Induction motor with indirect field oriented control is well suited for high
performance applications due to its excellent dynamic behavior. However it
is sensitive to variations in rotor time constant, especially variation in rotor
resistance. In this study a scheme based on the Rotor flux Model Reference
Adaptive Controller is used for on line identification of the rotor resistance
and thus improving the steady state performance of the drive. The overriding
feature of this estimation technique is the accurate identification of rotor
resistance during transient and steady state conditions for drive operation at
full load and at zero speed condition. Moroever, the effectiveness of the TS
fuzzy controller utilizing rotor flux for online estimation of rotor resistance
for four quadrant operation of motor drive is investigated and compared with
the conventional PI and Mamdani fuzzy controller.Simulation results in
MATLAB/Simulink environment have been presented to confirm the
effectiviness of the proposed technique.
Control of Four Switch Three Phase Inverter Fed Induction Motor Drives Based ...IJPEDS-IAES
This paper presents sensorless position and speed control for a four-switch three-phase inverter (FSTPI) fed induction motor drive. Accurate knowledge of stator resistance is of utmost importance for correct operation of a number of speed sensorless induction motor control schemes in the low speed region. Since stator resistance inevitably varies with operating conditions, stable and accurate operation at near-zero speed requires an appropriate identification algorithm for the stator resistance. The paper proposes such an identification algorithm, which is developed for the rotor flux based model reference adaptive system (MRAS) type of the speed estimator in conjunction with a rotor flux oriented control scheme. In this speed estimation method only one (out of the two available) degree of freedom is utilized for speed estimation. It is utilize the second available degree of freedom as a mean for adapting the stator resistance. The parallel stator resistance and rotor speed identification algorithm is developed in a systematic manner, using Popov’s hyper stability theory. It increases the complexity of the overall control system insignificantly and enables correct speed estimation and stable drive operation at near-zero speeds. The proposed speed and position estimator with parallel stator resistance identification for FSTPI fed induction motor at very low speed under high load operation is verified by simulation and experimental results. The results show the robustness of the proposed method with FSTPI.
DSP-Based Sensorless Speed Control of a Permanent Magnet Synchronous Motor us...IJPEDS-IAES
In this paper, experimental results of 3-phase permanent magnet synchronous motor (PMSM) sensorless speed control are presented. To estimate the rotor position, a sliding mode current observer (SMCO) was implemented. This observer estimates the back emfs of the motor in the stationary reference frame using only the measured voltages and currents of the motor. These emfs were utilized to obtain the rotor position. The speed of the motor was calculated by differentiating the rotor position angle. The stability of the proposed SMCO was verified using Lyapunov method to determine the observer gain. The saturation function was adopted in order to reduce the chattering phenomenon caused by the SMCO. A vector control method was employed to achieve the sensorless drive system. The control application was developed in C/C++ language and implemented using the Texas Instruments TMS320LF2812 digital signal processor (DSP). This new processor enables intelligent control for motors. We used to test the drive the MCK2812 which is a professional development kit available from Technosoft Company. The theoretical finding is validated with experimental results that show the effectiveness of the real-time implementation.
Adaptive Variable Structure Controller Application to Induction Motor DriveIJERA Editor
Variable structure control is an adaptive control that gives robust performance of a drive with parameter variation and load torque disturbance. Variable control structure is a robust control scheme based on the concept of changing the structure of the controller in response to the changing state of the system in order to obtain a desired response. The control is nonlinear and can be applied to the linear or nonlinear plant. A high speed switching control action is used to switch between different structures of the controller and the trajectory of the system is forced to move along a chosen switching manifold in the state space. The controller detects the deviation of the actual trajectory from the reference trajectory and corresponding changes the switching strategy to restore the tracking. Prominent characteristics such as invariance, robustness, order reduction, and control chattering are discussed in detail. Methods for coping with chattering are presented. Both linear and nonlinear systems are considered. By using Variable structure controller to control the step change in reference speed and drive system under load torque variations.
Fuzzy-Logic-Controller-Based Fault Isolation in PWM VSI for Vector Controlled...iosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Nowadays, the elimination of the speed sensor in Permanent Magnet Synchronous Machine (PMSM) is greatly recommended to increase efficiency and reduce the cost of the drives. This paper proposes a simple estimator for speed and rotor position of PMSM drives using adaptive controller. The novelties of the proposed method are the simple estimator equations and the absence of the voltage probe which depend on direct and quadrature reference current only. The simplified mathematical model of the PMSM is formulated by using V-I model, based on adaptive control. Then, the speed estimation error of the voltage and current model based are analyzed. Thus, an adaptation mechanism model is established to cancel the error of the measured and estimated d-q currents. Since the output of the estimator is the position feedback, the performances of speed responses are presented. The hardware implementation of proposed sensorless drives is realized via dSPACE DS11103 panel. dSPACE Real Time Implementation (RTI) is the linkage between software and hardware set-up. It automatically processes the MATLAB Simulink model into dSPACE DS11103 processor. The experimental-hardware results demonstrate that the speed and position estimator of the proposed method is able to control the PMSM drives for forward and reverse of speed command, acceleration, deceleration and robustness to load disturbance.
High frequency signal injection techniques are widely used to extract rotor position information from low speed to stand still. Accuracy of estimated rotor position is decreased when stator winding resistance is neglected. Position estimation error also results in output Torque reduction. Parasitic resistance of stator winding causes significant position estimation error and Torque reduction, if not compensated. Signal injection techniques developed in the literature does not provide detailed analysis and compensation methods to improve rotor position estimation of PMS Motors, where stator winding resistance cannot be neglected. This work analyzes the stator winding resistance effect on position estimation accuracy and proposes novel compensation technique to reduce the position estimation error and torque reduction introduced by stator winding resistance. Prototype hardware of a self-sensing PMSM drive is developed. The effectiveness of the proposed method is verified with the MATLAB/Simulink simulations and experimental results on a prototype self-sensing PMSM drive.
Effect of Parametric Variations and Voltage Unbalance on Adaptive Speed Estim...IAES-IJPEDS
Speed Estimation without speed sensors is a complex phenomenon and is overly dependent on the machine parameters. It is all the more significant during low speed or near zero speed operation. There are several approaches to speed estimation of an induction motor. Eventually, they can be classified into two types, namely, estimation based on the machine model and estimation based on magnetic saliency and air gap space harmonics. This paper analyses the effect of incorrect setting of parameters like the stator resistance, rotor time constant, load torque variations and also Voltage unbalance on various adaptive control based speed estimation techniques fed from the machine model. It also shows how the convergence mechanisms of the adaptation schemes are affected during these conditions. The equivalent models are built and simulated offline using MATLAB/SIMULINK blocksets and the results are analysed.
Control of Four Switch Three Phase Inverter Fed Induction Motor Drives Based ...IJPEDS-IAES
This paper presents sensorless position and speed control for a four-switch three-phase inverter (FSTPI) fed induction motor drive. Accurate knowledge of stator resistance is of utmost importance for correct operation of a number of speed sensorless induction motor control schemes in the low speed region. Since stator resistance inevitably varies with operating conditions, stable and accurate operation at near-zero speed requires an appropriate identification algorithm for the stator resistance. The paper proposes such an identification algorithm, which is developed for the rotor flux based model reference adaptive system (MRAS) type of the speed estimator in conjunction with a rotor flux oriented control scheme. In this speed estimation method only one (out of the two available) degree of freedom is utilized for speed estimation. It is utilize the second available degree of freedom as a mean for adapting the stator resistance. The parallel stator resistance and rotor speed identification algorithm is developed in a systematic manner, using Popov’s hyper stability theory. It increases the complexity of the overall control system insignificantly and enables correct speed estimation and stable drive operation at near-zero speeds. The proposed speed and position estimator with parallel stator resistance identification for FSTPI fed induction motor at very low speed under high load operation is verified by simulation and experimental results. The results show the robustness of the proposed method with FSTPI.
DSP-Based Sensorless Speed Control of a Permanent Magnet Synchronous Motor us...IJPEDS-IAES
In this paper, experimental results of 3-phase permanent magnet synchronous motor (PMSM) sensorless speed control are presented. To estimate the rotor position, a sliding mode current observer (SMCO) was implemented. This observer estimates the back emfs of the motor in the stationary reference frame using only the measured voltages and currents of the motor. These emfs were utilized to obtain the rotor position. The speed of the motor was calculated by differentiating the rotor position angle. The stability of the proposed SMCO was verified using Lyapunov method to determine the observer gain. The saturation function was adopted in order to reduce the chattering phenomenon caused by the SMCO. A vector control method was employed to achieve the sensorless drive system. The control application was developed in C/C++ language and implemented using the Texas Instruments TMS320LF2812 digital signal processor (DSP). This new processor enables intelligent control for motors. We used to test the drive the MCK2812 which is a professional development kit available from Technosoft Company. The theoretical finding is validated with experimental results that show the effectiveness of the real-time implementation.
Adaptive Variable Structure Controller Application to Induction Motor DriveIJERA Editor
Variable structure control is an adaptive control that gives robust performance of a drive with parameter variation and load torque disturbance. Variable control structure is a robust control scheme based on the concept of changing the structure of the controller in response to the changing state of the system in order to obtain a desired response. The control is nonlinear and can be applied to the linear or nonlinear plant. A high speed switching control action is used to switch between different structures of the controller and the trajectory of the system is forced to move along a chosen switching manifold in the state space. The controller detects the deviation of the actual trajectory from the reference trajectory and corresponding changes the switching strategy to restore the tracking. Prominent characteristics such as invariance, robustness, order reduction, and control chattering are discussed in detail. Methods for coping with chattering are presented. Both linear and nonlinear systems are considered. By using Variable structure controller to control the step change in reference speed and drive system under load torque variations.
