Fuzzy Direct Torque Control Research Articles

Comparative Study of Electric Traction Control Techniques: Application to Motor Vehicles

Abstract: Climate change and evolution of technology have shown the important of electric vehicles (EV). Its performance strongly depends on the type of control techniques used to control their motor. In this paper, we compare the electric traction control techniques used in motor vehicles. We consider an electric vehicle with two driving wheels and we model it to bring out the mechanical, electrical and electromechanical equations. For our obtained road, we develop the control laws of our vehicle using Indirect Flux Oriented Control (IFOC) method, Direct Torque Control (DTC) method and Fuzzy DTC (DTFC) method. A comparative study of these control techniques is made using performance tools such as response-time, static error and ripple rate. Our study shows that DTFC method is better to obtain the motor instruction requested by the driver.

Field programmable gate array hardware in the loop validation of fuzzy direct torque control for induction machine drive

Introduction. Currently, the direct torque control is very popular in industry and is of great interest to scientists in the variable speed drive of asynchronous machines. This technique provides decoupling between torque control and flux without the need to use pulse width modulation or coordinate transformation. Nevertheless, this command presents two major importunities: the switching frequency is highly variable on the one hand, and on the other hand, the amplitude of the torque and stator flux ripples remain poorly controlled throughout the considered operating speed range. The novelty of this article proposes improvements in performance of direct torque control of asynchronous machines by development of a fuzzy direct torque control algorithm. This latter makes it possible to provide solutions to the major problems of this control technique, namely: torque ripples, flux ripples, and failure to control switching frequency. Purpose. The emergence of this method has given rise to various works whose objective is to show its performance, or to provide solutions to its limitations. Indeed, this work consists in validation of a fuzzy direct torque control architecture implemented on the ML402 development kit (based on the Xilinx Virtex-4 type field programmable gate array circuit), through hardware description language (VHDL) and Xilinx generator system. The obtained results showed the robustness of the control and sensorless in front of load and parameters variation of induction motor control. The research directions of the model were determined for the subsequent implementation of results with simulation samples.

Different Control Techniques of Permanent Magnet Synchronous Motor with Fuzzy Logic for Electric Vehicles: Analysis, Modelling, and Comparison

This paper presents a detailed analysis and comparative study of three torque control methodologies with fuzzy logic, namely direct torque control (DTC), fuzzy direct torque control (FDTC), and model predictive direct torque control (MPDTC), for PMSM control applied to an electric vehicle. The three control strategies are designed and developed to control torque in order to achieve vehicle requirements, such as minimum torque and flux ripples, fast dynamic response, and maximum efficiency. To enhance the performance and efficiency of the overall drive, a bidirectional DC/DC buck-boost converter is connected to the Li-ion battery. In addition, a fuzzy logic controller (FLC) is used in the outer loop to control the speed of the PMSM. As a result, the tuning difficulty of the conventional proportional-integral (PI) controller is avoided and the dynamic speed response is improved. Simulation results obtained from the three control techniques establish that the proposed system via the MPDTC technique reduces the torque ripples, flux ripples, reduces the THD of the PMSM current, and achieves a faster transient response. Additionally, the MPTDC technique enabled the electric vehicle to cover the longest distance, with approximately 110.72 km in a charging cycle. The real-time simulation is developed using the RT LAB simulator, and the obtained results confirm the superiority of the MPDTC technique over conventional DTC and FDTC techniques.

A novel reference flux estimation technique for performance improvement of fuzzy DTC controlled IM drive in an electric vehicle using teamwork optimisation algorithm

ABSTRACT The tailpipe emissions caused by the transportation sector are a significant contributor to greenhouse gases. Electric vehicles (EVs) are becoming more popular due to their environment friendly nature. An appropriate motor drive is essential for an efficient EV. Due to its numerous benefits, Direct Torque Control (DTC) is commonly utilised in EVs, yet its ripples and harmonics make it inefficient. This paper provides a dynamic stator reference flux estimation strategy for the Fuzzy Logic-based DTC to minimise torque ripples and improve performance. The Teamwork Optimisation Algorithm is integrated with the fuzzy DTC for optimal selection of the stator flux depending on the driving scenario to eliminate ripples. The simulated results demonstrate efficacy by minimising torque ripple, harmonics, and energy consumption. Using performance indices such as ISE, ITAE, and ITSE, the efficacy of the suggested strategy is validated. The dynamic behaviour is also examined using ECE, EUDC, and HWFET driving cycles, and an energy saving of 8% to 10% reduction in energy consumption is observed. The results also indicate a 49.92% and 27.97% improvement in torque ripple at low and high speeds, respectively.

