speed-sensorless
induction motor drive based on a constant switching-frequency DTC method, IEEE Trans. Ind. Appl.,
2003. – Vol. 39 – No. 2 – P. 476–484.
Kaboli, S., Zolghadri, M.R., Haghbin, S.,Emadi, A., “Torque ripple minimization in DTC of
induction motor based on optimized flux value determination,” IEEE Ind. Electron. Conf., 2003, pp.
431–435.
Kioskeridis, I., Margaris, N., “Loss minimization in induction motor adjustable speed drives,” IEEE
Trans. Ind. Electron., 1996, vol. 43, no. 1, pp. 226–231.
Kioskeridis, I., Margaris, N., “Loss minimization in scalar-controlled induction motor drives with
search controllers,” IEEE Trans. Power Electron., 1996, vol. 11, no. 2, pp. 213–220.
P. Vas, Sensorless vector and direct torque control. Oxford UniversityPress,2003
Zhenyu Yu "Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software
Determined Switching Patterns" Texas Ins. Application Report, SPRA524, pp. 5., 1999.
39
10. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.2, No. 5/6, December 2013
Authors
Fatih Korkmaz was born in Kırıkkale, Turkey, in 1977. He received the B.T.,
M.S., and Doctorate degrees in in electrical education, from University of
Gazi,
Turkey, respectively in 2000, 2004 and 2011.
His current research field includes Electric Machines Drives and Control
Systems.
smail TOPALOGLU was born in Adana, Turkey, in 1983. He received the
B.Sc , M.Sc. and Ph.D degrees in electrical education from University of Gazi
in 2007,2009 and 2013, respectively.
His current research interests include Computer aided design and analysis of
conventional and novel electrical and magnetic circuits of electrical machines,
sensors and transducers, mechatronic systems.
Hayati Mamur was born in Bolu, Turkey, in 1974. He received the B.Sc ,
M.Sc. and Ph.D degrees in electrical education from University of Gazi in
1996,2005 and 2013, respectively.
His research interests include automatic control, SCADA, PLC,
microcontroller, DSP control applications, renewable energy, and
thermoelectric modules.
40