Fuzzy-Logic-Controller-Based Fault Isolation in PWM VSI for Vector Controlled...iosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Nowadays, the elimination of the speed sensor in Permanent Magnet Synchronous Machine (PMSM) is greatly recommended to increase efficiency and reduce the cost of the drives. This paper proposes a simple estimator for speed and rotor position of PMSM drives using adaptive controller. The novelties of the proposed method are the simple estimator equations and the absence of the voltage probe which depend on direct and quadrature reference current only. The simplified mathematical model of the PMSM is formulated by using V-I model, based on adaptive control. Then, the speed estimation error of the voltage and current model based are analyzed. Thus, an adaptation mechanism model is established to cancel the error of the measured and estimated d-q currents. Since the output of the estimator is the position feedback, the performances of speed responses are presented. The hardware implementation of proposed sensorless drives is realized via dSPACE DS11103 panel. dSPACE Real Time Implementation (RTI) is the linkage between software and hardware set-up. It automatically processes the MATLAB Simulink model into dSPACE DS11103 processor. The experimental-hardware results demonstrate that the speed and position estimator of the proposed method is able to control the PMSM drives for forward and reverse of speed command, acceleration, deceleration and robustness to load disturbance.
High frequency signal injection techniques are widely used to extract rotor position information from low speed to stand still. Accuracy of estimated rotor position is decreased when stator winding resistance is neglected. Position estimation error also results in output Torque reduction. Parasitic resistance of stator winding causes significant position estimation error and Torque reduction, if not compensated. Signal injection techniques developed in the literature does not provide detailed analysis and compensation methods to improve rotor position estimation of PMS Motors, where stator winding resistance cannot be neglected. This work analyzes the stator winding resistance effect on position estimation accuracy and proposes novel compensation technique to reduce the position estimation error and torque reduction introduced by stator winding resistance. Prototype hardware of a self-sensing PMSM drive is developed. The effectiveness of the proposed method is verified with the MATLAB/Simulink simulations and experimental results on a prototype self-sensing PMSM drive.
Effect of Parametric Variations and Voltage Unbalance on Adaptive Speed Estim...IAES-IJPEDS
Speed Estimation without speed sensors is a complex phenomenon and is overly dependent on the machine parameters. It is all the more significant during low speed or near zero speed operation. There are several approaches to speed estimation of an induction motor. Eventually, they can be classified into two types, namely, estimation based on the machine model and estimation based on magnetic saliency and air gap space harmonics. This paper analyses the effect of incorrect setting of parameters like the stator resistance, rotor time constant, load torque variations and also Voltage unbalance on various adaptive control based speed estimation techniques fed from the machine model. It also shows how the convergence mechanisms of the adaptation schemes are affected during these conditions. The equivalent models are built and simulated offline using MATLAB/SIMULINK blocksets and the results are analysed.
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
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.
Implementation of pi, fuzzy & ann controllers to improve dynamic response...eSAT Journals
Abstract Nowadays, vector controlled induction motor drives with variable speed applications are widely used in order to achieve good dynamic performance and wide speed control. In this paper a new method of controlling technique based on Artificial Neural Network is proposed to improve the speed control of indirect vector controlled induction motor drive. Indirect vector controlled induction motor with conventional PI controller is developed and is replaced with Fuzzy logic controller to overcome the problem of overshoot occurred in conventional PI controller. To obtain quick steady state response and better speed control, ANN technique is proposed and implemented using MATLAB/Simulink. In this paper the speed, torque and stator voltage responses with conventional PI controller, Fuzzy logic controller and proposed artificial neural network based controller are compared and found that the proposed ANN based controller showed increased dynamic performance. Keywords: ANN, FLC, PI controller, IVCIM
Field oriented control and direct torque control are the most popular methods in high
performance industrial control applications for induction motors. Naturally, the strengths and
weaknesses of each control method are available. Therefore, the selection of optimum control
method is vitally important for many industrial applications. So, the advantages and the
disadvantages of both control methods have to be well defined. In this paper, a new and
different perspective has been presented regarding the comparison of the inverter 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
induction motors in the FOC and the DTC systems. The dSPACE 1103 controller board has
been programmed with Matlab/Simulink software. As expected, the experimental studies have
showed that the FOC controlled motors have had a lessened torque ripple. On the other hand,
the FOC controlled motor switching frequency has about 75% more than the DTC controlled.
Novel Method of FOC to Speed Control in Three-Phase IM under Normal and Fault...IJPEDS-IAES
This paper proposes a novel method for speed control of three-phase
induction motor (IM) which can be used for both healthy three-phase IM and
three-phase IM under open-phase fault. The proposed fault-tolerant control
system is derived from conventional field-oriented control (FOC) algorithm
with minor changes on it. The presented drive system is based on using an
appropriate transformation matrix for the stator current variables. The
presented method in this paper can be also used for speed control of singlephase
IMs with two windings. The feasibility of the proposed strategy is
verified by simulation results.
Low Speed Estimation in Sensorless Direct Torque Controlled Induction Motor D...IJPEDS-IAES
Sensorless Direct Torque Control (DTC) is a powerful control scheme for
high performance control of induction motor (IM) drives, which provides
very quick dynamic response with simple structure and a decoupled control
of torque and flux. The performance of the DTC drive greatly depends on the
accuracy of the estimated flux components, torque and speed, using
monitored stator voltages and currents. Low speed estimation is a great
challenge because of the presence of transient offset, drift and domination of
ohmic voltage drop.Extended Kalman filter (EKF) is a non linear adaptive
filter which performs the process of finding the best estimate from the noisy
data based on state space technique and recursive algorithm.This paper
mainly focuses on the accurate estimation of speed ranging from very low
speed to rated speed using the equation of motion. A new state space model
of the IM is developed for estimation in EKF, with load torque as an input
variable and not as an estimated quantity which is the case in most previous
studies.The developed algorithm is validated using MATLAB-Simulink
platform for speeds ranging from low speed to rated speed at rated torque and
at various torque conditions. An exhaustive analysis is carried out to validate
the performance of DTC Induction motor drive especially at the low speeds.
The results are promising for accurate estimation of speed ranging from low
speed to rated speed using EKF.
Speed Sensorless Vector Control of Unbalanced Three-Phase Induction Motor wit...IAES-IJPEDS
This paper presents a technique for speed sensorless Rotor Flux Oriented Control (RFOC) of 3-phase Induction Motor (IM) under open-phase fault (unbalanced or faulty IM). The presented RFOC strategy is based on rotational transformation. An adaptive sliding mode control system with an adaptive switching gain is proposed instead of the speed PI controller. Using an adaptive sliding mode control causes the proposed speed sensorless RFOC drive system to become insensitive to uncertainties such as load disturbances and parameter variations. Moreover, with adaptation of the sliding switching gain, calculation of the system uncertainties upper bound is not needed. Finally, simulation results have been presented to confirm the good performance of the proposed method.
The paper proposes Direct Torque Control (DTC) of a five-phase induction motor drive with reduced torque ripple. The method presented here is the DTC Backstepping based on the classic DTC working with a constant switching frequency of the inverter. Another remarkable aspect is the complexity of the method proposed, both in the control unit of the inverter and in the number of correctors necessary for the control of the torque. The selection table and hysteresis have been eliminated. This method significantly improves the torque and flux oscillations and improves the dynamics of the drive by making it less sensitive to load torque disturbances. The proposed method is developed and designed using Matlab/SIMULINK to show the eectiveness and performances of the DTC-Backstepping.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Speed Sensorless Vector Control of Induction Motor Drive with PI and Fuzzy Co...IJPEDS-IAES
This paper directed the speed-sensorless vector control of induction motor drive with PI and fuzzy controllers. Natural observer with fourth order state space model is employed to estimate the speed and rotor fluxes of the induction motor. The formation of the natural observer is similar to and as well as its attribute is identical to the induction motor. Load torque adaptation is provided to estimate the torque and rotor speed is estimated from the load torque, rotor fluxes and stator currents. There is no direct feedback in natural observer and also observer gain matrix is absent. Both the induction motor and the observer are characterized by state space model. Simple fuzzy logic controller and conventional PI controllers are used to control the speed of the induction motor in closed loop. MATLAB simulations are made with PI and fuzzy controllers and the performance of fuzzy controller is better than PI controller in view of torque ripples. The simulation results are obtained for various running conditions to exhibit the suitability of this method for sensorless vector control. Experimental results are provided for natual observer based sensorless vector control with conventional PI controller.
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.
Speed Control System of Induction Motor by using Direct Torque Control Method...ijtsrd
Escalator is useful and act in the important part to carry passengers to the targeted floors of building. Every escalator must be driven by its own motor and this motor speed must be controled. To drive escalator with a constant speed, direct torque control technique is used to drive three phase squirrel cage induction motor. In this paper, the development of speed control system for three phase squirrel cage induction motor using a direct torque control method is presented and simulation for proposed system is done with the help of MATLAB SIMULINK. Soe Sandar Aung | Thet Naing Htun "Speed Control System of Induction Motor by using Direct Torque Control Method used in Escalator" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27903.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/27903/speed-control-system-of-induction-motor-by-using-direct-torque-control-method-used-in-escalator/soe-sandar-aung
Permanent magnet synchronous motors (PMSMs) are increasingly used in high performance variable speed drives of many industrial applications. PMSM has many features, like high efficiency, compactness, high torque to inertia ratio, rapid dynamic response, simple modeling and control, and maintenance free operation. Presence of position sensors presents several disadvantages, such as reduced reliability, susceptibility to noise, additional cost and weight and increased complexity of the drive system. For these reasons, the development of alternative indirect methods for speed and position control becomes an important research topic. Advantages of sensorless control are reduced hardware complexity, low cost, reduced size, cable elimination, increased noise immunity, increased reliability and decreased maintenance. The key problem in sensorless vector control of ac drives is the accurate dynamic estimation of the stator flux vector over a wide speed range using only terminal variables (currents and voltages). The difficulty comprises state estimation at very low speeds where the fundamental excitation is low and the observer performance tends to be poor. Moreover, the noises of system and measurements are considered other main problems. This paper presents a comprehensive study of the different sliding mode observer methods of speed and position estimations for sensorless control of PMSM drives.
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.