Fuzzy logic direct torque control of induction motor for photovoltaic water pumping system

This study presents a fuzzy logic direct torque control for induction motor to be used in photovoltaic (PV) water pumping system. The system is intended to be less expensive and simple while maximizing PV array power utilization. For this purpose, a smart technology based on fuzzy logic controller (FLC) has been implemented to track the maximum power which has been successfully used in solar water pumping systems under different irradiance levels. Next, to alleviate the disadvantages of standard DTC, we chose fuzzy direct torque control (FDTC) for induction motors driving a centrifugal pump. Furthermore, this study includes the usage of IP with antiwindup and slide mode speed controller (SMC) instead of the traditional proportional-integral speed controller. Finally, the induction motor (IM) speed has been optimized with an optimum speed control in order to maximize the pump’s hydraulic parameters. The FDTC, with its SMC outperforms the photovoltaic pumping system (PVPS) in terms of dynamic performance and robustness. To develop a full simulation model of the proposed PVPS configuration under various climate conditions, MATLAB environment and associated Simulink are used.

Enhanced Intelligent Closed Loop Direct Torque and Flux Control of Induction Motor for Standalone Photovoltaic Water Pumping System

This paper aims to search for a high-performance low-cost standalone photovoltaic water pumping system (PVWPS) based on a three-phase induction motor (IM). In order to control the IM, a fuzzy direct torque control (FDTC) is proposed in this paper for overcoming the limitations of the conventional direct torque control (CDTC). In fact, the CDTC suffers from several problems such as torque ripples, current distortion, and switching frequency variations. These problems can be solved with the proposed FDTC. To ensure high performance of the PVWPS, the reference torque is generated using a fuzzy speed controller (FSC) instead of a conventional proportional integral speed controller. In order to extract the maximum amount of power, the proposed maximum power point tracking controller is based on variable step size perturb and observe to surmount the weakness of the conventional perturb and observe technique. The performance of the proposed FDTC based on the FSC under variable climatic conditions is demonstrated by digital simulation using Matlab/Simulink. The obtained results show the effectiveness of the suggested FDTC based on the FSC compared with the CDTC in terms of pumped water, reduction in flux and torque ripple, diminution of losses, and decrease in the stator current harmonic.

Sensorless fuzzy direct torque control of induction motor with sliding mode speed controller

In this work, a fuzzy direct torque control (DTC) is developed for asynchronous motor drive powered by two-level inverter. The main objective is to enhance the system performance by reducing electromagnetic torque and stator flux ripples while improving stator current waveforms. The hysteresis comparators and voltage vector switching table of classic DTC are replaced by fuzzy logic block to ensure robust control against various disturbances. The outer speed loop is initially executed by PI regulator and secondly by sliding mode controller, for both systems stator flux MRAS estimator is adopted. A critical and comparative study between the DTC based on fuzzy logic and non-linear sliding mode DTC was done under MATLAB/SIMULINK. The performance analysis was carried out under different operating conditions such as steady and transient states, low , medium and high speeds, speed reversal and application of two different loads at various times.

Fuzzy logic-based direct torque control for improvement of the fault-tolerant drive of a five-phase induction motor

Torque ripple reduction is one of the major challenges in switching table-based direct torque control (DTC) while operating for open phase faults of an induction motor, as the switching vectors are unevenly distributed. This can be minimized by increasing the level of the inverter and with the use of multi-phase motors. Fuzzy logic-based DTC is another solution to the above problem. In this paper, a comparative analysis is done between switching table-based DTC (ST-DTC) and fuzzy logic-based DTC for increasing the performance during open phase faults of a five-phase induction motor. The result shows that in fuzzy logic-based DTC with a two-level inverter, the torque ripple is reduced by 5.164% as compared with ST-DTC with a three-level inverter. The fuzzy logic-based DTC with the three-level inverter also gives better performance as compared with fuzzy logic-based DTC with the two-level inverter. The current ripple also reduced by 9.605% with respect to ST-DTC. Thus, fuzzy logic-based DTC is more suitable and cost effective for open phase fault-tolerant drives.