Recently of the main topic of research is the sensorless vector control of induction motor drive, In this paper presents the predictive model reference adaptive system (PMRAS) rotor speed observer, This observer developed from the classical MRAS rotor flux scheme associated with predictive adaptation mechanism designed from the Finite Control Set Model Predictive Control (FCS–MPC) by using a search optimization algorithm for calculate the rotor position which guarantee a minimum speed tuning error signal at each sampling period. The effectiveness of the proposed observer proved with the simulation results, show high dynamic performance speed and position observed in sensorless vector control process at low and zero speed as well robustness against motor parameter variation with different loading conditions.
This paper deals with the problem of estimation of rotor angular position for the indirect pulse-vector control of wound rotor induction motor drive. The paper considers issues of thematic justification and expanding of the field of using sensorless motor drives. With a view to improve energy consumption readings during design and modernization of motor drives of massive mechanisms with moderate standards for accuracy of velocity control, requiring long-term velocity decrease during load reduction (according to technological process conditions), using the system of the pulse-vector control of wound rotor induction motor is suggested. The paper provides the solution for the problem of developing math models of this motor drive system both for the motor-mounted sensor, and for indirect angular position sensing. The models were developed in ANSYS Electromagnetics Suite using the finite element method for studying electromagnetic processes. Based on the models, the investigation of transition and steady states of a motor drive was carried out, process quality parameters were obtained, namely: max and root-mean-square currents, torques; velocity control errors caused by pulse operation mode. From that simulation, the result illustrates the effectiveness of the proposed approach.
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
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.
Implementation of pi, fuzzy & ann controllers to improve dynamic response...eSAT Journals
Abstract Nowadays, vector controlled induction motor drives with variable speed applications are widely used in order to achieve good dynamic performance and wide speed control. In this paper a new method of controlling technique based on Artificial Neural Network is proposed to improve the speed control of indirect vector controlled induction motor drive. Indirect vector controlled induction motor with conventional PI controller is developed and is replaced with Fuzzy logic controller to overcome the problem of overshoot occurred in conventional PI controller. To obtain quick steady state response and better speed control, ANN technique is proposed and implemented using MATLAB/Simulink. In this paper the speed, torque and stator voltage responses with conventional PI controller, Fuzzy logic controller and proposed artificial neural network based controller are compared and found that the proposed ANN based controller showed increased dynamic performance. Keywords: ANN, FLC, PI controller, IVCIM
Field oriented control and direct torque control are the most popular methods in high
performance industrial control applications for induction motors. Naturally, the strengths and
weaknesses of each control method are available. Therefore, the selection of optimum control
method is vitally important for many industrial applications. So, the advantages and the
disadvantages of both control methods have to be well defined. In this paper, a new and
different perspective has been presented regarding the comparison of the inverter 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
induction motors in the FOC and the DTC systems. The dSPACE 1103 controller board has
been programmed with Matlab/Simulink software. As expected, the experimental studies have
showed that the FOC controlled motors have had a lessened torque ripple. On the other hand,
the FOC controlled motor switching frequency has about 75% more than the DTC controlled.
Novel Method of FOC to Speed Control in Three-Phase IM under Normal and Fault...IJPEDS-IAES
This paper proposes a novel method for speed control of three-phase
induction motor (IM) which can be used for both healthy three-phase IM and
three-phase IM under open-phase fault. The proposed fault-tolerant control
system is derived from conventional field-oriented control (FOC) algorithm
with minor changes on it. The presented drive system is based on using an
appropriate transformation matrix for the stator current variables. The
presented method in this paper can be also used for speed control of singlephase
IMs with two windings. The feasibility of the proposed strategy is
verified by simulation results.
Low Speed Estimation in Sensorless Direct Torque Controlled Induction Motor D...IJPEDS-IAES
Sensorless Direct Torque Control (DTC) is a powerful control scheme for
high performance control of induction motor (IM) drives, which provides
very quick dynamic response with simple structure and a decoupled control
of torque and flux. The performance of the DTC drive greatly depends on the
accuracy of the estimated flux components, torque and speed, using
monitored stator voltages and currents. Low speed estimation is a great
challenge because of the presence of transient offset, drift and domination of
ohmic voltage drop.Extended Kalman filter (EKF) is a non linear adaptive
filter which performs the process of finding the best estimate from the noisy
data based on state space technique and recursive algorithm.This paper
mainly focuses on the accurate estimation of speed ranging from very low
speed to rated speed using the equation of motion. A new state space model
of the IM is developed for estimation in EKF, with load torque as an input
variable and not as an estimated quantity which is the case in most previous
studies.The developed algorithm is validated using MATLAB-Simulink
platform for speeds ranging from low speed to rated speed at rated torque and
at various torque conditions. An exhaustive analysis is carried out to validate
the performance of DTC Induction motor drive especially at the low speeds.
The results are promising for accurate estimation of speed ranging from low
speed to rated speed using EKF.
Speed Sensorless Vector Control of Unbalanced Three-Phase Induction Motor wit...IAES-IJPEDS
This paper presents a technique for speed sensorless Rotor Flux Oriented Control (RFOC) of 3-phase Induction Motor (IM) under open-phase fault (unbalanced or faulty IM). The presented RFOC strategy is based on rotational transformation. An adaptive sliding mode control system with an adaptive switching gain is proposed instead of the speed PI controller. Using an adaptive sliding mode control causes the proposed speed sensorless RFOC drive system to become insensitive to uncertainties such as load disturbances and parameter variations. Moreover, with adaptation of the sliding switching gain, calculation of the system uncertainties upper bound is not needed. Finally, simulation results have been presented to confirm the good performance of the proposed method.
The paper proposes Direct Torque Control (DTC) of a five-phase induction motor drive with reduced torque ripple. The method presented here is the DTC Backstepping based on the classic DTC working with a constant switching frequency of the inverter. Another remarkable aspect is the complexity of the method proposed, both in the control unit of the inverter and in the number of correctors necessary for the control of the torque. The selection table and hysteresis have been eliminated. This method significantly improves the torque and flux oscillations and improves the dynamics of the drive by making it less sensitive to load torque disturbances. The proposed method is developed and designed using Matlab/SIMULINK to show the eectiveness and performances of the DTC-Backstepping.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Speed Sensorless Vector Control of Induction Motor Drive with PI and Fuzzy Co...IJPEDS-IAES
This paper directed the speed-sensorless vector control of induction motor drive with PI and fuzzy controllers. Natural observer with fourth order state space model is employed to estimate the speed and rotor fluxes of the induction motor. The formation of the natural observer is similar to and as well as its attribute is identical to the induction motor. Load torque adaptation is provided to estimate the torque and rotor speed is estimated from the load torque, rotor fluxes and stator currents. There is no direct feedback in natural observer and also observer gain matrix is absent. Both the induction motor and the observer are characterized by state space model. Simple fuzzy logic controller and conventional PI controllers are used to control the speed of the induction motor in closed loop. MATLAB simulations are made with PI and fuzzy controllers and the performance of fuzzy controller is better than PI controller in view of torque ripples. The simulation results are obtained for various running conditions to exhibit the suitability of this method for sensorless vector control. Experimental results are provided for natual observer based sensorless vector control with conventional PI controller.
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.
Speed Control System of Induction Motor by using Direct Torque Control Method...ijtsrd
Escalator is useful and act in the important part to carry passengers to the targeted floors of building. Every escalator must be driven by its own motor and this motor speed must be controled. To drive escalator with a constant speed, direct torque control technique is used to drive three phase squirrel cage induction motor. In this paper, the development of speed control system for three phase squirrel cage induction motor using a direct torque control method is presented and simulation for proposed system is done with the help of MATLAB SIMULINK. Soe Sandar Aung | Thet Naing Htun "Speed Control System of Induction Motor by using Direct Torque Control Method used in Escalator" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27903.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/27903/speed-control-system-of-induction-motor-by-using-direct-torque-control-method-used-in-escalator/soe-sandar-aung
Permanent magnet synchronous motors (PMSMs) are increasingly used in high performance variable speed drives of many industrial applications. PMSM has many features, like high efficiency, compactness, high torque to inertia ratio, rapid dynamic response, simple modeling and control, and maintenance free operation. Presence of position sensors presents several disadvantages, such as reduced reliability, susceptibility to noise, additional cost and weight and increased complexity of the drive system. For these reasons, the development of alternative indirect methods for speed and position control becomes an important research topic. Advantages of sensorless control are reduced hardware complexity, low cost, reduced size, cable elimination, increased noise immunity, increased reliability and decreased maintenance. The key problem in sensorless vector control of ac drives is the accurate dynamic estimation of the stator flux vector over a wide speed range using only terminal variables (currents and voltages). The difficulty comprises state estimation at very low speeds where the fundamental excitation is low and the observer performance tends to be poor. Moreover, the noises of system and measurements are considered other main problems. This paper presents a comprehensive study of the different sliding mode observer methods of speed and position estimations for sensorless control of PMSM drives.
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.
Recently of the main topic of research is the sensorless vector control of induction motor drive, In this paper presents the predictive model reference adaptive system (PMRAS) rotor speed observer, This observer developed from the classical MRAS rotor flux scheme associated with predictive adaptation mechanism designed from the Finite Control Set Model Predictive Control (FCS–MPC) by using a search optimization algorithm for calculate the rotor position which guarantee a minimum speed tuning error signal at each sampling period. The effectiveness of the proposed observer proved with the simulation results, show high dynamic performance speed and position observed in sensorless vector control process at low and zero speed as well robustness against motor parameter variation with different loading conditions.
This paper deals with the problem of estimation of rotor angular position for the indirect pulse-vector control of wound rotor induction motor drive. The paper considers issues of thematic justification and expanding of the field of using sensorless motor drives. With a view to improve energy consumption readings during design and modernization of motor drives of massive mechanisms with moderate standards for accuracy of velocity control, requiring long-term velocity decrease during load reduction (according to technological process conditions), using the system of the pulse-vector control of wound rotor induction motor is suggested. The paper provides the solution for the problem of developing math models of this motor drive system both for the motor-mounted sensor, and for indirect angular position sensing. The models were developed in ANSYS Electromagnetics Suite using the finite element method for studying electromagnetic processes. Based on the models, the investigation of transition and steady states of a motor drive was carried out, process quality parameters were obtained, namely: max and root-mean-square currents, torques; velocity control errors caused by pulse operation mode. From that simulation, the result illustrates the effectiveness of the proposed approach.
Speed Control System of Induction Motor by using Vector Control Methodijtsrd
In the Vector Control method of induction motors, one of the advantages of the separately excited DC motor of being able to decouple the flux control and the torque is thereby opened up. The field orientation control of induction motor allows decoupling the control of magnetic flux and the control of the torque produced by the stator current. To drive three phase squirrel cage induction motor with a constant speed, vector control technique is used. In this paper, the development of speed control system for three phase squirrel cage induction motor using a vector control method is presented and simulation for proposed system is done with the help of MATLAB SIMULINK. Soe Sandar Aung | Thet Naing Htun "Speed Control System of Induction Motor by using Vector Control Method" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27914.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/27914/speed-control-system-of-induction-motor-by-using-vector-control-method/soe-sandar-aung
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.
This paper presents the comparative performances of Indirect Field Oriented Control (IFOC) for the three-phase induction motor. Recently, the interest of widely used the induction motor at industries because of reliability, ruggedness and almost free in maintenance. Thus, the IFOC scheme is employed to control the speed of induction motor. Therefore, P and PI controllers based on IFOC approach are analyzed at differences speed commands with no load condition. On the other hand, the PI controller is tuned based on Ziegler-Nichols method by using PSIM software which is user-friendly for simulations, design and analysis of motor drive, control loop and the power converter in power electronics studies. Subsequently, the simulated of P controller results are compared with the simulated of PI controller results at difference speed commands with no load condition. Finally, the simulated results of speed controllers are compared with the experimental results in order to explore the performances of speed responses by using IFOC scheme for three-phase induction motor drives.
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.
Performance Characteristics of Induction Motor with FielIJPEDS-IAES
With development of power electronics and control Theories, the AC motor
control becomes easier. So the AC motors are used instead of the DC motor
in the drive applications. With this development, a several methods of control
are invented. The field oriented control and direct torque control are from the
best methods to control the drive systems. This paper is compared between
the field oriented control and direct torque control to show the advantages
and disadvantages of these methods of controls. This study discussed the
effects of these methods of control on the total harmonic distortion of the
current and torque ripples. This occurs through study the performance
characteristics of the AC motor. The motor used in this study is an induction
motor. This study is simulated through the MATLAB program.
Induction motor harmonic reduction using space vector modulation algorithmjournalBEEI
The vector control was proposed as an alternative to the scalar control for AC machines control. Vector control provide high operation performance in steady state and transient operation. However, the variable switching frequency of vector control causes high flux and torque ripples which lead to an acoustical noise and degrade the performance of the control scheme. The insertion of the space vector modulation was a very useful solution to reduce the high ripples level inspite of its complexity. Numerical simulation results obtained in MATLAB/Simulink show the good dynamic performance of the proposed vector control technique and the effectiveness of the proposed sensorless strategy in the presence of the sudden load torque basing on the integral backstepping approach capabilities on instant perturbation rejection.
Keywords
This paper deal with the problem in speed controller for Indirect Field Oriented Control of Induction Motor. The problem cause decrease performance of Induction Motor where it widely used in high-performance applications. In order decrease the fault of speed induction motor, Takagi-Sugeno type Fuzzy logic control is used as the speed controller. For this, a model of indirect field oriented control of induction motor is built and simulating using MATLAB simulink. Secondly, error of speed and derivative error as the input and change of torque command as the output for speed control is applied in simulation. Lastly, from the simulation result overshoot is zero persent, rise time is 0.4s and settling time is 0.4s. The important data is steady state error is 0.01 percent show that the speed can follow reference speed. From that simulation result illustrate the effectiveness of the proposed approach.
STATOR FLUX OPTIMIZATION ON DIRECT TORQUE CONTROL WITH FUZZY LOGIC cscpconf
The Direct Torque Control (DTC) is well known as an effective control technique for high
performance drives in a wide variety of industrial applications and conventional DTC technique
uses two constant reference value: torque and stator flux. In this paper, fuzzy logic based stator
flux optimization technique for DTC drives that has been proposed. The proposed fuzzy logic
based stator flux optimizer self-regulates the stator flux reference using induction motor load situation without need of any motor parameters. Simulation studies have been carried out with Matlab/Simulink to compare the proposed system behaviors at vary load conditions. Simulation results show that the performance of the proposed DTC technique has been improved and especially at low-load conditions torque ripple are greatly reduced with respect to the conventional DTC
Comparative analysis of PID and neural network controllers for improving star...TELKOMNIKA JOURNAL
Unlike 3-phase squirrel cage induction motor, starting-up of 3-phase wound rotor counter part can be improved by adding an external resistance to the rotor circuit.Thus, leads to reduce starting current and increase starting torque. In this paper two controllers for 3-phase wound rotor induction motor have been proposed include conventional proportional integral derivative (PID) controller and the other based on artificial neural network (NARMA-L2). A comparison between these controllers has been conducted. It has been shown that starting torque of the motor has been improved, when utilizing the neural network controller compared to the conventional counter part. It should be noted that MATLAB/SIMULINK has been used to implement both controllers.
Comparison of different controllers for the improvement of Dynamic response o...IJERA Editor
As the technology is fast changing, there is more and more use of machine intelligence in modern motor controllers. These controllers are employed in advanced electric motor drives in particular, the present day Induction motor drives. These systems emulate the human logic. This is particularly useful when the application has poorly defined mathematical model. In this present paper the analysis of fuzzy logic as the artificial intelligence is used. The comparative study of Fuzzy PI, Fuzzy MRAC is made. There is always a compromise of the cost and complexity. So this paper presents a new approach and its dynamic response in comparison to the Fuzzy PI and Fuzzy MRAC. The proposed controller is Fuzzy PI with scaling factors. This approach is validated with the Speed, torque responses of Indirect vector controlled Induction motor (IVCIM) drive.
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.
Similar to A Novel Rotor Resistance Estimation Technique for Vector Controlled Induction Motor Drive Using TS Fuzzy (20)
42 30 nA Comparative Study of Power Semiconductor Devices for Industrial PWM ...IAES-IJPEDS
The growing demand of energy translates into efficiency requirements of
energy conversion systems and electric drives. Both these systems are based
on Pulse Width Modulation (PWM) Inverter. In this paper we firstly present
the state of art of the main types of semiconductors devices for Industrial
PWM Inverter. In particular we examine the last generations of Silicon
Carbide (SiC) MOSFETs and Insulated Gate Bipolar Transistors (IGBTs)
and we present a comparison between these devices, obtained by SPICE
simulations, both for static characteristics at different temperatures and for
dynamic ones at different gate resistance, in order to identify the one which
makes the PWM inverter more efficient.
Modeling and State Feedback Controller Design of Tubular Linear Permanent Mag...IAES-IJPEDS
In this paper a state feedback controller for tubular linear permanent magnet
synchronous motor (TLPMSM) containing two gas springs, is presented.
The proposed TLPMSM controller is used to control reciprocating motions
of TLPMSM. The analytical plant model of TLPMSM is a multi-input
multi-output (MIMO) system which is decoupled to some sub single-input
single-output (SISO) systems, then, the sub SISO systems are converted to
sub-state space models. Indeed, the TLPMSM state space model is decoupled
to some sub-state spaces, and then, the gains of state feedback are calculated
by linear quadratic regulation (LQR) method for each sub-state space
separately. The controller decreases the distortions of the waveforms.
The simulation results indicate the validity of the controller.
Analysis of Harmonics and Ripple Current in Multi-Module Converters with Incr...IAES-IJPEDS
Controlled rectifiers are considered as the most important hardware part in
the field of HVDC systems in transmission lines and can be used for a
number of power electronics based system operation, control and utility
applications. In this paper, a brief design of a 12-pulse, 24-pulse, 36-pulse
and a 48-pulse converter connected to the grid is presented along with the
harmonic and ripple current analysis with its comparison statistics and thus
providing a justification for the suitable ones. The performance of the
12, 24, 36 and 48-pulse converters are compared for their effectiveness in
both quantitatively as well as qualitatively. Further, comparison of the
48-pulse converter on its THD and current ripple which is connected towards
the grid with simple pulse width modulation technique is also proposed. It
combines all features of the low switching concepts and DC current reinjection
techniques. Some basic topological explanation of the controlled
rectifiers and simulation results using MATLAB are also presented in this
paper in order to justify the harmonic analysis. The simulation results along
with the quantitative results shows the effectiveness of the proposed scheme
for the cancelation or the elimination of the harmonics result in maximum
harmonic mitigation, for high power utility applications, the 48-pulse
converter is most fitting to improve the conversion efficiency, low di/dt
and dv/dt and active and reactive power controllability.
Comparative Study of Various Adjustable Speed Drives during Voltage SagIAES-IJPEDS
This Paper compares the sensitivity of various adjustable speed drives to
voltage sag for the process control applications. Three phase voltage sag of
type B caused due to SLG fault is considered and four topologies of ASD’s
are compared in this paper. The comparison is done especially in speed,
voltage, current and torque of the ASDs. Diode rectifier without z source
inverter, diode rectifier with z source inverter, single phase two leg Vienna
rectifier and single phase neutral linked Vienna with z source inverter are
compared and the best one is highlighted. The circuits of various ASD’s are
simulated using Matlab /Simulink.
Modified Distribution Transformer for Enhancing Power Quality in Distribution...IAES-IJPEDS
The percentage of non-linear loads in the power distribution sector is increasing
day by day. Harmonics injected by these non-linear loads circulate in the delta
windings of the conventional distribution transformer thereby increasing the
temperature and losses. This reduces the efficiency and life of the transformers.