Novel fuzzy direct torque control based on constructed functional transformed grey model

To reduce the ripple of the magnetic flux and torque of motors and the reduce the hysteresis in motor speed control, an improved grey model predictive fuzzy direct torque control (DTC) method based on function transformation is proposed. First, a function transformation is used to transform the sampled sequences to nonnegative values. This overcomes the disadvantages caused by fluctuant and random sampling of the motor torque and stator flux linkage. Second, an equal dimensional new information model is used to keep the dimensions unchanged, which reduces the time to predict the motor parameters through the model. Moreover, the voltage space vector plane is divided into six sectors, which simplifies the fuzzy control system rules. Simulation results show that the proposed fuzzy direct torque control based on the improved grey model method reduces the influence of hysteresis on the control system, decreases the motor flux chain and torque ripple, improves the response speed of the torque and rotational speed, reduces overshoot, achieves good effects in terms of anti-interference capability and dynamic response, and improves the real-time performance and accuracy of the fuzzy control system.

Fuzzy Direct Torque Control for Induction Motor Sensorless Drive Powered by Five Level Inverter with Reduction Rule Base

Fuzzy Direct Torque Control for Induction Motor Sensorless Drive Powered by Five Level Inverter with Reduction Rule Base

Improved DTC strategy of doubly fed induction motor using fuzzy logic controller

Abstract This paper presents an improved Direct Torque Control (DTC) strategy for a Doubly Fed Induction Machine (DFIM) powered by two voltage source inverters (VSI) at two levels. This strategy is based on the fuzzy logic controller. The main objective is to improve the performance of the system by reducing electromagnetic torque ripples and improving the currents shape by optimization of the total harmonic distortion (THD). The hysteresis regulators and voltage vectors selection table of the conventional DTC are replaced by fuzzy logic blocks to realize fuzzy DTC control. The two control strategies are simulated in the MATLAB/SIMULINK environment followed by a comparative analysis to validate the effectiveness of the proposed strategy. Many improvements in term of rise time, torque ripples, flux ripples and current harmonics have been done, namely stator and rotor flux ripple and torque ripple have been reduced more than 50%, 69.2% and 47.7% respectively. The stator and rotor currents THD have been reduced around 84.5% and 84.3% respectively.

Control with high performances based DTC strategy: FPGA implementation and experimental validation

ABSTRACTThis paper aims to improve the induction motor performances using a modified Direct Torque Control (DTC). The DTC is featured by its simple structure and fast dynamic response. Also, it does not require a speed sensor and it is less dependent on the motor parameters. However, the basic handicaps of this method are the torque ripples and the current distortions due to the presence of the hysteresis controllers. This paper aims; firstly, to replace the hysteresis controllers and the switching table by a fuzzy logic system in order to overcome these handicaps. Furthermore, the sampling frequency is another parameter which must be investigated to reduce the commutation losses and the harmonic stator current waves. The second purpose of this paper is to reduce the execution time using a Field Programmable Gate Array (FPGA). The FPGA is able to execute the Fuzzy DTC (FDTC) with a higher sampling frequency, thanks to its parallel processing relative to the Digital Signal Processor (DSP). The FDTC model is verified by simulation using system generator tool and validated by experimentation utilizing an FPGA Virtex 5. Thus, excellent performances at low processing time are obtained using the Xilinx FPGA Virtex 5.

Direct torque control improvement of a variable speed DFIG based on a fuzzy inference system

In this paper, a fuzzy direct torque control (DTC) for a variable speed doubly fed induction generator (DFIG) based wind turbine is investigated. The DTC has been widely applied to doubly fed induction machines in recent years due to the high performances that it provides in comparison with the classical field oriented control. Meanwhile, it has a major drawback that is the significant torque and flux undulations generated by the hysteresis band controllers. To overcome this problem, the improvement of this technique by removing these controllers is proposed in this paper. The proposed control technique is based on replacing the hysteresis controllers by a fuzzy inference system which will have the same inputs as these controllers plus the sector angle determination so that the look-up table can be replaced by a fuzzy rule-base matrix. The simulation was performed in MATLAB/SIMULINK, and the results obtained make it possible to evaluate the performance of the proposed technique over the classical one.

A Fuzzy Direct Torque Control of Induction Motor for FPGA Implementation

A Fuzzy Direct Torque Control of Induction Motor for FPGA Implementation

Improved Performance and Power Quality of Direct Torque Control of Asynchronous Motor by Using Intelligent Controllers

Direct torque control of asynchronous motors has good dynamic performance of torque and flux. However, the use of hysteresis controllers leads to a variable switching frequency. This lack of control over frequency is the origin of torque and flux ripples. To overcome these problems, this article proposes modified fuzzy direct torque control for an induction motor. In addition, a three-phase pulse width modulation rectifier controlled by the fuzzy direct power control is used. This rectifier draws a sinusoidal current from the grid and operates with a power factor close to unity. The pulse width modulation rectifier feeds the inverter of the direct torque control, ensuring a speed control loop. The proposed direct torque control–direct power control method is investigated based on theoretical analysis, computer simulation, and experimental validation that provide acceptable results.