In a modified distribution transformer configuration proposed recently, called
star-star-delta_utilized configuration (YYD_utilized), the harmonics circulating
in the delta winding was utilized and the drainage power thus recovered was
used to power auxiliary loads. This paper presents the experimental studies
conducted on YYD_utilized distribution transformer. When compared to
conventional star-star, delta-star and star-star-delta transformers, the new
configuration of YYD_utilized transformer has shown considerable
improvement in transformer efficiency. The results obtained show that when
the power from the circulating harmonics is recovered and utilized, it not only
improves transformer efficiency but also improves the power factor
and reduces the harmonic distortions at the primary side of the transformer.
The results obtained also suggest the existence of maximum power point or an
optimum loading for the recovered harmonic power.
Modelling of Virtual Synchronous Converter for Grid-Inverter Synchronization ...IAES-IJPEDS
In this paper, virtual synchronous converter (VSCon) is been developed
which mimic the behavior of synchronous generator as in order to have fast
synchronization between the inverter with the grid. This synchronization is
important before can sent the power among inverter-grid connection. This
technique can also been applied at the distributed generated sources when are
connected to the local microgrids. Here, the frequency and voltage
synchronization also can be controlled at the same time some improvement
on synchronous generator mathematical model that is suitable to be
implemented into the inverter control. The whole unit of VSCon is operated
and simulated in Matlab/Simulink in order to observe all consequences
during synchronizing the voltage, frequency and phase-angle. It has been
verified by the simulation circuit where, the power converter can be
synchronized with the microrids without using a PLL unit for self
synchronization. This VSCon technique has proven that, by applying the
concept of the synchronous generator model in inverter control, it can cause
the inverter to behave as generator system, which does not required any
phase information from the grid in order to be synchronized.
Enhanced Crowbar Protection for Fault Ride through Capability of Wind Generat...IAES-IJPEDS
Due to increasing demand in power, the integration of renewable sources like
wind generation into power system is gaining much importance nowadays.
The heavy penetration of wind power into the power system leads to many
integration issues mainly due to the intermittent nature of the wind and the
desirability for variable speed operation of the generators. As the wind power
generation depends on the wind speed, its integration into the grid has
noticeable influence on the system stability and becomes an important issue
especially when a fault occurs on the grid. The protective disconnection of a
large amount of wind power during a fault will be an unacceptable
consequence and threatens the power system stability. With the increasing
use of wind turbines employing Doubly Fed Induction Generator (DFIG)
technology, it becomes a necessity to investigate their behavior during grid
faults and support them with fault ride through capability. This paper
presents the modeling and simulation of a doubly fed induction generator
according to grid code compatibility driven by a wind turbine connected to
the grid. This paper analyses the voltage sag due to a three-phase fault in the
wind connected grid. A control strategy including a crowbar circuit has been
developed in MATLAB/SIMULINK to bypass the rotor over currents during
grid fault to enhance the fault ride through capability and to maintain system
stability. Simulation results show the effectiveness of the proposed control
strategies in DFIG based grid connected wind turbine system.
An Improved of Multiple Harmonic Sources Identification in Distribution Syste...IAES-IJPEDS
This paper introduces an improved of multiple harmonic sources
identification that been produced by inverter loads in power system using
time-frequency distribution (TFD) analysis which is spectrogram.
The spectrogram is a very applicable method to represent signals in
time-frequency representation (TFR) and the main advantages
of spectrogram are the accuracy, speed of the algorithm and use low memory
size such that it can be computed rapidly. The identification of multiple
harmonic sources is based on the significant relationship of spectral
impedances which are the fundamental impedance (Z1) and harmonic
impedance (Zh) that extracted from TFR. To verify the accuracy of the
proposed method, MATLAB simulations carried out several unique cases
with different harmonic producing loads on IEEE 4-bus test feeder cases. It is
proven that the proposed method is superior with 100% correct identification
of multiple harmonic sources. It is envisioned that the method is very
accurate, fast and cost efficient to localize harmonic sources in distribution
system.
Performance and Energy Saving Analysis of Grid Connected Photovoltaic in West...IAES-IJPEDS
The paper presents performance and energy saving analysis of 1.25 kWp grid
connected photovoltaic system under difference weather condition in West
Sumatera. The measured data were performed during weather data that often
occur in West Sumatra i.e. sunny, overcast, raining and cloudy.
The synchronizing process successfully done even bad weather conditions
when sunlight was low automatically. Photovoltaic in average start
producing power from 7:00 AM to 6:00 PM for normal or clear sky, however
under overcast, raining and cloudy weather, the PV power decreased and
disconnected earlier before sunset. During intermittent raining, overcast and
cloud covered the PV power output show an irregular profile. The PV energy
saving performed for three residential connection cases: 1300 VA, 900 VA
with subsidized and 900 VA without subsidized. The solar PV installation
have more benefits and energy saving for 1300 VA, 900 VA without
subsidized with payback period around 8.5 years. However, the 900 VA with
subsidized take longer 20.8 years, but still in PV lifespan 25 years. In the
future, household subsidies may be reduced or eliminated, the solar energy
will be viable alternative of energy resources when it can produce electricity
at a cost equivalent to utility grid PLN rate.
An Improved Constant Voltage Based MPPT Technique for PMDC MotorIAES-IJPEDS
Stand-alone photovoltaic (SAPV) systems are being used in remote areas
and are being seen as one of the promising solution in this regard. The SAPV
system as presented in the paper consists of solar PV panel, a DC-DC
converter, a controller and a PMDC motor. The current-voltage and powervoltage
characteristics being nonlinear, the SAPV system require maximum
power point techniques (MPPT) control techniques to extract maximum
power available from the PV cell. A voltage based MPPT technique which is
capable of tracking MPP has been selected because of numerous advantages
it offers such as: simple and low cost of implementation. The limitation of
constant voltage method is that its efficiency is low as the PV panel has to be
disconnected from the load for measurement of the open circuit voltage
(Voc). In the presented paper, the authors have removed this limitation by
using a pilot PV panel for measurement of Voc. A proportional-integrator (PI)
based controller is used in implementation of constant voltage MPP
technique and the modeling is done in MATLAB®/SIMULINK simulation
environment. The simulation results are presented and discussed in the paper,
the results shows that the efficiency of the system has increased.
A Discrete PLL Based Load Frequency Control of FLC-Based PV-Wind Hybrid Power...IAES-IJPEDS
The sun and wind-based generation are considered to besource of green
power generation which can mitigate the power demand issues. As solar and
wind power advancements are entrenched and the infiltration of these
Renewable Energy Sources (RES) into to network is expanding dynamically.
So, as to outline a legitimate control and to harness power from RES the
learning of natural conditions for a specific area is fundamental. Fuzzy Logic
Controller (FLC) based Maximum Power Point Tracking (MPPT) controlled
boost converter are utilized for viable operation and to keep DC voltage
steady at desired level. The control scheme of the inverter is intended to keep
the load voltage and frequency of the AC supply at aconstant level regardless
of progress in natural conditions and burden. A Simulink model of the
proposed Hybrid system with the MPPT controlled Boost converters
and Voltage regulated Inverter for stand-alone application is developed in
MATLAB R2015a, Version 8.5.0. The ongoing information of Wind Speed
and Solar Irradiation levels are recorded at BITS-Pilani, Hyderabad Campus
the performance of the voltage regulated inverter under constant and varying
linearAC load is analyzed. The investigation shows that the magnitude of
load voltage and frequency of the load voltage is maintained at desired level
by the proposed inverter control logic.
An Adaptive Virtual Impedance Based Droop Control Scheme for Parallel Inverte...IAES-IJPEDS
This paper presents an adaptive virtual impedance based droop control
scheme for parallel inverter operation in low voltage microgrid. Because it is
essential to achieve power sharing between inverters in microgrid, various
droop control schemes have been proposed. In practice, the line impedance
between inverters and the point of common coupling (PCC) in microgrid are
not always equal. This imbalance in line impedance often results in a reactive
power mismatch among inverters. This problem has been solved by
introducing a virtual impedance loop in the conventional droop control
scheme. However, the reactive power sharing performance of this method is
still deteriorated when the line impedances change during operation. To
overcome such a problem, a new control scheme that is based on a virtual
impedance loop and an impedance estimation scheme is proposed.
To monitor the changes in line impedances, the impedance estimator is
implemented by using the output voltages and currents of inverters as well as
the voltages at the PCC. To compensate for the reactive power mismatch due
to the line impedance changes, the estimated line impedance is fed to the
virtual impedance loop in which it adjusts the virtual impedance value.
Comparative simulation results with the conventional ones verify the
effectiveness of the proposed adaptive virtual impedance based droop control
scheme.
Open-Switch Fault-Tolerant Control of Power Converters in a Grid-Connected Ph...IAES-IJPEDS
This paper presents the study of an open switch fault tolerant control of a
grid-connected photovoltaic system. The studied system is based on the
classical DC-DC boost converter and a bidirectional 6-pulse DC-AC
converter. The objective is to provide an open-switch fault detection method
and fault-tolerant control for both of boost converter and grid-side converter
(GSC) in a grid-connected photovoltaic system. A fast fault detection method
and a reliable fault-tolerant topology are required to ensure continuity of
service, and achieve a faster corrective maintenance. In this work, the mean
value of the error voltages is used as fault indicator for the GSC, while, for
the boost converter the inductor current form is used as fault indicator. The
fault-tolerant topology was achieved by adding one redundant switch to the
boost converter, and by adding one redundant leg to the GSC. The results of
the fault tolerant control are presented and discussed to validate the proposed
approach under different scenarios and different solar irradiances.
Photovoltaic System with SEPIC Converter Controlled by the Fuzzy LogicIAES-IJPEDS
In this work, a fuzzy logic controller is used to control the output voltage of a
photovoltaic system with a DC-DC converter; type Single Ended Primary
Inductor Converter (SEPIC). The system is designed for 210 W solar
photovoltaic (SCHOTT 210) panel and to feed an average demand of 78 W.
This system includes solar panels, SEPIC converter and fuzzy logic
controller. The SEPIC converter provides a constant DC bus voltage and its
duty cycle controlled by the fuzzy logic controller which is needed to
improve PV panel’s utilization efficiency. A fuzzy logic controller (FLC) is
also used to generate the PWM signal for the SEPIC converter.
An Approach to Voltage Quality Enhancement by Introduction of CWVM for Distri...IAES-IJPEDS
This paper presented with problems related with voltage flicker in power
system networks. Several international standard issued to control the voltage
flicker are briefly described and some important methods to analyse
electrical circuits with sinusoidal and non-sinusoidal waveforms are
introduced and evaluated. One of these methods-Cockcroft Walton Voltage
Multiplier (CWVM) has been used to increase the voltage of a filter, which is
also described in this paper as a practical application. The filter can
compensate for harmonic currents, power factor, and unbalance voltage.The
simulation results using Multisimare presented, showing that good dynamic
and steady-state response can be achieved with this approach.
Electric Power Converter with a Wide Input Voltage RangeIAES-IJPEDS
The electric power converter for downhole telemetry systems of oil-well
pumps include a downhole block connected to the pump that contains
electronic circuits required for the operation of the motor pump sensors
and transmission of data about their condition to the surface are described.
A few methods of electric power conversion for this purpose are considered.
The circuit contained two steps of voltage converting are proposed.
The electrical scheme of this method is considered in the article. Proposed
decisions are simulated and verified experimentally. The input high supply
voltage range (200-4200 V) without loss of efficiency (even temporary) was
obtained. The results of simulation and experimental studies have shown
very close results.
Design and Implementation of Real Time Charging Optimization for Hybrid Elect...IAES-IJPEDS
Electric vehicle (EV) has gained incredible interest from the past two decade
as one of the hopeful greenhouse gasses solution. The number of Electric
Vehicle (EV) is increasing around the world; hence that making EVs user
friendly becomes more important. The main challenge in usage of EV is the
charging time required for the batteries used in EV. As a consequence, this
subject matter has been researched in many credentials where a wide range
of solutions have been proposed. However those solutions are in nature due
to the complex hardware structure. To provide an unswerving journey
an Android application based charging optimization is proposed.
This application is aimed at giving relevant information about the EV’s
battery state of charge (SOC), accurate location of the EV, booking of the
charging slots using token system and route planner. At emergency
situations, an alternative service is provided by mobile charging stations.
Route planner indicates the temperature by which prediction of reaching the
destination can be done. In addition to that nearest places such as parks,
motels are indicated. The estimated time and distance between the electric
vehicle and the charging station is calculated by the charging station server
according to which the parking lot is allocated. Vehicle to charging station
communication is established for the time estimation of charging. This will
help the EV users to know about charge status and charging station, which
support fast charging method and availability of the station on the go
and also when to charge their EV. The Arduino UNO board has been used
for the hardware part. The hardware results are confirming the conceptual of
the proposed work.
Performance Analysis of Photovoltaic Induction Motor Drive for Agriculture Pu...IAES-IJPEDS
This paper presents water pumping system using renewable source (solar)
without the use of chemical storage batteries. In this converter-inverter
circuit is used to drive Induction motor. The Converter used here is Two
Inductor boost converter (TIBC), which consists of a resonant tank, voltage
doubler rectifier and a snubber circuit. TIBC is designed to drive the three
phase induction motor from PV energy. TIBC converter is also known as
current fed multi resonant converter having high voltage gain and low input
current ripple. Converter switches are controlled through hysteresis controller
and ZCS resonant topologies. Solar PV power fluctuates according to
irradiation level of sunlight and hence tracking of maximum power at all
time is mandatory. SPWM control with third harmonic injection is used to
trigger the IGBT’s in the inverter. The development is oriented to achieve a
more efficient, reliable, maintenance free and cheaper solution than the
standard ones, that uses DC motors or low voltage synchronous motors.
The proposed method is verified with MATLAB/SIMULINK and the system
simulation confirms the performance of the proposed system.
Comparison of Sine and Space Vector Modulated Embedded Z-Source Inverter fed ...IAES-IJPEDS
This paper deals with performance of photovoltaic powered Embedded
Z-Source Inverter (EZSI) fed Induction motor drive. The DC output from the
PV-Panel is boosted and converted into AC using Embedded Z-Source
Inverter. EZSI system based on the concept of Z-Source Inverter (ZSI),
which provides single stage power conversion. The EZSI also produce same
voltage gain as that of the ZSI based system. In EZSI the DC source is
embedded within the X-shaped LC impedance network, due to this EZSI has
the added advantage of inherent source filtering capability, this can be
achieved without any extra passive filter. EZSI can produce the AC output
voltage which is greater than the DC link voltage. EZSI system also provides
ride-through capability under voltage sags. In this paper the performance of
space vector modulated EZSI fed Induction Motor Drive is compared with
sinusoidal PWM controlled EZSI fed Drive system. The PV powered EZSI
fed three phase Induction Motor System is designed, modeled and simulated
using MAT LAB-SIMULINK and the corresponding results are presented.
This drive system has advantages like voltage boosting ability and reduced
harmonic content.
Single-Phase Multilevel Inverter with Simpler Basic Unit Cells for Photovolta...IAES-IJPEDS
This paper presents a single-phase multilevel inverter (MLI) with simpler
basic unit cells. The proposed MLI is able to operate in two modes, i.e.
charge mode to charge the batteries, and inverter mode to supply AC power
to load, and therefore, it is inherently suitable for photovoltaic (PV) power
generation applications. The proposed MLI requires lower number of power
MOSFETs and gate driver units, which will translate into higher cost saving
and better system reliability. The power MOSFETs in the basic unit cells
and H-bridge module are switched at near fundamental frequency, i.e. 100
Hz and 50 Hz, respectively, resulting in lower switching losses. For low total
harmonic distortion (THD) operation, a deep scanning method is employed
to calculate the switching angles of the MLI. The lowest THD obtained is
8.91% at modulation index of 0.82. The performance of the proposed MLI
(9-level) has been simulated and evaluated experimentally. The simulation
and experimental results are in good agreement and this confirms that the
proposed MLI is able to produce an AC output voltage with low THD.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
CW RADAR, FMCW RADAR, FMCW ALTIMETER, AND THEIR PARAMETERSveerababupersonal22
It consists of cw radar and fmcw radar ,range measurement,if amplifier and fmcw altimeterThe CW radar operates using continuous wave transmission, while the FMCW radar employs frequency-modulated continuous wave technology. Range measurement is a crucial aspect of radar systems, providing information about the distance to a target. The IF amplifier plays a key role in signal processing, amplifying intermediate frequency signals for further analysis. The FMCW altimeter utilizes frequency-modulated continuous wave technology to accurately measure altitude above a reference point.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
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knowledge of rotor resistance, rotor inductance and magnetizing inductance values and is estimated from the
equivalent circuit model [5].
It has been given that the variations of rotor resistance and therefore the rotor time constant is the
most critical in indirect field oriented vector controlled drives [6]. If this change is not estimated, the
orthogonality between the synchronous frame variables is lost leading to cross coupling and poor
dynamic performance of the drive system. Therefore major efforts were put in for online estimation of rotor
resistance. The online parameter estimation technique can be broadly classified as spectral analysis
technique, observer based technique, model reference adaptive system technique and artificial intelligence
techniques [7-12].
The model reference adaptive systems scheme as shown in Figure 1 is the most popularly used for
rotor resistance estimation because of its simpler implementation and less computational efforts compared to
other methods. The technique proposes calculation of a parameter to be identified in two different ways [13-
15]. The first calculation is based on references inside the control system known as the estimated value and
the second known as the reference value depends on measured signals. One of the two values should be
independent of the parameter which is to be estimated. The accuracy of this technique is based heavily on the
machine model. The difference obtained between the reference and the estimated value is taken as an error
signal and is used to drive an adaptive mechanism .Based on the formulation of the error signal the MRAC
are further subcategorized as electromagnetic torque based, rotor flux based, voltage based and
reactive power based. The adaptive mechanism normally uses a PI controller for the generation of the change
in rotor resistance ∆ [16]. The PI controller may not give satisfactory performance for operating condition
where frequent variation in motor speed and load torque is required. Fuzzy logic controllers as compared to
PI controller do not require precise mathematical model,can handle nonlinearity and are more robust [17, 18].
Based on the rule consequent the fuzzy controllers are further classified as Mamdani and TS fuzzy controller.
In TS-Fuzzy the linguistic rule consequent is made variable by means of its parameters and hence, it can
produce an infinite number of gain variation characteristics [19] .Morever it has a definite edge over the
Mamdani fuzzy due to the less number of fuzzy sets used for the inputs, leading to lesser rule sets.
Figure 1. Block diagram of MRAC
As per the author’s knowledge, no work has been reported where the TS fuzzy controller has been
used as an adaptive mechanism for identification of rotor resistance based on Rotor Flux Model Reference
Adaptive Controlller (RF-MRAC) instead of the existing PI and Mamdani fuzzy controllers as stated in paper
[16-18]. In this paper the RF-MRAC using TS fuzzy controller as adaptive mechanism is devoloped and is
investigated for an IRFOC induction motor drive.The objective of the proposed work is 1) to obtain an
accurate online rotor resistance identification scheme for a four quadrant drive operation and also to
minimize the over excitation/under excitation of the motor flux due to rotor resistance variations, 2) accurate
identification of rotor resistance under symmetrical short circuit condition of rotor circuit and 3) to oberve the
effectiveness of the identification technique when the drive is operating at zero speed with rated load torque
condition. This paper evaluates the performance index of the rotor resistance identification as integral time
square error (ITSE) for the proposed scheme and is compared with the other two controllers i.e. the PI and
the Mamdani fuzzy.