Direct Torque Fuzzy Control of PMSM based on SVM

In this article, we present the strategy of the direct Torque control (DTC) of the permanent magnets synchronous machine (PMSM) with fuzzy comparator in controlled by the technique SVM (Space Vector Modulation). This method of control allows reducing the fluctuations of the torque and of the flux also in the low speed contrary with control of the classical DTC where the frequency of switching is incontrollable. Simulations results obtained allow demonstrate the performances of this command especially in the behavior of the couple and the flux.

Design and Implementation of Direct Torque Control Based on an Intelligent Technique of Induction Motor on FPGA

In this paper the hardware implementation of the direct torque control based on the fuzzy logic technique of induction motor on the Field-Programmable Gate Array (FPGA) is presented. Due to its complexity, the fuzzy logic technique implemented on a digital system like the DSP (Digital Signal Processor) and microcontroller is characterized by a calculating delay. This delay is due to the processing speed which depends on the system complexity. The limitation of these solutions is inevitable. To solve this problem, an alternative digital solution is used, based on the FPGA, which is characterized by a fast processing speed, to take the advantage of the performances of the fuzzy logic technique in spite of its complex computation. The Conventional Direct Torque Control (CDTC) of the induction machine faces problems, like the high stator flux, electromagnetic torque ripples, and stator current distortions. To overcome the CDTC problems many methods are used such as the space vector modulation which is sensitive to the parameters variations of the machine, the increase in the switches inverter number which increases the cost of the inverter, and the artificial intelligence. In this paper an intelligent technique based on the fuzzy logic is used because it is allows controlling the systems without knowing the mathematical model. Also, we use a new method based on the Xilinx system generator for the hardware implementation of Direct Torque Fuzzy Control (DTFC) on the FPGA. The simulation results of the DTFC are compared to those of the CDTC. The comparison results illustrate the reduction in the torque and stator flux ripples of the DTFC and show the Xilinx Virtex V FPGA performances in terms of execution time.

Fuzzy direct torque control for induction motor drive system based on space vector modulation

A new approach of a fuzzy direct torque control and drive (FDTC) for induction motor drive system based on space vector modulation (SVM) technology is proposed in this paper. By comparing the conventional direct torque control using space vector modulation technology (SVMDTC) method with the fuzzy direct torque control, a fuzzy controller is used to replace the PI conventional speed regulator. In the proposed strategy, the error between the estimated and the referred linkage flux of the stator and torque will be compensated by an accurate synthesised space vector voltage. Simulation results show that the proposed SVM-DFTC method can improve the system robustness, evidently reduces flux and torque ripples, and in turn obtain a swift speed response with extraordinarily high improvement of its performance.

IJIREEICE - Electrical, Electronics, Instrumentation and Control

In this paper a fuzzy logic scheme is applied for direct torque fuzzy control (DTFC) of five phase induction machine (FPIM). The proposed DTFC based on fuzzy logic technique switching table is described and compared with conventional direct torque control (DTC). The proposed fuzzy control strategy is simulated using Matlab/Simulink software. The simulation results show that DTFC method reduces torque ripple and stator flux variation and improves dynamic response. High Phase Order (HPO) multiphase motor a type of AC motor that has been developed in the last decade and due to its advantage over the three phase motor, many scientists and researchers focus on it. Each electrical motor that have over three phase stator winding can be in HPO class. Researcher demonstrated that HPO drive motor many advantage over conventional three phase motor drives. Multiphase Motor drives are mostly proposed for high power application such as traction and hybrid vehicles aircraft and etc. The advantage of multiphase machines, with respect to conventional three-phase machines are reduced torque pulsations, reduced dc-link harmonics, higher torque density, greater fault tolerant, improvement of the drive noise characteristic, reduction in the required rating per inverter leg and achieving a high power motor

Fuzzy Adaptive PI Controller for DTFC in Electric Vehicle

This paper presents a technique to control the electric vehicle (EV) speed and torque at any curve. Our propulsion model consist of two permanent magnet synchronous (PMSM) motors. The fuzzy adaptive PI controller is used to adjust the different static error constants, as per the speed error. The suggested based on the direct torque fuzzy control (DTFC). A Mamdani type fuzzy direct torque controller is first developed and then rules are modified using stator current membership functions. The computations are ensured by the electronic differential, this driving process permit to steer each driving wheels at any curve separately.Modeling and simulation are carried out using the Matlab/Simulink tool to investigate the performance of the proposed system.