The paper is organized as follows: Section 2 provides a brief overview of the dynamic modeling of
the field oriented vector control drive. Section 3 describes the functions of the various block involved in the
modeling of the vector controlled I.M drive and also the rotor resistance identification scheme using RF -
.MRAC. Section 4 describes the Mamdani fuzzy control scheme as an adaptive mechanism of the rotor flux
model reference adaptive system. Section 5 describes in detail the design and implementation of the proposed
TS fuzzy control scheme as the adaptive mechanism of RF-MRAS. Section 6 details the simulation results of
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the PI, Mamdani and proposed TS fuzzy adaptive scheme under different drive operating conditions and
conclusion is given in Section 7.
2. DESIGN FOR VECTOR CONTROL DRIVES
The dynamic model of induction motor for rotor flux oriented vector control application can be
written as follows
_ _
0
1
0
1
0
0
(1)
Where denotes the derivative operator , , are the stator currents and , the rotor
fluxes in frame. Similarly , , and are the stator résistance, stator self inductance, rotor
resistance and the rotor self inductance respectively. The rotor time constant is given as and leakage
inductance is where 1 .
For rotor flux oriented control the rotor flux is directed along the d-axis and is equal to and
therefore 0. Thus the equation (1a) modifies to as shown below
0
_ _
0
0
0
1
0
0 0 0 0
0 0
0
(2)
From equation (2b) it can be seen that the axis voltage are coupled by the following terms:
(3)
(4)
To achieve linear control of stator voltage it is necessary to remove the decoupling terms and is
cancelled by using a decoupled method that utilizes nonlinear feedback of the coupling voltage.
3. MODELING OF VOLTAGE CONTROLLED IM DRIVE WITH ROTOR RESISTANCE
ESTIMATOR
The main aim of the vector control of induction motor is to control it just like a separately excited
DC motor drive where one can obtain independent control of the two variables armature and field current
which are orthogonal to each other thus having independent control over torque and flux. The block diagram
of an indirect rotor flux oriented speed control of induction motor is shown in Figure 2. The scheme consists
of the current control loop within the speed control loop. The scheme uses PI controllers for the d-axis and q-
axis current whose proportional and integral gains are as shown in Appendix-III, the bandwidth of the inner
current loop is chosen higher than the flux and speed controller. The voltage decoupling equations (3) & (4)
are adjusted with the output of the controllers to obtain good current control action. The d-axis and q-axis
reference voltages and thus obtained are transformed to the stationary i.e. stator reference frame
with the help of field angle .The two phase voltage and in the stator reference frame are then
transformed to three phase stator reference voltages , , which acts as modulating voltage for the
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modulator by using the sine-triangle pulse width modulation (SPWM) scheme . The modulator output which
is in the form of pulses is used to drive the IGBT with anti-parallel diode acting as switches for the
conventional two level voltage source inverter (VSI).
As shown in Figure 2 the stator currents are measured and transformed as d-q axis currents, which
are then used as feedback signals for the current controller. The d- axis current is passed through a low
pass filter with time constant equal to rotor time constant to obtain the rotor flux which acts as feedback to
the flux controller. The rotor speed , torque current rotor flux and rotor time constant are used
to determine the slip speed and from it the rotor flux position for and transformation.
Figure 2. Block diagram of a voltage controlled IFOC drive.
a. Rotor Resistance Identification using Rotor Flux
The block diagram of the rotor flux based MRAC for identification of rotor resistance is shown in
Figure 3, where the inputs , , , & are the motor terminal voltages, current and speed feedbacks.
The rotor flux obtained from the voltage model which acts as the reference output of the model adaptive
reference scheme is obtained by measuring the machine terminal voltage and currents, which are then
transformed to the stationary reference frame as , , & .
Figure 3. Proposed rotor flux based MRAC for rotor resistance estimation
The rotor flux where and are the d-axis and q-axis rotor flux in the
stationary reference frame which are derived as:
(5)
and
(6)
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given that = and = are the stator d-q flux in stationary
reference frame, is the leakage inductance and is the stator resistance.
Similarly the flux output is obtained from the current model for the adjustable
model is obtained by measuring the current and motor speed , where
1
(7)
and
1
(8)
The difference between and acts as the error signal for the adaptive mechanism whose
output indicates the change in rotor resistance ∆ which is then added up with the nominal resistance value
i.e. to achieve the actual rotor resistance .The obtained new value of corresponding to change in
rotor resistance is then used to determine the slip speed and is added up with the rotor speed to obtain
the synchronous speed .
4. IMPLEMENTATION OF FUZZY CONTROLLER
In this study the conventional PI controller as an adaptive mechanism has been replaced by
Mamdani fuzzy controller. The fuzzy controller as shown in Figure 4 consists of two inputs e k and
e k and one output ∆u. The input e k is the difference between the reference rotor flux “ψr ” and actual
rotor flux "ψr i.e. k ψr ψr , and the input e k which indicates the change in error and is given
as e k e k e k 1 . There are two normalizing factors k1&k2 for inputs e1and e2 and one de-
normalizing factor for output ∆u. In normalization process the input values are scaled in the range [-1, 1] and
the de-normalization process converts the crisp output value of the fuzzy controller to a value depending on
the output control element. In the fuzzifier the crisp values of input and are converted into fuzzy values
[20]. For this purpose seven triangular fuzzy membership functions are defined for each input as well as the
output.
Figure 4. Block diagram of a Fuzzy controller
Figure 5 illustrates the triangle membership functions of the first input i.e. which are defined
by seven linguistic variables as Negative Big (NB) Negative Medium (NM), Negative Small (NS), Zero (Z),
Positive Small (PS), Positive Medium (PM) and Positive Big (PB). The overlap rates of the membership are
taken as 50%.
The fuzzy rule base represent the knowledge of human operators who make necessary changes in
the controller output to obtain system with minimum error and faster response. For this the behavior of the
error signals and has to be observed and accordingly it is to be decided whether the controller
output ∆ is to be increased or decreased. The controller for the study make use of the sliding mode rule base
shown in Figure 6 as it is easy to implement for real time application
The developed fuzzy logic uses the min – max compositional rule of inference. The inference
mechanism of the fuzzy controller is implemented with regard to the rule base given by μ
min μ 1 , μ 2 .
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The defuzzifier process makes use of the centre of gravity method and is given as ∆μ
∑
∑
where, n is the number of fuzzy sets in the output.
Figure 5. Input variable e1 (k) membership function
NB NM NS Z PB PM PB
NB NB NB NB NB NM NS Z
NM NB NB NB NM NZ Z PS
NB NB NB NM NS Z PS PM
Z NB NM NS Z PS PM PB
PS NM NS Z PS PM PB PB
PM NS Z PS PM PB PB PB
PB Z PB PM PB PB PB PB
Figure 6. Mamdani Fuzzy rule base for rotor resistance estimation
5. DESIGN OF PROPOSED TS FUZZY CONTROLLER
The major difference betweenthe Mamdani and the TS fuzzy controller is that the former employ
fuzzy sets as the consequent where as the later employ linear function as the consequent [21]. The linguistic
rule consequent is made variable by means of its parameters and therefore the TS fuzzy control scheme can
produce a large number of gain variations. For the study the input variables are and same as
defined above.for Mamdani fuzzy. Each variable was fuzzified by two inputs fuzzy sets named as positive
(P) and negative (N) respectively as shown in Figure 7. The mathematical representation of positive and
negative membership function for the input variables are given below.
μ
0,
2
1,
, (9)
μ
1,
2
0,
, (10)
The value of μ μ is either 0 or 1 when is outside the interval [-L, L]. The value
of L plays an important role in the controller performance and should be judiciously chosen. As there are two
fuzzy sets for each input, there will be (2 x 2) fuzzy values to cover all these combinations. The fuzzy control
rules for the two inputs use the following simplified rules as shown in Table 1.
-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4
0
0.2
0.4
0.6
0.8
1
Eflux
Degreeofmembership
NL NM NS Z PS PM PL
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Figure7. Input variables membership function
Table 1. TS fuzzy rule set
Rule No. IF 1 AND 2 THEN
R1 Positive Positive 1 1 1 ∗ 1 2 ∗ 2
R2 Positive Negative 2 2 ∗ 1
R3 Negative Positive 3 3 ∗ 1
R4 Negative Negative 4 4 ∗ 1
The corresponding incremental output of the fuzzy controller is
μ 1 ∗
∑ μ
∑ μ
(11)
where 1 1 ∗ 1 2 ∗ 2
For this study the algorithm of the proposed TS fuzzy controller is developed and programmed in
MATLAB M-file and is then used as a Simulink block in the model with the help of Embedded M Function
block available in the MATLAB/Simulink library. The values of the six constants 1, 2, 3, 4 1 2
as given in Appendix-II are determined by trial and error with performance indice as the integral time square
error of (k). In general the number of unknown constants for 2 rules are given by 2 , where M
stands for the number of inputs.
6. RESULTS AND ANALYSIS
A simulation model of voltage controlled IRFOC as shown in Figure 2 is developed in a
MATLAB/Simulink environment to ascertain the effectiveness of the proposed adaptive algorithm. The
parameters and ratings of the test motor are given in Appendix-I. The SPWM based indirect rotor flux
oriented controller is tested for step increase in rotor resistance by connecting a three phase star connected
resistor bank to the rotor of the three phase slip ring induction motor externally. Similarly a step decrease in
rotor resistance is obtained by instrumenting the wrong rotor resistance value in the controller. The
simulation time used are only to explain the concepts, as such sudden practical changes in rotor resistance
due to temperature variation rarely occurs in practice due to the large thermal time constant of the motor. The
IRFOC drive is subjected to different operating conditions noted as Case-II to IV below, during which step
increase and decrease in rotor resistance is initiated to test the effectiveness of the adaptive mechanism.
Under these operating conditions the performance analysis of the proposed TS fuzzy controller based RF-
MRAC in terms of settling time and steady state error is made and is compared with the other established
controllers i.e. the PI and Mamdani fuzzy controller.
6.1. Case-I: Speed and Load Torque Constant with RF-MRAS Disabled
The IRFOC drive is operated at constant speed set of 1000 rpm and load torque of 4 Nm. as shown
in Figures 8 and 9. A step change in motor rotor resistance above by 50% and below by 30% of its nominal
value is done at t=12sec with rotor flux model reference adaptive mechanism kept inactive. From
Figure 10 (a) & (b) it is observed that the actual and the reference value of the d-axis flux remains same i.e.
0.936 ωb till the instrumented and actual value of rotor resistance are equal. At t=12 sec when the change in
rotor resistance is initiated it is seen that, the increase in rotor resistance has resulted in sudden changes in the
motor actual flux with its value increasing from 0.936 ωb to 1.195ωb. Similarly the decrease in rotor
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resistance has resulted in the actual flux decreasing from 0.936 ωb to 0.6 respectively. The increase in
rotor flux may lead to over excitation of the motor resulting in increased core losses and saturation. It also
seen from Figure11 that the electromagnetic developed by the motor has also decreased when the rotor
resistance is decreased.
Figure 8. Tracking of constant speed reference of 1000 rpm
Figure 9. Tracking the constant load torque reference 4Nm
(a)
0 5 10 15 20 25
0
100
200
300
400
500
600
700
800
900
1000
1100
time (sec)
Rotorspeed(rpm)
Reference rotor speed
Actual rotor speed for PI based MRAS
Actual rotor speed for Mamdani fuzzybased MRAS
Actual rotor speed for TS fuzzybase MRAS
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(b)
Figure 10. Rotor flux for step (a) increase (b) decrease in rotor resistance with identification disabled
Figure 11. Effect on Torque devolped for step increase in rotor resistance with identification disabled
6.2. Case-II: Speed and Load Torque Constant with RF-MRAS Enabled
The IFOC drive is now subjected to the same operating condition as above, with step change in rotor
resistance at t = 12 sec. The integral time square error performance index is used for finding the coefficients
k and k of the PI controller acting as the adaptive mechanism and are found to be 5 and 80 respectively. It
is observed from Figure 12 (a) and (b) that during motor starting condition with PI controller, peak overshoot
of rotor flux occurs which lasts for about 1.5sec before tracking the reference flux value whereas for
Mamdani and TS fuzzy controller no such overshoot in rotor flux during starting transient is observed. At
t=12 sec the change in resistance has resulted in increase of the d-axis flux from its nominal value of 0.936
ωb for all the three controllers with peak overshoot again more pronounced for the PI controller before
settling to its steady state flux value. From Figure 13 (a) & (b) it is also seen that the performance of the TS
fuzzy controller is excellent as it can track the step change in rotor resistance in 1.5 sec compared to the other
two controllers with its steady state error taken as integral time square error (ITSE) very low as shown in
Table 2. The same performance index is obtained from the TS fuzzy controller when the instrumented value
of the rotor resistance is made less than the actual motor resistance value.
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(b)
Figure13. Rotor resistance identification for step (a) increase (b) decrease in rotor resistance, Case-II
6.3. Case III: Variable Motor Speed with Constant Load with RF-MRAS Enabled
The IFOC drive is subjected to speed changes as shown in Figure 14 where the drive operates at
1000 rpm from 2-16 sec and then operates at zero speed at full load torque from 16-22 sec and thereafter
operates in the reverse direction at 500 rpm from 22 -25 sec. exhibiting the condition of industrial overhead
crane drive. The step increase and decrease in rotor resistance as described above is again initiated at t
=12sec. It is seen from Figure 15 (a) that the actual flux oscillates from its reference value with PI adaptive
mechanism during motor starting and again sustained oscillation in rotor flux is observed when it is rotating
in the reverse direction, which becomes more pronounced when the step decrease in rotor resistance is made
as seen in Figure 15 (b) It is also observed from Figure 16 (a) the steady state error in terms of rotor
resistance estimation is the lowest for TS fuzzy., but its performance when the rotor resistance is decreased
detoriates considerably when compared with Mamdani fuzzy controller and also sustained oscillations in
rotor resistance estimation is obseverd in Figure 16 (b) when the drive is operating at zero speed.
Figure 14. Variable reference rotor speed track for step increase in rotor resistance
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(b)
Figure 16. Rotor resistance identification for step (a) increase (b) decrease in rotor resistance, Case-III
6.4. Case IV: Motor Speed Constant with Variable Load Torque and RF-MRAS Enabled
The IRFOC drive is subjected to variable load torque as shown in Figure 17 depicting the operating
condition of a crusher motor drive with load torque made negative equal to 2 Nm at t=22sec representing
regenerative braking condition. It is very well observed from Figure 18 (a)& (b) and from Figure 19 (a) & (b)
that amongst the three controllers the steady state error in terms of rotor flux and estimation of rotor
resistance value is the lowest for TS fuzzy controller as shown by the performance index listed in Table 2.
Figure 17. Tracking of variable torque reference with RF-MRAS enabled
(a)
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551
(b)
Figure 18. Rotor flux for step (a) increase (b) decrease in rotor resistance, Case-IV
(a)
(b)
Figure 19. Rotor resistance identification for step (a) increase (b) decrease in rotor resistance, Case-IV
7. CONCLUSION
A new approach for the rotor resistance identification of induction motor drive based on rotor flux
model reference adaptive system using TS fuzzy controller as an adaptive mechanism has been presented.
The identification is online and is based on the steady state model of indirect field oriented controller. From
the investigations it can be appreciated that the performance of the TS fuzzy controller is better than the PI
and Mamdani fuzzy controller under stringent motor operating condition as well as when the drive is under
zero speed operating condition. It is observed from the simulation results that the d-axis flux settles
approximately in 2-2.5 sec and its peak overshoot during change in operating condition or motor rotor
resistance parameter variation is less compared to the other two controllers. Moreover, it is also observed
from the results that leaving apart Case- III. (b) which, of course can be improved by optimizing the fewer no
15. IJPEDS ISSN: 2088-8694
A Novel Rotor Resistance Estimation Technique for Vector Controlled Induction Motor…(Saji Chacko)
552
of TS fuzzy parameters as compared to Mamdani fuzzy using Evolutionary Algorithm, the tracking of change
in rotor resistance by TS fuzzy controller in terms of steady state error (ITSE) and peak overshoot is superior
to both PI and Mamdani fuzzy controller.
Table 2. Comparison of controller performance with regard to rotor resistance identification for step (a)
increase (b) decrease in I.M rotor resistance at t=12 sec for Case II-IV
Description
Controller Type
PI Mamdani Fuzzy TSFuzzy
Steady State error
(ITSE)
Steady State error
(ITSE)
Steady State error
(ITSE)
CCase
II
(a) 4.738 4.929 0.01505
(b) 1.201 2.067 0.06346
CCase
III
(a) 102.4 46.91 45.32
(b) 150 45.61 184.6
CCase
IV
(a) 62.52 20.87 7.43
(b) 22.64 17.79 6.6
APPENDIX-I
Parameters of the IM used
Ratings
Power: - 0.746 KW. Frequency: - 50Hz, Voltage:-415V, Stator current:-1.8Amp, Speed:-1450 rpm, Pole
pair:-2
Machine constants
Stator Resistance (Rs) = 10.75 Ω., Rotor Resistance (Rr) = 9.28 Ω, Stator/Rotor Self Inductance (Ls/Lr)
=0.5318 H Moment of Inertia (J) = 0.011787 kgm2,
Friction coefficient (B) = 0.0027 Nm/rad/sec
APPENDIX-II
TS Fuzzy Parameters Used In Simulation: a1 = 3; a2 = 1.5; k1 = 1.18; k2= 0.15; k3=0; k4= 5;
APPENDIX-III
Proportional ( ) and Integral ( ) Gains of PI Controller
PI Controller
Speed control loop 1.295 0.2967
Flux control loop 110.6 1083.5
Inner current loops 98.61 9087.04
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BIBLIOGRAPHIES OF AUTHORS
Saji T Chacko was born in Chattisgarh, (C.G), India in 1968. He is a faculty of Electrical and
Electronics Engineering at Shri Shankaracharya Technical Campus, Bhilai, C.G, India and is
currently pursuing his PhD from Maulana Azad National Institute of Technology, Bhopal, M.P,
India. He is the author of 3 International Journal and Conference and 5 National conferences. His
area of research interest is Power Electronics and drives, Application of soft computing techniques
for estimation and fault detection in Electric Drives.
Chandrakant Narayan Bhende was born in Nagpur, Maharashtra, India in 1977. He got his PhD
degree from Indian Institute of Technology, Delhi, India in 2008 and thereafter did his Post
Doctoral Research from University of Wollongong, He is currently Assistant Professor, School of
Electrical Sciences, Indian Institute of Technology, Bhubhaneshwar, Orissa, India. He is the author
of 10 International journals His area of research interest includes Power Quality, Custom Power
Devices, Renewable Energy sources and application of Soft computing Techniques in Power
systems
Shailendra Jain was born in Madhya Pradesh (M.P), India in 1968. He got his Ph.D. degree from
Indian Institute of Technology, Roorkee, India, in 2003, and the PDF from the University of
Western Ontario, London, ON, Canada, in 2007. He is Professor in the Department of Electrical
Engineering, Maulana Azad National Institute of Technology, Bhopal, M.P, India, He is the
author of more than 70 Journals and 50 conference papers in National and International
Publication like IEEE, Elsevier etc and reviewer of National and International Journals.. He has
authored a book on “Modeling and Simulation “by Wiley, India. His area of research interests are
power electronics and electric drives, power quality improvement, multi-level inverters,
Rajesh Kumar Nema was born in Madhya Pradesh (M.P) India in 1963. He got his PhD degree
from Bhopal University, Bhopal, India in 2004. Received “Colombo award” under Cultural
Exchange programme “Indo-UK REC Project”. He is Professor in the Department of Electrical
Engineering, Maulana Azad National Institute of Technology, Bhopal, M.P, India, He is the author
of more than 7 Journals and 50 conference papers in National and International Publication. His
principle areas of research interest are Power Electronics, Solar Photovoltaics, Instrumentation,
Distributed Generation. Multilevel Inverters, Microprocessor and DSP.